Jul 29, 2008
Renewable energy: price and policy are key
Last week saw around 600 delegates gather at the World Renewable Energy Congress in Glasgow, UK. While many speakers stressed the almost endless supply of energy available from sources such as the sun, wind, waves, tides, and even the Earth itself, other recurrent themes included the challenge of bringing down the cost per kilowatt, introducing supportive policies and increasing the available capacity.
Rainer Hinrichs-Rahlwes from BEE, the German Renewable Energy Federation, pointed out how Germany is leading the way in installed solar energy capacity despite the country’s relatively poor sunshine levels. The nation accounts for nearly 50% of the world photovoltaics market and appromimately a quarter of a million people are employed in its renewable energy industry. Hinrichs-Rahlwes puts this success down to supportive government policies, which help provide investment security to businesses, and strong public support. That said, other nations are beginning to catch up – the US, Spain and China headed the table for new solar capacity installed in 2007.
Like many European nations, Germany uses a feed-in tariff to support renewable technologies, guaranteeing that electricity companies will buy up renewable energy for the next 20 years, at a price above market rates. The price decreases over time to allow for improvements in each technology. The UK, on the other hand, has a quota system dubbed the Renewables Obligation, where a certain percentage of the electricity that utilities provide must come from sustainable sources. David Elliott of the UK’s Open University believes that this system has actually hampered the introduction of renewable energies by encouraging the installation of wind farms at high wind-speed sites to keep costs down. Such sites are generally in scenic locations and opposed by the public. In Germany and Denmark, in contrast, wind farms tend to be at lower wind-speed locations and have met with little public opposition. Elliott believes that a quota system is also inefficient – it provides more support than is needed for established renewable technologies such as onshore wind, but not enough support for newer systems such as offshore wind, wave and tidal stream energy.
Obtaining planning consent for a new renewable energy project can be a fairly lengthy project and the kit is expensive to install, particularly offshore. It’s perhaps with these factors in mind that there’s a growing trend for installing a number of renewable energies at one site, perhaps even on the same structures. William Harvey of the University of Reykjavik, Iceland, explained how installing wind turbines at geothermal energy power plants can cut both the time and expense of the installation. Typically, wind data will already be available for geothermal plant locations as it’s needed to site the cooling towers correctly, there’ll be suitable spare land, and there will already be relationships with contractors, the public and local authorities. As geothermal plants don’t tend to be pretty – Harvey dubbed geothermal "a technology that only its mother could love" – there’s likely to be little objection to installing wind turbines on the same site. Meanwhile, Argentina’s Maximiliano Biancucci of the National University of Comahue has been investigating the use of tidal turbines and offshore wind turbines on the very same structures outside harbours in Patagonia to cut installation costs. And Ricardo Dutra of CEPEL, the Brazilian Electric Power Research Centre, discussed the use of wind turbines at hydroelectric plants.
With the European Union having set a 20% target for renewable energy by 2020 and worries about peak oil, energy security and climate change high on the agenda around the world, renewable energy is here to stay. Fortunately the next few years are likely to see considerable advances in many of the technologies.