Permaculture Explained (Vol III Issue 2): Catch and store energy
This principle deals with the capture and storage of energy within the environment, buildings and even society. If you think about a bank account, this principle is about how we can make our capital bigger, rather than how we spend the interest.
The vast majority of energy is supplied by the sun. Some of this is captured by plants who have learnt the clever trick of how to turn photons from the sun into complex carbohydrates. This basic trick powers every ecosystem on the planet. Using a combination of plant based systems and intelligent design approaches we can rebuild 'natural capital' in order to create the basis for a long-term sustainable society.
Storing energy in the landscape
In permaculture we design landscapes to maximise this energy capture. This is mainly by planting and nurturing new areas of 'biomass' - living things - mainly plants, usually as gardens, trees, woodlands, forest gardens, meadows, agroforestry, ponds, etc. We also make sure that the plant systems contribute to the development of deep healthy soils. Deep soils allow good crops, retain more rainfall, and also have the hugely important role of being the world's largest and most important living stores of carbon.
One advantage we have over nature is that we can also plan and decide how to catch energy in the landscape by capturing water in dams, ponds and reservoirs, that can then be used to do useful work for us. The Krameterhof project in Austria is an excellent example of how this has been achieved. They provide their own energy and enough for neighbouring farms using hydro-electic turbines, as well as creating amazing microclimates, abundant fish and wildlife.
Catching and storing energy in the built environment
We can design our buildings to catch energy too. By facing buildings towards the sun, sunlight can heat homes and provide light for free. Active solar technologies like solar photovoltaics and solar water heating can also catch the sun's energy and store it in well insulated water tanks and batteries. At the Earthship in Brighton, high thermal mass walls and floors soak up the heat from the sun and let it out slowly over night and after the summer has passed. Solar technologies, recycled materials and a beautiful design make this an excellent example of sustainable building.