Renewable Energy

Advances in technologies and scale, along with global environmental and economic concerns, have spurred the development and market viability of a number of renewable energy power generation technologies. The types of technologies that have reached a stage of marketability range from power plants fueled by geothermal energy and biomass, to wind farms of massive structures, to large photovoltaic arrays, and anaerobic digesters for on-site and regional biogas-fueled generators. Renewable energy is broadly defined as power derived from resources that are constantly replaced and are usually less polluting, such as the sun and wind and water movement but also using algae in a proces of making biodiesel from algae. These resources, requiring different technologies to harness them, are then converted into heat, electricity and mechanical energy.

Advocates of renewable energy argue that the demand for renewables would rise if conventionally generated electricity were priced to reflect its pollution costs. But a reasonable interpretation of the evidence suggests that the additional cost of further pollution reduction would exceed the additional health benefits. Even if current regulatory costs are insufficiently reflective of true environmental costs, "getting prices right" will not significantly affect consumer choices of fuel. For example, reducing emissions of nitrogen oxides and sulfur dioxide by 75 percent below 1997 levels would increase electricity prices by only about 1 percent, too little to trigger a shift from coal or natural gas to renewable energy. Renewable energy is naturally intermittent. Hydrogen provides a means to store renewable energy for times when the sun doesn't shine or the wind doesn't blow. When these resources are available, they can be used to generate electric power for immediate use, with surplus energy being converted to hydrogen using an electrolyzer. The hydrogen is stored until renewable energy is unavailable, at night or on cloudy or windless days. A fuel cell then converts the stored hydrogen to electric energy. To learn more about the connection between renewable energy and hydrogen and fuel cells go to the solar hydrogen cycle web page.

Other articles:
Production of Biodiesel - Renewable Fuels

The 2007 Renewables Global Status Report concludes that current trends are set to continue as the costs of renewable energy technologies decline and the sector continues to diversify production and technology development to a broad base of countries, including emerging economies. With more than 2.5 million jobs in the renewable energy industry, and strong rural development benefits, renewable energy is an avenue to economic development, energy security, local environmental benefits, and climate change mitigation.