Tuesday, September 7, 2010


The argument that solar energy is too expensive is slowly starting to crumble. Prices of photovoltaic panels have been literally cut in half over the past two years. First Solar, one of the largest solar manufacturers recently announced it is at the 76 cent/watt benchmark. Although this is still above the 50 cent/watt deemed for years as being the magic number where solar would be universally accepted, we’re at a major crossroads, and the optimism is that the cost will continue to decline.

I’d like to try and put all this in perspective. We use electricity in units of watts…a 100 watt light bulb, a 1500 watt toaster. We pay for electricity in units of kilowatts per hour…1 kwh means we use 1000 watts for 1 hour; and our cost is anywhere from 8 cents to 15 cents depending on where we live. This retail price includes the cost of production, transmission, maintenance, administration, taxes, insurance, profit…all the expenses associated with the business of a utility serving its customers. In order to produce the electricity, a “power plant” must be constructed. What First Solar is saying, is that its “production” modules now cost $760/kw to manufacture. Add to that the other construction-related costs, and the total cost of that power plant approaches $1000/kw. If we look at other kinds of power plants, a coal-fired plant costs roughly $4000/kw; the new natural gas-fired plant PG&E built at Humboldt Bay came in at $1500/kw; and the proposed new nuclear plants are estimated at $8000…$12,000…???????????$/kw.

The cost of solar is decreasing, while the cost of conventional fueled (fossil, nuclear) electricity generation is going up. Once the power plant is built, there are O&M (operation and maintenance) costs…the cost of fuel, replacement of parts that wear out, cost of water for cooling, cost of waste (air pollutants, CO2, nuclear spent fuel) disposal. PV solar has the advantage of no fuel costs, no emissions or wastes, a minimum of moving parts to wear out, and very low labor requirements once the plant is up and running. I recall in 1989, a colleague of mine from the Engineering Department at HSU and I visited two huge (by 1989 standards) PV facilities in Southern California. We were stunned that in the middle of the sunny afternoon, while each of these 1MW plants was producing electricity for the grid, we could not find anyone to talk to because the entrance gates were locked, and there was no one around. Just the birds chirping, and the steady creak of the trackers moving the PVs every 15 seconds to face the sun. Whether we place solar in dedicated “solar farms” or mount them on our rooftops, we have a relatively inexpensive source of electricity once the initial “cost of construction” is paid for. It is estimated that placing PVs on just 3% of the roofs of US structures could displace all the coal-fired electricity generation we have today.

The cost of solar is coming down. PVs are becoming more efficient, meaning less surface area and materials needed per watt. New technologies promise new materials that can be incorporated into almost everything in our lives…our homes and commercial buildings with PV coated roofing material and glass and solid walls, automobile and truck rooftops, highway median strips, even the clothing that we wear. And all this with no moving parts, no fuel costs, no emissions…no increasing bills from our local utility. In 2009, there were 146 new solar patents granted. The solar industry is making huge inroads in the economies of not only the US, but China, Japan, Germany, Spain, Italy, and South Korea.

The renewable and sustainable future is possible, yet enormous obstacles and issues remain and must be overcome. The sun does not shine all the time. The biggest challenge is storage of solar energy so it can be used whenever we need it. I will leave that discussion for another time, but we are moving forward towards our “green energy” future. Major advances in energy efficiency, smart grid technologies, and the blending of other renewable resources such as wind and biofuels will continue to progress hand in hand with solar energy. The main role for solar right now is to produce electricity when the maximum amount (peak power) is demanded by consumers. That is generally in the afternoon, on a hot summer day, when the sun is shining at its brightest. The transition has been slow, ands there will be ups and downs; but the pace is escalating as we move into the new “green” era beyond fossil fuels and nuclear.




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