Not everyone likes on shore wind farms, given that they can have a strong visual impact on treasured views and a range of other local environmental impacts and issues. In the past, in the USA in particular, there have been claims about local health effects, but they seem to have be effectively rebutted. More recently however, some anti-wind farm campaign groups, for example in Wales, say that off shore wind would be preferable and it is certainly true that, depending on location, offshore siting would reduce visual impact from the land – some off shore wind farms are 100 miles or more offshore.
The UK potential for offshore wind farms is very large, so it is a key option and it is being developed quite rapidly- the UK now has over 16 GW installed, the same amount as onshore wind. And both are expanding- now that the Labour government has removed the Tory block on local siting. But some objections to on land wind still persist. So is offshore a better option? There can of course also be local environmental and wild life impacts offshore, but a key point in making a comparison is that it costs much more to install wind turbines offshore – more than 50% extra, depending on location and size. In terms of final power costs, offshore siting does allow for the use of large more productive wind turbines, and wind speeds are generally higher and more consistent off shore, but the power has to be brought to land and undersea cables are very expensive.
In the most recent Contracts for Difference (CfD) auctions, on shore wind projects got a strike price of £92/MWh, offshore wind £113/MWh. Technology may improve in both cases. But floating offshore wind turbines, which avoid the need for costly sea-bed foundations and allow wind farms to go further out to sea in deeper water, so far still need higher CfD strike prices. And although higher wind speeds can be harvested on shore with taller wind turbines, they are much more intrusive and may need larger concrete bases.
Overall the price difference is unlikely to go away. So will people be happy to pay around 20% more for power from offshore sites to avoid onshore siting? And also possibly forgo the option of locally owned wind farm co-ops of the sort that are common in Germany and Denmark? In this context, it’s worth noting that the UK government now has a £1 billion community energy programme aiming to support over 1,000 local and community-led clean energy projects across the UK. In terms of responding to climate change, offshore wind is very important, and likely to be the UKs largest green energy source, but on shore projects are also important in the UK, as well as globally: not everywhere is near the sea, there are many land-locked countries in the world.
Not all on-shore sites are suitable, but, in some locations, local wind farm siting may reduce the need for long pylon links if local energy storage can also be installed to help with balancing the variable local availability of wind. Although that would add to the project costs. However, in most places, there will have to be a mix of locally generated/stored green power (solar included) and imported grid power- including from offshore wind.
The ratio between these options will vary by rural /urban location, but with the grid providing a way to balance the overall system. So sorry, still some pylons…and while new pylon designs are emerging, and a local impact compensation scheme will soon be in place, that may not placate everyone. There may some local alternatives. For example, focussing more on solar, as some suggest, may avoid some grid links, although not all - even with PV on rooftops and local solar farms, plus a lot of local storage, in most places there will still be a need to import power at times. And of course, although it is cheaper to install PV in solar farms than on roof tops, not everyone likes solar farms. For one thing they can take up valuable agricultural land. However on the positive side they can enhance wildlife, and agri-solar options are also available- in some locations they can actually improve agricultural productivity. Moreover, if solar farms are locally owned and properly sited, then, along with locally owned wind farms, perhaps they will be less objectionable - as the old Danish proverb says ‘your own pigs don’t smell’.
Wind leads overall in the UK: it is now at 32 GW versus 22GW for PV in capacity terms, but given the different capacity factors, solar has a much lower annual output (6-7%) compared with wind (around 30%) in UK power supply terms. However, as Dr David Toke says in a useful comparative overview, solar is overall cheaper and is also now moving ahead faster globally, although he also notes that wind has recovered from a recent slow-down resulting from rising costs.
It will be interesting to see what happens in the next CfD round in the UK, with solar, and on and offshore wind all competing. The administrative strike cap prices for offshore wind have been set at £113/MWh, £92/MWh for onshore wind and £75 for PV solar, but the auction process usually results in significantly lower actual prices being agreed. Although in a post Budget statement, the chancellor, John Healey, said that new offshore wind projects will only get signed off by ministers if the power generated could be accommodated by the electricity grid without pushing up costs for consumers: ‘there’s no sense building power that can’t connect and then paying to switch it off’. So some projects may get blocked. The results of the competitive auction should out soon.
However, there might be a pause before the next round to allow time for the CfD arrangements to be revamped e.g. to ensure that grid links would be available to avoid costly output curtailment losses. Energy Minister Michael Shanks told the House of Lords environment committee, ‘we do now want to pause before AR9 and look at whether we need some more significant changes to the contracts for different scheme to make sure they work for the consumers of the country’. That's all a bit worrying...
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