Monday, March 2, 2009

Part Three - Professional Experience to Date

The Potential of Solar Energy

I undertook a research project before I left Washington State for Las Vegas. I wanted to equate the capture-able solar energy that lands on a school roof in that environment and compare it with the energy required to operate the school. In order to do this accurately, I was able to get the help of a Scandia Labs solar specialist to provide resource data and guidance.

I selected a twenty classroom elementary school in suburban Seattle that was designed to meet pre-energy code criteria and was all electric. This made the energy consumption calculation simpler. The school was a 45,000 sq. ft.(funding area) single story four building complex with exterior circulation, using covered walkways and play areas for rainy day recesses. I estimated the net usable roof area for a photovoltaic system to be 62,000 sq. ft. The school did not have refrigerant cooling systems.

The system was assumed to be installed flat, or near flat, using the then state of the art silicon chip wafer system, with, I believe, 20% conversion efficiency. Because of the overcast/rainy weather typical of the area, I found that a flat system is somewhat more efficient with, a lower overall output than there would be in the sunny southwest.

I included the losses incurred with conversion to AC energy and did not consider storage to balance the internal loads, assuming instead that the off time energy would be used to “run the meter backward” for use by others.

Surprisingly, the result was very impressive in that the annual energy out was roughly equal to the average energy consumed on an annual basis over a three year period.

This is in my mind very significant as photovoltaic systems have progressed today and include film type collector technologies and improved efficiencies. It would be fun to revisit this project and see what today’s results would yield.

Needless to say, I could not at the time generate serious interest for funding a pilot project to demonstrate this reality. In the words of Scandia Labs, there must be a consumption angle in grant applications for the energy providers in order to get attention for any pilot solar project proposal. I understand that recently A utility co has entetained joining with school districts to jointly equip and service this type of system.

Solar energy landing on a un-equipped roof does no good and major degradation to many roofing systems. The energy is mostly wasted. These roofs, by and large, sit within electrical service grid systems, making their energy use possible around the clock without costly additions to the national grid system. The passive collection systems are low maintenance and at least, at that time, were considered not degradable with time.

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