The Directive 2010/31/EU on buildings’ energy performance approved this year opened new doors for manufacturers of urban wind turbines. The Directive urges European governments to elaborate laws that enforce the use of renewables in buildings and technologies that improve their energy efficiency.
Buildings use 40% of the total energy consumed in the EU. By making new zero-energy buildings and improving the efficiency of those in need of major renovation, Europe will have it easier to comply with the Kyoto protocol.
These measures will also help secure energy supply, reduce EU’s energy dependency, enhance technological progress, create new jobs and boost regional development, especially in rural areas.
New technologies are making “microwind” a reality and, in Europe, Dutch companies have developed small turbines that can be easily installed on rooftops today. It is the case of Donqi, a young company started in the Netherlands with the intention of providing decentralized power generation for urban and rural areas.
Sure, wind cannot be harvested on a rooftop the same way industrial wind farms do on the fields –weight, vibrations and noise being the main reasons–, but urban wind turbines are designed for built environment and work quietly on a reduced space. Donqi’s turbines have a capacity of 1.75kW, an outstanding 679kW/sqm (the highest in the industry), and they can generate an average of 2,000kWh/year with 5.5m/s (18fps) winds –up to three fourths of the energy consumed by a household or a small business–.
Also, they resist wind speeds of 200 km/h (124.2mph) and make the most of the “roof effect” –when wind hits the wall of a building it slows down and compresses, but by the time it reaches the top, it expands and increases its speed– . Further, Donqi’s turbines are assembled by social welfare with recycleable materials.
Wind turbines represent a good complement for solar panels, and are a valid way of harvesting energy in areas where sun does not always shine. They are particularly suitable for coastal areas with high wind speeds and constant wind flow.
Donqi’s urban turbines are easy to install and can be ready in a couple of hours; also, they can be connected to the grid. Prices are affordable, and both the EU and the different countries are putting several financial instruments in place to help households and businesses go green.
If you are thinking about installing urban windmills, Donqi suggests that you first measure the wind speed at turbine height and check the yearly prediction from the meteorological station for two months. If wind speed is equal to or higher than 4.5 m/s (14.8 fps), you may want to install one on your roof.
The challenge of making all new buildings nearly zero-energy by December 2020 makes me think that manufacturers of urban wind turbines will be very busy in the next years. The amount of energy to be produced is enormous and buildings will need several sources of renewable energy in place to make it happen.