Until recently, the expense of putting solar panels on the roof meant that only a few eco-warriors with money could adopting it. Everyone else felt that the payback period was too long. However, every cloud has a silver lining. With the hefty rises in electricity and gas prices over the past few years all over the world as well as the recent advancements in research, the lining is that solar power could now become a realistic, cost-effective option for most of us.
Within the US, many people still believe that the solar power is not as cost-effective as grid power. A search on Google reveals that this is not always the case. News articles indicate that photovoltaic solar cells (PSC) are cost effective in Hawaii and some parts of California — meaning that PSC became cheaper than electric grid power if you wish to power a remote home that is more than 2 miles from the nearest power line — because the electric company will charge at least $20,000 in the US to extend the power lines two miles to a single home. Diesel electric generators (and other fossil fuel burning generators) have relatively low up-front costs, but over a 30-year period they will cost a lot to maintain and fuel.
Let’s take an example. Mostly electric companies charge us a basic amount. Furthermore, there are other costs of the transmission lines, electric meter and hiring someone to go to the home to read the meter. If all these costs conservatively total to $120 per year that is $3,600 total over 30 years, then we have $3,600 for buying solar panels (that will last the same period).
Today, solar panels can be obtained for as low as $3.75 per watt. The $3,600 would thus be available to buy a 900 watt solar electric panel array. If one’s home receives an average of 4-5 peak hours of sunlight per day (common for homes perennially for more than half of India), then this array would generate 3.6 kwh to 4.5 kwh per day. In fact, if a home in India typically consumed 3-4 kwh per day — that would be one 1 kwh AC unit continuously running for 3-4 hours (not unreasonable in middle-income towns) — then the house could entirely subsist on the 900 watt solar electric panel array.
Furthermore, let us now consider the cost of electricity usage. Suppose an electric company charges 6.5 cents per kwh for residential electric usage. If a home used 3.6 kwh per day this would equal to about $2,564 over 30 years. That $2,564 could be applied towards the cost of the photovoltaic racks, wiring, meters, controllers, batteries and installation labour. At 4.5 kwh per day, the savings in electric utility usage costs equal $3,205 over 30 years.
However, these facts are not yet it. There is more goodness in using solar power. The calculation above assumed a constant electricity rate. Now, consider the fact that electric rates (especially from the coal-based power plants) are very likely to rise over the next 30 years, both in terms of the monthly base fee and the usage rate fee, whereas the solar panel equipment would already be paid for and the sunshine is free. There would, however, be occasional battery bank replacements. Secondly, many states will start offering tax credits for renewable energy systems. All this will make a lot of savings over a long time period.
Looking into the cost of the solar panels, one finds that the main costs are: wiring connecting the individual cells and the glass and the manufactured silicon solar cell materials. Most recently, researchers at the Duke University perfected a simple way to make tiny copper nano wires in bulk. The cheap conductors are small enough to be transparent, making them ideal for thin-film solar cells. Currently, indium tin oxide (ITO) is used as the transparent layer for the electrode in thin-film solar cells. Copper nano wires hold the key to replacing ITO in solar panels. The latest research quotes that it would take about $3.00 worth of copper nano wires, less than half a gram, to coat 1m² of glass of solar panel. If this fact is true then this will make the solar cell technology a very different economic proposition in the near future.
Lowering costs of solar technology is critically important. The other side also can benefit, more efficient display panels can cut the electrical energy needed to expand the human standard of living. The returns already justify the outlay and, if you are worried about global warming, going solar is going the right way.
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