This June, Professor Michael Gratzel of the Lausanne Federal Technology Institute, Switzerland, was awarded the 2010 Millennium Technology Prize for his invention of a low-cost solar cell that is used in electricity-generating windows. Inspired by photosynthesis, they turn light into energy, and US scientists hopes the cells will one day be used in the glass of New York high-rises.
This potentially revolutionary invention is further evidence of the continuing zeal with which inventors, research institutes and businesses are exploring all forms of renewable energy generation. Each year, new technologies are developed or introduced into the power market and ambitious renewable energy projects are taking place across the globe. Here is a look at five of the current top technologies and projects that will play an important role in the future global production of renewable energy.
1. Pelamis builds second-generation Wave Energy Converter
The Pelamis Wave Energy Converter by Pelamis Wave Power (PWP) came to prominence in 2004 when its full-scale prototype became the world's first commercial-scale wave energy converter to generate electricity for a national grid. Launched at the European Marine Energy Centre (EMEC) in Orkney, Scotland, the semi-submerged converter has hinged joints that use the motion of the sea to pump high-pressure fluid through hydraulic motors, which drive electrical generators to produce electricity. The power produced from the joints is fed down a single umbilical cable to a junction on the sea bed. If further devices are added, they can be connected together and linked to a shore through a single seabed cable, thus creating a wave farm.
The technology's potential was shown again in 2008, when three Pelamis machines were deployed off the coast of Portugal and began producing power for the Portuguese national grid. With a capacity of 2.25MW, it was estimated the wave farm produced enough electricity to meet the demands of more than 1,500 Portuguese homes.
The project only lasted a few months, but in June of this year PWP successfully completed trials of its second-generation wave converter, the Pelamis P2. The 750kW energy device has been built for the utility E.ON and will once again be connected to the UK grid via the EMEC site in Orkney.
PWP has also secured a second order for the Pelamis P2 from ScottishPower Renewables (SPR). Both SPR and E.ON have been awarded leases by the Crown Estate for projects off the west coast of Orkney to utilise the P2 technology, while PWP secured a lease for a project north of the Scottish mainland.
Once complete, the capacity of these projects is expected to total 150MW through 200 P2 machines. The move is expected to place Scotland at the heart of Europe's wave power revolution.
2. Aquamarine Power Oyster 2 unveiled
Rivalling the Pelamis P2 will be Aquamarine Power Technology's Oyster 2, the company's second-generation wave energy converter scheduled to be built later this year. Like the P2, it utilises the motion of the waves and has already been successfully deployed at EMEC. But unlike its rival, the Oyster focuses on near-shore waves and is attached to the seabed at a depth of roughly 10m and at a distance of about 0.5km from shore.
Once deployed, the Oyster's hinged flap sways back and forth, driving two hydraulic pistons that place high-pressure water onshore to drive a conventional hydro-electric turbine.
Earlier this year, Aquamarine Power Technology launched the designs for the Oyster 2, which is twice the size and expected to produce 250% more power than its predecessor. Aquamarine Power recently raised an additional £6m of funding for the 800kW device, which it hopes to deploy at the EMEC by the summer of 2011.
3. China plans world's largest solar PV plant
A report by Pew Charitable Trusts earlier this year confirmed that China had become the global leader in investing in low-carbon energy, investing almost twice as much in clean energy last year as nearest rivals the US. Symbolising China's newfound dominance in the renewables market is the construction of the world's largest photovoltaic solar power plant.
Located in Ordas City in inner Mongolia, the solar power plant is expected to grow to an astonishing 2GW in the next decade, dwarfing the world's existing largest solar installation, a 60MW farm in Spain. Estimated to cost between $5-6bn, the plant will be built in phases, with construction of the first 30MW phase expected to begin this year.
4. Introducing airborne wind turbines?
Interest in the technology of airborne wind turbines is continuing to grow and a small number of inventors and companies worldwide have been making strides towards turning the concept into a commercial reality.
Airborne wind turbines aim to use high-altitude winds - typically through kites, balloons or autogyros - to generate electricity that can be transferred to the ground via a tether. Controlling the turbines in hazardous weathers or electrical storms has proved a stumbling block in the past, but advances in technology and materials in recent years has given new hope to the concept.
Companies such as the US-based Joby Energy have been developing airborne wind turbines designed to operate in the upper boundary layer and the upper troposphere, where winds are faster and more consistent than winds nearer to the earth's surface. The company has been developing multi-wing structures, which support a series of turbines, which in turn are connected to motor-generators that aim to generate power during crosswind flights. The flight of the structure is maintained by a computer system that controls aerodynamic surfaces on the wings and rotor speeds. A tether can be used to both transmit electricity and moor the system to the ground. Joby Energy hopes the technology will take to the skies soon.
5. Masdar's carbon neutral city in the desert
One of the world's most oil-rich locations is now planning the world’s first carbon-neutral city. Masdar City, in Abu Dhabi, is designed to be completely reliant on solar power and other clean-energy sources, sticking so firmly to its sustainability principle that no automobiles will be permitted into the city and the only form of transport will be through public mass-transit and personal rapid-transit systems.
Funded largely by the Abu Dhabi government, built by the Abu Dhabi Future Energy Company (ADFEC) and designed by a British architectural firm, the 6km² sustainable development will be located 17km north-east of central Abu Dhabi. The carbon-free city is reported to cost US$22bn and it is estimated that it will take at least a decade to complete, following which it will reportedly house 45,000-50,000 people and 1,500 businesses.
ADFEC hopes also to make the site a leading research institute in alternative energy and sustainable technologies, meaning the emirate can become a major source of the world's power resources.