German solar city (Sonnenschiff) produces four times more energy than it consumes

by Michael Smith (Veshengro)

Sonnenschiff_web This proves that it can be done even in a country where the sun does not shine as much as in southern Europe and proves that the British government simply does not have the political will to get solar (and other renewables) going.

Although net-zero projects have been creating a lot of buzz lately in the field of green building, the Sonnenschiff solar city in Freiburg, Germany is very much net positive. The self-sustaining city accomplishes this feat through smart solar design and lots and lots of photovoltaic panels pointed in the right direction. It seems like a simple strategy – but designers often incorporate solar installations as an afterthought, or worse, as a label, and that is not an efficient way of doing it. Those installations that then don't bring the promised results are then used by the advocates of fossil fuel and nuclear energy as proof that renewables don't work and could not supply all our needs.

If, in fact, we would change the supply in our homes and would, predominately, use the 12V DC produced by PV panel and small wind turbines, etc. we would be able to run things even more efficient.

Designed by Rolf Disch, the Sonnenschiff (Solar Ship) and Solarsiedlung (Solar Village) emphasize power production from the start by smartly incorporating a series of large rooftop solar arrays that double as sun shades. The buildings are also built to Passivhaus standards, which allows the project to produce four times the amount of energy it consumes. A great result, I should say, proving that with design and vision it can be done, and it can also be done as retrofit, though maybe a little less efficient.

The project started out as a vision for an entire community and the medium-density project balances size, accessibility, green space, and solar exposure. In all, 52 homes make up a neighborhood anchored to Sonnenschiff, a mixed-use residential and commercial building that emphasizes livability with a minimal footprint. Advanced technologies like phase-change materials and vacuum insulation significantly boost the thermal performance of the building’s wall system.

The homes are designed to the Passivhaus standard and have great access to passive solar heating and daylight. Each home features a very simple shed roof with deep overhangs that allows winter sun in while shading the building from the summer sun. The penthouses on top of the Sonnenschiff have access to rooftop gardens that make full use of the site’s solar resources. The rooftops feature rainwater recycling systems that irrigate the gardens and while supplying the toilets with gray water. The buildings also make use of wood chip boilers for heat in the winter, further decreasing their environmental footprint.

If one would consider now adding to a settlement such as this methane gas production and the use of boilers fitted with Sterling engines further energy could be produced. Furthermore, if the 12V DC power created by those electricity systems all be stored in battery banks for use when there is a drop in production for some reason any area could become energy self-sufficient and even become energy exporting.

The project’s simple envelope design is brightened by a colorful and dynamic facade. Gardens and paths cross through the development as well, linking the inhabitants. Offices and stores expand the livability of the community while contributing a sense of communal purpose.

While the Sonnenschiff village was designed and created on a blank sheet of paper, so to speak, we must find a way, and the right kind of visionaries designers will be very much required here, to make our existing city blocks, towns and villages equally efficient and energy producing.

© 2012