| Renewable Energy |
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The prices for heating oil and natural gas have risen to the point where renewable energy can be a competitive alternative. Here are the basic renewable energy sources that should play a significant role in our energy future:BIO-POWERBio-Power is derived from biomass. The processes used to produce energy from biomass include direct firing, co-firing, and gasification. With proper handling, these processes can convert agricultural, municipal, and industrial waste into clean energy. To be cost competitive with coal, biomass power plants should be near an ongoing, reliable biomass source.
Anaerobic Digestion is a common gasification process. The process also uses high temperatures in an oxygen starved environment but uses bacteria to decompose the biomass into methane. The methane is used instead of natural gas as a power source to drive a turbine. Landfill methane gas is also created through anaerobic digestion and is a major source of energy because it can provide reliable power at prices competitive with fossil fuel. The first landfill gas projects began in the 1970’s and have grown to about 435 nationwide today, powering about 810,000 homes. It is a much cleaner resource to use for electrical generation than coal or other fossil fuels. When oxygen is totally eliminated, a process called pyrolysis turns biomass into liquid. This liquid is used for making plastics, adhesives, and other useful bio-products. GEO-THERMALGeo-Thermal energy is continually produced inside the earth by the slow decay of radioactive particles which are contained in rocks. The most powerful Geo-Thermal energy comes from drilling into steam and hot water reservoirs that are located deep within the earth’s surface.The most active of geo-thermal reservoirs are found along major plate boundaries where earthquakes and volcanoes are concentrated such as the area that rims the Pacific Ocean. Reservoirs are also located near the earth’s surface in Western states and in Alaska and Hawaii. Today there are over 20 plants providing reliable geo-thermal energy to over 100,000 homes. According to experts, we have the resources to provide another 100,000 megawatts of geo-thermal power which is enough to power another 5 million homes. Geo-Thermal is a readily available source of renewable energy and has no negative impact on the environment. It also takes up little land space and can blend well into the surrounding environment. There are three main methods of tapping Geo-Thermal energy: .
Geo-thermal heat pumps can also be a practical solution for home owners for heating and cooling their homes, especially if their city and state offer a good incentive program. SOLAR ENERGYThe amount of energy that falls on the earth’s surface from the sun is tremendous. All of the energy stored in the Earth’s oil, coal and natural gas reserves is matched by just 20 days of sunshine.The great thing about solar energy is that once you pay your original investment, your energy from the sun is essentially free. Financial incentives are also available from the government to reduce your costs. Finally, your utility company will buy any energy that is in excess of what you actually use. There are five basic solar energy systems that can be used to tap the sun’s energy.
The most common design for producing concentrated solar energy is with “parabolic troughs” which are long, curved mirrors that concentrate sunlight on a liquid inside a tube than runs parallel to the mirror. The liquid gets to about 300 degrees Celsius and runs to a central collector, where it produces steam that drives a turbine. There are already nine such systems in California’s Mojavi Desert. As a result of state and federal incentives, as well as State renewable energy standards and improved technology, there are now several more projects under development .
Another way of producing passive solar heating is through a method called day lighting. This is usually accomplished through the creation of sun spaces that act much like a green house. Sunlight warms up the sun space and the heat is slowly released into the building’s interior through special ventilating systems. Still another way of producing passive solar heating is to create a row of windows called a “clerestory” near the peak of the roof that allows light to bounce in open spaces throughout the building Passive solar can also be designed in a way that both heats the building in the winter and keeps it cool in the summer. Design strategies include window placement, glazing, proper shading, use of light colored materials, and good landscape design.
Solar Heat Collectors can also power a cooling system. The solar energy is used to heat a refrigerant under pressure. When the pressure is released, it expands, cooling the air around it. This is the same way refrigerators and air conditioners work. Is solar a practical solution for the home owner? The answer hinges on how much it can reduce your utility bills and how long it will take to pay back your original investment. The decision will vary depending on the electricity prices per kilowatt hour in your area of the country and on the incentives offered by your city and state. BP Solar offers a calculator for homeowners thinking of installing solar power that takes all of the variables under consideration WIND GENERATED POWERSince ancient times, people have harnessed the wind’s energy. Today, with the renewed interest in wind generated power, wind mills in the form of modern wind turbines dot the American landscape. Wind Turbines as small as 10 kilowatts can be used individually to cut individual electric bills or turbines as large as 1.8 megawatts can be used on a large scale basis in wind farms to provide electrical power to large utility companies. The largest wind farm, The Horse Hollow Wind Energy Center in Texas, has 421 wind turbines that generate enough electricity to power 230,000 homes per year.The U.S.is now third in the world behind Germany and Spain in wind generated power. Even so, we generate less than two percent of our nation’s total electricity production through wind energy. Its use, however, should continue to grow dramatically in the years ahead. There are over 100,000 backyard wind turbines powering individual homes across the country. These are only good investments for individual home owners, however, when you live in a place with steady winds of 10 mph or more and where zoning restrictions are not a problem. Again, your city and state must also offer appropriate incentives to make it worth the investment. HYDRO-POWERHydro-power from our rivers is the oldest method of generating power. It currently generates seven per cent of total electricity needs in the U.S. Hydro-power from rivers is derived by directing and channeling the water flow through a pipe, which turns blades on a turbine. The rotating turbine activates a generator to produce electricity. Transmission lines then conduct the electricity from the plant to homes and businesses.The amount of electricity a hydro-power plant produces depends on how far the water falls and on the total amount of water falling. These plants range in size from “micro-hydros” that power a few homes to giant ones like the Hoover Dam that provides electricity to millions of people. Hydro-power created from the construction of damns is probably going to be limited because of how it disrupts our natural habitats. Future hydro-power is expected to come from tidal power from our oceans. Hydro-power from tidal waves can be created from small turbines. The force of the waves drive the turbines at a much higher speed that the speed achieved from wind turbines. This means that fewer and smaller turbines are needed to produce the same amount of energy as wind turbines. Another approach to using the ocean to produce electricity employs buoys which are propelled up an down much like a piston. Either approach is an efficient and effective way to generate power. Ocean power systems work best at a depth of about 100-150 feet and about 1 to 3 miles offshore. Ideally, power stations can be built near major coastal cities and could provide most of those city’s electrical power requirements. Though Europe and Asia are ahead of us in utilizing ocean power, many entrepreneurs are currently surveying sites around the U.S. and we should see our first ocean power stations in the not too distant future. It can potentially power homes in major cities. CLEAN COAL AND NUCLEAR ENERGYThough clean coal and nuclear energy can also be included in our energy mix, they are not treated here because they cannot be considered “renewable” resources. Still, as alternative sources, they can be part of an overall solution in our march toward energy independence.THE FUTURE OF RENEWABLE ENERGYWe seem to be on the verge of a major transformation of our energy markets. States across the U.S. are adopting their own regulations which, in turn, will pressure the Congress to act. Both of our presidential candidates support strong alternative energy programs. According to The Clean Energy Trends Report, we can expect an eightfold increase in solar energy use within the next ten years. They see a four-fold increase in wind energy during the same time period. There will also be increases in geo-thermal and the development of ocean energy during the same period. The U.S. renewable energy industry expects that, collectively, it will produce 25% of our total electrical energy by 2025. All of this, along with new political leadership in Washington and pressure from the business community, bodes well for our energy future. |
Learn More
- US Department of Energy
- National Renewable Energy Laboratory
- Renewable Energy Policy Project
- Alternative Technology Association