New Energy Sources



 

Learning Objective

  • Discuss new energy sources and their effects

Key Points

    • Alternative energy is a form of renewable energy.
    • Renewable energy capacity is increasing as more countries introduce limits on carbon emissions.
    • As technology continues to improve, it is projected that the world will continue to shift to these forms of energy production.

Terms

  • biomassAn alternative energy source consisting of wood, corn, and some types of garbage, which can be burned for fuel.
  • alternative energyEnergy derived from any renewable source; i.e., energy not from fossil fuels or nuclear fission.
  • renewable energyEnergy that can be replenished at the same rate as it is used.

Renewable Energy

Renewable energy is energy that comes from natural resources, such as sunlight, wind, rain, tides, waves, and geothermal heat, which are all naturally replenished. About 16% of global final energy consumption comes from renewable sources, with 10% coming from traditional biomass, which is the burning of natural materials such as wood, corn, and some types of garbage to provide energy mainly used for heating, and 3.4% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) account for another 3% and are growing very rapidly. The share of renewables in electricity generation is around 19%, with 16% of global electricity coming from hydroelectricity, and 3% from new renewable sources.

Global energy capacity expansion by renewable sourceTotal renewable power capacity has been increasing over the past several years, from roughly 100 GW in 2005 to nearly 400 GW in 2007.

Various Alternative Energy Sources Worldwide

The use of wind power is increasing at an annual rate of 20%. At the end of 2011, a worldwide installed capacity of 238,000 megawatts (MW) was in use widely throughout Europe, Asia, and the United States. Since 2004, photovoltaics (solar cells) surpassed wind as the fastest growing energy source, and since 2007, the use of solar power has more than doubled every two years. At the end of 2011, the photovoltaic (PV) capacity worldwide was 67,000 MW. PV power stations are becoming increasingly popular in Germany and Italy. In addition, solar thermal power stations, which are power plants that generate electricity from the heat of the sun’s rays, operate in the USA and Spain. The largest of these is the 354 MW SEGS power plant located in the Mojave Desert. The world’s largest geothermal power installation is the Geysers complex in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugarcane. Ethanol now provides 18% of the country’s automotive fuel. Ethanol fuel is also widely available in the USA.

Sugarcane being harvested for ethanol productionEthanol is a quasi-renewable energy source. This is because, while the energy is partially generated by non-depletable sunlight, the harvesting process requires vast amounts of energy that typically comes from non-renewable sources.

While many renewable energy projects are large-scale, renewable technologies can also be suited to rural and remote areas, where energy is often crucial in human development. As of 2011, small solar PV systems provide electricity to a few million households, and micro-hydroelectricity plants configured into mini-grids serve many more. Over 44 million households use biogas (mixtures of gases produced by the breakdown of organic matter) made in household-scale digesters for lighting and/or cooking, and more than 166 million households rely on a new generation of more efficient biomass cookstoves.

The Future of Alternative Energy

United Nations’ Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity. Carbon neutral and negative fuels can be stored and transported through existing natural gas pipelines. Using the existing transportation infrastructure, thereby displacing fossil fuels, will reduce greenhouse gas emissions.

Climate change concerns, coupled with high oil prices, peak oil, and increasing government support, are driving more and more renewable energy legislation, incentives and commercialization. New government spending, regulation and policies are helping the industry weather the global financial crisis better than many other sectors. According to a 2011 projection by the International Energy Agency, solar power generators may produce most of the world’s electricity within 50 years, dramatically reducing the emissions of greenhouse gases that harm the environment.