Main navigation

Social sharing options

You are here:

  1. Home
  2. Blog


Offshore wind needs a break

I visited an offshore wind farm last week. The trip was organised as part of an inward visit by a number of government officials from other countries, as an example of low-carbon and renewable energy technologies in the UK. 

Wind power is one of those issues that tends to polarise opinion. Those in favour support a low-carbon electricity source, and some like the look of the turbines. Those against, cite noise and visual impact on the landscape (aka having their view spoilt) or seascape in the case of Donald Trump. Then there’s the economic lobby: they say that wind is intermittent, and when compared with fossil fuels, expensive and unreliable.

I’d never seen a wind turbine up close, and the offshore array was really quite something.  100 turbines with a maximum generating capacity of 300 megawatts (MW), at peak output supplying nearly a quarter of a million households. And the turbines don’t need a hurricane. On our visit it was blowing a healthy and not uncommon Force 6 – also known as a strong breeze – which is more or less optimal for a modern offshore wind farm. And the turbines really are beautiful, elegant things. I’ve seen many an uglier (and considerably less useful) sculpture. When you get up close to a wind turbine you can sense the precision engineering behind its construction; the graceful sweep of its blades and the precise angle at which they’re offered to the wind to maximise efficiency. I think modern wind turbines should command a lot more support than they currently do, and not just for the way they look; they symbolise a more enlightened and altruistic response to meeting energy demand than setting fire to stuff we’ve found in the ground, whose burning we know full well to cause serious damage to the natural systems that sustain us.

The main perceived problems with offshore wind are around cost and intermittency. Generating a kilowatt hour of electricity from offshore wind is currently more expensive than from fossil fuels. Wind technology is still high on the development cost curve and cannot yet compete in an open market with fossil fuels, where the technology is mature, efficient and proven. In addition, wind energy cannot provide a perfectly reliable electrical base-load because there are times when the wind doesn’t blow. For every megawatt of installed wind therefore, you need thermal plant – ideally gas-fired – on standby as back-up to plug gaps in the weather when the wind isn’t blowing anywhere but when electricity demand continues. The way fossil-fuelled power stations are currently financed means that they need to run at near full capacity all the time to justify the investment. A power station backing up wind energy will not be running all the time, and is therefore uneconomical. Overall then, you end up paying for more generating capacity than you need, but which is less efficient, financially, than conventional fossil-fuelled plant. Those who question the economic sense of offshore wind energy in the current market structure do have a point.

However, I do not believe these issues should be allowed to hold back the scaling-up of offshore wind. The cost of harnessing energy from wind is falling as the technology develops and matures. Further downward pressure on the price of wind energy will come in the form of running costs: around 75% of the cost of wind energy is associated with the up-front capital expenditure to build and install the turbines. Ongoing operation and maintenance costs are far lower and more predictable than for fossil-fuelled plant because generating electricity from wind does not require a fuel input and is therefore not subject to fluctuations in global wholesale fuel prices. And over the lifetime of a wind farm there is a significant saving in CO2 costs compared to fossil-fuelled plant.  

As for intermittency, the back-up scenario is a genuine argument against wind energy. But this is to judge wind energy on its current shortcomings as a direct, stand-alone replacement for fossil fuelled electricity generation and this is not where wind’s future lies. Wind is an essential component of a low-carbon energy system, but is exactly that: one component. In a low-carbon smart grid scenario, electricity is supplied from a variety of sources and critically, demand is managed carefully to buffer against fluctuations in supply. Integrated with other technologies (solar, marine and tidal, hydroelectricity, nuclear), coupled to effective demand-side measures (highly efficient energy use across all sectors) and managed by an integrated smart grid that is able to reduce demand when supply is scarce, wind is a perfectly viable energy source.  Saying we should not build wind capacity because we have not yet built the smart grid necessary to store energy and balance the electrical load is like saying we should not build a house we urgently need because we have not yet built the water main to service it. But just as with building a house and supplying its utilities, you have to start somewhere.

Harnessing wind energy does not produce greenhouse gases after the turbine is built and installed. And contrary to the views of some, it does not require more energy to produce a wind turbine than the turbine will return over its 25-year lifespan. The Energy Yield Ratio (EYR) of a typical offshore wind turbine is about 80,  meaning the turbine will generate 80 times more energy over its lifetime than was used in its manufacture. Wind energy is inherently sustainable where coal, oil and gas are not. Yes, wind currently requires subsidy. But if we bemoan the distortion to energy markets leveraged through the Renewables Obligation, we should also bemoan the large subsidy extended to fossil fuels through inaccurate pricing that shows no sign of adequately internalising the true environmental and human cost of their continued use.

We need to give wind a chance and look at its long-term role. The UK could be on the cusp of a low-carbon energy revolution where the integrated smart-grid of tomorrow starts to become a reality. I sincerely hope that we are, and that the relatively small 300MW wind farm is the first murmuring of what could be to come. If we want electricity we have, mostly, to use kinetic energy to spin a generator and there is a limited number of ways we can do that. Building yet another carbon-spewing fossil-fuelled thermal plant combusting coal or gas and hiding it behind a hill where we can’t see its smokestacks and where it doesn’t interfere with anyone’s view is to perpetuate some people’s state of denial around energy and climate change. A splendid array of clean and sustainable offshore wind turbines however, playing its role as a component of an integrated low-carbon smart grid, really is something we could be proud of.

Filed under: Renewable energy

Comments: 7 Comments on Offshore wind needs a break
Posted on: May 17 2012

7 Responses to “Offshore wind needs a break”

  1. Dave Howard says:

    This is a good, well balanced article Jonathan. Just to add a couple of points.

    It is very rare for there to be no wind anywhere around the UK so I doubt if 100% thermal backup is required for wind farms. Times of low wind speed are easy to forecast, usually several days in advance, so there is time to bring standby plant on line for such an event. This reinforces your points about the need for smart grids and diversity in the generator plant mix.


  2. [...] Department of Energy and Climate Change Blog [...]

  3. J Stevens says:

    The idea about a “smart grid” that could reduce the demand for electricity when supply is scare seems interesting. How exactly would demand be reduced? Is it likely that something like this will be developed in the foreseeable future (say, within ten years)?

    • Jonathan Hood says:

      The basic concept of a smart grid is to add monitoring, analysis, control, and communication capabilities to the national electrical delivery system to maximize the efficiency both of supply and demand.

      There’s a useful report on smart grids on the DECC website. It was produced under the last government so should not be treated as current policy, but the information on how smart grids work is relevant. It is available here:

      This is an extract from that report, specifically on reducing demand:

      “In the future, homes may produce their own electricity (through domestic microgeneration) and have smart appliances, which will communicate with the electricity network through a smart meter. Such a system offers a range of possible new services. For example, new appliances which do not need continuous power, such as fridges, freezers, washing machines or laptop computers with batteries, could be set automatically to stop drawing electricity from the mains (for varying lengths of time – perhaps only a minute or so) according to the demand and supply across the electricity system. Where a home produces its own electricity, for example from solar photovoltaic (PV) panels or a small-scale wind turbine, appliances might be programmed to run and take advantage of this on-site low carbon generation. When excess electricity is being produced it will be possible to export this and sell it to the network; smart meters will facilitate measurement of these exports of power. It could also be possible to integrate the recharging of electric vehicles to synchronise with a home’s own microgeneration, or to ensure it occurs during low tariff (and low carbon) periods. Links between a smart home meter and mobile phones or the internet may potentially also offer even more convenience. For example, consumers may be able to remotely change the time their heating or cooling system comes on, overriding automatic timers if their plans change.”

      We’re currently a fair distance away from this scenario and I’m afraid I don’t know what sort of timeframe we’re looking at, but in a carbon-constrained future, measures like this will be essential in maintaining our electricity supplies.

  4. rosemary rhodes says:

    I I have heard talk that these wind turbines are causing trouble for bird life.
    Is this true?

    • Jonathan Hood says:

      Yes, it’s true wind turbines have an impact on birds. Estimates from Denmark (where 9% of electricity is generated by wind turbines) put the number of birds killed there each year by wind turbines at around 30,000.

      It’s also true that in the UK, domestic cats kill around 55,000,000 (yes – that really is fifty-five million) birds each year*.




  5. I could not agree more, offshore wind turbines are like a modern take on lighthouses but with massive propellors, they are graceful to look at from afar and up really close they never fail to impress. The UK future energy mix must increase wind both in and offshore we truly need to ratchet up the pressure to grow this industry. It is also about time we published the league tables of the greenest Planning Authorities when it comes to allowing large scale renewables, those that don’t should be shamed publicly.

Leave a Reply

DECC @YouTube

DECC's YouTube feed

Share DECC's YouTube Channel

view all

Partners & Help