Zero-carbon, renewable energy which is cost-competitive with fossil-fuel-generated sources is surely the holy grail of the engineering world.
University of Nottingham spin-out company Nimrod Energy is aiming to prove that, far from being just a pipe dream, one new form of green energy could be in widespread use within 15 years and at a fraction of the cost of its nearest competitor.
The technology – Integrated Compressed Air Renewable Energy Systems (ICARES) – has been in development since 2006.
It is centred on a simple premise: using 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.
Professor Seamus Garvey, the brains behind the idea, said: “The UK has abundant offshore renewable energy resource – enough to supply all of our energy several times over.
“We also have a strong internal energy market – worth well over £60billion per year. We have an economy desperately in need of rebooting its manufacturing base and an engineering capability which is the finest in the world.
“Without an initiative like this, the UK will spend vast amounts of money (several times £10billion) abroad even before 2020 to buy offshore wind turbines, and much manufacturing activity will go abroad with that.
“Worst of all, we will pay substantially higher prices for that equipment than we really need to, and the UK energy consumer is going to feel that with sharp rises in unit energy costs over the next 10 years.”
Over the past year, Prof Garvey’s research has apparently shown that, by taking offshore wind turbines to a scale never before imagined – 230m (755ft) diameter is the baby of the family – and considering some radical redesigns, the total amount of structural material per kilowatt 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 per megawatt hour – less than 20% 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 euros (about £280,000) 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.
Prof Garvey added: “This is a classic case of a little foresight leading to technology becoming available exactly when the demand appears.
“The signals have been out there for years that offshore wind turbines need to grow much larger and that energy storage is going to become the key to integrating large amounts of renewable energy into the UK and world electrical power systems.”
