Friday, February 09, 2007

Talking Heads

I really question the value of our 'news' these days.

Hot on the heel of my last blog on the plastics recycling, here I sit with BBC Breakfast on, and up pops a presenter to tell us that the UK has hit a major milestone in alternative energy production - the establishment of a wind farm that 'produces 2GW.

And then we cut to the sole interviewee, the MD of something to do with wind ra-ra.

Apparently this is awesome, because it's enough to supply 2M people, or half of Scotland.

The line of questioning then dives off to shredding seagulls via a brief mention of too slow/too fast efficiencies, which are put to bed by the claim that they run at 70-80% of the time. At 2GW? Actually what is that figure? Per what?

I should be over the moon, but such is my level of trust in all parties, the government, the industry and the media that deals wit them, I am merely overcome with a deep unease that I am being fed a line.

It would have been so much better to have had at least some expert, independent (though where one finds anyone who is not in the pay of an agenda group is anyone's guess) balance to put these figures in context.

My letter:

The Power of Wind

This milestone is encouraging news. Is it possible to have more context on the figures quoted in layperson's terms?

What actual delivery does 2GW apply to? Is it an average? Over what period?

Times: Green light for energy station

In this day and age, I am intrigued by the way eco-initiatives are shared.
Hence, may we be told what '...the POTENTIAL to produce UP TO
200MW of electricity' translates to in reality?

If you are investing £280M surely one should know to a fair degree of
accuracy what WILL be produced?

If it means that half of Scotland gets supplied with wind energy 70-80% of the time that's fantastic.

Is this really the case?

Forbes - Green is the new black

BBC - UK wind power reaches milestone
Times - Wind farm ‘marks step towards cleaner energy’

9 comments:

Anonymous said...

Peter,

You are right to question the value of figures provided for wind farms – there seems to be a tendency for maximum outputs to become the actual outputs in many cases (as many of those who have purchased the mini turbine from B&Q will attest), so allow me to attempt to shed a little light on the wind farm figures you have queried this morning. However, I guess you will need to locate a real expert, which I definitively am not, to verify all of this.

This particular wind farm has 36 off 2MW (MegaWatt) turbines installed (which I’ll check up on because I’m sure I read sometime in the past that it would have enough turbines to have 100 MW capacity) which gives it a theoretical maximum rated capacity of 72MW per annum.

The 2GW (GigaWatt) figure mentioned has nothing to do with the output of this specific wind farm – all that has occurred is that this additional 72 MW coming on stream means that the UK as a whole now has a total theoretical maximum capacity of 2 GW per annum from all grid connected wind power sources.

However, glossing over which figure belongs to which is always a clever means of delivering obfuscation, and as you always so pertinently observe, a common media trick.

OK, now the bad news – most wind farms generally run at a capacity factor of around 30% (often there is only a slight wind, sometimes none at all). This means that the average actual power output of this particular new wind farm is going to be ~21.6 MW (i.e. 30% of 72MW) – this is enough to power ~45,000 homes (with an average consumption of ~4.7 KW (KiloWatts) per annum).

[ 216,000,000 / 4700 = 45,957 ]

Some wind farms run at nearly a 40% capacity factor, others at just over 20%).

On this basis (and by my admittedly always questionable calculations), to power 2 million homes would require ~9,400 MW (9.4GW), so I think that there is definitely something amiss with the figures as reported.

[ 2,000,000 x 4,700 = 9,400,000,000 KW (9.4GW) ]

The BWEA’s website is a very useful source of what seems to be genuine data – see http://www.bwea.com/ukwed/construction.asp

Anybody out there care to verify these numbers, or correct me if I've got things totally mixed up and incorrect?

Dave.

Anonymous said...

Dave,

It's correct that the 2 GW figure is the UK installed (maximum) power of windfarms to date, and that multiplying by a capacity factor is needed. For the 72 MW wind farm, 21.6 MW is therefore a good estimate of average power.

I think the argument then became unravelled because of a confusion between kW (power) and kWh (energy). If we use a figure of 4700 kWh of electricity per year in the home, then its average power is 4700/(365x24), or 0.54 kW. This means that 21.6 MW (21600 kW) of power would supply 21600/0.54 = 40 000 homes.

To power two million of these homes would require 2000 000 x 0.54kW = 1080 000 kW = 1080 MW = 1.08 GW. This would be beyond the capability of the UK's installed wind turbines (2 GW x 0.3 = 0.6 GW).

Sometimes a figure of 3 300 kWh per year is quoted as a UK average electricity use in the home. It would need 0.75 GW of power to supply 2 million of these homes.

My home uses 1 800 kWh per year, so 2 million of those would need 0.41 GW, emphasising the importance of energy saving in the home.

Its worth remembering that a capacity factor needs to be applied to the output of all power stations to take into account breakdowns and maintenance. A particular issue with wind is its intermittency, though this is not as big a problem as is sometimes imagined. See URL for peer-reviewed academic analysis: http://www.ukerc.ac.uk/content/view/258/852

A simple way of thinking about intermittency is that it's less likely that the wind has stopped blowing everywhere in the UK than the wind has stopped blowing in one wind farm. Also, it tends to be windier in the winter, when the demand for electricity is higher.

I certainly think that you and Peter have been asking the right questions, and hope that this posting is helpful.

Lawrence

Emma said...

Lawrence,

I have little to add other than to say that this is just the kind of factual, informed posting that I would like to encourage on this blog, and hence is more than helpful! By sincere asking, we get sincere answers. And the knowledge base advances.

I plan, when I have time (!) to move such highly useful feedback to an ongoing archive under the main site's categories, which will hopefully add variety and ever-increasing information (and, in the case of debate, some balance) on the various issues 'we' are called to base our consumer decisions upon.

For instance, I am looking at a bit of bumpf from Scottish & Southern that claims they are the largest user of alternative energy. Now... are they (I have to assume yes or they'll have the others, and the ASA, on their tails PDQ)? But even if they are, does this deliver the best enviROI (benefit to my kids future on ther planet)?

Another half-started (as oppossed to half-ar*ed) article on this is in the offing, but a journey worth making and inviting others along on for the sharing!

Your input on intermittency is something I had not appreciated as well as I should.

In fact one thing I had been told of, perhaps less than accurately, was that when the wind drops more conventional (ie: carbon based) systems have to fire up to take up the slack, and that can be very inefficient by every measure.

So creating a redistribution system that can accomodate drop-outs is encouraging, but lurking in my mind is a concern on the losses involved in transmission as things get shunted around over longer distances.

As Ken Livingstone was advocating at the Guardian Climate Change Summit (I wish I could easily insert hyperlinked URLs here), the best way seems to be lots of localised generation points, delivering only to a restricted surrounding area.

Not too likely, though, by my reading of things. And obviously a logistical issue on the redistribution issues.

Well done on your frugal home consumption. For all my involvement, and many toys to measure such things, I have no clue what ours is. I must find out.. if I dare.

Anonymous said...

Peter,

Firstly, thank you for your kind remarks.

Scottish and Southern do supply a lot of renewable electricity, but they don't do much to increase the generation of new renewables. They have lots of large hydroelectric plants, which in some cases they have de-rated so that they get extra income from the Renewables Obligation. (The RO is a subject in its own right.....)

For an interesting post on intermittency, see post 112 on BBC's Newsnight blog http://www.bbc.co.uk/blogs/newsnight/2006/12/i_am_not_a_transsexual_i_just_want_to_talk_green_e_1.html
It appears to be informative and links to sources that you can check. Post 114 reminds us that average loss of power in transmission lines in the UK is 6.5% (again refers to a source that can be checked).

The benefits of local generation I think are more to do with exploiting combined heat and power, so that 'waste' heat from the power station is used to heat buildings. Decreasing transmission losses is useful, but a relatively small part of the picture.

As far as monitoring home electricity consumption, I just use the meter and make readings on the same dates several times a year, so that I can measure consumption over a whole year. I tried a remote meter (the Electrisave, which lets you see the effect of switching things on and off on power consumption). These can be an education: e.g. I lent it to a friend and we found that his stray cat operated security light was using 300 W (more than all the rest of the lamps in the house put together).

Good luck, and remember that if your use of electricity is very high, then it will be relatively easy to bring it down!

Lawrence

Emma said...

More than useful, thanks, Lawrence. The Newsnight blog can be a pretty rich seam, I find!

The problem is archiving for easy retrieval, which I am hoping to do on Junkk.com.

I have an Electrisave, but have still to create a worthwhile 'control' to adequately use it to measure some individual items I have for testing accurately. I really need a lone supply without all sorts of things clicking on and off affecting it it.

One review scheduled (when is another matter) is one on on-unit plug meters.

stewgreen said...

- Yes I was listening a "science reporter" on the radio talk about the huge huge London array ..then he ended by saying it's 1000 MW

- and I'm like .."uh, but 1000MW isn't huge it's not even the size of a normal power plant ?"

- Don't these media types have any grasp of real world maths ? Once again a Climate story has grown huge huge legs.

- Then it's even worse when you realise that you can't just rack of the peak power of wind as it has a optimistic load factor of 30% as against 80-90% for conventional.
That makes it an average of 300MW

- So anyone saying that it's huge is lying or naive.

- Seems to me there is a huge influence of "let me sell you a solution" in the debate. People get convinced, that all they need to do is to SHOP to change something - They'll be a magic green solution and everything will be OK.

- And of course these salemen's figures are hopelessly over optimistic and spun like : quoting the number of houses as if there were no use in industry or losses. (UK use averages 46GW consumption so 1GW wind means 0.3GW usable = 0.65%). But for the media questioning "pseudo-green" buzz is like criticising Communism when you were a Pravda reporter.

- My own maths shows wind is pretty much a scam
- it won't break even unless energy prices rocket.
- And blase claims like "of course it's carbon neutral as regards construction after 4 months", don't seem to stand up as that seems to say only about 2.5% of construction cost was spent on energy.

- I have an idea to open a website where people can buy a green solutions from me. They can pay me money and I will tell them to wear jumpers, use birth control and go to bed when it's dark etc.

- BBC Radio 4 Costing The earth has an archived programme quite negative about wind. At times it overstates, but also misses out on other negatives.

stewgreen said...

- Yes I was listening a "science reporter" on the radio talk about the huge huge London array ..then he ended by saying it's 1000 MW

- and I'm like .."uh, but 1000MW isn't huge it's not even the size of a normal power plant ?"

- Don't these media types have any grasp of real world maths ? Once again a Climate story has grown huge huge legs.

- Then it's even worse when you realise that you can't just rack of the peak power of wind as it has a optimistic load factor of 30% as against 80-90% for conventional.
That makes it an average of 300MW

- So anyone saying that it's huge is lying or naive.

- Seems to me there is a huge influence of "let me sell you a solution" in the debate. People get convinced, that all they need to do is to SHOP to change something - They'll be a magic green solution and everything will be OK.

- And of course these salemen's figures are hopelessly over optimistic and spun like : quoting the number of houses as if there were no use in industry or losses. (UK use averages 46GW consumption so 1GW wind means 0.3GW usable = 0.65%). But for the media questioning "pseudo-green" buzz is like criticising Communism when you were a Pravda reporter.

- My own maths shows wind is pretty much a scam
- it won't break even unless energy prices rocket.
- And blase claims like "of course it's carbon neutral as regards construction after 4 months", don't seem to stand up as that seems to say only about 2.5% of construction cost was spent on energy.

- I have an idea to open a website where people can buy a green solutions from me. They can pay me money and I will tell them to wear jumpers, use birth control and go to bed when it's dark etc.

- BBC Radio 4 Costing The earth has an archived programme quite negative about wind. At times it overstates, but also misses out on other negatives.

- BWEA site says 1.4GW wind, supplies 0.7m homes (0.45GW effective) 24m UK homes So they are saying the 1% of UK power that wind produces supplies 3% of homes

Emma said...

Stew, welcome!

This issue has only gathered pace, and what I have learned since has done little to put my mind at ease on the actual facts behind the deliverables and their enviROI over their lifespans.

It just seems incredible that we cannot be given much more accurate information by all involved. I guess it's understandable that those with an interest in making money would try and spin things positively, but there still seems to be a whole wave (excuse the mixed alt. eng. allusion) of unquestioning support from authority, activist and media quarters no matter what.

I really want such free (well, after the payback period, whatever that may be) clean (well, assuming it a) is and b) doesn't spend a ton more than could be directed better elsewhere) energy to power all my needs (if it can, and without needing dirty, inefficient - predicting demand is a key factor I'm told -back-ups to make it seem that it is doing its job).

But as you suggest, there are now some questions at least being asked, though sadly not too many where it counts, in the corridors of power. Last I heard the UK is going to be ringed by the things, which will 'solve' carbon emissions at a stroke. Pop WIND or CATEGORY - ALT. ENERGY in the search Do-dad on blogger and you should see a bunch more subsequent posts that may help... or you can help with.

I'm not the greatest fan of the BBC's science coverage, and I do worry that if there is something as 'Costing the Earth' the pendulum can often swing too far the other way. Ratings can lead to the search for extremes. The true value to us all is balance and objectivity and accuracy... at least where possible. Which is why I tend to now be a little weary of how the MMGW debate keeps chugging away in such a predicable manner. But if there are sensible questions being asked there, maybe they will make it through to the more mass appeal programmes, and not just with a talking head who either knows nothing or from a single source 'expert' who may have an agenda.

I have been communicating with a more techie blog on this issue of late, and had a few useful exchanges which I will share here soon.

stewgreen said...

- Thanks, whether one is left wing or right wing one needs real facts and real numbers to make good decisions.

- I feel like I did when Princess Diana died, the media are banging on and on, they're all one one track and they say everyone else is. They come up with so many pseudo-facts. Yet when I go on the internet I find there are many places like the Newsnight blog discussion where normal turnip head like me ARE DOING THE MATHS .. and saying whooa hang on a moment. (Sometimes we are wrong, but at least we are tackling them)

- Climate catastrophe stories keep arising which I feel obliged to pick apart cos they are sometimes such howlers. Yet when it comes to actions I would be even more extreme than Monbiot as I believe every time you consume something the enviroment is harmed without even thinking about CO2.
- The people who bark the loudest seem to the ones who take the least effective actions like buying even more stuff to make themselves green.
- Keep it simple just like the message from Walden 150 years ago.

- I suppose that media is after all now Infotainment spoon fed by people who want free advertising for their product/agenda not a free source of reliable education.