Some Wake Forest University researchers have developed a solar collector design that captures both electric power and heat for a higher overall efficiency.
A new polymer-based solar-thermal device is the first to generate power from both heat and visible sunlight Ė an advance that could shave the cost of heating a home by as much as 40 percent.
Geothermal add-ons for heat pumps on the market today collect heat from the air or the ground. This new device uses a fluid that flows through a roof-mounted module to collect heat from the sun while an integrated solar cell generates electricity from the sunís visible light.
If this approach can be commercialized then it could lower water and home heating bills.
Only a relatively small portion of the light hitting photovoltaic (PV) material gets converted into electric power. Check out this table of average PV conversion efficiencies by type with silicon crystals at 20% on average. Much of the remaining energy in the light can be captured as heat.
The design of the new solar-thermal device takes advantage of this heat through an integrated array of clear tubes, five millimeters in diameter. They lie flat, and an oil blended with a proprietary dye flows through them. The visible sunlight shines into the clear tube and the oil inside, and is converted to electricity by a spray-on polymer photovoltaic on the back of the tubes. This process superheats the oil, which would then flow into the heat pump, for example, to transfer the heat inside a home.
Houses of the future will do more work. They will combine the German Passivhaus (Passive House) design ideas (where a house leaks very little heat) with solar panels that collect electric and heat energy. As a result houses will do more work to supply a comfortable environment and to power appliances and highly efficient lighting fixtures. Houses will also contain computers with sensors and software that will monitor your health, let you know when your kids or pets are up to trouble, do self-cleaning, and other tasks. Future houses as capital assets will have higher productivity than they do today.
|Share |||Randall Parker, 2011 April 26 07:35 AM Energy Solar|