Irish Offshore Wind and Wave power-an unreliable energy source? Think Again!

No, its not a sea monster it is a Pelamis Sea Snake Wave Energy converter which has been feeding electricity into the Scottish Grid since 2010. But will they keep our lights on? Image is open sourced from Wikipedia as usual.

One of the most persistent of these is that wind and wave energy would not be reliable, and would require expensive back-up conventional power stations. This is the so called base-load problem. In fact the actual technical details of ‘base-load’ are quite complex and vary from site to site and utility to utility. But firstly, in technical terms there would be no reason to have every MW of installed capacity from wind and wave literally matched by a reserve MW on land from some other energy source on permanent standby. In fact, what happens already is that some extra capacity at natural gas plants generating electricity are able to come on stream pretty quickly to plug gaps in supply or spike in demand. As one source points out: Intermittent renewables can provide 10-20% of our electricity, with hydroelectric and other base-load renewable sources (see below) on top of that. Even if the rapid growth in wind and other intermittent renewable sources continues, it will be over a decade before storage of the intermittent sources becomes a necessity.”

In the longer term, it is plausible that we will develop ways of storing wind and wave energy, for example via compressed air storage. Yet even if that doesn’t work out so well in many situations, it is more likely that connection to grids becomes a central feature of making renewables resilient enough to provide reliable supply all year round around the clock, and making them more attractive from a commercial perspective. If the wind is not blowing in Donegal (an unlikely scenario!), it will be probably blowing off the Arklow bank, or at least over in Wales, which from 2012 we will be connected to. The whole point about investing in offshore wind and wave in Ireland is that our natural climate and weather provides typically more than enough wind and wave throughout the year. Indeed the technical worry would not be that that the waves or wind wouldn’t be there, it might be that the they could be too strong, or at certain times of the year, unpredictable. Ironically then if climate change may cause greater intensity and unpredictably in Atlantic storm fronts this will pose a serious engineering challenge for future Irish wind and wave farms on our Atlantic coast-and the two technologies may be combined at joint sites by the way.

Note here that greater connection to trans-European electricity is one way of making a switch the much greater use of renewables both technically more reliable and also likely to reduce costs in the longer term. However, the idea of ‘smart grids’ takes that principle a stage further and imagines a much more distributed electricity infrastructure which would no longer be dominated by a top-down national electricity grid featuring a small number or mega electricity plants, but rather a dense network of clusters of smaller and diverse producers, even perhaps some micro producers feeding electricity into small distributed networks where electricity flows both ways. It could well be that given the unique nature of Ireland’s geography, which features the large sprawling conurbation of Dublin contrasted with the the midlands and western Atlantic seaboard where population density is low but scattered, will make for a major challenge in developing any efficient grid system. It could be that we need a distributed smart grid for the more rural part of the Island, and a more traditional grid for the greater Dublin-Belfast seaboard region. Therefore one of the greatest technical and economic challenges for renewables is nothing to do with whether we use wave, wind, onshore or offshore, but with the mundane and opaque technologies of evolving electricity grids. The building of the inter-connector between Ireland and Wales is a step in the right direction, but it is arguably only a first step in what we should be doing over the next decade: renewing and rethinking our electricity grid.

This project is due for completion in 2012 and has been estimated at costing Euro 600m. It has been funded with a significant tranche (€110m) of direct capital under the EU TEN-E project, a further €300m from the European Investment Bank, and the balance from a variety of national sources. The capacity of the inter-connector will be 500MW. As of June 2011, the Irish grid had some 1678mw of renewable electricity installed capacity, which puts the scale of this in perspective: it is roughly 30% of existing Irish renewable capacity. See: and also

Aside form this concern with grids, would the threat of greater climate change induced Atlantic storms put a stop to Irish hopes in harvesting wind and wave? There are as yet simply too many uncertainties to provide any answer to that question (see next post), but it would be prudent to assume greater frequency and severity of storms and build this into designs. Designing such robustness in from the outset is not only an engineering challenge but also possibly an area where Irish firms could find a niche in the growing and crowded offshore renewables sector globally. Moreover, existing land based electricity and energy infrastructure may have to be future proofed as well-suggesting that this question of greater resilience to extreme weather events is part of a wider and generalized challenge which our future energy infrastructure will have to be mindful of.

In fact if we want to consider the Baseload problem more seriously we should keep in mind that some studies have been made of 100% renewable energy solutions, and while such ideas might sound crazy, these studies suggest it is possible.  See for example from 2005 the ECOfys report at:

These studies typically point out that the best way to achieve this ambitious goal is through much greater energy efficiency and energy saving and conservation, but that by the middle of this century, the technology should be available to allow some countries, especially maybe small countries like Ireland, to move towards energy mixes which are predominantly or exclusively from renewables

Probably the most systematic study was undertaken in Denmark in 2008* as part of a National Climate Change Commission report which examined the feasibility and desirability of a 100 per cent renewable energy policy for Denmark, with perhaps wind energy contributing as much as 80 per cent of total electricity capacity by 2050. An explicit part of the study was a detailed day by day, week by week modeling of how much greater use of wind power specifically would impact on the Danish grid. The conclusion was broadly positive as regards the technical feasibility and reliability. Moreover the cost implications overall were suggested to be rather manageable. The study did note that the transport sector, which is massively reliant on oil and for which a switch to electricity is probably not unproblematic, would however face problems. One could also note that because Denmark has an extensive system of community combined heat and power plants, the scope for energy efficiency, savings and energy storage are much greater than in Ireland where such systems are a rarity. Crucial also is the assumption that as much as 30 per cent of electricity demand in Denmark could be met from nearby states to whom they are connected.

The bottom line is that the base-load bogeyman is just that-a scare story that lacks technical validity. Existing renewables can be fed into a grid like Ireland’s or the UK’s up to a level of 10-20% of electricity capacity.  It may even be higher than this level of integration without the need for any major changes. 

Bart Ummels who did doctoral research at the Technical University of Delft argues that:

There are however limits to the integration of wind power. This is, for example, because coal-fired power plants cannot be turned off just like that. Therefore, if there is a lot of wind and little demand, there will be a surplus of wind power. Instead of the often posed question ‘What to do when the wind does not blow?’, the question ‘What to do with all the electricity if it is very windy at night?’ is much more relevant. An important solution for this lies in the international trade of electricity, because foreign countries can often use this surplus…..The integration of wind energy in the Dutch system would provide a reduction of the operating cost of the system as a whole of euro 1.5 billion a year. This is because the wind is free, while coal and natural gas are not. By using less coal and natural gas, also the emission of CO2 decreases by 19 million tons a year. This research also shows that with the amounts of wind energy investigated here, no facilities for energy storage have to be developed” (See:

Putting all this together, one can say that the base-load argument is not a good argument to prevent Ireland investing in a much greater share of renewables from wind. Moreover, the pessimism of the Irish ESRI report towards non-terristial wind renewables must stand in stark contrast with a recent (2011) authoritative and optimistic report on the scope for renewables to meet future energy needs (Lewis, et al, 2011)** under the auspices of the UN Intergovernmental Panel on Climate Change (IPCC).

This suggests offshore wind in particular is already a competitive energy source today.

What are we waiting for?

*Halsnæs, Kirsten and Kenneth Karlson (2011) ‘The Cost of Renewable Energy Past and Future’, pp. 270-284 in Galarraga, Ibon, Mikel Gonzalez-Eguino and Anil Markandya (eds.) Handbook of Sustainable Energy. Edward Elgar.

** See Moomaw, W., F. Yamba, M. Kamimoto, L. Maurice, J. Nyboer, K. Urama, T. Weir. (2011) “Introduction”. Chapter 1 in O. Edenhofer, R. Pichs‐Madruga, Y. Sokona, K. Seyboth, P. Matschoss, S. Kadner, T. Zwickel, P. Eickemeier, G. Hansen, S. Schlömer, C. von Stechow (eds). IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation. Cambridge University Press, Cambridge, United Kingdom and New York, NY, US. Available at:


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s