VOBREDIMET Design Framework
I first published this article on 10.2.2022 but as usual it was not final. I had written the Vision, Needs and Observations of the current situation, evaluated how it works and possibilities to tweak. 

I came back to the design in September 2023. Now I decided I need to narrow down the scope from "Buildings and Energy systems" to "Energy at Iso-orvokkiniitty". Possible spin-offs (i.e. other designs) are "Water and Hygiene" (essentially the same as "Household water system at Iso-orvokkiniitty" which was a spin-off from Design 1) and "Food".  

This article is building heavily on previous articles, especially those about the site and the article about the House which are basically the observation part of this design. 


Tweaking the OBREDIM to circular.

This is the Design of our House (including other buildings) including the perspective of the Main System Energy (see The Permaculture Pathway). The Design Framework is VOBREDIMET (Vision, Observation, Boundaries, Resources, Evaluation, Design, Implementation, Maintenance, (Re)Evaluation, and Tweaking).

Designing a house and buildings is very much about Needs so I added that as a separate box in the graph although it would normally fall under Observation. I have named the Design box Tweak, as my aim here is to start from what has already been done until now (instead of trying to reconstruct the design process from 5 years back). So the result of this Design are the Tweaks that we need to do now. The original design process is described in the separate article about the House, which in this case falls under Observation. Let’s see how it works.


In 2017 I wrote: "To us natural building means dynamic breathing structures, natural materials, ecological energy solutions and based on permaculture principles local, self-sufficiency and closed loops. Of course a traditional log house would be natural building but we chose straw bale-clay construction, which enables good insulation and dynamic structures. 
Key principles in our house are: 
- natural and breathing materials, i.e. avoiding by all means use of plastics and styrofoam. 
  - the only exception to this is electric coils and water piping etc
  - the clay is from our own field and the bales from an organic farm
  - the floor and roof insulation is borax-free cellulose with clay powder (fire prevention)
  - the foundation is insulated with Leca gravel and the earth cellar with glass foam gravel 
- Location in a SW facing slope protected from the N by forest and the slope
- Gravitational ventilation
- Heating with wood (fireplaces) supplemented with solar collectors. Firewood from our forest. 
- Off-grid electricity with solar panels and windmill
- Traditional well for water
- Willow waste water treatment to keep nutrients on the site.  

I think the Values and our Vision have remained largely the same over the years since we bought the place. Our values and visions were and are very much based on environmental concerns, our long history in the organic farming movement, naturalness and broadly speaking ecological Green political ideas.

Here I will define our Vision about the House based on Permaculture Ethics:

    • Use natural materials and construction technologies with as small an environmental footprint as possible.
    • Enable an ecological lifestyle with a high degree of self-sufficiency in energy, food and materials.
    • Minimise waste
    • Create a healthy and inspiring living environment for ourselves
    • Enable social life and living according to our values
    • Share our experiences
    • Hospitality

The Off-grid vision

An important choice we have made in the beginning was to be off-grid. In hindsight it was a part of the Earth Care Ethics, an experiment to see if it was possible – and a also a political declaration in terms of opposing Finnish energy policy which relies heavily on nuclear power. I wrote about the reasons for this choice in November 2014 in: “Own energy and electricity” (Googlenglish, original in Finnish). In the article I refer

  1. To the fact that the use of fossil fuels has led to climate change and is destroying our possibilities to live on this planet but nevertheless nothing is done about stopping usage of fossil fuels.
  2. Nuclear energy is not a solution and even nuclear fusion power would lead to disaster (for several reasons) – even though it might be clean.
  3. We need to take responsibility ourselves for an energy descent.
  4. It is not possible to connect to the grid and only be supplied with renewable sustainable electricity (in practise wind). You get electricity from your socket even if the windmills are standing still.

So this part of our vision was pretty radical but still included the idea of a more or less normal lifestyle in terms of having electricity for all kinds of modern appliances. Basically all the technology we need for this (solar panels, wind mills, chargers, inverters etc) are linked to the economic system that is leading to the demise of humankind as we know it. So what we envision here is still some kind of high-tech driven but de-centralised society that is able to descend to a sustainable level of consumption. Are off-grid homes a part of that vision? Already in my November 2014 article I concluded that if there was a de-centralised and smart energy system based on local energy sources it would make sense to connect – but as it does not exist we don’t want to connect.

This brings us to the thinking of David Holmgren in “Permaculture. Principles & Pathways Beyond Sustainability” (2002). As a part of the principle “Catch and store energy” he suggested in Chapter “Appropriate Use of Non-Renewable Resources” (p 48) that “The transition to declining energy availability provides unique strategic opportunity to make the best use of existing wealth and non-renewable resources to rebuild natural and human capital”. This could be used as justification to build an off-grid system even if it does not make short-term economical sense. However Holmgren continues (p 50) in Chapter “Idealism versus Pragmatism” to describe how they are at Melliodora connected to the grid – although using only 20% of the electricity a typical household would use – and concludes “for the present we can make better use of the money that would be required to develop other aspects of our property”. According to Holmgren the most important thing is to use as little electricity as possible. Of course that is easiest to achieve if energy supply is limited (i.e. if one is off-grid).

Our Needs

Seven Essential Needs as proposed by Sosteric & Ratkovic (1).

The house where one lives relates obviously to ones needs, some of them basic. An article by Mike Sosteric and Gina Ratkovic (1) builds on Maslow’s well known hierarchy of needs which is usually represented with the pyramid. However the pyramid was never proposed by Maslow himself and is a simplified representation of his thoughts. Therefore Sosteric & Ratkovic propose a circle that attempts to represent a further development of Maslow’s (and their own) holistic view of people’s needs and motivations. The needs are grouped as:

  • The basic needs in the outer circle
    • physiological
      • need for substances (like food, water, vitamins, air)
      • need for physical activity (exercise)
      • biological drives for sex
      • etc
    • environmental
      • safety and security
      • protective, nurturing, and aesthetically pleasing environments
    • cognitive
      • our need to know and understand the world
    • emotional
      • our need for unconditional love, support, acceptance, and inclusion in family, friend groups, and society
    • psychological
      • need for esteem, power and freedom
  • Alignment (self-actualization)
    • with the inner self
    • with what is right and proper
  • Connection (transcendence)

“Full health and full human development requires reasonable satisfaction of all essential needs. Basic human needs can be fulfilled only by and through other human beings, i.e., society” (A. H. Maslow, 1964)(1). (Conclusion: we don’t need things – we need people.)

Your house probably relates strongly to your physiological needs but also very much to your environmental needs so I quote the description of that below in full:

Environmental Needs (1)

– Maslow’s original theorization included needs for safety and security; in other words, a safe and secure environment. We reconceptualize these needs as environmental needs. We include in this category the need for a safe and secure environment but go further and include the need for protective, nurturing, and aesthetically pleasing environments at home, work, and everywhere. Note that safety includes the absence of assault of any kind, including physical assault (e.g., spanking, pushing, slamming objects, shaking etc.), emotional and psychological assault (screaming, name-calling, racism, sexism, shaming, passive aggressive assaults) (A. H. Maslow, 1954, p. 40). Stability includes financial stability, which removes anxiety about work and survival, but also the emotional and psychological consistency of emotionally and psychologically stable parents and stable familial relationships. Sufficient environments are environments free of chaos and uncertainty, where all essential needs are met. There is sufficient evidence to assert that safe, calm, stable, and nurturing environments are a prerequisite to psychological health, well-being, and growth, and that lack of said environments leads to various forms of distress and disease (Sosteric & Ratkovic, 2016). Ultimately, we need an environment that is safe, nurturing, secure, calm, aesthetic and that encourages “free, uninhibited, uncontrolled, trusting, unpremeditated expression of the self ” (A. H. Maslow, 1967, p. 197) and the expression of “pure spontaneity.”

The concept of a house in a given culture is pretty predefined and one seldom thinks thoroughly about one’s needs when designing a house. We normally have a kitchen, living room, dining room, bed rooms, bathroom & toilet, storage room so those are where your needs will be satisfied. It’s a well-tested concept and works in most cases but if you are planning to change your lifestyle (f.ex moving from an urban setting to countryside and hoping to develop a more self-sufficient lifestyle) it makes sense to think about your needs and what it means for the house more carefully. Self-sufficiency in food and energy changes the material flows in the house and must be taken into account. Carrying in 1,5-2 m3 of firewood per month is different than lighting the fireplace sometimes on Saturday evenings. A lifestyle where you “toil in the dirt” in different weather conditions sets different requirements to the house than where you are walking to the car that is waiting for you in the garage.

NeedVisionBuildings & infrastructure
  • Enable an ecological lifestyle with a high degree of self-sufficiency in energy, food and materials.
    • Minimise waste
  • – Heating system, source of energy, access to food and drink and other materials.
    Composting bio-waste, sorting and circulation
    – Food
  • high degree of self-sufficiency
  • – Connection to the garden and outside
    – Kitchen: prepare and store food (energy)
    – Dining room: eat and enjoy
    – Possibility to store larger volumes of food: pantry, cellar
    – Chicken and other animals
    – Water
  • self-sufficiency
  • – own well
    – pump, piping (energy)
    – Waste water system
    – Hygien
    • Minimise waste
  • – toilet
    – bathroom
    – keep and use the waste
    – Excercise– the lifestyle requires daily physical activity to maintain the material flow
    – local mobility with bicycle and walking
    – enjoying the nature: walking, skiing, skating etc
    – storage for tools, where to keep working clothes, boots, shoes etc
    – storage for bicycles and other gear
    – Sleep – bedroom
    Environmental– Use natural materials and construction technologies with as small an environmental footprint as possible– air quality inside
    – “save the planet”
    – Safety and security– doors can be locked
    – fire alarms and extinguishers
    – Protection from the elements– insulation and heating the house
    – energy
    protective, nurturing, and aesthetically pleasing environments
  • Create a healthy and inspiring living environment for ourselves
  • Cognitive– create spaces for reflection, discussing, reading, writing
  • Enable social life and living according to our values

  • Hospitality
  • – create social spaces
    – space for friends and visitors
    – privacy
  • Share our experiences
  • Alignment


    The observation part of the Site is covered in previous articles:

    The article “House” contains a detailed description of the house planning and the house in early January 2021. If nothing else, read it before going further in this article. Building the house is quite well documented: see links to our blog in the House article. Here I am observing what was already done (and the proposed Design will be Tweaks to the existing.

    Summary of the timeline of the buildings:

    Firewood sheds on the left, the storage building on the right and house in the background. 30.1.2022.
    • The dry toilet was built 2015
    • The summer kitchen was built 2015-16
    • The main house was build 2016-18 and we moved in spring 2018. Official final inspection was done in December 2021.
    • I built the first firewood shed in 2019.
    • In 2020 we started several projects which were more or less finalised during 2021:
      • storage building for the generator, beekeeping and mushroom growing equipment, gardening equipment and car and bicycle related stuff.
      • earth cellar
      • sauna
    • In January 2022 I built the 2nd firewood shed.

    Borders and resources

    Physical borders and resources have been discussed in the earlier site analysis. Relating to the Buildings and Energy systems and how to tweak them borders and resources relate to

    • Financial limitations and resources
    • Human resources
    • Material resources on-site and off-site
    • Limitations created by our choices (mainly the off-grid system).

    Our financial position is pretty good. Erkki’s business is creating cash-flow and Marja’s business in ecological landscape design has got a good start and is creating some income for her. We expect to pay our house loan by the end of 2028 and try not to take on more loan in the meantime. Cashflow allows us to do some investments year by year as long as Erkki is in business.

    Erkki is in good health and physical condition but of course as 63 year old it will not be true for ever. Marja has had some health challenges in the recent years but she is better now. Help can be got in the form of “talkoo” (gathering together at each others places or common projects for communal work), volunteers, help from family and friends, workshops, hiring school children for summer work or hiring professionals for specific tasks.

    Material resources on-site are (for constructions)

    • wood for firewood or construction, fence poles etc
    • clay for building projects
    • reed from Puujärvi lake

    External help could mean professionals for construction (our son Jaakko is an architect and Santeri a carpenter; both have been a great help in the building projects but are busy with their own lives). Professionals for off-grid electricity systems and small scale power plants are scarce and apart from solar panels commercial solutions are not readily available.

    Evaluate how it works

    The “House” article contains also evaluation – most importantly:

    • “Permaculture construction checklist” inspired by Paul Jennings (2) and my thoughts and comments to the raised points.
    • Functions-Elements analysis of the House
    • Functions-Elements analysis of the Energy system

    Needs are also discussed but not analysed in detail.

    NeedHow was it realised?Is it ok?
    – Food
    — cultivation
    Storage for gardeing, beekeeping and mushroom cultivation gear. ok
    — storageA cold pantry in the kitchen (ventilated from outside NE side of house so cold in winter), a fridge with standard freezer, extra fridge below the house for the summer, Earth cellar. see below
    — preparation and processingThe kitchen is relatively big with big sink for preparing and processing bigger volumes, wood fired stove (with small oven) with a lot of space for simultaneous cooking, electric single stove and water boiler used in the summer, big wood fired bakery oven, dining table for baking. At summer kitchen we have gas stove and pizza oven.see below
    — washingbig sinks, dishwashing machine
    — enjoyingdining room table comfortable for 6 persons but we can fit more when needed. In the summer we can use the summer kitchen. ok
    – Waterstandard water piping in kitchen and bathroom
    carried or hosed to sauna
    can be hosed to summer kitchen
    – Hygienstandard bathroom with WC and shower, separate traditional log sauna
    dry toilet outside
    – ExcerciseStorage space for gear mainly under the house or in the loftok
    – Sleep bedroom, extra sleeping space in loft and study, sauna, army tent for volunteersonly temporary short term accommodation for visitors
    – Safety and securityFinland is in general a safe country. Risks are mainly self-made (hurting yourself with machines, falling if slippery, cleaning solar panels from snow , etc). ok
    – Protection from the elementsIsn’t that the main function of a house? Protect ourselves from the cold, snow and rain, winds, heat, mosquitoes etc.ok
    protective, nurturing, and aesthetically pleasing environmentsAll natural materials and surface textures (inside: clay, wood), timber frame structures visible in the house, massive fire places, massive wood kitchen cabins etc.
    Beautiful log sauna.
    Wooden storage building matches the house
    Earth cellar and the stair path on and around it.
    See the House article for photos
    Emotional, Psychological, Alignment, ConnectionOpen spaces for connection but possibility to find privacy behind the massive fireplaces (study, bedroom) or loft. Living room for relaxation, library in the loft, sauna for sauna (pause, reflection and connection)
    The garden with stairs on top of the earth cellar.
    Sources of electricity in Finland 2021: starting from the orange: Nuclear 26,3%, Combined heat power stations, Combined industry power stations, Electricity power stations, Import, Water, Wind, Sun. Source: Finnish Energy.


    Energy is not normally recognised as a separate need but it is needed for the satisfaction of most basic needs so this design focuses on energy at Iso-orvokkiniitty.


    We wanted to design an off-grid system for electricity in our house. See blog posting in November 2014: In Googlenglish or original in Finnish.

    This was in line with Earth Care “Enable an ecological lifestyle with a high degree of self-sufficiency in energy, food and materials“. In Finland over 50% of produced electricity was with renewables in 2020, including renewable fuel, wind and water. However Nuclear is the biggest single source and 20% of electricity was imported (2021) which could be Russian nuclear or Norwegian water power. Even though renewables are growing, Finland relies heavily on nuclear (more nuclear being built) so we didn’t want to connect to that kind of grid.

    Production of electricity in Finland 2000-2020, from top down: Peat, Fossil, Nuclear, Wind, Water, Renewables. Source: Statistics Finland.

    In 2015 we asked Janne Käpylehto to consult us in designing the off-grid electricity system. He gave us a proposal which you can see below (the whole report was 14 pages). The system was implemented by REPS Oy in 2016-17 with the solar panels installed on the darkest possible day 21.12.2016. (Unfortunately REPS Oy has stopped their activities shortly after so we have not had proper support for the system.)

    The main differences between the plan and how it was implemented were:

    1. more solar panels (12 x 260 W)
    2. less battery capacity (32 kWh of which 50% usable)
    3. No 12V system, i.e. everything is built with 230V
    4. The Windmill is a 2,6 kW Skystream.
    5. The generator is missing in the illustration but it was proposed also in Janne’s plan.
    Our electricity design 2015 (Janne Käpylehto).

    All our home appliances are high quality with lowest possible energy consumption at time of purchase.

    Overall the electricity system works well from March to October. Electricity (and hot water) are in abundance in the summer. The main challenge is insufficient electricity production in the winter months (November until early February) and as a consequence lack of water in the house. We have adapted to this with some changes in behaviour in the winter months compared to summer when electricity is in abundance. From a modern urban lifestyle point of view our summer is when we can behave “normally”.

    In the winter months we have these adaptations:

    • If the wind is not blowing, we power the house with the 3 kW Honda generator, usually 2-3 hours per day in the morning which means 3-4 kWh power per day. That is only half of what we calculate we would normally use. We run the generator most days in November, December and January. Windy days give us a break but solar panels don’t produce enough even on a sunny day until first week of February – and sunny days are scarce in November – January anyway. In summer 2021 I finalised the storage building which has one room for the generator (+ other equipment which use fuel, mainly the chain saws). I installed fire protective walls inside and an exhaust pipe through the wall with an exhaust silencer to reduce the outside noise level. We have 2 Honda generators (2nd for backup).
    • Prepare food and boil water only on the wood fired stove (electric stove and water boiler are put away October – March – both use 2kW max power)
    • Dishwashing by hand, water heated in 10L kettle on the stove (we have a dishwasher – when it heats water it uses 2 kW so we use it only in summer)
    • Washing laundry with washing machine more seldom, necessary to use generator if it’s not a very windy day (heating water takes 2 kW)
    • Often fast showers (the colder it is outside the more hot water we have)
    • Use battery powered lights in the evening and morning if electricity is off (so we have electricity every day but not necessarily all the time)(Candles decrease inside air quality.)
    • Store water for the periods when we don’t have the power on.
    • Use rainwater to flush the toilet (not possible if freezing).
    • We have 2 extra 200 Ah batteries which are used to run some vital functions:
      • the pump for the floor heating system. this is vital because it keeps the cellar from freezing so the incoming water pipe does not freeze.
      • wifi and weather station
    • The fridge does not have an electricity back-up so electricity shouldn’t be off more than 10 hours at a time (overnight). In the original electric plan the fridge was not supposed to be cut off electricity but that has not been implemented.
    January Wind Rose at 50m altitude at Iso-orvokkiniitty according to Tuuliatlas.

    So there are quite a few adaptations which may or may not be acceptable to someone striving to develop self sufficiency In their lifestyle. In our case we are 2 adults living in the house so it is acceptable – if we were a family with kids it would be more challenging. Living in an energy-squeezed situation is acceptable but the main irritation is the need to run the generator most of the days in the 3-4 winter months. For that we use 150-200 litres of petrol (benzin) per winter with current prices a cost of up to 400 €/year. It’s not a huge amount of petrol – if you compare f.ex. to a car, but still definitely a fault in the design.

    The bottomline is that I was way too optimistic regarding how much power the wind mill would produce in the winter months. In my posting in November 2014 I estimated 270-400 kWh per month production. The estimate in Janne Käpylehto’s report was more realistic at 1300 kWh/year (110 kWh/month) with a 3kW wind turbine. We don’t have a meter for following cumulative power production but my estimate based on how many days we have not needed the generator is 40-50 kWh per month. I presume Janne Käpylehto’s estimate could be correct in more optimal wind conditions.

    July Wind Rose at 50m altitude at Iso-orvokkiniitty.

    Analysing reasons why the wind mill did not meet expectations:

    Location in general: Wind speeds inland at accessible height (for small wind mills) are much lower than on the sea coast or archipelago. It is questionable if it makes sense to install a small mill inland unless it can be located on a very high spot in the landscape. (I wasn’t willing to believe this back in 2015-16.)

    Map from kartta.paikkatietoikkuna.fi with wind rose (blue = winter, red = summer)

    Location in the landscape: We originally considered 2 locations for the wind mill: Down on the field or in the eastern corner of our property in the forest, which is the highest point on our property. I still presume the chosen location in the forest was correct as it is over 10m higher than the field. However the location is problematic because it is in the forest and trees certainly cause a lot of turbulence. The mast is 24 meters high which is not enough when tree tops are at 16-17 meters beside the wind mill and 20 meters in the old spruce forest to the NW (I believe there should be 10 meters between treetops and turbine). NW to W winds hit the mill well and 4-5m/s wind speed is sufficient to revolve the mill although it takes 6m/s to produce reasonable amount of electricity (energy production increases exponentially in 3rd power compared to wind speed). But winds from W to NW which are also typical in the winter come from the direction of the old spruce forest and it requires a 7-8m/s wind for the mill to revolve. N and NE winds work ok at least at 6-7 m/s wind speeds but they are not so common. E winds seem to be blocked by the hill to the east but east winds are also not common.

    Photo taken on 24.4.2017 showing the wind turbine appr. 8 meters above the surrounding tree tops. In SE individual higher trees and in SW the old spruce forest.
    Photo taken 1.1.2022 from similar angle. It doesn’t look like 5 years of forest growth would have made any significant difference (not sure if the photo angle is exactly the same). I have taken down the tall birch on the east of the turbine.

    To summarise:

    • Wind conditions inland are not ideal for small wind mills that cannot be raised high enough.
    • The windmill is a Skystream 3.7 with a rated power of 2,6 kW which it reaches at 11 m/s wind speed. The swept area of the rotor is 10,9 m2 (diameter 3,7m) which is the most important parameter especially in low wind situations (a mill could have a similar rated power with smaller swept area if it is meant for high wind speed conditions). In general the wind speeds are not sufficient to generate excess electricity to fill up the batteries. The turbine should be bigger.
    • The mast is 24 meters. It is difficult to go higher with reasonable cost, but it would certainly improve the situation.
    • If the turbine was bigger, also the battery capacity should be bigger to store energy for the days with no wind.

    SWOC of off-grid electricity: current situation

    – Abundance of electricity in the summer months.
    – Low maintenance cost.
    – Develops consciousness of energy and electricity usage and natural availability when it is in limited supply.
    – Possibility for energy self-sufficiency
    – Insulated from problems in the grid (electricity outages due to storms etc)
    – Cheap to run
    – Lack of electricity in winter months.
    – External energy in the form of f.ex. a generator running on fossil fuel could totally offset the benefits in terms of CO2, particle emissions and noise.
    – Starting the generator not automised. Starting the backup generator requires “manpower” (in 2022 switched to generator with electric start).
    – Solar energy is available at relatively low investment level
    – Cover electricity need in the buildings and mobility.
    – In winter months some form of external electricity generation is needed.
    – High investment cost to cover electricity gap in the winter.
    – Feasible small scale electricity solutions are not available for the winter period.


    Heating is a key part of meeting our Physiological and Environmental needs. It is needed for heating the house (target about 20°C inside), heating water for hygiene use and for processing food and beverages. The main fuel for heating in Finland has traditionally been wood and burning firewood is still the easiest way to achieve a high degree of self-sufficiency in heating energy. The other standard heating solutions in Finnish countryside today are oil and electricity. Increasingly thermal energy systems, heat exchangers and air conditioners (air heat pump for heating) are installed to save energy. Why don’t we have any of those?

    • Oil is obviously a fossil fuel so a no-go.
    • Electricity as an external resource could be produced with fossil, nuclear, peat or also renewable sources. In an off-grid setting there is no way enough electricity could be produced in a sensible way for heating in the winter.
    • A thermal heating system can save 2/3 of the energy needed for heating. 1/3 is still a lot of energy and it needs to be electricity. Not possible in an off-grid system.
    • Heat exchangers capture heat from the outflowing air into the inflowing air in the ventilation pipes. It requires electricity to run, it makes a noise, gets dirty and it requires maintenance. It is a no-go in a house with traditional gravitational ventilation.
    • An air conditioner requires electricity, makes a noise and doesn’t produce a lot in the coldest weathers.

    In January 2016 I posted on our blog about Energy design more from the heating point of view (in Googlenglish, and original in Finnish). The Elements and Functions (energy) analysis is in the “House” article. I am not repeating it here.

    Below I try to illustrate the energy system.

    Our Energy system: electricity and heating.
    Thinning out mainly birch north from our house. I cut and chopped it in the woods.

    Overall I think the energy system works well for us. The main physical challenge is the firewood production but in this kind of a lifestyle you need to get more or less addicted to forest works and chopping firewood. It requires you to be in good condition and at the same time offers the exercise you need for that goal. Some external resources are needed. Making firewood includes these steps:

    Cleaning the field edge. These were taken with car trailer to the house. Tapio was a great help.
    Cut and chopped at the house.
    • Trees need to be felled. For this I am using a chainsaw that runs on petrol.
      • It would be possible to use a hand saw but to me it seems a bit extreme. Petrol consumption is quite low – I think I’m not using more than 15-20 litres per year (appr. 3kWh of energy).
      • Battery driven chainsaws are developing fast. Probably the best ones would already do the job. However I have invested in a good chainsaw so I will probably wait for a few years before investing in a battery-driven chainsaw. Anyway the chainsaw is used mainly in the winter when we are not self-sufficient in electricity. I have a small electric chainsaw for summer use.
    • I either cut and chop the wood into appr. 40 cm pieces in the woods or bring them to the house as longer trunks.
    • Bringing to the house depends on where I am logging.
      • If in the forest without access with tractor, I chop the wood in the forest and bring them to the house with a battery-driven wheelbarrow. The distance should be less than 100 meters from the house – preferably less that 50 m.
      • If logging close to the field with access with tractor or car I either ask our neighbour to help with tractor or pull them with our car trailer.
      • A horse would be nice for this job but not sufficient justification to get a horse (need to feed the horse etc).
    • If I didn’t cut and chop the wood in the forest I do it at the house. Cutting with chainsaw and chopping with ax (alternatives exist but I am old-school and enjoy chopping with ax).
    • I have built 2 sheds for firewood and there is a smaller shelter next to the sauna. I’m not sure yet how much firewood we need but I presume 8-10 m3 for the house and 3 m3 for the sauna. I now have space for some 25 m3 so in the spring optimally we should have enough firewood for 2 years. 10m3 chopped and piled mixed firewood is about 15000 kWh worth of energy (6)
    Bringing firewood down the hill with the battery driven wheelbarrow.
    Zone 4 is where firewood can be harvested by thinning the forest or cleaning the field edges. Behind the 100 meter distance line it is however unpractical. Zone 5 is not touched.

    I am trying to avoid investing into any heavier equipment like tractors, ATV, chopping machines etc. If those are necessary for the job I might as well buy the firewood. When it comes to machine work professionals are for sure doing it more efficiently than I could ever do. Firewood costs in our region appr. 60 €/m3 so our annual cost for buying it would be 700-800 €/year (that was in 2021 – now they are 90 €/m3 so now it would be >1000 €/year). I’ve invested that much just in one chainsaw so economically the whole operation is questionable (becoming less questionable).

    The Zone 4 forest that we can harvest for fire wood is appr. 3 ha. As it is young mixed forest we can presume forest growth to be up to 8-10 m3/ha so our need of 15 m3 is possibly only half of the growth on that 3 hectares.

    Use of firewood

    The use of firewood in the house depends mainly on outside temperature. Once we can’t use electricity for cooking (October-March = 6 months) we fire the kitchen stove in average 2 times per day using average 15 kg fire wood per day (7 m3) and thereby generating about 60 kWh heat per day or 10000 kWh per winter. In the winter 2019-20 we fired either one of the big ovens 35 times but in 2020-21 67 times and in 2021-22 it looks to be appr 50 times. If average is 50 times and we burn 15 kg per time it means 750 kg (almost 2 m3) and appr 3000 kWh. So total heating of the house is 9-10 m3 per winter and 13000 kWh of heating energy which includes heating the water. We heat the sauna once a week using 35 kg per heating meaning an additional 4,5 m3 fire wood bringing the total to 14-15 m3 per year.

    A 100 m2 house is estimated to need 20000 kWh heating energy per year. In our case the calculated 13000 kWh covers October to March but there is heating energy needed also earlier in the autumn and later in the spring and for hot water the year round. This is covered by the solar collectors and passive solar energy coming in from the windows.

    Our baking oven from the side. The wood is burned on the backside of the massive oven (facing our study) while the baking oven opens to the kitchen/dining room. The oven is insulated so I can bake several batches of bread with one heating (we heat the oven first, close the chimney and then bake). Therefore heat release into the house is slow. © Heikki Hyytiäinen

    Finnish Massive Fireplaces

    A typical fireplace in Central or Southern Europe is an open fireplace with a chimney directly up through the roof. Sometimes the chimney is on the outside wall of the house. It seems that the purpose is to ventilate out both the smoke and the heat as effectively as possible – so totally contrary to why we build fireplaces here in the north. That kind of fireplace is not for heating.

    Our baking oven from the front. From the tertiary chamber the hot air enters the cheeks going down to floor level where it enters the chimney. © Heikki Hyytiäinen

    A Finnish Massive Fireplace has an efficiency of 85% or more. The main idea is to burn efficiently and cleanly in high temperature and to store the heat in the masonry. This is achieved by regulating the air inflow, secondary air fed above the flame to ensure sufficient oxygen for the flame and a secondary burning chamber above the primary chamber. After the fire is off the chimney is closed in order not to ventilate the heat out. Here I am illustrating the design of our baking oven but the same principles apply for all massive ovens. It burns not only efficiently but has low emissions. Our ovens were designed by architect Heikki Hyytiäinen from Tulisydän. You can read about the workshop where our ovens were built in our blog.

    SWOC of our heating system

    – Possible to be self-sufficient in heating the house.
    – Wood based heating is carbon neutral when need is less than forest growth.
    – Solar collectors provide hot water from April to October without any effort or cost.
    – Passive house format (big windows to the south) provides heating in Spring and Autumn months when the sun shines.
    – Possibility for physical exercise in forest, chopping wood and carrying it inside.
    – A sizeable material flow has to be managed.
    – Firewood is readily available locally if need to buy.
    – External inputs in the form of chainsaw and fuel.
    – Good physical health required

    Fossil Fuels

    Fossil fuels should be avoided by all means. However we use some fossil fuels:

    • The generator we need for electricity in the winter uses 120 – 200 litres petrol per year depending on how windy it is and our electricity need. A little bit machine oil.
    • The chainsaw I use for firewood work runs on petrol but uses only 15-20 litres per year. The chain oil is bio-based. The chainsaw is mainly used in the winter months when forest work is mostly done. A battery driven chainsaw wouldn’t have a positive impact if the electricity is generated with the generator.
    • We don’t have a tractor but we occasionally ask our neighbour to do tractor work for us. In the winter the snow ploughing is done by tractor. Occasional excavation work.
    • Mobility: Cars are a necessity in the countryside. So far we have had 1 car and a van but it looks like we are going to have 2 cars and a van. (August 2023: planning to sell the van)
      • The van is a gas VW Caddy that we leased new in 2015. It runs almost purely on biogas which in Finland we can consider zero-emission as biogas here is produced from sidestreams of food industry that earlier was waste and other methane emissions of waste. We estimate the van uses less than 50 litres of petrol per year.
      • We had a diesel car until 2019. Biodiesel is available only in Helsinki so it was mostly run with regular diesel. I changed to a petrol car in 2019 with the plan to convert it to biogas. However this was never done for various reasons. In January 2022 we changed to a used 2015 bifuel Volvo V70 that runs on biogas. The aim is to run it purely on biogas but of course some petrol will be consumed. However the Volvo will probably decrease milage on the Caddy, so 60-70 litres of petrol per year for both cars is a realistic estimate.
      • I have placed an order for an electric car which has V2L; i.e. it is possible to get electricity out of the car for other uses. In the summer we can charge the car at home for free with solar. In the winter we can charge it elsewhere and use it as a mobile battery pack. Obviously an electric car has a huge environmental footprint but common thinking seems to be that it is offset already with 10000 km drive compared to a petrol / diesel car if the electricity is renewable (?).

    Alternative or additional electricity sources

    Obviously I have put quite a lot of though into how to solve the winter electricity deficit. I can group possible solutions in three groups:

    1. More solar and wind
    2. Electricity from wood
    3. External sources
    1st January 2022 at noon. Our solar panels are getting sun but any panels on ground level would be in the shadow.

    More solar and wind and battery capacity

    Theoretically solar panels produce in December 10% of what they produce in June. So one option would be just to add more solar panels. Those could be installed vertically on the top of the house roof to catch the winter sun as efficiently as possible. The house roof is the only practical spot on our property which is high enough to catch the December sun. Ground level installations would be in the shadow.

    Even now we have excess electricity in the summer. I am presuming we have so much that we can charge the to-be electric car in the summer but that remains to be seen. If this is not true it would make sense to install more solar panels.

    More solar panels
    Relatively easy to install and well-known technology.
    Suppliers easy to find.
    Relatively high cost relative to produced power in the winter.
    On cloudy days no amount of solar panels can help. (Especially November and December are mostly cloudy.)
    Even on a sunny day the panels would have only 3-4 hours to produce the needed electrity in winter. Doubling the current amount of panels would not suffice.
    Lengthen the time (spring, autumn) we are electricity self sufficient including charging an electric car.
    Integration to existing system.
    The only spot for installation that makes sense is vertical on the roof ridge (the roof itself is already full)

    In our conditions our current wind mill is too small. The aim should be that on a windy day the batteries would be filled from empty (50%) to full, i.e. 16 kWh. My estimate is that that would require 3-4 times more swiping area, i.e. 30-40 m2 so the windmill diameter should be 6-7 meters and nominal power 8-10 kW.

    More wind power
    Well known technology
    Power on cloudy days (if there is wind)
    If big enough gives sufficient power.
    Relatively high cost
    Existing tower probably not sufficient for a bigger mill.
    If there is no wind even a bigger mill can not help.
    Potential electricity self sufficiency in the winter.
    Excess electricity in the winter can be used for warming the house (5kW resistant cord already installed in the hot water tank) or charging the electric car.
    Integration to existing system.
    Requires more batteries to match the max power output.
    Almost no local suppliers for small wind mills in 8-10 kW range.
    Higher tower.

    With a quick look in the internet it seems that a 10 kW turbine could be purchased at roughly 10000€. The cost of tower and installation could be an other 10000€, so total cost would be 20000€. For comparison – with an other quick search in the internet it seems that a big industrial 2-3 MW windmill requires an investment of 1,1 M€/MW (5), so the investment is roughly half of a small wind mill per kW power.

    More battery capacity
    Catch and store energy
    Bridge over the winter days when there is neither sun nor wind.
    Battery prices are decreasing and f.ex. used electric car batteries are becoming available.

    Integration to existing system.
    Only makes sense with more power generation

    Overall the biggest challenge is cost – the technology is available.

    Additionally Hydrogen Fuel technology is a potential way to store summer solar energy as hydrogen and back to electricity. An example from Sweden: Bränslecell i källaren: ”Nu är det vätgasdrift som gäller” and Skippar elnätet – med bränsleceller I källaren. This technology is however not readily available.

    Electricity from wood

    Finland has an abundance of wood and anyone who owns land in Finland almost inevitably owns forest. So transforming wood into electricity would be the natural choice for self sufficient electricity production. There are three different technologies that come up in this context.

    1. Thermoelectric generators. These can be pretty much dismissed because of very low efficiency and low power output (could be used for charging a mobile phone).
    2. Biomass gasifiers
    3. Stirling motors
    Biomass gasifiers
    – Produce gas that can run a generator for electricity.
    – DIY and commercial solutions available.
    – Biochar as a sidestream
    – Small DIY solutions are extremely laborious, inefficient and cause high level of emissions (air pollution). (They can’t be considered a sustainable solution.)
    – Professional versions are very expensive (35000 € and up) and small solutions for single house needs are not available.
    – Must be fed with wood chips or pellets so they need to be purchased or a machine chain created for producing them (fossil fuels difficult to avoid).
    – Integrate the gasifier to the house heating system (50-80% of energy is heat)
    – Difficult efficiently retrofit in existing house heating system.
    – Commercial solutions not available

    It is easy to find information about gasifiers with google but difficult to find serious information without picking up the phone. F.ex Q Power in Finland has interesting technology but these are not single house solutions. There are several DIY experts in Finland and even books written about the subject (including gasifier powered cars).

    Stirling generators

    Basic information about Stirling generators: https://www.stirlingengine.com/generators. A Swedish company Inresol has developed small scale Stirling generators but I suspect the company is not operating anymore. I tried to buy a 5 kW version some years ago but they would not offer it saying the technology was not ready. The Austrian company Ökofen now offers a combined pellet boiler (for heating) and Stirling Engine which they call Ökofen_e. Less than 10% of the energy output is electricity (10 kW heat, 600W electricity).

    – Renewable energy (wood)
    – Automatic system.
    – Generates electricity with Stinger engine.
    – Uses wood pallets: they must be bought.
    – Connect to our hot water tank and floor heating system (would probably eliminate most need for using fireplaces)
    – Use excess heat to heat some other building, f.ex hen house.
    – Proportion heat/electricity is too high (15 to 1): to generate sufficient electricity we generate too much heat.
    – We probably need to fire the kitchen stove anyway resulting in even more excess heat.
    – No space in/under the house for the Ökofen boiler (even though they are quite compact)

    We have floor heating piping in the house which is largely unused currently as we are unable to drive sufficient heat into the hot water tank. The Ökofen boiler could be connected to our existing hot water tank and thereby we could produce enough heat to run the floor heating system, largely eliminating the need to use the fireplaces. At the same time the Stinger engine would produce electricity.

    On the negative side is that the Ökofen runs on wood pallets, which – while renewable – is a purely external resource as we can not produce it ourselves (it’s not even available locally). If it would run on wood chips we could theoretically produce it ourselves in the summer with solar panel powered equipment (Catch and store energy). Or at least buy the wood chips locally.

    The other main problem is that the proportion electricity/heat is too low. On the other hand excess heat opens up other opportunities, i.e. heating some other space like a hen house.

    And f finally, we have made a rather big investment in fireplaces which would not be needed anymore.

    External sources

    The simplest solution of course would be to connect to the grid. At the moment that is a no-go just for the simple reason that we have built an off-grid house and want to keep it that way.

    An other external source that has become possible only recently is a “”mobile battery pack” aka electric car with V2L (vehicle to load). Until now you could not get electricity out of an electric car for other uses (or not in a simple way) but some recent models have V2L, i.e. a standard socket which in the case of Hyundai Ioniq5 and Kia EV6 (the first models that enable this) gives you 3,6 kW power for other uses. So if you make the comparison:

    • our house at the moment has 16 kWh usable battery capacity and the inverter gives 3,6 kW
    • a Kia EV6 ha 77 kWh usable battery capacity and the inverter gives 3,6 kW

    you realise that this gives some possibilities to develop a solution that is not perfect in terms of self sufficiency but sounds better than running a petrol powered generator.

    Electric car with V2L
    – In the summer the car can be charged with our solar panels for free (this electricity is otherwise lost because we cannot sell it to the grid).
    – The car can store a high amount of electricity.
    – In the winter the car can be charged elsewhere and thereby electricity can be “imported” to the house.
    – Design Principle; Integrate rather than segregate. The V2L car has several functions: apart from the above listed it is a car and provides mobility.
    – Eliminate fossil fuels in driving a car.
    – Limited power from the house inverter for charging the car in the summer (currently 100 km requires 20 hours charging).
    – The car can’t charge the house when it is needed for driving (Mobility).
    – In the summer plug the car to the house in order to charge the car batteries from the solar panels.
    – In the winter plug the car to the house in order to charge the house batteries from the car.
    – Use electric appliances (f.ex. a garden shredder) at locations that are too far from the house for extension cords.
    – Avoid fossil fuels in cars (Mobility)
    – Cost of the electric car
    – Slow charging of car from house (1 kW power). However max 100 km driving per day is sufficient in almost all situations.
    – High ecological footprint in manufacturing an electric car.

    The electric car is a big investment but after all it is a car, not only a mobile battery pack. I probably wouldn’t have bought a new car otherwise but now the electric car is a solution for our winter electricity problem. I am aware about the sustainability issues of electric cars and especially the batteries which use materials that need to be mined. Finland is one of the countries that will be affected as many of the rare metals can be found here. Obviously I don’t want an open mine in my backyard (NIMBY) but – even if we forget about carbon emissions – it is also not ethical to forget about the environmental and social problems caused by fossil fuel extraction around the world. All that is happening somewhere else far away and we only get the benefit of cheap energy. If and as we still need cars electricity is the way to go for personal cars. Biogas is also good and essentially zero-emission (we also have a biogas car) but there is not enough production potential for sustainable biogas to transform all traffic into biogas (although there is potential for much more than is produced today). (7)(8)

    Water & Hygien

    Water will be discussed in a separate Design. In the below picture I am showing the Water System connected to the House.

    The Water System connected to the House

    Here I would like to discuss the main challenges related to water in the house and energy. The summer does not pose challenges in this respect as electricity is in abundance. Here I am thinking of the winter period.

    • In the winter we are squeezed for electricity. The water system in the house relies on pumps that run on electricity. When the electricity is off we don’t get water in the house. Back-ups are:
      • store water in the kitchen and bathroom
      • use the dry toilet outside to avoid need to flush the toilet
      • hand pump and carry water from the well (at the moment the hand pump is not installed)
    • The efficient production period of solar collectors (hot water) is shorter than for solar panels. Hot water can be expected from April until October. In the summer there is an abundance of hot water.
      • solar collectors stop being effective for heating household water before the heating season starts in the autumn. It means that in October – November there is either no hot water or the living room massive oven needs to be heated just for the water even if heating the house is not yet necessary.
      • In the spring the situation is similar but for a shorter period. After the winter the house structures are cold so heating is necessary at higher outside temperatures than in the autumn when the house structures are warm.
    • The energy consumption of the washing machine and dishwashing machine are high so we avoid using them in the winter period. Dishwashing is mostly done by hand and water heated on the stove. Washing machines in most cases require running the generator.


    Food and drink are one of the key basic needs of humans. We normally eat and drink several times per day. Therefor a kitchen is a key part of any living quarters at least in our part of the world where it is considered normal to prepare food and eat at home most of the times. If striving for some degree of self-sufficiency you also need to process and conserve food as well as store it. I will do a separate design about our “Food system” so here I will only briefly touch on the connections between food and energy.

    • Water (energy to move it) is needed in the kitchen for food preparation, washing and drinking. Water is discussed above.
    • A stove is needed for preparing food.
      • In the summer we have a small electric induction stove and a water boiler. The limitation is that there is place only for one kettle. The wood stove can also be used but it creates excess heat.
      • In the winter we use the wood stove, which has the secondary function to heat the house. If the outside temperature is above 0°C heating the stove twice a day is sufficient to keep the house warm. Firewood needs to be carried in.
      • Store hot water in the termos for coffee later.
    • In the winter months I bake bread 2-3 times per month. The bakery oven has the secondary function to heat the house. If the outside temperature is below -10°C either big oven needs to be heated almost every day anyway. When the oven is warm, food can be prepared in the oven.
    • Dishwasher has been mentioned earlier (not used in the winter).
    • Other appliances in the kitchen that need electricity
      • stone mill: the traditional Finnish sour rye bread is 100% wholemeal. I mill the flour just before making the dough.
      • kitchen universal machine. It is not used on a daily basis – mainly for larger food preparation.
      • Fridge + freezer.
    • We have an extra full-size fridge under the house for summer use. Mainly for storing shiitake or other larger harvested volumes.
    • Earth cellar is not connected to electricity.

    Again the biggest challenge is the water in the winter period. Other than that a few things stick out if compared to a “normal” Finnish or western lifestyle:

    • A wood fired stove requires a different mentality. You can’t just press the button to get the water boiling. In the summer we can do that but in the winter it has to be “slow life”.
    • The induction stove has a single cooking spot so it is limiting food preparation in the summer. The stove’s max power input is 2000 W. Bigger induction stoves with 3-4 cooking spots typically use 6000 W which exceeds our inverter capacity.
    • Hand washing dishes in the winter.
    • We don’t have a big freezer for food storage due to lack of electricity. However placing the freezer in our cold veranda would mean that energy consumption would be very low in the winter.
    • You need a headlight when going to the earth cellar.

    How does the Design relate to Holmgren’s Design Principles?

    DESIGN PRINCIPLE (Holmgren)Evaluation

    How does the Design relate to Planetary Boundaries?

    Have we realised our Vision?

    Use natural materials and construction technologies with as small an environmental footprint as possible.I think we have achieved this pretty well.
    Enable an ecological lifestyle with a high degree of self-sufficiency in energy, We have a high degree of energy self sufficiency but there is still room for improvement in terms of minimising fossil fuel usage. Mobility is a challenge in the countryside but biogas and electricity should be a way forward although not perfect when the whole lifecycle is calculated. (Perfect would be no mobility.)
    FoodThe house and buildings enable us to develop a high food self sufficiency. We have space for preparation, dry storage in the kitchen, earth cellar for potatoes and root vegetables and preserves. I would like to make a shelter for proper compost management.
    and materials.Self sufficiency in other materials is low and difficult to achieve. Fiber for textiles could be grown (Marja is interested). Wood works can be done from own material. A lot of modern gear is not possible to produce yourself and should be considered critically. We posses most appliances and gear that are considered normal in today’s world so in that respect we are not “better” than anyone else.
    Minimise wasteAll biological waste is kept on the property except solids froms the septic tank (even those could be kept and composted). Newspapers are mostly used for lighting the fires. Other paper, cardboard, glass and plastic is circulated. We try to minimise “Mixed waste” and should work more on minimising plastic. The amount of cardboard and plastic correlates strongly with food bought from shops so food self sufficiency is a way to decrease waste.
    Create a healthy and inspiring living environment for ourselvesI think we have done it.
    Enable social life and living according to our valuesWe have had more friends and new acquantacies visit us at Iso-orvokkiniitty than in our lifetime before this. Covid19 changed that temporarily but let’s hope we can get back to normal.
    Share our experiencesOur blog, this Diploma work, workshops etc at our place.
    We need space for workshops and accommodation.
    HospitalitySee above. We need more space for accommodation.

    More buildings?

    Accomodation could be developed in the form of a “little house” or yurt. A little house could temporarily house family members, volunteers at Iso-orvokkiniitty and could even be rented for some income. A yurt could provide more space for more adventure minded people f.ex. during a PDC course etc. In this design I will not do a full design for these but just review possibilities from the point of view of energy and electricity.


    The house was designed in 2015 and we built it 2016-18. Outside buildings (storage, earth cellar, sauna) were build in 2020-21. Now I am looking at what tweaks would help us meet our vision and needs better than the current situation.

    Need to tweakHow to tweak
    Electricity I will write about the electricity system below.
    – lack of electricity from solar and wind in the winter months see above
    – need to generate electricity with the generator in November, December, January, early February see above
    – need to have 200 Ah back-up batteriesPossible to take electricity for prioritised appliances from the main batteries when electricity is otherwise off. Needs an electrician to do it.
    – chainsaw runs on petrol Replace with battery driven chainsaw when winter electricity is sufficient and sustainable.
    – requires a lot of physical work That’s ok as long as I am in good health.
    – transport of wood from the forest to the house The nicest solution would be a horse. For horse powered forestry to be sustainable the horses also have to be fed with horse driven farming. Then it becomes challenging.
    Water & hygiene
    – lack of water in the winterThis is connected to the winter electricity challenge.
    – need to store water in kitchen and bathroom in the wintersee above
    – need to restrict use of washing machine (laundry) in the winter see above
    – lack of hot water especially autumn and spring (limited hot water in the winter)Heat the living room oven anyway.
    A gas water heater could be installed but I think we’ll just adapt to cold showers periodically.
    – saunaWe have build a very traditional log sauna with single-fired wood stove, which means the sauna experience is perfect but it takes 3-4 hours to heat the sauna up. A quicker continuous-fired sauna would be more flexible as it can be heated up in 30 minutes and decrease the problem of lacking hot water for shower in the house. Might sound crazy but in Finland it is quite normal for a sauna enthusiast to have 3-4 different saunas on a property.
    – freezer: limited capacityPut big freezer in the cold veranda. Electricity consumption in the winter will be very limited.
    – limited space for cooking in the summer A multispot electric stove is not an option because they need more power than the inverter can generate (2kW per spot). Could use a gas cooker on the wood stove in the summer. Challenge where to put the gas bottle. Install biogas system?
    – dish washing in the winter by hand electricity
    – fridge doesn’t get backup electricity when power is off see above
    – petrol carWas finally changed to a biogas car in January 2022. Electric car is coming.
    – limited space for accommodation Build a “Little house” or Yurt

    Tweaking the electricity system

    Our biggest frustration is lack of electricity in the winter which has various other effects as described above. Above I have analysed different options for solutions. The concrete question is how to eliminate the need to regularly generate electricity with the generator. We want to find a short term solution that functions already in the winter 2022-23 and explore longer term solutions.

    Short term (this chapter was written in February 2022)

    As described above a quick fix to the situation is an electric car with V2L (vehicle to load). I envision that this enables a situation where we need to go shopping to Lohja once a week and at the same time charge the car at the hypermarket parking lot. The full car battery should run the house for a week even if there is no wind (most weeks there is some wind). For the time being there are no charging stations in Karjalohja but on the other hand we pretty regularly go to Lohja anyway for services or shopping that is not available here (and new charging stations are popping up). I have placed the order for a Kia EV6 which at the same time will serve as a good quality car for my “business-self”. Lead times for cars are long, I hope to receive it in May 2022.

    Of course, how this solution will work in practice is not completely clear. Questions I already have that can be answered only by observing once the car is here are:

    • Summer: Do we have enough power from the solar panels and wind mill in summer to charge the car?
    • Will it become a problem for our everyday life if we are charging the car most of the time with 1kW power, leaving other needs with only 2,6 kW (inverter is 3,6 kW)?
    • Can we charge the car 24/7 without depleting the house batteries in the night (summer nights are short)?
    • Winter: For how long can we in practise run the house with the car and will it allow us a more relaxed usage of electricity without going to charge the car in Lohja more than once a week?

    How would this compare to the current situation? Now we are running the generator with 160-200 litres of petrol per winter producing some 300 kWh electricity and emitting 360 kg CO2 (3).

    If we make the calculation for the Kia EV6 we get the following numbers:

    • battery capacity 77 kWh but recommendation is not to repeatedly charge to 100%. Also the last 15-20% charging is slower. So we can calculate in practise with 65 kWh when the car is charged (85%).
    • Consumption of the car in the winter is 25 kWh per 100 km so we nead 8 kWh for the 30 km distance to Lohja (closest charging station at the moment).
    • There should be some reserve when we start from home so let’s say 15-20 kWh left.
    • So when we are back from Lohja we have 57 kWh charge and we need to go get more when 15 kWh is left so 42 kWh is usable .
    • With the calculated 8 kWh/day consumption that would last us 5 days but if we squeeze a bit we could make it for a week. Also most weeks there is some day with wind.
    • In the course of the roughly 100 days of electricity deficiency we would import some 600 kWh into the house.
    • Average CO2 emission of electricity in Finland is 131 kg CO2/MWh (4). So 600 kWh equals 79 kg or appr. 20% of what we emit with the generator. The car will be charged with wind power so the difference is actually much bigger.
    • In the fast charging stations electricity is pretty expensive but can vary widely. To be on the safe side we can calculate 0,25€/kWh. Then the cost of 600 kWh would be 150 €.
    • Even if the period when we need to import electricity to the house is only 3 months the period when the car needs to charged elsewhere is much longer. Probably only the 4-5 summer months we produce enough electricity to load the car at home. If we calculate 20000 km/year and 8 months loading elsewhere (16000 km) we need to buy an additional 4000 kWh for the car at a cost of max 1000 €.

    So the conclusion is that we still need to be conscious about our electricity consumption but we could use double the electricity than now.

    The electric car charging stations usually declare that they are using 100% wind power. So all the electricity we use would be renewable. Of course it doesn’t mean that it is without an environmental footprint. Both the car and industrial size windmills have a pretty heavy footprint.

    Solar panels and wind mills.

    If the above works as planned and we consider purchased wind power just as good as our own wind power (if self-sufficiency is the goal then it should be own wind power) the rest becomes an economical calculation. Does it make economic sense to try to eliminate the 1100-1200 €/year cost of buying electricity for the car and house? This is the kind of calculation that depends on the pay-back time and interest rate that we choose. If we calculate with 20 years payback and 4% interest rate we could invest 15000 € to save 1100 €/year cost (presuming there are no running costs in 20 years). If we presume 30 years payback and 3% interest rate we could invest 20000 € so let’s consider that the absolute maximum.

    Would it be possible to totally eliminate the need to buy electricity to the house and car with 15000-20000€ investment? What would be the best way to do that? In the above analysis the conclusion was that only a big enough windmill (10 kW nominal power) and more batteries could be a solution. It also shows that 20000€ most probably would not be enough. We also noted that a big industrial windmill is half the price relative to power generation – probably much less because they are located in optimal location and high enough to reach the winds. What if we made an investment in a tiny piece of an industrial windmill to cover our external electricity need? The investment would even pay a part of the cost we have in charging the car.

    Experiences with the “Mobile battery pack” (September 2023)

    So the tweak I did was to buy the Kia EV6 electric car with V2L. The car finally arrived in December 2022 – 16 months after placing the order. So now we have experience of the car for most of last winter and also this summer.

    The situation in the winter was more or less as expected above. A new 100 kW power charging station was opened at the Sale supermarket in Saukkola 26 km from here which means about 14 kWh power consumption to drive back and forth. Of course mostly I would charge the car on my way home from somewhere but I did drive to Saukkola quite a few times. When there was no other need for mobility we could run the house for 4-5 days with the car. As expected electricity use became more relaxed when it was more easily available than before. Overall the system worked well.

    Obviously the failed cell had to be in the left back corner so I had to move the other 3-cell packs out of the way. Each one weighs 140 kg.

    In March 2023 we had a problem. One battery 2V cell in house’s battery pack failed and therefore the batteries could not be charged or used. Fortunately the external electricity source (car or generator) bypasses the batteries but as soon as the car was disconnected the house was without electricity. It took until end of May until we received the repalcement cell and could fix the problem, so the car had to be hooked to the house even though the sun was already shining.

    The situation in the summer was more mixed. Until now the feeling has been that we have more electricity in the summer than we could ever use. But the situation changes if you are charging the car with 1,2 kW power most of the time. We never ran out of electricity but I also did not charge the car 24/7. 24 x 1,2 kW = 28,8 kWh so that would be most of the electricity we have on a sunny day. So I could charge the car only during daytime on sunny days.

    (1) Sosteric, M., & Ratkovic, G. (2020, December 19). Eupsychian Theory: Reclaiming Maslow and Rejecting The Pyramid – The Seven Essential Needs. See also “The Heroes Journey, The Myth of Heroic Independence, and the Circle of Seven Essential Needs

    (2) Paul Jennings. 26.8.2018. What might buildings, settlements and even regions look like through the lens of Permaculture design?

    (3) https://www.openco2.net/fi/co2-muunnin

    (4) https://www.openco2.net/fi/co2-muunnin

    (5) https://weatherguardwind.com/how-much-does-wind-turbine-cost-worth-it/

    (6) https://www.halkoliiteri.com/polttopuuinfo/energialaskuri

    (7) https://julkaisut.valtioneuvosto.fi/bitstream/handle/10024/162032/TEM_2020_3_Biokaasuohjelmaa%20valmistelevan%20tyoryhman%20loppur%20.pdf?sequence=1&isAllowed=y&fbclid=IwAR03jYkdaU4odL_F7vlQcTeW7LxZ76atlIyRrhYdEpMfgcrANt6gariTR8o

    (8) https://liikennefakta.fi/fi/ymparisto/liikenteen-kasvihuonekaasupaastot-ja-energiankulutus?fbclid=IwAR1yd6-9o_gdR0VEqL-hxRYDsVp86f5L4KHMahQuHC8iabXYeLCPk24fxFM