Energy Resources

Energy resources fall into two main categories, often called renewable and non-renewable energy resources. Renewable resources are also often called alternative sources of energy as they are not as widely used today as some non-renewable energy resources. But, as its name suggests, these resources won’t last forever.

Estimates do vary, because we do not know where all the resources are and we do know how quickly we will use them. Collectively, this information advances the scientific understanding of energy resources, contributes to plans for a balanced and secure energy future, and facilitates the strategic use and evaluation of resources. The remaining world energy resources are large, compared to world energy consumption.

Advantages of renewable sources of energy are relatively cheap and most are easy to get and can be used to generate electricity. Ultimately the Sun is the source of most energy resources available to us. Global warming theories that do focus on mankind’s contribution point towards the important side-effects of human energy consumption, such as greenhouse gases added to the earth’s atmosphere. Even that amount is also only a minute amount of the sun’s total energy output, due to the small solid angle the earth’s outline makes with the sun.

Solar power is the conversion of sunlight into electricity. Sunlight can be converted directly into electricity using photovoltaics (PV), or indirectly with concentrating solar power (CSP), which normally focuses the sun’s energy to boil water which is then used to provide power. The Sun’s energy can be gathered anywhere, but obviously more can be gathered in areas on or near the Equator. Because there is no burning involved, there are no polluting gases. The simple types use flat collector panels that are mounted on the south facing roof or wall. The panels have a transparent cover to admit sunlight.

Many of the Sun’s rays are scattered by the Earth’s atmosphere or reflected by clouds. But some solar radiation can be collected by special panels and used to heat water. Photovoltaic cells are made of semiconductors, similar to those used to make computer chips. One other application of solar power is that it can be used as an alternative water heating system. Water circulates through channels or pipes inside a solar panel situated on the roof of a home or building. The inside is usually painted black, because black surfaces readily absorb heat. The water is heated, then the hot water is pumped to a heat exchanger that extracts the heat for use within the house.

Solar power is a predictably intermittent energy source, meaning that whilst solar power is not available at all times, we can predict with a very good degree of accuracy when it will and will not be available. Some technologies, such as solar thermal concentrators with an element of thermal storage, have the potential to eliminate the intermittency of solar power, by storing spare solar power in the form of heat; and using this heat overnight or during periods that solar power is not available to produce electricity. This technology has the potential to make solar power “dispatchable”, as the heat source can be used to generate electricity at will. Solar power installations are normally supplemented by storage or another energy source, for example with wind power and hydropower.

Solar energy is not available at night, making energy storage an important issue in order to provide the continuous availability of energy.Wind power and solar power can be complementary, in locations that experience more wind in the winter and more sun in the summer, but on days with no sun and no wind the difference needs to be made up in some manner.

Solar energy can be stored at high temperatures using molten salts. Salts are an effective storage medium because they are low-cost, have a high specific heat capacity and can deliver heat at temperatures compatible with conventional power systems.

This entry was posted on Wednesday, December 23rd, 2009 at 7:00 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.