They can be used both in residential houses and in central power plants. Here is a list
of five main alternative energy sources:
- Hydropower- the mechanical energy of moving water, which can be used to spin a turbine connected to an electric generator to produce electricity;
- Biomass- organic material of plant and animal origin, such as wood and municipal solid waste. When burned biomass releases its chemical energy as heat. It can also be converted to other usable forms, such as methane gas, ethanol and biodiesel.
- Wind- the kinetic energy of moving air molecules can be harvested in wind power turbines.
- Geothermal - the heat from within the Earth. It can used to heat buildings or generate electricity at steam-turbine plants.
- Sunlight - the electromagnetic radiation from the Sun that can be directly converted to heat, electricity or chemical energy.
All these sources and particularly photovoltaic and wind power can be used in private houses, especially those that are located in a rural area. For example, like many homeowners, you can install solar panels in your home and produce your own electricity.
PROS AND CONS
Each source of electricity generation has pros and cons and has a certain impact on the environment.
Renewable fuels generally emit less air pollution than conventional ones. This is their main advantage. Utilization of AE also reduces to some degree U.S. dependence on foreign oil, and thus reduces the flow of money to some oil-exporting totalitarian and terrorism-sponsoring regimes. However, currently, most of the alternative technologies are utilized in electricity generation, while most of petroleum is used in transportation. Therefore, at this moment AE may not have a significant effect on our oil dependence. In addition, our reliance on fuel imports can also be lessen by relaxing restrictions on the drilling. This would let us tap our own large oil and gas resources.
One of the mains disadvantages
of alternative energy is its higher initial cost. For example, the installation of a photovoltaic generator
in private homes costs in average $6,000 per kW of peak power. In addition to this, with some forms of AE it is difficult to continuously produce the large quantities of electricity the conventional fuels are able to (see for example, solar power advantages and disadvantages
Currently, almost half of the electricity produced in the U.S. uses coal. The cost of generating electricity from coal is about $0.10 per kilowatt-hour-- lower than that from any other sources except for natural gas. For comparison, the average cost to produce utility-scale solar electricity is $0.16/kW-hr (see cost comparison
of renewable energy sources). As the result of the reliance on coal, US so far enjoys one of the lowest electricity rates in the world. The Penn State University study
showed that hundreds of billion dollars of household income and 6.8 million U.S. jobs will be attributed to the production, transportation and jobs in energy consuming industries that rely on low-cost electricity. The combustion of coal does produce carbon dioxide emissions blamed for global warming, but these emissions can be captured by using so-called clean coal technologies that are being developed throughout the world. Of course, fossil fuels are finite and over time they will be depleted. Eventually most of power generation will use renewable resources. However, the strategy for expanding renewable power should focus on making it cost effective and avoiding large increases in energy costs and utility bills.
Skeptical Science - examining the science of global warming skepticism