Renewable and alternative energy resources exist as huge but relatively untapped sources of clean energy to power our economy into the future. Existing in many forms, they can be converted into a variety of useful fuels and electricity sources to power homes, businesses, and transportation needs. The key to utilizing them will be in the development of cost-effective means to convert the raw resource into a useable form of energy.
Solar energy is one of the most abundant and visible renewable resources on Earth. Many national, state, and local governments are engaged in programs to expand programs that enable homes, businesses, and large-scale project developers to make use of this clean energy resource.
Solar power technologies convert radiant light energy to into more usable forms of energy such as electricity or hot water. Photovoltaic cells made from silicon are the most well known, and can leverage mature silicon electronics manufacturing technology to lower their manufacturing cost in order to expand their market reach. Other solar technologies concentrate the sunlight into a small area to heat a working fluid such as water to generate electric power or provide useful hot water for space conditioning.
Bioenergy resources refers to renewable plant and animal wastes that are easily available to be converted into energy. These resources are large, but with a low energy density, the cost-effectiveness of these technologies rests on the ability to gather large amounts of the resource cheaply and convert it efficiently. Currently many resources such as grains are also used in existing agricultural markets so that often the difficult issues of collecting this widely-dispersed resource for conversion to energy only need to be expanded.
Currently, many bioenergy projects only convert a portion of the collected biomass material to usable energy because of low-efficiency processes. Significant efforts are underway from ethanol and biochemical conversion facilities to power projects aimed at increasing operating efficiency in order to lower the cost of the end-product. Additional work is also underway so that non-traditional resources such as cellulose can be converted into the same useful (or new) end-products.
Mankind has used the Earth's wind resources throughout recorded history—first for sailing and then for milling and pumping water, especially in remote areas. Now, wind turbines are being used to convert wind into electricity. This multi-billion dollar global industry is growing fast, with significant resources located in a variety of remote locations such as in the mountains, on flat prairies, and off-shore in the ocean.
Wind turbine technology has advanced steadily over the last few decades, and now can produce electrical power competitively with power plants fueled with fossil fuels. The progress of these wind turbines will continue as very large and very small wind turbines find more locations where they are cost effective and promise an alternative means of harnessing a readily available resource.
The movement of water holds great potential for another resource of renewable, clean energy. Hydro power is already a significant generator of electricity, but the environmental impact of large dams on rivers is driving the development of smaller types of water technology that will not have as great an impact on the environment. Ocean power is also becoming an area of growing interest because of the immense energy resources to be found just off-shore.
New hydro power technologies include run-of-the river facilities that capture part of the energy within the fast moving flow of rivers. Other water energy technologies include tidal and wave power. Wave power technologies promise significant growth in the near term as their level of technology improves and as they start to leverage all of the additional marine engineering capabilities found across the globe.
Deep beneath the surface, the Earth holds great amounts of energy in some locations hot spots can be found near the surface and captured. Some of the largest resources are found inCaliforniaandIceland, but a number of other locations exist around the World, holding out promise for continued expansion of locations to access this energy resource.
The most common application of geothermal technology is to use superheated water and steam from circulation pipes that extend into the ground for use in a turbine to generate electricity. Although the basic technology is not evolving, the use of new materials and processes to increase the efficiency of the process continues unabated.