Renew On Line (UK) 160

Extracts from NATTA's journal
Renew, issue160 March-April2006

1. Intermittency

On 18th Jan, in a House of Lords debate, Lord Tebbit weighed in against wind power: surely, he said, ‘common sense tells us that, in those periods of cold weather when there is no wind, these generators deliver absolutely no power? Does that not make them rather like an umbrella that will open only when it is not raining?’

Clearly the issue has come to the fore.

The January issue of the trade journal Windpower Monthly saw it somewhat differently: ‘Nuclear’s claimed upside as a provider of “firm power” compared with wind is nonsense. Power generation plant of the so-called firm power variety have a habit of tripping off-line about once a month. Anything up to 1300 MW of nuclear capacity can disappear instantaneously- and does. The UK transmission link to the French nuclear fleet is out of action every fourth week or so. The chance of an entire fleet of wind turbines stopping in its tracks is negligible. When the wind dies or increases, it does so gradually- and the system operator has advance warning. The reserves scheduled for a (sudden) nuclear trip only need to be increased slightly to cover for wind- and barely at all until wind is supplying a significant proportion of a system’s needs.’ 

And the EERU Conference on ‘Coping with Variability’ at the OU in January came to basically the same conclusion- see the Reviews section of Renew 160. By contrast, at a conference which ran in parallel at the Institution of Civil Engineers in London, Hugh Sharman, who has been studying the Danish & German systems, concluded that, due to its variability, Britain can only cope with up to 10 GW of wind capacity. 

Hopefully the issue will be resolved by the review of the intermittency debate being carried out for the UK Energy Research Centre by the Technology and Policy Assessment group at Imperial College. It had been hoped that this would have been completed in time for a report on it at the OU Conference, but there have been delays. However Prof. Dennis Anderson from Imperial/TPA did present a paper of his own at the OU event, which concluded that most studies were in reasonable agreement about (a) capacity credit (≈ 19- 23 %) (b) reserve requirements (≈ 18-21 %), and hence: (c) costs of intermittency (≈ 0.5 to 0.7 p/kWh).

For the OU  conference webcast, see under ‘past events’ at: http://stadium.open.ac.uk

The Power Point slides are under ‘ Conferences’  at http://eeru.open.ac.uk