World energy usage nearly doubled between 1975 and 2005, while China’s energy usage doubles every decade. Worldwide oil production has peaked and is now declining. The U.S. burns a billion tons of coal per year; natural gas supplies are at critically low levels.
Additionally, 250 years of relying upon these fossil fuels for global energy needs has caused potentially catastrophic climate change – whose effects may take centuries to reverse. These hydrocarbons currently supply 83% of world energy demand.
13% of the world’s primary energy supply comes from traditional biomass, primarily from burning wood. While biomass is a renewable and potentially sustainable energy source, burning wood for fuel in open hearths produces greenhouse gases and adds particulate matter to the atmosphere.
Hydropower from dammed rivers and streams contributes some 3% of the energy used worldwide. There are no more viable rivers to dam, and existing dams have caused significant losses in natural resources by blocking access to upstream spawning areas used by fish and other marine animals. Many subspecies of salmon, for example, are now extinct due to damming of the rivers to which they have returned for millennia to spawn.
Modern renewable energy technologies like wind, solar, geothermal, wave and tidal power together now produce less than 1% of the energy being used. Yet these renewable energy sources have the potential to provide far more energy than is currently available from all traditional sources.
The primary challenge facing the renewable energy industry is finding ways to make the cost of clean energy more directly competitive with traditional fossil fuel-generated energy – environmental benefits aside. Investment capital allocated to renewable energy climbed from $80 billion in 2005 to $100 billion in 2006. This investment is producing real savings in the cost of renewable energy as technologies are refined, economies of scale are created, and renewable energy is made increasingly available to consumers.
For reference purposes, coal-generated energy, in 2001 dollars, cost between .04-.08 per kilowatt hour. Wind energy, now costing .04-.08/kWh, is projected to drop as low as .03/kWh. Solar photovoltaic energy, now .25-1.60/kWh, is expected to cost .05-.25/kWh in the near future. Solar thermal energy, now .12-.34/kWh, is projected to come in between .04-.20/kWh. Geothermal power, now generated at .02-.10 per kilowatt hour, should be available at .01-.08/kWh.
Many projects for producing clean, renewable energy are underway worldwide. Wind power generation increased 8-fold between 1997 and 2006; new wind generating equipment installed in 2006 alone is valued at $23 billion. One project now underway in the U.K. will eventually consist of 341 turbines and will provide one-third of London’s residential power needs, saving 1.9 million tons of carbon dioxide emissions annually.
Solar thermal power plants are under construction around the world, primarily in remote areas that enjoy an abundant supply of sunshine. California’s Mojave Desert, a location outside Seville in Spain, and Boulder City, Nevada are sites of major installations. The California Solar Initiative subsidizes the installation of residential and commercial solar power systems and is spearheading the development of additional solar generation capacity. Large photovoltaic power plants are under construction in Germany, Portugal and Australia.
Biofuels projects are also underway around the world, particularly in Brazil and the U.S. Brazil’s renewable energy program produces ethanol fuel from sugar cane, providing 18% of the country’s automotive fuel. Brazil is now self-sufficient in oil, with no need to import petroleum for domestic consumption. The U.S. has 113 ethanol distilleries currently operating and at least 78 more under construction. Farmers are responding to subsidies for growing corn for ethanol production by increasing the acreage they devote to it.
A commercial wave-power generating installation has been completed in Portugal. The first wave power plant in the U.S. will be built off the coast of Northern California. Other wave farms are planned for Scotland and the U.K.
Tidal power, although not yet widely used, has the potential for more predictable power generation than wind or solar power. Tidal power stations are in place in France, Nova Scotia, the Soviet Union, and China. Scotland has a tidal power station under development.
Geothermal power is being generated in over 20 countries around the world, including Iceland, the U.S., Italy, France, Lithuania, New Zealand, China, and Japan. Geothermal power is cost-effective in areas of the world where there is volcanic activity: molten lava or superheated steam are close to the surface, thus available to create steam to turn power-generating turbines. The U.S. has the greatest geothermal energy production of any country in the world, with generating plants in California, Nevada, Oregon, Idaho, Arizona, and Utah.
The books on renewable energy selected here provide a comprehensive introduction to and analysis of the developing technology, policy issues, economics, and environmental impact of these sustainable energy resources worldwide.
