Advanced search

Energy storage gets second wind

Few topics polarise the opinion of UK armchair energy analysts more than wind energy. To its champions, it will become an ever more vital component of our energy mix over the coming decade, making up much of the shortfall as up to a quarter of our existing generating capacity comes offline. To its detractors, it is an expensive, inefficient technology that is overly reliant on subsidies and so unpredictable that it is impossible to deal with.

While the extreme ends of both arguments should be treated with scepticism, there is certainly no disputing the fact that when the wind stops blowing, turbines stop generating.

With wind currently forming a relatively low proportion of total demand, intermittency isn’t a major problem yet. But if, as the energy industry and the government hope, this proportion rises, it will become more of a headache.

According to industry trade body RenewableUK, an average wind turbine will, over the course of a year, generate 20-30 per cent of its theoretical maximum output. Some claim this figure is overoptimistic. A recent report published by wildlife charity the John Muir Trust and based on National Grid wind data concluded that for a third of the time 2010 wind output was less than 10 per cent of capacity. Compare this with coal, gas, or indeed nuclear, where availability assumptions creep towards 100 per cent and it is easy to see why many, including National Grid’s research chief Ian Welch - interviewed here - believe that how we deal with the intermittency issue will have a profound impact on the UK’s future energy landscape.

One potential solution is explored in our latest Big Story which looks at intriguing technology that could enable energy companies to effectively save wind energy for later.

The idea behind compressed air energy storage (CAES) is elegantly simple: when the wind blows, turbines are used to compress air, which is stored in pressure vessels. In times of high demand, this pressurised air is released and used to power an electricity generator.

The concept has been around for a while but until recently the heat lost during the compression process made it inefficient. With researchers now nibbling away at these inefficiencies, CAES is now looking like an increasingly compelling technology, and could one day be just the kind of energy storage system that Welch and his National Grid colleagues dream about.

On a different note, The Engineer Technology and Innovation Awards 2011 are now open for entries. If you’re involved in a technology-led collaborative project with a commercial or academic partner and believe your work could have a major impact in its field visit our awards website before 15th July for a chance to join other finalists at the Royal Socety in London on 2 December

Readers' comments (22)

  • CAES is the most cost-effective way to firm wind power. It is cheaper and cleaner than coal power, natural gas, or nuclear power. Every nation needs to explore development of wind/CAES projects.

    Unsuitable or offensive? Report this comment

  • Compressed air is one of the most expensive forms of energy and this is a long way from getting any cheaper. It is true that with technological advances the costs will marginally be reduced, but other forms of energy will deliver bigger savings with the same effort and finance applied to it.

    Unsuitable or offensive? Report this comment

  • I have always thought that coupling wind with pumped hydro should be investigated.

    Unsuitable or offensive? Report this comment

  • I wonder why pumped water storage doesn't get a stronger look in? The pumping site and storage could be remote from the windfarm. Wind in Cornwall, storage in Scotland, say. The times when, on average, the wind turbines are generating could be linked to the time pumping to storage took place and the hydroelectric power generated when wind power was poor or unavailable. I would have thought that there are lots of highland areas that are suitable and , like the Snowdonia schemes, they could be developed very sympathetically. This is an interesting discussion on the proposition.
    withouthota ir/c26/page_190.shtml

    Richard Woods

    Unsuitable or offensive? Report this comment

  • Any CAES means extra investment including storage itself plus a complicated pump/generator. Low CAES efficiency decreases real power provided to the grid.
    The best way is either to use exsisting hydropower accumulating plants (Emmet is right) or compressed air for a gas tubine power plant to increase gas turbine efficiency by cutting air compressor losses (I think it was done in Germany).

    Unsuitable or offensive? Report this comment

  • Windfarms storing energy by pumping water up hill is the answer for instantaeous hydroeletric power on demand.

    Some countries will only use wind power if the wind power pumps water uphill as stored potential energy for hydroelectric power generation on demand at peak demand - Why doesnt the UK specify the same as wind only generates electricty for 20% to 25% of the time in onshore wind farms.

    What's more - wind doesn't occur in cold weather like last winter when we needed it most AND has to be switched off in dry weather as it is fanning grass and bracken first - On the radio news yesterday and today for Northern Ireland and Yorkshire!

    Unsuitable or offensive? Report this comment

  • Very low friction flywheels, using magnetic/superconductor bearings, are a cost-effective and efficient method for energy storage.

    Unsuitable or offensive? Report this comment

  • We have a very suitable distributed energy storage solution on most people's doorstep, it is currently used for water supply but could be harnessed to absorb excess wind energy if the right incentives were in place. The technology and means to exploit this opportunity are all readily available. Municipal water pumping accounts for some 3%of energy demand it is a realistic dynamic storage option.
    Other forms of dynamic energy storage such as therma

    Unsuitable or offensive? Report this comment

  • Pumped-storage is a good match for wind-turbines. Usually both exist in remote/rural areas, often the same areas so that transmission losses are minimised. Here's an ambitious, perhaps unattainable plan to link both on a massive scale:

    Unsuitable or offensive? Report this comment

  • There is a better way of making the turbines rotate more of the time when there is not much wind. And that is to make a wind tunnel that is angled to the turbines made by trees in a certain direction to the turbines. This would produce wind and keep the turbines turning when it appears that there is not much wind.

    Unsuitable or offensive? Report this comment

View results 10 per page | 20 per page | 50 per page

Have your say


Related images

My saved stories (Empty)

You have no saved stories

Save this article