Renewable energy debate

There is debate about the constraints and opportunities associated with the use of renewable energy.

Renewable energy technologies have been criticized for being intermittent, unsightly or with other negative environmental impacts, or too distributed. Climate change concerns, coupled with high oil prices, peak oil, and increasing government support, are driving increasing renewable energy legislation, incentives and commercialization. New government spending (including subsidies to users and suppliers), regulation and policies helped the industry weather the 2009 economic crisis better than many other sectors.

Availability and reliability

There is no shortage of renewable energy - however, converting that energy to a usable form in acceptable ways and transporting it to consumers has so far limited the use of renewables. Chief in the difficulties to-date have been selecting locations and the intermittent nature of some chief forms of renewable energy.

Various energy storage means and energy demand management methods are being utilized or have been proposed to address the above problems.

Generally one advantage of renewables is that they are national in nature, and thus more secure sources of energy.

Scientists from the University of Kassel are testing if Germany can power itself entirely by renewable energy.

Aesthetics

Both solar and wind generating stations have been criticized from an aesthetic point of view. However, methods and opportunities exist to deploy these renewable technologies efficiently and unobtrusively: fixed solar collectors can double as noise barriers along highways, and extensive roadway, parking lot, and roof-top area is currently available; amorphous photovoltaic cells can also be used to tint windows and produce energy. Advocates of renewable energy also argue that current infrastructure is less aesthetically pleasing than alternatives, but sited further from the view of most critics.

Environmental, social and legal considerations

Land area required

One environmental issue, particularly with biomass and biofuels, is the large amount of land required to harvest energy, which otherwise could be used for other purposes or left as undeveloped land. However, it should be pointed out that these fuels may reduce the need for harvesting non-renewable energy sources, such as vast strip-mined areas and slag mountains for coal, safety zones around nuclear plants, and hundreds of square miles being strip-mined for oil sands. These responses, however, do not account for the extremely high biodiversity and endemism of land used for ethanol crops, particularly sugar cane.

In the U.S., crops grown for biofuels are the most land- and water-intensive of the renewable energy sources. In 2005, about 12% of the nation’s corn crop (covering 11 million acres (45,000 km²) of farmland) was used to produce four billion gallons of ethanol—which equates to about 2% of annual U.S. gasoline consumption. For biofuels to make a much larger contribution to the energy economy, the industry will have to accelerate the development of new feedstocks, agricultural practices, and technologies that are more land and water efficient.

The efficiency of biofuels production has increased significantly and there are new methods to boost biofuel production, although using bioelectricity, by burning the biomass to produce electricity for an electric car, increases the distance that a car can go from a hectare (about 2.5 acres) of crops by 81%, from 30,000 km to 54,000 km per year. However, covering that same hectare with photovoltaics (in relatively sunless Germany or England) allows the electric car to go 3,250,000 km/year, over 100 times as far as from biofuel.

Hydroelectricity

The major advantage of hydroelectric systems is the elimination of the cost of fuel. Other advantages include longer life than fuel-fired generation, low operating costs, and the provision of facilities for water sports. Operation of pumped-storage plants improves the daily load factor of the generation system. Overall, hydroelectric power can be far less expensive than electricity generated from fossil fuels or nuclear energy, and areas with abundant hydroelectric power attract industry.

However, there are several disadvantages of hydroelectricity systems. These include: dislocation of people living where the reservoirs are planned, release of significant amounts of carbon dioxide at construction and flooding of the reservoir, disruption of aquatic ecosystems and birdlife, adverse impacts on the river environment, potential risks of sabotage and terrorism, and in rare cases catastrophic failure of the dam wall.

Large hydroelectric power is considered to be a renewable energy by a large number of sources, however, many groups have lobbied for it to be excluded from renewable electricity standards, any initiative to promote the use of renewable energies, and sometimes the definition of renewable itself. Some organizations, including US federal agencies, will specifically refer to "non-hydro renewable energy". Many laws exist that specifically label "small hydro" as renewable or sustainable and large hydro as not. Furthermore, the line between what is small or large also differs by governing body.

Hydroelectric power is now more difficult to site in developed nations because most major sites within these nations are either already being exploited or may be unavailable for other reasons such as environmental considerations.

Wind farms

Wind power is one of the most environmentally friendly sources of renewable energy

Mark Diesendorf, formerly Professor of Environmental Science at the University of Technology, Sydney and a principal research scientist with CSIRO has summarised some of the benefits of onshore wind farms as follows.

A wind farm, when installed on agricultural land, has one of the lowest environmental impacts of all energy sources:

• It occupies less land area per kilowatt-hour (kWh) of electricity generated than any other energy conversion system, apart from rooftop solar energy, and is compatible with grazing and crops.
• It generates the energy used in its construction in just 3 months of operation, yet its operational lifetime is 20-25 years.
• Greenhouse gas emissions and air pollution produced by its construction are very tiny and declining. There are no emissions or pollution produced by its operation.
• In substituting for base-load (mostly coal power) [...] wind power produces a net decrease in greenhouse gas emissions and air pollution, and a net increase in biodiversity.
• Modern wind turbines are almost silent and rotate so slowly (in terms of revolutions per minute) that they are rarely a hazard to birds.
  — Mark Diesendorf, Dissent, no. 13, Summer 2003/04, pp.43-48

Studies of birds and offshore wind farms in Europe have found that there are very few bird collisions. Several offshore wind sites in Europe have been in areas heavily used by seabirds. Improvements in wind turbine design, including a much slower rate of rotation of the blades and a smooth tower base instead of perchable lattice towers, have helped reduce bird mortality at wind farms around the world. However older smaller wind turbines may be hazardous to flying birds. Birds are severely impacted by fossil fuel energy; examples include birds dying from exposure to oil spills, habitat loss from acid rain and mountaintop removal coal mining, and mercury poisoning.

Community debate about wind farms

The wind turbines at Findhorn Ecovillage which make the community a net exporter of electricity.

U.S. Landowners typically receive $3,000 to $5,000 per year in rental income from each wind turbine, while farmers continue to grow crops or graze cattle up to the foot of the turbines.

Wind turbines such as these, in Cumbria, England, have been opposed for a number of reasons, including aesthetics, by some sectors of the population.

Sheep graze before the Ardrossan Wind Farm

Many wind power companies work with local communities to reduce environmental and other concerns associated with particular wind farms. In other cases there is direct community ownership of wind farm projects. Appropriate government consultation, planning and approval procedures also help to minimize environmental risks. Some people may still object to wind farms but, according to The Australia Institute, their concerns should be weighed against the need to address the threats posed by climate change and the opinions of the broader community. Surveys of public attitudes across Europe and in many other countries show strong public support for wind power.

In Germany, for example, hundreds of thousands of people have invested in citizens' wind farms across the country and thousands of small and medium sized enterprises are running successful businesses in a new sector that in 2008 employed 90,000 people and generated 8 percent of Germany's electricity. Wind power has gained very high social acceptance in Germany.

In America, wind projects are reported to boost local tax bases, helping to pay for schools, roads and hospitals. Wind projects also revitalize the economy of rural communities by providing steady income to farmers and other landowners.

The Intrepid Wind Farm, in Iowa, is an example of one wind farm where the environmental impact of the project has been minimized through consultation and co-operation:

"Making sure the wind farm made as gentle an environmental impact as possible was an important consideration. Therefore, when MidAmerican first began planning the Intrepid site, they worked closely with a number of state and national environmental groups. Using input from such diverse groups as the Iowa Department of Natural Resources, the Nature Conservancy, Iowa State University, the U.S. Fish and Wildlife Service, the Iowa Natural Heritage Foundation, and the Iowa Chapter of the Sierra Club, MidAmerican created a statewide map of areas in the proposed region that contained specific bird populations or habitats. Those areas were then avoided as site planning got underway in earnest. In order to minimize the wind farm's environmental impact even further, MidAmerican also worked in conjunction with the Army Corp of Engineers, to secure all necessary permits related to any potential risk to wetlands in the area. Regular inspections are also conducted to make certain that the wind farm is causing no adverse environmental impact to the region."

Other examples

• January 29, 1997: Baywind Energy Co-operative began operating a 2.5 megawatt five-turbine wind farm near Ulverston, Cumbria. It was the first co-operative to own wind turbines in the United Kingdom. It has raised two million pounds and has 1,300 members. A proportion of the profits are invested in local community environmental initiatives through the Baywind Energy Conservation Trust.
• June 29, 2003: After the Cape Wind project was proposed several miles off the coast of Cape Cod, some people raised objections, including U.S. Senator Ted Kennedy who owned a summer home in the area. Although he objected he finally came around and supported the idea. But attitudes to the proposed wind farm have become more positive in recent years. A 2007 public opinion survey found that more than four out of five Massachusetts residents (84 percent) -- including 58 percent of those who live on the Cape—explicitly supported the proposed Cape Wind offshore wind farm.
• On October 16, 2003 in Galway, Ireland, construction of the foundation of a wind farm caused almost half a square kilometre of bog to slide 2.5 kilometres down a hillside. The slide destroyed an unoccupied farmhouse and blocked two roads. Nearby residents expressed concern over these environmental impacts.
• On January 12, 2004, it was reported that the Center for Biological Diversity filed a lawsuit against wind farm owners for killing tens of thousands of birds at the Altamont Pass Wind Resource Area near San Francisco, California. In February 2008, a state appeals court upheld an earlier ruling that rejected the lawsuit.
• January 21, 2005: Three wind turbines on the island of Gigha in Scotland generate up to 675 kW of power. Revenue is produced by selling the electricity to the grid via an intermediary called Green Energy UK. Gigha residents control the whole project and profits are reinvested in the community. Local residents call the turbines "The Three Dancing Ladies".
• On December 4, 2007, environmentalists filed lawsuits to block two proposed wind farms in southern Texas. The lawsuits expressed concerns over wetlands, habitat, endangered species and migratory birds. In August 2008, a federal court judge dismissed the lawsuit, clearing the way for the completion of the wind farms by the end of 2008.
• On December 7, 2007, it was reported that some environmentalists opposed a plan to build a wind farm in western Maryland But other local environmentalists say that the environmental effects of wind farms "pale in comparison to coal-burning generators, which add to global warming and lead to acid rain" that is killing trees in the same area.
• On February 4, 2008, according to British Ministry of Defence turbines create a hole in radar coverage so that aircraft flying overhead are not detectable. In written evidence, Squadron Leader Chris Breedon said: "This obscuration occurs regardless of the height of the aircraft, of the radar and of the turbine."
• A February 21, 2008 article in Scoop reported on environmentalist opposition to a proposed wind farm in New Zealand.
• An April 16, 2008 article in the Pittsburgh Post-Gazette said that three different environmental organizations had raised objections to a proposed wind farm at Shaffer Mountain in northeastern Somerset County, Pennsylvania, because the wind farm would be a threat to the Indiana bat, which is listed as an endangered species.
• July 25, 2008: The Australian Hepburn Wind Project is a proposed wind farm, which will be the first Australian community-owned wind farm. The initiative emerged because the community felt that the state and federal governments were not doing enough to address climate change.
• August 12, 2008: The Ardrossan Wind Farm in Scotland has been "overwhelmingly accepted by local people". Instead of spoiling the landscape, they believe it has enhanced the area: "The turbines are impressive looking, bring a calming effect to the town and, contrary to the belief that they would be noisy, we have found them to be silent workhorses".
• A March 8, 2009 article in the Hawaii Free Press reported on an environmentalist organization called Maui Tomorrow that was against a proposed off-shore wind farm between O'ahu and Moloka'i.
• March 22, 2009: Some rural communities in Alberta, Canada want wind power companies to be allowed to develop wind farms on leased Crown land.

Longevity issues

Though a source of renewable energy may last for billions of years, renewable energy infrastructure, like hydroelectric dams, will not last forever, and must be removed and replaced at some point. Events like the shifting of riverbeds, or changing weather patterns could potentially alter or even halt the function of hydroelectric dams, lowering the amount of time they are available to generate electricity.

Some have claimed that geothermal being a renewable energy source depends on the rate of extraction being slow enough such that depletion does not occur. If depletion does occur, the temperature can regenerate if given a long period of non-use.

The government of Iceland states: "It should be stressed that the geothermal resource is not strictly renewable in the same sense as the hydro resource." It estimates that Iceland's geothermal energy could provide 1700 MW for over 100 years, compared to the current production of 140 MW. Radioactive elements in the Earth's crust continuously decay, replenishing the heat. The International Energy Agency classifies geothermal power as renewable.

Biofuels production

See also: Ethanol fuel energy balance and Cellulosic ethanol commercialization

All biomass needs to go through some of these steps: it needs to be grown, collected, dried, fermented and burned. All of these steps require resources and an infrastructure.

Some studies contend that ethanol is "energy negative", meaning that it takes more energy to produce than is contained in the final product. However, a large number of recent studies, including a 2006 article in the journal Science offer the opinion that fuels like ethanol are energy positive. Furthermore, fossil fuels also require significant energy inputs which have seldom been accounted for in the past.

Additionally, ethanol is not the only product created during production, and the energy content of the by-products must also be considered. Corn is typically 66% starch and the remaining 33% is not fermented. This unfermented component is called distillers grain, which is high in fats and proteins, and makes good animal feed. In Brazil, where sugar cane is used, the yield is higher, and conversion to ethanol is somewhat more energy efficient than corn. Recent developments with cellulosic ethanol production may improve yields even further.

According to the International Energy Agency, new biofuels technologies being developed today, notably cellulosic ethanol, could allow biofuels to play a much bigger role in the future than previously thought. Cellulosic ethanol can be made from plant matter composed primarily of inedible cellulose fibers that form the stems and branches of most plants. Crop residues (such as corn stalks, wheat straw and rice straw), wood waste, and municipal solid waste are potential sources of cellulosic biomass. Dedicated energy crops, such as switchgrass, are also promising cellulose sources that can be sustainably produced in many regions of the United States.

The ethanol and biodiesel production industries also create jobs in plant construction, operations, and maintenance, mostly in rural communities. According to the Renewable Fuels Association, the ethanol industry created almost 154,000 U.S. jobs in 2005 alone, boosting household income by $5.7 billion. It also contributed about $3.5 billion in tax revenues at the local, state, and federal levels.

Diversification

Template:Globalize/USA The U.S. electric power industry now relies on large, central power stations, including coal, natural gas, nuclear, and hydropower plants that together generate more than 95% of the nation’s electricity. Over the next few decades uses of renewable energy could help to diversify the nation’s bulk power supply. Already, appropriate renewable resources (which excludes large hydropower) produce 12% of northern California’s electricity.

Although most of today’s electricity comes from large, central-station power plants, new technologies offer a range of options for generating electricity nearer to where it is needed, saving on the cost of transmitting and distributing power and improving the overall efficiency and reliability of the system.

Improving energy efficiency represents the most immediate and often the most cost-effective way to reduce oil dependence, improve energy security, and reduce the health and environmental impact of the energy system. By reducing the total energy requirements of the economy, improved energy efficiency could make increased reliance on renewable energy sources more practical and affordable.

Comparison with other power sources

Main article: Comparisons of life-cycle greenhouse gas emissions

Competition with nuclear power

See also: Nuclear renaissance and Nuclear power debate

Nuclear power continues to be considered as an alternative to fossil-fuel power sources (see Low carbon power generation), and in 1956, when the first peak oil paper was presented, nuclear energy was presented as the replacement for fossil fuels. However, the prospect of increased nuclear power deployment was seriously undermined in the United States as a result of the Three Mile Island accident, and in the rest of the world after the Chernobyl disaster. This trend is slowly reversing, and several new nuclear reactors are scheduled for construction.

Physicist Bernard Cohen proposed in 1983 that uranium dissolved in seawater, when used in fast neutron reactors, is effectively inexhaustible and constantly replenished by rivers, and could therefore be considered a renewable source of energy. However, this idea is not universally accepted, and issues such as peak uranium and uranium depletion are ongoing debates.

Legislative definitions of renewable energy, used when determining energy projects eligible for subsidies or tax breaks, usually exclude nuclear power.