Plants have been capturing the sun's energy and converting it into chemical energy for millions of years. Photovoltaic cells, which convert some of the sun's energy into electricity, were developed by Bell Labs in the 1950s for use in the space program.

Environmental concerns and the rising cost of fossil fuels have brought the idea of using solar cells to generate electricity for commercial and residential use more into the mainstream. The practicality of using the sun's energy to power a modern broiler house is being put to the test in a three-year study on an Allen Family Foods' broiler farm located just outside of Laurel, Del.

A partnership of government agencies, private enterprise and the University of Delaware has been formed to put solar power to the test in a real-world, on-farm situation.

Allen's Portsville Road farm, which is company owned, was chosen as the demonstration site. The farm has five broiler houses, but only one will use solar power.

The two solar panels on the farm can generate up to 42 kilowatts of electricity. This is more power than is needed to run the one broiler house. The study will test using solar panels to power the broiler house, charge back-up batteries, and to put electricity on the power grid.

Power generated by the solar panels is direct current, and inverters are used to convert this power to alternating current for use in the broiler house or for sale back to the power grid. Energy in the batteries, which were sized to power the house for up to eight hours, is stored as direct current. The farm's back-up generator is also available if all else fails.

The battery system, invertors, switching equipment and monitoring equipment are housed in a trailer on the farm. A typical solar installation would not have the sophistication of this set-up, but the equipment was necessary for data collection.

Bob James, live production manager, Allen Family Foods, said that the system had one hiccup in the first couple of flocks. For a brief period, the switching equipment left the house without power, even though power was available from multiple sources.

While a major catastrophe was averted, this shows that even with sophisticated equipment, backup procedures need to be in place and everyone needs to know exactly what to do when the "automatic" systems don't function as intended.

The system being tested at the Portsville farm was built by WorldWater & Power Corp. with help from the University of Delaware, at a cost of $500,000. Chris Schering, vice president of national accounts for WorldWater & Power Corp., said that future farm installations, without all of the monitoring equipment, would cost half to two-thirds of the demonstration project's equipment.


This means that a solar system large enough to power a new poultry house could cost as much as the house itself.

Payback for a solar system can come from a number of different sources. First, a federal tax credit of 30 percent of the initial investment is available. Some states have their own tax credits or rebates, and state credits can be as much as 50 percent of the system cost.

If the technology proves to be effective, USDA rural development grants or low-interest loans may be available. Also, some states have mandates for a certain amount of power being generated by alternative means.

A market is developing in these states for "green" credits. Solar panel owners could get paid for these credits based on how much electricity they generate. Green credits have been valued at over $0.20 per kilowatt hour in Delaware, which is more than double the electric rate.

Allen Family Foods is paying for this demonstration project and it is expected that tax credits and rebates will offset over half of the project's cost.

Schering said that after considering tax credits and rebates, which vary by state, and depending on local electric rates, a solar-powered, electric-generating system for a poultry farm could pay for itself in as little as four years.

Commercially available solar panels generate 10 watts per square foot and weigh around three to four pounds per square foot. Panels can be mounted on the roof of many poultry houses, but this might not provide the best placement for capturing sunlight.

Without tax credits and rebates, solar power is not practical today, but this could change in the future. Research is ongoing to improve the efficiency of solar cells. Manufacturing costs for solar equipment should drop as the technology gains greater acceptance.

Prices for all sorts of consumer electronic products, like cell phones, CD players, DVD players, etc., have fallen as they have become mainstream items, and the same should be true for solar cells.