11 FEBRUARY 2004

Dr Brenda Boardman and Mr Graham Sinden

  Q140  Baroness Platt of Writtle: There are one or two times in your wind data for hours in January.

  Mr Sinden: There will be times when you have quite low speeds and consequently you have low electricity output from it. The analysis that I ran was of wind speeds being so low that electricity would not be generated, that was the criteria for it. As I said, the single worse case in the last 21 years was 11 hours over summer when that did happen. If you raise the bar higher and say "We want 20 per cent output or 30 per cent output" then it may look a little bit different but we have not carried out that analysis.

  Q141  Lord Sutherland of Houndwood: Did you test the model on the basis of suppose you were in charge of the switching mechanism somewhere, there might come a dip that would affect the National Grid in some way because clearly collusion of circumstances could produce that? Is there any prospect that you could test the model?

  Mr Sinden: We have looked at this area in the load-following capacity of the grid. If you look at what happens with fluctuation and hourly demand, you have the maximum amount of changes around 7,500 megawatts and with ten per cent of your electricity supply coming from a mix of wind, solar and dCHP you see the maximum hourly change that the rest of the grid will have to accommodate rising from around 7,500 to around 8,500 megawatts. It is not a very large change at all. In fact, the average hourly change that the grid experienced over the years is virtually unchanged.

  Q142  Lord Wade of Chorlton: For the purposes of your submission you assume that ten per cent of electricity demand would be met from renewable sources, which equates roughly to the Government's target for 2010. Would you arrive at similar conclusions if you looked at a 20 per cent target over a 20 year period, which is also commented on by the Government?

  Mr Sinden: The same results apply to 20 per cent of electricity coming from intermittent sources as well, the same concepts of distribution of diversity across the country and diversity of technologies. With 20 per cent of electricity coming from intermittent sources you do require more standby but the benefits of distributing your generating capacity and the smoothing that this provides you in the electricity supply from your intermittent sources still holds at the 20 per cent level as it does on the 10 per cent level, so you still gain a benefit by doing it this way.

  Q143  Lord Wade of Chorlton: What worries me, which goes back to the question that the Chairman asked at the very beginning about where you assume the wind farms will be, and from your answers to both this question and the previous question it does make an enormous difference. The tendency and pressure from other sectors of the industry seem to be to create very large offshore wind farms where there would be a great concentration of turbines in small areas because the tendency is that people do not want them dotted one in every field throughout the country. How do you reconcile those two issues? You seem to be saying that in order for your system to work there has to be a lot of turbines all over the place.

  Mr Sinden: I do not see a problem with having large concentrations of turbines creating one wind farm in a specific area. What is important is that there are a number of wind farms that are quite distant from one another, so you would not want all of your generating capacity in the Wash. It is quite fine to have one large or two large wind farms there so long as they are not being built in isolation, that there are large wind farms being developed in the Thames Estuary or in Northern Scotland. It is covering the geographic area of the UK and exposing turbines to different wind regimes at the same time that is the important factor. It does not mean that you have to put little wind farms all around, it is that you have a good representative coverage of different wind speeds around the UK.

  Q144  Lord Wade of Chorlton: What you are suggesting tells me that if we want a successful outcome of the use of wind farms and the uses of different forms of electricity generation as well to cope with the 10 or 20 per cent output, there would need to be some strategic plan that said from the very beginning, "This is where the wind farms have got to be and these are the sorts of sizes and this is how they have got to be linked". There is no indication that is happening at the present time. How would that strategic plan be evolved? How would you fix it and say, "This is the way it has got to be and if we do not do it that way it will not work"?

  Mr Sinden: There are a number of approaches that we could use to this. With the work that we have done at the moment we can take a number of sites and suggest which would be the best sites to develop that in combination would provide you with the most reliable supply. If Government or a developer comes along and says, "We want to build something in Northern Scotland, here is a range of sites", we could look at the wind data from these different sites and say, "This is the preferred site in terms of minimising the intermittency that you will experience across the system". With an evolving system like that, each time there is a new option to build more wind power, or the Government may want to emphasise solar electric power or invest money into domestic combined heat and power, we can suggest what level of generating capacity is appropriate for that technology or how much capacity should go into a particular location.

  Q145  Chairman: I think Lord Wade is actually making a slightly different point and saying that there could be quite a conflict of interest in a sense between the private investor who wants to put his wind farm where there is the most wind and perhaps the national interest where we would like wind farms to be distributed in such a way as to minimise intermittency.

  Dr Boardman: We would agree with that. There is this possible tension.

  Chairman: That is all we want to know.

  Q146  Lord Wade of Chorlton: The next question is, who does it?

  Dr Boardman: What we are saying is if you want to have the lowest cost over the whole system you do have to have a strategic approach, you do have to have this diversity in geographical terms, you do have to have this diversity in terms of technology. You can plan that to different degrees and the more you have a best fit, the lower the cost of having back-up, the lower the cost of the fuel that goes into that back-up and the lower the cost of switching on and off that back-up. There are three ways in which you can reduce cost for the benefit of the whole system if what you do is you take this strategic approach, yes.

  Q147  Baroness Sharp of Guildford: Can I pick up on diversity of technologies because, as I understand it, one of the key issues here is not just to have wind power but you have written into your modelling solar power and domestic CHP.

  Mr Sinden: That is correct.

  Baroness Sharp of Guildford: You have not mentioned either biomass generation or tidal power, but I take it that is partly because, as you said at the beginning, you have taken London as your base. Can you tell us a little bit more about how you modelled the solar power and domestic CHP into this? What assumptions have you made about that? If you were looking at other areas, tidal power and biomass, how would you see those feeding into the system?

  Q148  Chairman: If I could add a supplementary to that. It would be nice to know what acreage of solar panels you envisage.

  Mr Sinden: To address the first question, the modelling of solar, the Met Office records hourly radiation levels in about 25 locations around the UK. London is one of them and it has a very good record. We used that and, knowing the performance relationship between solar panels and solar radiation, we were able to infer how much electricity would come from solar panels if they had been exposed to this radiation. From that we could build an historic profile of what the electricity output would look like. For domestic combined heat and power it is a little bit different. We have a profile of what the electricity output would look like from a large number of dCHP units all operating within the same geographic area and we scaled that output based upon what the temperature is, in this case in London, so on cold days we see more output from it and on warm days we do not. That is how we approached both of those. We did not include biomass because we do not see it as an intermittent supplier, certainly renewable but not intermittent, and we were really trying to target the whole intermittency issue. Tidal we did not include at the time but it is a very interesting one. We have done some very preliminary work on it since which is not yet included in the model. It shows similar properties to wind power in that if you diversify the tidal systems around the country you have high tides occurring at different times, therefore you have different tidal stream currents occurring at different times. This initial work suggests that the lowest output that you would see from a diversified tidal system is about 50 per cent of its maximum output. You would probably see output from tidal divided into a base load supply and then a predictable intermittent supply on top of that.

  Dr Boardman: Can I just supplement that? What Graham has modelled in terms of the quantity of dCHP and solar is that about 1.4 million homes in the London area have one of them, so that gives you an idea of how much quantity we have looked at.

  Q149  Chairman: You were going to tell us what area of solar panels we would need?

  Mr Sinden: The area I cannot give you off the top of my head. For what we modelled, to supply ten per cent from wind solar and dCHP you would be looking at around 800,000 roofs in London with four kilowatt peak solar panels on their roofs.

  Q150  Lord Winston: Eight hundred thousand roofs?

  Mr Sinden: That is right.

  Q151  Chairman: At four kilowatts?

  Mr Sinden: At four kilowatt peak.

  Q152  Chairman: You cannot tell us what area that would be?

  Mr Sinden: That is around 30 square metres to produce a four kilowatt peak.

  Q153  Baroness Sharp of Guildford: A standard size panel that you can buy now?

  Mr Sinden: I think a standard size panel is about a square metre.

  Q154  Chairman: These vary. You can get photovoltaic roof tiles.

  Mr Sinden: Of course, the area that you need depends on the efficiency of the panels that you buy.

  Q155  Chairman: You have made assumptions about efficiency but have you looked into the cost-effectiveness of doing this?

  Mr Sinden: No, not really. Brenda, did you want to say more on the cost?

  Dr Boardman: I have already mentioned that you can reduce the cost through careful planning, that is the single most important point. We cannot go into a lot of the detail about it, we are not economists and we have not done that. If what you are comparing is an unplanned system with the same quantity as the same system but planned through its location then you will reduce your cost if it is planned, if there is a strategy. That was the only way in which we could really cover costs.

  Q156  Chairman: At present photovoltaic methods of generating electricity are very expensive in comparison with others.

  Dr Boardman: Yes.

  Q157  Chairman: So this match, although it might be made in heaven, is not quite there yet as an economic proposition?

  Dr Boardman: I think what we would say about that is that we are adding intermittent supplies, we are adding renewables, into a system which is designed for centralised, large scale, conventional fossil fuel generation capacity. We are adding in completely new types of generating capacity, therefore the system, if it is going to adequately support them, does need to change. We are not good on regulation but we understand fully that many of the renewables are not being adequately supported. You will not have the dCHP, you will not have the PV, unless in some way the system supports them much more. It might be that you give priority to electricity from renewables, it might be that you need a feed-in tariff, we are not competent to answer those questions. I agree with you entirely, we are not confident the supply will be there with the present system.

  Q158  Baroness Platt of Writtle: Have the results of your research been communicated to the Government? Have you found the Government receptive? There was a lot of detail here which I found very interesting.

  Mr Sinden: We ran a workshop which was based around these results a little over a year ago. We did invite representatives from the DTI, House of Commons and House of Lords, but, unfortunately, the DTI was quite busy at the time with the Energy White Paper so they were not able to attend on the day but we did follow up with letters afterwards and we made information available on the net and hopefully that explained it.

  Q159  Baroness Platt of Writtle: Have you sent it to the Minister and has the Minister replied?

  Dr Boardman: We could have done more. To be fair to the Minister, we have not sent it direct.

  Baroness Sharp of Guildford: It might be a good idea.