Friday, May 22, 2009

Corrections and clarifications (Wind, Whitelee, Wales...)

Perhaps I need to stop doing media interviews...
I wrote some notes about Whitelee recently. Last weekend, the BBC asked me to record some comments in advance of the official Whitelee switch-on. My comments focussed on the scale of renewables required to really make a substantial contribution to British energy consumption. Unfortunately my comments may have been misinterpreted - partly because I wasn't actually sure what I was being asked! The interview was recorded by a nice subcontracted interviewer who had been fed the 3 questions to ask me. The first question was "are the government's targets achievable?" ... with no indication of what targets the question referred to. The child poverty targets? "No more boom and bust"?
I answered the question assuming we were discussing long term climate targets. In one take I referred to "the government target of a complete decarbonisation of our electricity supply system by 2030." This was an error, as the government hasn't adopted that target (yet); it is the Committee on Climate Change that has indicated that they think almost-complete decarbonization of electricity by 2030 is essential.
As I have discussed in this article, if the UK is to get off fossil fuels, we need to be talking about big efficiency measures, probably lots of electrification of transport and heating, and big growth of 'green' electricity sources - for example, something along the lines of windfarms with size similar to the area of Wales, and a five-fold increase in nuclear power. Each of these two sources would deliver roughly 20 kWh per day per person.
Do I think Whitelee is a figleaf? Not at all. It's awesome, and it does generate real power, on average - enough to power hundreds of thousands of electric vehicles, for example - though not quite enough to "power Glasgow".

Sunday, May 17, 2009

Wind farm power-per-unit-area data complete

I have updated my data on windfarms.
I've gone through roughly 75 farms, finding the power per unit area. You can see the results here.
The conclusion is that many Scottish wind farms, located on hilltops, have powers per unit area of about 4 W/m2. English and Welsh wind farms are in the range 2-3 W/m2 for the most part, though there are a few in England below 2 W/m2.
Incidentally, while looking at the windfarms, I had a think about the Braes of Doune photo above, which shows a windfarm ruining the view of Stirling castle. The distance from Stirling Castle to the wind farm is actually about 15km. The photograph subtends an angle of about 3 degrees. It is the sort of view you get through a 670-mm zoom lens.
The two summary figures from my wind farm survey are shown below. The top one shows power per unit area versus turbine diameter; the lower one shows it versus wind farm size. The point style indicates the type of windfarm location.

Thanks to Oswald Consultancy and the Renewable Energy Foundation for collating most of the power generation data and turbine specifications. All the original data can be found at OFGEM. Thanks to Ordnance Survey for their getamap service.

Saturday, May 16, 2009

"Better than BS 7671 : 2008 IEE Wiring Regulations 17th Edition!"

Friends have been asking "how is the book selling?" - I'm happy to report that Sustainable Energy - without the hot air has been doing quite well. On, its sales rank among all books has been wandering around the 100 mark for some time now. And in the list of the most popular Science and Nature books, it's at number 4, ahead of Dawkins' God Delusion, and (a great personal triumph, this) ahead of the IEE's renowned "On-site Guide; BS 7671 : 2008 IEE Wiring Regulations 17th Edition".

I made a graph showing how the sales rank of SEWTHA has evolved on and on The light vertical lines mark events, with the most significant ones being the Economist's review, the Cory Doctorow review, and the coverage by the Guardian, which took the sales rank to 47.

The latest piece of good news is that I've been elected a Fellow of the Royal Society. The Society's press release mentions me and the book, which is very nice of them!

Oh no! Green electricity spat!

As I mentioned in another post, I switched from electricity-generator, Powergen, to "Good Energy", out of irritation at Powergen's perpetual greenwash.
Now I've learned from The Guardian that Good Energy may have been duping me with greenwash too!
One of the minor advantages of Good Energy over the competition was that they claimed to actually retire some ROCs (renewable obligation certificates), which has a genuine "additional" effect, as it increases (slightly) the financial incentive to people putting up renewable generation facilities.
However, according to the Guardian, Good Energy have not been retiring as many ROCs as their blurb led customers like me to believe. Oh dear.
Their blurb said things like:
"Good Energy goes above and beyond the percentage required by the government (8.9 per cent in 2008), by retiring an extra five per cent of ROCs (ie, 13.9 per cent in 2008)."
but in fact, they've been retiring only about two per cent.
It's an awkward consequence of the slightly goofy Renewables Obligation system.
To get your subsidy for generating wind power, you have to cash in the certificates. (The certificates are then bought by brown companies like Powergen that are not generating enough renewables, to get them off the hook.) If you retire the certificates instead then you don't get any subsidy. So it's really hard to do anything "additional". People trying to do Good get no subsidy.
If Britain had a feed-in tariff instead, like Germany, I think this Catch-22 would be removed. Everyone who generated extra renewable electricity would be rewarded for doing so, and no-one else would be let off any hook thanks to their generation.
It's sad that Good Energy and Ecotricity are having this spat with each other. I was at a round table meeting in London, organized by the Ecologist magazine, attended by both the CEOs of both companies, and there, everyone seemed to be on the same side.
I think, going by the news article, that Good Energy have been naughty. And as a customer I feel a bit disappointed. My advice to Good Energy would be "stop trying to make out, through funny accounting, that you have been retiring 5%. Just give up on the retiring idea".

Whitelee powers Glasgow again

Whitelee wind farm, the biggest wind farm in Europe, is to be completed and 'switched on' this week. And
the news says that the power company is applying to extend the wind farm to increase its capacity from 322 MW to 614 MW.
I mentioned the predicted output of Whitelee in my book (page 33). Since the predictions for Whitelee were one of the sources for my estimated wind-farm-power-per-unit-area of 2 watts per square metre, I thought it was a good idea to look at Whitelee's updated numbers.
When I was writing my book in October 2006, Whitelee's predicted output was said to be "enough to power Glasgow" (Independent, Oct 10, 2006). And now, the latest news says
that, with the proposed increase in capacity from 322 MW to 614 MW, the farm will... generate enough power for [all the homes in] Glasgow
Curious, Alice might say. We run, and we stay in the same place?
Here are the new numbers.
With two extensions, the total number of turbines would be 221, the capacity would be 614 MW, and the predicted total output is "340,000 households", which in sensible units is 184 MW (assuming that "a household" is defined to be 0.54 kW). This implies a load factor of 30%. The area of the site (according to the Sunday Herald) will increase to 75 km2. So the average power per unit area of the enlarged wind farm is predicted to be 2.45 W/m2.
What is the honest relationship of Whitelee to Glasgow? (I think talking about 'households' is a bit misleading.) The predicted output of Whitelee, shared between the 616,000 people of Glasgow, would deliver 7 kWh per day per person on average. That's roughly 40% of the total electricity consumption of Glasgow, and roughly 6% of the total power consumption of Glasgow (that's 'total power' including transport, heating, etc; not just electricity).

Implications for the scale of wind farms required for a substantial contribution to British power consumption

If we assume Whitelee (including its planned extension) is representative of future big wind farms that could be built in Britain, here are some more numbers.
  • The government's 2020 target is for "33 GW" of wind capacity. That would require 54 more Whitelees. The area of those wind farms would be about 4000 km2, about 20% of the area of Wales. The power delivered by those wind farms would be about 4 kWh per day per person, which is roughly 4% of the UK total power consumption today. (That's 'total power' including transport, heating, etc; not just electricity).
  • If we wanted to get 20 kWh per day per person from wind power, we'd need 270 Whitelees, which would take up an area of 20,000 km2. That's roughly the area of Wales, or 8% of the area of the UK.

If we want to get off fossil fuels using renewables, we must expect those renewable facilities to be somewhat intrusive.

End notes (in anticipation of the responses people often make)

  1. Yes, the wind-farm land in between the wind turbines can also be used for agriculture or other activities.
  2. Yes, the output of wind farms fluctuates, so if we build wind farms we will have to do some other smart stuff, as discussed in chapter 26 of my book. For example, ensure that lots of smart [easily switch-off-and-on-able] demand is added to the grid, for example, charging electric vehicles and running heat pumps to make hot air and hot water.

Friday, May 8, 2009

Hot Air Oscars nomination: GO-GREEN

We are happy to nominate for the "best GREEN advertising" Hot Air Oscar, the "Eco-Smart" organization in America who advertise "877-47-Go-GREEN" on the side of their tastefully green HUMMER.

Is David MacKay "trying to make wind sound useless"? Let's look at more data

I'm delighted to see that the response to Sustainable Energy - without the hot air so far has been remarkably positive. There's just one or two folks who have become convinced that I am anti-wind, that I am deceitfully making wind sound worse than it really is; and they have been running round leaving comments on blogs (for example, you can find one lurking in the comments on this excellent article about the financial cost of wind power (the oil drum), who asserts "MacKay has made a serious error in his calculations of on-shore wind energy resources. ... Some of the wind farms initially built were in poorer locations but close to electric transmission lines, so his calculations are not good examples of what is possible in UK.")
I've written three blog posts about this topic already, encouraging people to provide real data rather than just spreading poisonous rumours. I've now worked through the ordnance survey maps and ROC register entries for about 15 windfarms around the UK, and included the data and maps in a presentation I made at a wind energy conference in St Andrews this week. I am still working on this; what I have focussed on so far is mainly the newest windfarms for which data is available, with the largest numbers of turbines, with biggest diameters, and mainly on scottish hilltops or welsh hilltops or near to the coast. The new data starts at slide 30 and is summarised on slide 41. These onshore wind farms have powers per unit area between 2 and 4.6 watts per square metre. To indicate the rough scale of windfarms required to deliver large amounts of power, I assumed in the book a power per unit area of 2 watts per square metre. So yes, there are windfarms that have powers bigger than 2 watts per square metre. Was I deliberately "making wind power seem worse than it is"? No. I chose 2 watts per sq metre as an estimate of what we could get if we put up lots of wind farms (with the area of Wales), which is obviously going to be less than the power per unit area of the very best spots. Yes, I willingly agree that if we want wind to make only a small contribution (for example, less than 1 kWh per day per person), then it would be appropriate to assume a higher power per unit area - perhaps 3 or 3.5 W/m2 instead of 2 W/m2, if we keep building in the best spots.

As evidence that I am not deliberately biased against wind, take a look at the data for offshore wind farms.

In my book I assumed a power per unit area of roughly 3 watts per square metre for offshore wind. But the two offshore windfarms in my data have powers per unit area below 2.5 watts per square metre.
There are several other scientists who have used a power per unit area similar to mine when estimating wind resources. For example, Socolow from Princeton uses 2 watts per square metre when discussing his "wedges". On page 234 of my book I cite a study by Elliott et al. (1991) in which windfarms in the best locations in America, covering an area equal to that of California, were estimated to have an average power density of 1.2 W/m2.
While my book is technology-neutral, the truth is that personally I am pro-wind! I think wind farms are brilliant, and I'd be very happy be within eye-shot of one almost anywhere in the ordinary countryside.
Please could the commentors call off the dogs?
Thanks! David

More or Less - the Director's Cut

I was on "More or Less"a couple of weeks ago, and wrote an article for the BBC. One topic mentioned was how much good it does to unplug phone-chargers when they are not in use.

On today's programme (8 May 2009) they are going to read out an indignant listener's letter pointing out that "if everyone unplugs their phone chargers, it adds up to a HUGE saving". More or Less asked me to write a short response, which is going out today. I'm worried that people will get the impression I am against switching anything off. So for the record, I would like to point anyone who's interested to the relevant pages of my book (p114) and Chapter 22 (p155) which should make clear that I do think that it's a good idea to find the big vampires and switch them off!
Here's what I wrote for today's More or Less, in full:
Yes, if sixty million people all make a figleaf gesture that saves half a watt (which is roughly one ten thousandth of their power consumption), then the total power saved is,
sixty million times half a watt
which is 30 megawatts, which sounds like quite a lot. It's one thirtieth of the output of a modern power station, for example. But this "if-everyone" multiplying machine is just a misleading way of making something tiny sound big:
30 megawatts is still just one ten thousandth of Britain's total power consumption.
Multiplying tiny things by sixty million to make them sound big is BAD because it distracts people from thinking about sixty million bigger things that are more deserving of our attention. [Heating sixty million buildings, and driving sixty million cars, for example.]

Sunday, May 3, 2009

Hot Air Oscars nomination: biodegradable tat from 'I love planet'

I went to Edinburgh botanic garden today. The visitors' shops of such places are often nesting places for the monsters that spawn green tat.
Here I found the "biodegradable ballpoint pen". Pick it up and look at it: apart from the reassuring "planet loving" messages screaming out from its barrel, it looks and feels like a completely normal pen. And I'd be happy to bet that all its biodegradable parts are made from fossil fuels.
Is it really 'loving the planet' if you buy this fossil-fuel-plastic pen and chuck it away, rather than buying a (ten times cheaper) normal fossil-fuel-plastic pen and chuck it away?
I nominate this pen for the Hot Air Oscars consumer feel-good tat award.

Renewable planning map for the USA

One thing I've wanted to do, after the Energy book, is to make an interactive tool that conveys the scale of renewable facilities required to make a difference, and gives the user choices, subject to the "it has to add up" constraint. Here is an NRDC Google map; it's a start - it shows "where renewables have potential" in the USA; but it's not quantitative - it just shows "lowest potential" and "highest potential" on a colour scale, for one renewable at a time. The image above shows the map of Montana for Cellulosic Bioethanol. I suspect the main uses of this map will be (1) wishful thinking [about the 'HUGE' potential of renewables] and (2) NIMBYism [using the argument 'this isn't the best place for it'].
PS - when you drill down into the meaning of the map, the colour scales are given a quantitative meaning, but it's not human friendly and it does not use comparable units. For example the colour code of the Cellulosic map is explained thus:
Each county is color-coded based on total dry tons of cellulosic biomass per year, by county. [12,000; 50,000; 100,000; etc]
If I understand right, they are showing potential per county. That is bizarre. So if there are two identical regions but one happens to be divided into 10 counties and one is a single county, the single-county region will be shown as having big potential and the ten-county region will come out two notches lower.

Friday, May 1, 2009

Hot Air Oscars nomination: Tesco again!

Philip Fowler has nominated Tesco for the "Every Little Helps" lifetime achievement award, in recognition of their services to consumer awareness through labellling toilet paper with its carbon footprint - 1 gram per sheet, giving a new meaning to the motto "Cut the Crap!"