2 Contenders At General Electric's Ecomagination Challenge Propose Solar Cpv/wind Turbine Combo

Together with a Dutch team, a wind turbine that fits on the ridge of gable roofs was designed.The wind turbine is typically placed over the full width of the roof and -as the diameter is only 45 cm (22")- it is aesthetically pleasing and not intrusive, while being very economical. They designed a grid intertied inverter, which additionally accepts solar PV. Traditional technologies (both vertical and horizontal axis) turbines require at least a 10' (3m) diameter turbine for the same output, are bulky (and aesthetically unacceptable) and difficult to mount on a residential roof.

The developers believe this is the first serious attempt to introduce residential wind energy and their team's approach is to obtain exemption for building permits and zoning requirements,considering the limited impact on the construction of the building and acceptable aesthetics that will even please the NIMBY (Not In My Back Yard) crowd. They recognize the strategic importance to have contractors and architects on their camp.

Shawn Buckley and partners developed a solar PV concentrator. Using Fresnel mirrors, the sunlight is concentrated on an amount of silicon that is only 5% of the silicon normally required by a traditional solar photo-voltaic panel with a similar output. As the silicon is expensive and the Fresnel mirrors are cheap - especially in large volume - this technology may well change the solar PV arena.

What makes Shawn's system different is that in addition to delivering electricity, the module also captures solar heat that can heat tap water. The solar CPV panel thus doubles as a solar water heater, while improving efficiency because of cooling. This clearly improves the savings offered by the solar PV concentrator.

Both designs are breakthrough approaches and during the ECOmagination Competition they recognized each other's strengths. After brainstorming they came with the following concept, marrying their technologies in a very efficient way: On top of the wind turbine, a custom solar PV concentrator is mounted that replaces the cap that normally covers the wind turbine. This combination has a series of advantages:

1. The installation cost isnot much higher than that of the wind turbine (or solar PV concentrator) alone.

2. Placing it on top of the roof ensures unobstructed sunlight exposure to the solar concentrator, regardless of the position of the roof.

3. Both systems share one inverter; causing significant cost savings.

This is a link to the ECOMagination challenge: http://challenge.ecomagination.com/home/SmartWind-RidgeBlaster-18-kW-wind-turbin In Phase two of this Challenge, participants from all over the world share their best concepts on how to improve our energy future. Phase II of the ECOmagination Challenge focuses on "Powering Your Home": and shows innovative concepts about capturing, managing, and using energy in the home and it is amazing that this generated more than 800 ideas. Although the Challenge closed 15 March 2011 the website is still active so if you are interested to see some of the ideas you can still do that.