Insight The search for alternative energy sources has included wind, solar, geothermal and hydroelectric power, each with inherent drawbacks.
Clean fuels have dirty secrets
Green energy is apparently not without its drawbacks. To the frustration of consumers everywhere, the quest to replace fossil fuels with abundant supplies of clean, renewable energy has had many unintended consequences, some posing severe threats to the environment and to human life.
Forests lost to biofuel plantations and wetlands dried up by hydroelectricity projects are among the costs already piled up on the negative side of the renewable energy ledger. Furthermore, using more wind and solar power may require enormous construction in pristine areas. Even in Iceland, which is generally viewed as having got it right, the reality of generating "clean" electricity is more complex than it seems.
"We know better than anyone else how many things can go wrong," says Bjarni Palsson, a drilling engineer with the Iceland Deep Drilling Project, which is trying to tap into deeper and hotter geothermal energy sources. So how viable, safe and economical are these alternative forms of energy? It depends. Take geothermal wells. At first glance, they seem to offer access to a vast source of clean, renewable energy. But Icelanders, who have tapped into the great underground heat stores on their volcanic island since the beginning of the last century, have a better understanding of its complexities.
They know too well the pitfalls of tapping into underground hot spots, including acidic groundwater corroding the wells' steel casings, toxic gases leaking into the atmosphere and explosive blowouts. Others have also experienced the drawbacks at first hand. In Switzerland, a 5km-deep geothermal well near the city of Basel set off a series of earthquakes in 2006, with the strongest registering 3.4 on the Richter scale. They were accompanied by an "air shock", likened to the sonic boom of a fighter jet, that startled city residents.
Geopower Basel, the consortium which drilled the well, quickly shut down the project. The same technology, which involves injecting water into super-hot underground rocks to fracture them and create steam, is being tested in the US and Australia and more technical problems have ensued. The gases known to leak from geothermal wells include deadly hydrogen sulphide and radioactive radon, a by-product of the radioactive decay of naturally occurring uranium and thorium. In effect, the earth is a huge nuclear reactor, which is why its core is such a powerful heat source. It is therefore not surprising that geothermal wells unleash a form of radioactive waste.
Geothermal energy may not be inexhaustible, as is commonly believed, because the supply of hot spots accessible with current technology is limited and their heat can be drained faster than it is replenished. "We need to better assess this resource and how to use it wisely," Svandis Svavarsdottir, the environment minister of Iceland, told The New York Times in July. "We do know that geothermal areas are rare worldwide, even if they are common in Iceland, and we have a duty towards ourselves and the rest of the world to conserve them and tread carefully regarding further use."
Instead of drilling or digging for energy, many countries are turning to agriculture for new supplies of transport fuel. However, numerous studies have shown that growing crops for biofuel has exacerbated world hunger. Even in the developed world, increased biofuel production is raising concerns about food security. In Britain, a £300 million (Dh1.81 billion) plant in the Northumberland district will be Europe's largest bioethanol refinery when it opens later this year.
That facility and another being built in northern England will consume about 2.3 million tonnes of grain annually, equalling roughly 19 per cent of the UK wheat crop and ending Britain's self-sufficiency in the food staple. While British agricultural lobbyists expect ethanol plants to support local grain prices, consumers could soon face higher prices for basic foods. Environmentalists have also voiced concerns.
"Using wheat for fuel involves the displacement of agricultural land used for food production. At the end of that displacement chain you need to create new farmland and that usually means cutting down forests," says the environmental group Friends of the Earth. Many experts agree. US researchers led by Timothy Searchinger, a senior fellow at the Georgetown Environmental Law and Policy Institute in Washington, DC, warned this month that without a change to internationally agreed rules governing their production, biofuels were a "false" method of reducing greenhouse gases that "could lead to the loss of most of the world's natural forests as carbon caps tighten".
"Direct and indirect land-use changes associated with an aggressive global biofuels programme have the potential to release large quantities of greenhouse gases to the atmosphere," said Dr Jerry Melillo, a professor at the Ecosystems Centre Marine Biological Laboratory at Woods Hole, Massachusetts. A study he led predicted that using fertilisers in biofuel production would significantly boost emissions of nitrous oxide, a potent greenhouse gas linked to global warming.
Wind and solar power also have drawbacks such as their relatively high cost, large land requirements and the intermittent nature of their energy supply. That will remain a big problem without breakthroughs in efficient, affordable storage. Without such advances, most electricity must be consumed almost as soon as it is produced, so relying on unpredictable power sources can lead to shortages and overloaded power cables. Wind farms especially require backup, which in practice has meant more gas and coal-fired plants and power-grid expansions.
Danish and German researchers have found carbon emissions from the extra facilities built to guard against supply disruptions cancelled any emissions reductions from wind parks in their countries. One German economic policy think tank said German renewable energy policy, which in the US has often been cited by the Obama administration as a success, had "failed to harness the market incentives needed to ensure a viable and cost-effective introduction of renewable energies into the country's energy portfolio.
"To the contrary, the government's support mechanisms have in many respects subverted these incentives, resulting in massive expenditures that show little long-term promise for stimulating the economy, protecting the environment, or increasing energy security," the Rheinisch-Westfalisches Institut fur Wirtschaftsforschung said. One promising solution to the problems of harnessing intermittent power might be to link renewable electricity sources through a "smart grid" capable of detecting where power is available and sending it to where it is needed. However, adding sensitive electronics to power grids could increase their vulnerability to failures and security threats, including cyber attacks.
The British have recently proposed linking North Sea wind farms to Norwegian hydroelectric developments for carbon-free backup. Hydropower is the world's oldest and largest-scale renewable electricity technology, tapping the planet's solar-powered hydrological cycle. Big hydro projects involving dams on major rivers, however, are intensely controversial because they destroy ecosystems and displace human populations.
They have been associated with significant greenhouse gas emissions and the leaching of toxic metals from the decay of inundated vegetation. They can also threaten the safety of downstream communities, as dams can burst. While even the largest hydro projects cannot deplete the sun's power to lift water, there are a limited number of locations suitable for building them. Also limited, usually to a few decades, are the lifespans of hydroelectric developments, because dams eventually silt up and become useless.
Another problem is that even large hydropower developments cannot guarantee output during droughts. Oil-rich Venezuela, which depends on hydroelectricity for 75 per cent of its power supply, has recently instituted power-saving measures during a months-long drought. Last week, the government rescheduled all professional football matches from evenings to daylight hours to avoid using stadium lights.
Helene Pelosse, the director general of the International Renewable Energy Agency, opposes including large hydro projects in the UN Clean Development Mechanism, the scheme for generating funding for projects to reduce carbon emissions in developing countries. Her preferred renewable sources include geothermal, wind and solar. Many others saythose sources could not be developed fast enough to avert climate change.