An Iraqi engineer has developed a mini wind turbine that could revolutionise the world's energy market.

Dr Mouafak Zaher says his novel design will be small enough to fit on the roof of an average house, with much less noise and vibration than traditional windmills.

The Foundation for Research, Science and Technology has given him $266,000 to develop the design during the next four years.

The design is based on a spiral blade originally developed in Sweden for large-scale industrial wind turbines.

Dr Zaher has subtly changed the shape of the blade to alter the way it catches gusts of wind.

"It's an aerodynamic problem that has not been fully solved by others. We have a solution," he said. "For sure, it will be cheaper than the conventional existing power supplies."

He said the turbine "shouldn't be larger than the antenna of a TV aerial", and would generate electricity in typical wind conditions in most parts of the world.

Born in Iraq, Dr Zaher was educated in Cairo and London and worked for 20 years in the oil industry in the Gulf. He came to New Zealand after the first Gulf War in 1990-91.

"My contract had ended so there were many options in front of me. The best option was to come here and work at Unitec," he said.

He has already registered two patents in Unitec's name - one to stop bubbles developing and eroding the blade in a centrifugal pump, and one to pump two fluids at once, or air and water. Unitec is now looking for companies to commercialise both inventions.

Another wind power pioneer, Dr Geoff Henderson, expressed doubts about Dr Zaher's design because its vertical blade would be subject to higher fatigue loads than blades with a horizontal axis.

But he confirmed that wind power was already cost-competitive at recent power prices of about 6c a kilowatt-hour.

Tauranga-based Trust Power is doubling the size of its Tararua wind farm near Palmerston North, and Dr Henderson plans to build six new $800,000 turbines next year.

The foundation has also announced new grants for projects to develop renewable energy from waves, forest industry wastes and sewage treatment sludge.

Dr John Huckerby, a Wellington energy consultant who has formed a wave power consortium with Industrial Research and the National Institute of Water and Atmospheric Research (Niwa), said New Zealand's near-shore waves produced more than 40 times as much energy as the country's existing power consumption.

He proposes pilot generators in water between 30 and 50 metres deep on south and south-west facing coasts such as South Taranaki, Cook Strait and the south and west coasts of the South Island.

"We hope this will be better than the other prototypes."