Sydney-based company Oceanlinx is one of four wave energy device developers chosen to take part in creating the world's first large-scale wave energy farm, 16km off the coast of Cornwall.

The $58million project, to be installed offshore within two years, will grant each company a lease of 2sqkm of sea area to test their technology on a large-scale. The four different types of wave energy generators will be connected to a giant electric socket, known as a Wave Hub, on the seafloor. Cables running from the Wave Hub to land will feed 20megawatts of renewable electricity into the national power gird enough to power 7500 homes and save 24,300 tonnes of carbon dioxide every year.

British surfers have complained the Hub will ''drain energy'' from the waves they ride along the Atlantic coast, reducing wave height by 11 per cent. But New Zealand physical oceanographer, Dr Kerry Black, estimates the impact on wave height will be less than 5cm off a metre-high wave.

Britain is determined to establish its credentials as a global leader in renewable energy innovation, and the public company behind the Wave Hub project the South-West England Regional Development Agency claims it could transform the wave energy technology industry. They're hoping it will make Britain ''the location of choice'' for companies developing wave energy, attracting expertise and long-term foreign investment in renewable energy innovation.

''This is public sector investment at its best taking the long view, taking risks the private sector can't take, and making significant investment in the technology we need to tackle climate change,'' chief executive of south-west England's renewable energy agency, Matthew Spencer said. Oceanlinx is a world-leader in wave energy technology, chiefly due to the Denniss-Auld turbine invented by the company's founder, mathematician and oceanographer, Dr Tom Denniss.

A year ago, the company's wave energy technology was named by the International Academy of Science as one of the 10 most outstanding technologies in the world. But like many home-grown renewable energy innovations, the rest of the world seems more excited by the future clean energy delivery prospects of the Oceanlinx turbine than governments in Australia. Hawaii has signed a deal for three of the company's floating wave energy converters and Rhode Island the smallest state in the United States wants a pilot plant. A power company on the Oregon coast is negotiating with Oceanlinx to build a 15MW wave energy park, and Mexico's Federal Electricity Commission (the world's biggest electricity provider) is conducting a feasibility study for two new wave plants using the Australian technology.

Back home, there's a pilot plant at Port Kembla, a feasibility study for King Island and negotiations to establish a 27MW wave energy project off the Victorian coast at Portland. ''Australia has great wave energy potential, but has lagged a little behind the rest of the world because of the low cost of coal. But if you took all the existing energy technologies back to a level playing field, wave energy is actually the cheapest,'' Denniss says.

The Earth's oceans are the world's largest solar energy collector and energy storage system, covering 70 per cent of the planet. The World Energy Council estimates the amount of energy generated by ocean waves, currents, tides, swells and thermal gradients could supply all the world's current electricity needs, more than 5000 times over. ''It's estimated that in 50 years, wave energy will be providing around 20 per cent of the world's energy needs. The potential is huge,'' Denniss says.

He developed the idea of a turbine to extract wave energy in the mid-1990s, and describes it as ''acting like a giant blowhole''. Water moves up and down inside a chamber, and the turbine is driven by the air flow. A sensor system measures the pressure exerted on the ocean floor by each wave as it approaches the capture chamber, and sends a voltage signal identifying the height, time and shape of each wave.

It produces ''around the same level of noise as a household vacuum cleaner'' and has no moving parts underwater. ''There's nothing to affect ocean wildlife, and we've screened off any sections of the turbine open to the air with mesh, so there's no danger to sea birds.''

Like many Australian renewable energy companies, Oceanlinx has relied on foreign venture capital to expand its operations. The company was established in 1997, and received a $750,000 grant from the Federal Government two years later. Two US energy companies and three European investment groups specialising in energy technology innovations provided the venture capital for the company to grow. ''We have more interest around the world in the technology than we can service at the moment. The market for us is unlimited,'' Denniss says.

Small scale wind turbines are predicted to be another boom growth area in renewable technology, with vertical axis turbines out-performing the conventional, and controversial, giant propeller-blade style turbines. The smart money is not on wind farms, but roof-mounted microgeneration turbines. A British energy study estimates small scale wind generation can provide 40 per cent of the country's energy needs by 2050.

Australian technology could be a winner here too. Perth inventor, Graeme Attey, better known as the man who designed the phenomenally successful Dirtsurfer (a kind of streamlined snowboard with wheels), has developed a barrel-style wind turbine that could sell for about $700. He estimates five turbines should generate enough power to supply the average suburban home, and recently received $34,000 from the WA Government to help commercialise the technology.

The biggest renewable energy technology project to be undertaken in Australia is the $800million Environmission solar tower, near Mildura in north-west Victoria. It will be a massive solar power station, capable of producing up to 200MW of clean electricity, or enough to power 200,000 homes. China has invested $11million in the project, and will own 75 per cent of an Australian-based company developing new solar tower technology for China. The 1km-high solar tower power station, will be surrounded by a ''skirt'' of solar collector panels 7km wide. The project received support from the Howard government in the lead-up to the 2007 federal election, but last month the company claimed the project had stalled due to insufficient federal support and they are now concentrating on projects in China and the US.

''Under the previous government they changed their policy from really renewable to low emission and that meant a lot of clean coal, and the prime minister's favourite thing nuclear,'' a company spokesman told the ABC. ''We would be looking to the new Government to see a firm change to renewable and we will be lobbying that Government very heavily.''

Meanwhile newspapers in the US last week were celebrating new plans to build an Australian-designed ''bloody big solar tower'' somewhere in the country's south-west. The History Channel took up the story and calculated 630 solar towers ''would power every home in the US making America energy independent.''

The construction cost would be ''over $US500billion, roughly half the cost of the Iraq war''.

Pope Benedict is also backing renewable energy, installing solar cells on the roof of the Vatican's main auditorium as the first step in a plan to make the Holy See the world's first carbon neutral country. Asked about climate change during a recent press conference, Pope Benedict replied it was not his intention to ''enter into the technical questions which politicians and specialists have to resolve, but to offer essential impulses for seeing the responsibility, for being capable of responding to this great challenge''.