Grid Scale, Solar, Wind Power

Solar PV: Buy Now or Wait for a Better Deal Later?

Dear Scott, I’m seriously considering adding PV to my passive solar home. I’ve heard a rumor that new, more efficient PV technology is on the horizon. Should I wait a few years to get the most effective PV system? Evette H., Chapel Hill, NC

Evette and Readers, I have been getting numerous inquiries on breakthroughs on photovoltaics and whether consumers should ‘hold off and wait’. When I ran the Solar Energy Industries Association for 15 years, I had heard the same questions as I have had from my clients these past five years. I can honestly say that even if photovoltaic modules become 20 percent more efficient in 2006 (which I think is extremely unlikely), the consumer would not see such efficiencies reflected in the price of a photovoltaics system for many years to come. First, the time to buy solar thermal or electric systems is in 2006 and 2007 when there are 30 percent federal investment tax credits and numerous grants, tax credits and tax waivers at the State and local government level. Second, any breakthroughs in efficiency take many years to become integrated into a product and scaled-up in automated manufacturing plants, at the yearly output levels of 25 – 100 MW scale that we are seeing today. Third, hefty increases in the cost of silicon, aluminum, and glass — all materials incorporated in solar modules – are going up in price steeply and they appear to be on the rise in the future, as well. And fourth, solar photovoltiacs modules or panels, are only part of a photovoltaics system – which may include inverters, charge controllers, disconnects, battery banks, and roof or ground mounting frames, wires and electric conduits and boxes – which generally are rising in cost, though we do see some downward trend in the cost of inverters. What I suggest to residential homeowners who are considering solar is to first look at solar water or solar pool heating – very cost effective solar options. Second, select a photovoltaics system that meets some critial functions and is designed to be expanded. Start on the garage roof or a subroof on your house, and dedicate your solar electric power to certain key circuits to run your home office, or kitchen loads (refrigerator, phone, and maybe electric ignition on your natural gas stove), or maybe the sump pumps in your basement or the television and stereo units in your den, where clean power quality is important not to burn out expensive equipment. I followed this advise in my own home where I have 1.2 kW of polycrystalline photovoltaics (Solarex) and I added 0.5 kW of UniSolar’s ‘peal and stick’ modules for the metal-seamed roof I added on my front porch, in addition to my solar water heating system. On my office building in Virginia, I have 1 kW of UniSolar’s photovotaics roofing shingles, in additon to a small Southwest Windpower turbine tied into the first ‘plug and play’ smart battery bank offerd by GridPoint, and I also added a 5 kW Plug Power fuel cell back-up system. And on the roof of my Washington, DC office are 1.2 kW of photovoltaics from an assortment of photovoltaics manufacturers IsoFoton (Spain), Shell Solar (CA), Schott Solar (MA), Spire (MA), and UniSolar (MI) tied to a Xantrex SW Inverter. In each case, I am assured of pristine power quality protecting my appliances and electronics against the surges and swells of my local electric grid, back-up electricity from the many outages we have had in this region, offsets to steadily increasing electricity rates, and a tangible sense of doing my part both personally and professionally to reduce pollution in an area that receives most of its electricity from coal. I have no regrets that I didn’t wait another ten years for better technology. And with my recent purchase of a Toyota Prius, I have no regrets in achieving 50 mpg even though a more fuel efficient car may come along shortly. Don’t be shy. Good luck with your decison and I hope you make the ‘leap’ to photovoltaics on your passive solar home. – Scott Sklar