CO2 calculator Energy balance calculator

Since there is not a single footprint calculator where you can enter the values of a GEMINI next generation, here is our CO2 energy balance calculator for housing and mobility.

  We do not have 37 million km² of growing forest

Footprint calculators assume that 1 m² of growing forest can absorb 1 kg CO2 per year. This would work very well with 1 to 2 billion tons of CO2 emissions per year. Creating 1 to 2 million km² of new forest would not be a feat.

But one thing is certain: we do not have 37 million km² for new forest areas. This fact is expressed with the saying "We need 2 Earths". Since we don't have 2 Earths, we need a more efficient method to reduce CO2. Filtering one kg of CO2 from the atmosphere and splitting it into carbon and oxygen requires 8 kWh of electricity. A square meter of photovoltaic can produce 320 kWh per year in a sunny desert and thus supply a facility with electricity that reduces 40 kg of CO2 with these 320 kWh. Instead of 37 million km² growing forest around 1 million km² photovoltaic in sunny deserts. We have them, that is feasible.

  Energy balance calculator

Our energy balance calculator evaluates every kWh of electricity you feed into the grid as 1 kWh positive in your balance and every kg of CO2 emission as 8 kWh negative.

The values come from Calculation of greenhouse gas (GHG) emissions from various energy sources Federal Environment Agency Austria as of 2017. The upstream chain is taken into account at the Federal Environment Agency Austria. For example, from the borehole via transport to the refinery and to the filling station. There are also information on air travel and other emissions.

Deviating from this, the CO2 default for electricity is 474 g/kWh according to Umweltbundesamt Deutschland 2018

Deviating from this, we do not believe that a tree that would stand for 300 years is CO2 neutral, we therefore calculate 50% of the carbon present in the wood for burning.

The preset values correspond to a GEMINI next Generation house between 47 and 50 degrees latitude with 20,000 km per year driving an electric car.

Electricity purchasing kWh
Electricity mix g CO2/kWh
Electricity feed-in kWh
Heating oil kg
Diesel Liter
Gasoline Liter
Natural gas (10 kWh/m³ 13 kWh/kg) kWh
Wood kg
Other CO2 emissions kg
Your energy balance in electricity 2000 kWh

  Electricity purchasing

The electricity that you draw from the mains, the electricity that you charge your car with at charging points.

  Electricity mix

Use the electricity mix of your country for this, even if you purchase "100% certified green electricity". This is useless as long as your neighbour has "100% electricity from local lignite".

A snapshot of the power mix can be found on

  Own consumption

This point simply does not exist in the energy balance. If you consume a lot of your solar power yourself, this will only reduce your electricity sales.

  CO2 Emission from production

CO2 emissions from production are constantly changing. The electricity mix becomes cleaner, the production is energetically optimized. But this can also go in the opposite direction. Oil wells that are easy to use are diminishing, new oil wells can only be tapped at extremely high cost. German coal mines close, coal is sourced by ship from other continents.

Let's assume that a GEMINI next Generation is transported 200 km from the production hall to the building site. For the way to the ground 15 l diesel/100 km, for the way back 7 l diesel/100 km. 264 liters of diesel for house transport. In a few years Electric cars will be available, which can also pull a house segment . For the way to the building site 55 kWh/100 km, for the way back 25 kWh/100 km. That is 960 kWh electricity, the largest part of the photovoltaic roof of the production hall.

  Only a snapshot of housing and mobility

Production is not included in this calculation. It does not include emissions from food production. A balance in red shows how many kWh of electricity future generations will have to produce during the period of planetary renovation to filter your CO2 emissions from the atmosphere and split them into carbon and oxygen.

It also does not take into account the possible interest on our greenhouse gas emissions, thawing permafrost soils, outgassing methane hydrate. Perhaps every kg of CO2 from fossil combustion is accompanied by one kg of CO2 equivalent from thawing permafrost soils.

GEMINI next generation - 64 or 98 m² most modern living comfort GEMINI next generation - 64 or 98 m² most modern living comfort
What can housing cost? Where can you build? How much Energy should a house produce? How much building material is needed? GEMINI n.G. is looking for completely new answers to these questions.

Prehistory of the GEMINI next Generation project
It started in autumn 1991 with the GEMINI habitable solar power plant, 2011 with the initiative Solar Building Land and 2018 with GEMINI 66 - we build our house ourselves.

Where can and should GEMINI next Generation be built?
Using existing land better and building where conventional houses cannot or are not allowed is an important objective of the GEMINI next Generation project.

How much energy should a house generate?
As much as possible! Because we need to get out of oil, coal, biofuel, natural gas and uranium. Our houses should contribute as much as possible.

Security in living Security in living
This concerns immediate disasters such as flood, nuclear accident, forest fire, but also future oil crises and changes in the tax system or electricity price system. Download PDF

Project GEMINI next Generation 2019
News about the GEMINI next Generation project in 2019.

Project GEMINI next Generation 2020
News about the GEMINI next Generation project in 2020

  How much energy should a house generate?

As much as possible! Because we need to get out of oil, coal, biofuel, natural gas and uranium. Our houses should contribute as much as possible.

Climate protection superiority house Climate protection superiority house
Start into the solar age with a Climate protection superiority house. Lowest possible energy consumption for production, maximum possible energy surplus during operation.

Photovoltaics replace almost everything
We have to get out of oil, coal, biofuel, natural gas and uranium. Photovoltaics must bear the brunt of this exit. No more ridiculous fig leaf PV systems.

Energy for room heating becomes insignificant Energy for room heating becomes insignificant
How much do you save when you freeze in your own house? Between 18 and 23 degrees interior temperature are only 1000 kWh heat, less than 250 kWh electricity, less than 20 EUR.