Solar Power and Other Renewable Energy Forms

The claims of enthusiasts are sometimes overstated but it is still true that solar power and alternative energy forms are viable and valuable. Solar energy generates little pollution despite the effects of manufacturing in the making of the components. They are, in principle, inexhaustible sources of energy and do not require the supply of raw materials from unstable countries.

Solar energy, in the form of light emanating from the sun, is converted to usable power by a process that is now well understood. Sunlight strikes a PV (photovoltaic) module which responds by generating a current of electricity that flows into a home or business by the same components (wires, circuit breakers) as are used by the utility company.

Wind-generated electricity works by an entirely different principle; there are however, some similarities. Wind turns a propeller on a shaft surrounded by a magnet wrapped by a coil of wire, as the magnet turns near the wire or vice versa electrons in the wire experience a force. This force then moves them along inside the wire; and it is that movement which creates an electrical current. In principle both methods are simple, the sun and wind cost nothing; it is converting those energy sources into usable electricity which has costs as well as some interesting physical limitations and engineering challenges.

Creating the materials required to build a wind turbine or PV (photovoltaic) module, is not free of course. These have to be transported and installed, and, unfortunately, that costs money; nonetheless they are relatively cost-inefficient in terms of the amount of power produced when compared to coal, oil and natural gas.

The problem is that they don’t produce the same amount of power as other sources for the same cost even though improvements have been made. For example, roughly 1,000 watts per square meter of solar energy reaches the surface (at the equator) but latitude, weather and other factors often reduce the amount to between 125-375 W/m2. When you add that to the fact that the efficiency of a solar-powered PV (photovoltaic) module is generally 10-15% depending on how it’s made, and the available energy is relatively low.

Nevertheless given the ability to cover an area the size of a house roof with panels, even that relatively small amount can generate about 1.35 kWh/m2 a day. That’s enough to power an average home providing the homeowner is careful about how much power they use.

Wind systems also have their own unique problems. They regularly kill birds and rely on almost continual wind – otherwise they have to be connected to storage systems like solar powered systems. More to the point they don’t put out the amount of power demanded by most applications.

Despite their limitations, solar, wind and other alternative energy technologies can sensibly form part of a total power generation strategy. They are clean and this makes them highly desirable in a society which is continually striving to reduce pollution and improve the quality of their environment. These systems are not reliant on imported oil or the mining of coal and other materials which often cause environmental and political controversy.

With continued technological improvements to increase efficiency and lower costs, these alternative systems can contribute to meeting the demand for electricity supplies. However, it will be some time before they can reasonably be expected to replace a significant percentage of the supply from other sources – but there is always hope for the future.