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A Bright Future for Renewable Energy Technologies


   In the wake of the recent Fukushima nuclear plant disaster, controversy over fracking in natural gas extraction, severe weather patterns, wars fought over oil and global climate change, it is puzzling how little discourse is seen in the media about renewable energy options.
   What isn’t surprising is that the primary barrier to renewable energy solutions is political.  A little publicized report released by the UN this May outlined the potential for global renewable energy. Over 120 researchers worked with the Intergovernmental Panel on Climate Change (IPCC) and came to the conclusion that close to 80 percent of the world’s energy supply could be met by renewable energy by the year 2050. This could result in a reduction of up to a third of greenhouse gas emissions reduced from their current levels.
   Ramon Pichs, Co-Chair of the IPCC Working Group III, said, “The report shows that it is not the availability of the resource, but the public policies that will either expand or constrain renewable energy development over the coming decades.”
   While the barriers seem insurmountable in the US, the rest of the world is forging ahead. Switzerland just followed Germany by starting a 100 percent nuclear phaseout by the year 2034 following a rally of 20,000 anti-nuclear citizens—the largest demonstration since the 80s in that country. Despite the bad economy, 2009 showed substantial growth in renewable energy worldwide—wind by over 30 percent; hydropower by 3 percent; grid-connected photovoltaics (solar) by over 50 percent; geothermal by 4 percent; solar/water heating by over 20 percent and ethanol and biodiesel production rose by 9 to 10 percent.
   The thousand-page report, approved by government representatives from 194 nations, reviewed the potential six renewable energy technologies and how they could be integrated into existing and future energy systems and the likely cost benefits. Developing countries host more than 50 percent of current capacity.
   Supply of renewables is not a limiting factor. The scientists found that 97 percent of the available resources are untapped.
Key Technologies
   Bioenergy – The UN report found that bioenergy will likely decline over the coming decades but will still play a part in the overall mix. These technologies can generate electricity, heat and fuels from a range of sources, both good and bad. Converting land for energy crops can result in more greenhouse gas emissions than they save. In contrast, a system that converts woody wastes into liquid fuels can deliver an 80 to 90 percent reduction in emission compared to the current fossil fuels used today.
   Direct Solar Energy—These technologies produce electricity, heat and light. Solar constitutes only a fraction of a percent of the total energy supply today but depending on innovation, cost reduction and public policies, it has the potential of becoming one of the major sources of energy supply.
   Geothermal Energy – The technologies utilize heat stored in the Earth’s interior directly or to generate electricity. The report estimated it could meet about 3 percent of global electricity demand and about 5 percent of global heat demand.
   Hydropower – Currently the largest renewable resource for electricity at 16 percent of worldwide supply, hydropower technologies range from large to small including dam projects with reservoirs, river and stream projects.  Long term scenarios show the use of hydropower possibly decreasing to 10 to 14 percent.
   Ocean Energy – Most ocean energy technologies are in pilot stages and are unlikely to be used before 2020.  The potential is unclear.
   Wind Energy – Electricity is produced by large wind turbines on land or offshore. Some projections put wind energy share at more than 20 percent by 2050 with reviews showing a high expansion rate in Europe, North America, China and India.
    The cost of renewable energy technologies are, in some cases, economically competitive, but are more often higher than current energy prices. However, factoring in the environmental impacts like pollutants and greenhouse gases and including them in the cost of energy makes renewable technologies more attractive. Still, the costs of renewable technologies have gone down over the past decades and are predicted to further decline in the future.
   Renewable energy technology is not always a perfect solution. The Three Gorges Dam located on the Yangtze River in China is the world’s largest hydroelectric power project.  Originally envisioned by revolutionary and political leader Sun Yat-sen in 1919, preliminary plans were started by Chiang Kai-shek in 1932.  Construction didn’t start until 1994.  Over 1.2 million people were displaced with plans to displace more in the future. The Dam began initial operations in 2008 before reaching capacity and was heralded by the Chinese government as an engineering, social and economic success and a giant step toward reducing greenhouse gas emissions. It provides two percent of China’s electricity and eliminates the use of at least 30 million tons of coal per year.
  Unfortunately, the area is experiencing its worse drought in 50 years and the dam has to release water for area irrigation and drinking water. Having ignored decades of warnings about the pending
ecological disasters, the Chinese government admitted in May that urgent problems of pollution, silt accumulation, ecological deterioration and geological hazards created by the dam need to be resolved.
These problems are causing frequent landslides. Scientists believe
that dam reservoirs can trigger earthquakes and, already, small tremors are being observed. The dam represents the delicate balance between technology and nature and the race to find solutions as the climate evolves and changes.

For more information:

Special Report on Renewable Energy Sources and Climate Change
   Mitigation SRREN Website  www.srren.org

Intergovernmental Panel on Climate Change www.ipcc.ch
Working Group III Mitigation of Climate Change www.ipcc-wg3.de

Renewable Energy Technologies Defined: A Short List

    Bioenergy: Useful, renewable energy produced from organic
matter, which may either be used directly as a fuel or processed into liquids and gases.

    Biofuels: Liquid fuels and blending components produced from biomass (plant) feedstocks, used primarily for transportation.

    Direct Solar Energy: The radiant energy of the sun, which can be converted into other forms of energy, such as heat or electricity.
Includes photovoltaics and concentrating solar power.

   Photovoltaic (PV) Cell: An electronic device consisting of layers of semiconductor materials fabricated to form a junction (adjacent layers of materials with different electronic characteristics) and electrical contacts and being capable of converting incident light directly into electricity (direct current).

   Photovoltaic (PV) Module: An integrated assembly of interconnected photovoltaic cells designed to deliver a selected level of working voltage and current at its output terminals, packaged for protection against environment degradation, and suited for incorporation in photovoltaic power systems.

    Geothermal Energy: As used at electric power plants, hot water or steam extracted from geothermal reservoirs in the Earth’s crust that is supplied to steam turbines at electric power plants that drive generators to produce electricity.

    Hydropower: Includes run-of-river, in-stream or dam projects with reservoirs.

    Ocean Energy:  Ranging from barrages to ocean currents and one which harnesses temperature differences in the marine realm.

    Renewable Energy Resources: Energy resources that are naturally replenishing but flow-limited. They are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time. Renewable energy resources include: biomass, hydro, geothermal, solar, wind, ocean thermal, wave action, and tidal action.

    Wind energy: Energy present in wind motion that can be converted to mechanical energy for driving pumps, mills, and electric power generators. Wind pushes against sails, vanes, or blades radiating from a central rotating shaft.

   Wind power plant: A group of wind turbines interconnected to a common utility system through a system of transformers, distribution lines, and (usually) one substation. Operation, control, and maintenance functions are often centralized through a network of computerized monitoring systems, supplemented by visual inspection. This is a term commonly used in the United States. In Europe, it is called a generating station.

Sources: Intergovernmental Panel on Climate Change www.ipcc.ch
US Energy Information Administration/Department of Energy www.eia.doe.gov

Published: June 13, 2011
Issue: Summer 2011