Solar power is the conversion of sunlight to electricity. Sunlight can be converted directly into electricity using photovoltaics (PV). A solar cell, or photovoltaic cell (PV), is a device that converts light into electric current using the photoelectric effect. This is based on the discovery by Alexandre-Edmond Becquerel who noticed that some materials release electrons when hit with rays of photons from light, which produces an electrical current.

Solar energy is not available at night, making energy storage an important issue in order to provide the continuous availability of energy.

Both wind power and solar power are intermittent energy sources, meaning that all available output must be taken when it is available and either stored for when it can be used, or transported, over transmission lines, to where it can be used.


ScienceDaily (Mar. 3, 2009) A new study on the installed costs of solar photovoltaic (PV) power systems in the U.S. shows that the average cost of these systems declined significantly from 1998 to 2007, but remained relatively flat during the last two years of this period.
The study examined 37,000 grid-connected PV systems installed between 1998 and 2007 in 12 states. It found that average installed costs, in terms of real 2007 dollars per installed watt, declined from $10.50 per watt in 1998 to $7.60 per watt in 2007.

Costs differ by region and type of system

Other information about differences in costs by region and by installation type emerged from the study. The cost reduction over time was largest for smaller PV systems, such as those used to power individual households. Also, installed costs show significant economies of scale. Systems completed in 2006 or 2007 that were less than two kilowatts in size averaged $9.00 per watt, while systems larger than 750 kilowatts averaged $6.80 per watt.

Installed costs were also found to vary widely across states. Among systems completed in 2006 or 2007 and less than 10 kilowatts, average costs range from a low of $7.60 per watt in Arizona, followed by California and New Jersey, which had average installed costs of $8.10 per watt and $8.40 per watt respectively, to a high of $10.60 per watt in Maryland. Based on these data, and on installed-cost data from the sizable Japanese and German PV markets, the authors suggest that PV costs can be driven lower through sizable deployment programs.

The study also found that the new construction market offers cost advantages for residential PV systems. Among small residential PV systems in California completed in 2006 or 2007, those systems installed in residential new construction cost 60 cents per watt less than comparably-sized systems installed as retrofit applications.

Solar Packaged Systems:

A number of companies and manufacturers put together solar packaged systems-complete packages that take the nitty-gritty 'component picking' work out of buying a solar energy system.

These can come in the following sizes:

bullet Grid-inter-tie kits that retail for around $20,000 but will include everything you need. A basic starter kit will retail for $8,000 to $10,000.
bullet Cabin or remote kits that will give you electric power for your off-grid home. These can start at $1,500, up to a full size system for $5,000.
bullet RV kits starting at under $1,000. These are used to power a few small appliances for your RV, to give you some of the benefits of home while you are on the road.

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