Christopher Booker proves that wind energy is intermittent
- 15 Aug 2012, 13:35
- Robin Webster
Wind power is a variable energy source and we need to be able to
get power all the time. So how much will it cost us increase the
amount of power we get from wind in the UK, and will our energy
system be able to cope?
This week, Christopher Booker
argues that our national energy policy is "a shambles" because
it is "wholly focused" on the prospect of getting power from wind.
"At one point last week, Britain's 3,500
turbines were contributing 12 megawatts (MW) to the 38,000MW of
electricity we were using. (The Neta website, which carries
official electricity statistics, registered this as '0.0 per
Wind power varies - some days are windier than others. This is
Booker's point. Sometimes, when it isn't windy, the amount of power
produced from wind turbines can be very low.
This means, he argues, that wind power is much, much more
expensive than other electricity-generating technologies. As well
as building wind turbines, he says:
"...we would have to build dozens of
gas-fired power stations just to provide back-up for all the times
when the wind is not blowing at the right speed."
Balancing intermittent power production from power sources like
wind does require energy from a range of other sources, and that
costs money. But does it require as much expensive gas plant as
Gas turbines - open cycle and closed
At the moment, the data shows that the UK gets electricity from
two kinds of gas turbine, coal plants and nuclear plants, and a
certain amount of power that is shunted back and forth along
interconnectors to the Netherlands, France and Ireland.
As the amount of wind on the grid increases, it becomes more
challenging to back up.
In order to support his argument that gas backup will be very
expensive, Booker uses the conclusions of a report published by
climate skeptic think tank the
Global Warming Policy Foundation in March. We discussed the
work, written by Professor Gordon Hughes, last
Hughes projected costs for wind an "
order of magnitude" higher than he did for his alternative
scenario, in which gas is used to produce electricity. Why?
reason is that he doesn't include the costs of the fuel (gas)
in his gas scenario, arguing that they are not particularly
significant. Hughes also argues that wind power will have to be
backed up by less efficient gas plant known as Open Cycle Gas
Turbine (OCGT) plant, instead of the more modern and efficient
Closed Cycle Gas Turbine (CCGT) plant, because OCGT are
more flexible and responsive, and designed to start and stop
generating electricity quickly.
oral evidence to the Energy and Climate Change Committee, Rob
Gross of Imperial College disagreed with this interpretation. We
asked the National Grid, which is responsible for ensuring the grid
copes with changes to the energy system over the next few years,
whether this was a reasonable contention. It replied:
"When we call on generation for
balancing we are obliged to do this in the most cost effective way.
It would be highly unlikely to be OCGT which is relatively
expensive and small scale."
In contrast, renewables trade body
RenewableUK estimates that large-scale wind rollout would allow
CCGT to be used. This is because single windfarms' output is more
variable, so OCGT backup would be necessary. It says, however, that
once you get into using large amounts of wind across the system,
CCGT backup is possible as output is more balanced.
So unless Professor Hughes knows something that everyone else
doesn't, this probably means the GWPF report overstates the cost of
providing backup to wind power.
Imperial College, the 'intermittent' nature of wind has been
"comprehensively studied by academics, utilities and consultancies
from around the world". Imperial concludes that the cost to
households from intermittency in 2020 is likely to be around £6-£8
per year, far less than Hughes's estimate. Imperial bases its
conclusion on an assessment of
all the data it collected in 2006.
energy consultancy Poyry undertook a study in 2011 for the
government's decarbonisation advisers, the Committee on Climate
Change, which also concluded that the electricity system would be
able to accommodate high levels of renewable generation up to
Intermittency aside, Booker's worries about the UK's shambolic
energy policy's ability to deliver enough power sound more
Estimates from - among others - the National
Grid, the Committee
on Climate Change and the
energy regulator Ofgem - suggest that the UK could meet its
renewable energy and climate change targets without jeopardising
the country's reliable electricity supply - it's technically
experts have recently raised concerns about the government's
progress. UK energy policy has often been characterised by delay
and dithering - and if this continues, then Booker's worries about
the lights going out might be on more solid ground.
Energy geek out
For those of you still reading, this is a good opportunity to do a
serious energy geek-out and introduce you to a really interesting
source of energy statistics referenced in the Sunday Telegraph
website, which Booker cites, provides half-hourly information
on how much power is produced by all the different power sources in
the UK. This chart, for example, shows the amount of power
generated from wind for the past 24 hours or so:
Source: Neta website,
screenshot taken 10:12, 14/08/12. Each bar refers to one half hour
period. Yellow bars are the initial prediction for the amount of
electricity the wind will produce; green is the most recent
prediction; the red line is the actual reading.
At the time of writing, Neta says that wind power generated 28023
megawatt hours of power over the last 24 hours, or 3.4 per cent of
the UK's total output.
It looks as though it hasn't been that windy over the last day or
so. According to
official statistics from the Department for Energy and Climate
Change (DECC), wind power generated 15.75 TWh of electricity in
2011 - 4.3 per cent of the total output in the UK (see p.135).
website (screenshot taken 10:14, 14/08/12) Table
shows wind power generated 28023 megawatt hours of power over the
last 24 hours. NB. Image has been adjusted so that figures are
aligned in the table.
The Neta website also gives the raw
data for production of energy all the way back to 2008 (login
required). The data is released quarterly - last week's isn't
available yet, but we looked at the most recent data covering May
During this period, the data shows that wind power is indeed an
intermittent power source. Over the three months, the amount of
power generated by wind per half-hour varied from almost nothing up
to around 3500 megawatt-hours - producing an average of 1041.9
megawatt-hours per half hour period over the three