A new spin-out company from The University of Nottingham aims to lower wind energy costs by four times and reduce the cost of storing excess wind energy by five times. NIMROD Energy Ltd is being launched this week by Professor Seamus Garvey. The system is also four times more efficient in terms of the amount of steel and concrete is needed to generate a megawatt. This system and kite generated wind and the improved storage of the uneven energy generated would make wind competitive with the factory mass produced deeper burn nuclear fission systems that I like. It will be good to have more of both to meet growing world energy demand.
The industry has converged on a consensus that large wind turbines should be three-bladed, horizontal-axis machines on top of a tubular tower. This is good up to 150 meters in diameter.
Prof Garvey turbine is dramatically different: a horizontal-axis machine with eight blades — four long and four short. A floating framework replaces the tower, and it converts wind power internally within the blades. Think of a bicycle wheel rotating slowly, and a loose bead on each spoke. The beads represent pistons travelling back and forth inside tubes in the blades, compressing air as they do so.
The baby of the family is a 200 meter-diameter machine producing 18MW in a decent wind and costing less than 40% of the 40 million pounds you’d spend on a corresponding set of direct-generating machines. Her big sisters might easily reach 400 meter in diameter and could be 50% more cost-effective.
Energy-storage capability comes as an added bonus. I am suggesting “energy bags” held down on the ocean floor with ballast weights about 600m below the surface. Ireland has such deep water in the Atlantic suitably close to shore.
To store 10% of our average total daily electricity generation in this way would would cost less than €300m. That would mean 1,000 bags 25m wide when full.
If you think that all of this is hot air, you would be right — in part. Air compressed to 60 times atmospheric pressure will get hot — up to 630C.
His turbines create energy differently to conventional ones, using falling masses within the blades to compress air.
The technology is uses giant wind turbines to compress and pump air into huge undersea Energy Bags™ anchored to the seabed — or geological formations where deep water is not available. The high pressure air would be expanded in special turbo-generator sets to provide electricity as required — not just when the wind is blowing. It would see vast floating offshore ‘energy farms’ created off the coastline around the UK.
shown are the prototype energy bags for storing compressed air
Professor Garvey’s research has proven that by taking offshore wind turbines to a scale never before imagined — 230m diameter is the baby of the family — and considering some radical redesigns, the total amount of structural material per kW of rated power can be slashed, effectively cutting costs by a factor of four or more. He believes it is possible to store energy at costs well below £10,000/MWh — less than 20 per cent of pumped hydro energy, the cheapest competing technology.
Testing of scale-model prototype Energy Bags ™ has already commenced. A research project funded with €310,000 from the EON International Research Initiative has already funded the development of analysis and design tools for the energy bags and will provide further prototype testing in seawater leading to an energy storage product that will be ready for use in energy systems by May 2011.
2007 Interview with Seamus Garvey
the One Thousand Foot Wind Turbine Video
Seamus Garvey travels to the Waltham transmitter to better comprehend the scale of his wind turbine plan. His turbines create energy differently to conventional ones, using falling masses within the blades to compress air.
Test Tube UK on the Energy Bags