6 Renewable Energy Is More Than
Photovoltaic Panels and Wind Turbines

By Robert J Schmidt

Renewable energy is produced in many different ways. Some of the most notable besides photovoltaic panels and wind turbines are hydroelectric, biomass, geothermal, hydrogen and fuel cells, and tidal and ocean currents. Research is being done in most of these areas already. Many states have begun to invest in both large and small renewable energy projects.

There are several classifications of hydroelectric power plants from large power plants like Grand Coulee Dam or the Hoover Dam to pico sized plants. They are categorized by the amount of power generated. Large plants produce from several hundred mega-watts to over 10 giga-watts while the smaller ones generate no more than 30 mega-watts. These plants are built to serve communities that are too far from standard grid connections and the terrain offers a good local source of water power. There are also micro and pico size hydroelectric plants that serve much smaller needs.

Biomass is another source of renewable energy. It uses organic waste as the fuel for steam generators. The agriculture waste comes from food processing. Wood waste from logging operations and sawdust from milling are also sources of biomass. Landfills where organic waste is deposited can be another source of energy. Capturing the gases produced by the decomposition of the organic matter produces methane gas, the main ingredient of natural gas. Another interesting biomass source is plants producing electricity directly. This technology uses a plant microbial fuel cell, to produce electricity. In this scenario plants use sunlight to produce carbohydrates from the carbon dioxide they inhale. The carbohydrates are converted to electricity with the use of microbial fuel cells. Plants convert sunlight into green electricity and produce hydrogen gas, another useful source of green energy, as a by-product.

Geothermal energy is heat from below the surface of the earth. We know that not far below the earth's surface is molten rock which we see when volcanoes erupt. This resource has can provide very large amounts of electricity when used to heat water for conventional steam generators. Another use of geothermal energy is for heating and cooling of homes and other buildings.

Fuel cells offer energy solutions for transportation from private vehicles, to city buses, and to the trucking industry. Right now car manufacturers are developing cars that are all-electric and the fuel cell can be the missing link for their power source. Now these cars must be plugged into an electric source to charge the on-board batteries but research is being done to use PEM (proton exchange membrane) technologies to serve as the power for an all-electric car. There are existing demonstration projects on-going now for PAFC (phosphoric-acid fuel cell) engines in city buses in Montreal, Washington DC, Oakland, CA, Chicago and other major cities. What is needed is a non-fossil fuel source of hydrogen and a distribution system for the hydrogen as the source fuel for fuel cells.

Tidal and ocean current have both strong pros and cons. They are environmentally friendly because they produce no greenhouse gases and are around 80% efficient. But, they are very expensive to construct and therefore not very cost-effective. Also they cause a displacement of wildlife habitats and they can only be used on coastlines.

There is not one renewable resource that is going to solve all our energy requirements just as it takes more than one fossil fuel to supply all our energy demands. The research and work that is being done now will eventually ween us off fossil fuel as our primary source of energy and reduce the growth of global warming. The catastrophe of the Deep Water Horizon's impact has and will continue to spur more and greater efforts to develop these new technologies and resources and grant us our freedom from the foreign oil producers to which we are now bound. The state of the economy is turning out to be another driving force for research into new technologies for both greater efficiency in our use of energy and finding new ways to produce green energy. The American Recovery and Reinvestment Act of 2009 while touted as a jobs bill is also a long-term push to change the country by investing in these and other green technologies.