As we all know hydropower is capable of producing enormous amounts of electric energy. But there may be serious side effects creating loss of habitat for various species; communities lose their ancestral ground, fish get killed in the turbines, etc.. So why does hydropower has such an aura of sustainability?

First of all, water is always flowing. The hydropower plants don't produce CO₂ and the live span of hydroelectric installations is several decades. Beside that, hydropower is very effective: around 70-80% of the potential energy is converted in electricity. And they run at full power around 80% of the year. So the materials used for fabricating the plant is more effective than any other energy resource.

With these advantages and the possible drawbacks in mind Gratia Hydro found the way to bring hydropower back to the people. As it was in the 19^th century and before. When inhabiting North America settlers would build water mills to saw lumber, grind corn or extract oil form linseed. These are the installations that got abandoned when cheap electrical power came abundant in the 20^th century. But we can restore these old water mills and make them to use for our 21^st century life. Without destruction. Without loosing habitat. Without killing fish and other water fauna. But in harmony with nature. With respect for historical heritage. Showing our children where energy comes form and what enormous forces are at work.

But restoring an old water mill is expensive. Your budget should be around 10.000 $/€ per installed kW of power. Most times too expensive for a mill owner. And when you have the installation restored you would generate too much electricity for your own use. With that in mind there are two possibilities which are widespread. One: burn the electricity in electric heaters. Two: sell it on the grid. Burning electricity in an electric heater is very efficient from a physical point of view, but a waste of a valuable energy carrier. Selling it to the grid gives the mill owner a sort of income, but revenue is small since the naked price for green electricity is a few cents; way less that you would pay as a consumer due to grid costs, energy tax and VAT.

The solution is as simple as sustainable; both form CO₂ perspective as for communities: restore old watermills together as a community and make use of the electric energy in your car. When you would have a plug out car (like the Sion from Sono Motors) you can harvest your electricity at the mill and take it to your home. And not only you. You do it together with 10 other households, hence creating a sustainable community. You might be connected to the grid for stability and as a way to get rid of the excessive energy, but the majority of the electricity comes right to the participants without gird transport costs, energy tax and VAT. Restoring a small water mill is still expensive, but the return on investment is high as well. Depending on local tax rules the payback time is between 6 and 12 years for a typical 5 kW mill. And after that you can still use it for the next 50 to 100 years. That is sustainability as it should be.