Several weeks ago Joshua Pearce at Clarion University in Pennsylvania released a study titled “ Thermodynamic limitations to nuclear energy deployment as a greenhouse gas mitigation technology .” In the study he stated... nuclear energy production would have to increase by 10.5% per year from 2010 to 2050 to both replace fossil-fuel-energy use and meet the future energy demands. This line, of course, made the headlines and has been picked up by several outlets and blogs . When looking into his calculations for this statement, he made one assumption error that overstated the above sentence by nearly a factor of three. Page 121, Section 4.1 of the study states: Richard Smalley pointed out that in 2004, the global economy consumed the equivalent of 220 million barrels of oil per day, which converted into electricity terms is the equivalent of 14.5 TeraWatts (TW), or 14,500,000 MegaWatts (MW) (2005). … With a nuclear plant having about 1000 MW (1 GW) of capacity, we would need 14,500...
The Wall Street Journal's Environmental Capital blog today points to a WSJ op-ed by European writer Edgar Gärtner on the link between wind and gas. He cites European experience showing that increasing deployment of wind turbines in Spain and Germany coincides with greater dependence on gas, needed to support wind generation that can drop off at any time. He suggests that this may be why gas producers are eagerly promoting wind development - it is an effective way to promote demand for natural gas and the value of natural gas holdings. Gärtner concludes:
Comments
For most countries, hydro is limited. Once we have installed wind that matches the reservoir hydro capacity, additional wind will find itself entrenching gas usage in the same way.
For countries that have new gas generation plant, I'd say that using some wind to reduce gas usage during the phase-out will be good - that infrastructure needs to show some return. But after that, 20, 30 years? It would need a miracle of CO2 reclamation technology to make it worthwhile to keep the gas+wind system.
It is not at all clear that gas use will go down, for the reasons Joffan gives.
A significant amount of highly variable wind generation capacity all but requires a similar amount of gas (not coal or nuclear) capacity to be present. Given that the gas plants will be operating ~2/3 of the time, it means that the annual gas generation (kW-hrs) will have to be almost twice the annual wind generation. Thus, for wind to provide 20%, gas would have to be almost 40%, i.e., twice the fraction we have today.
We had a discussion about this over at EnergyPulse, in the comment section for a given article. Check it out at:
http://www.energypulse.net/centers/article/article_display.cfm?a_id=1790
Jim Hopf
Why not add wind to the system? When the wind is blowing that'll reduce the need for gas or hydro and when it's not you burn as much gas as you usually do.
The key to understanding the usefullness of wind is to see it as an intermittent gas saver in gas plants and as a way of saving water in the dams for later more profitable use.
Coal's history in rapid response systems like ship propulsion units, however, is a bit ancient and requires either conveyors that can be speeded up or slowed down along with smaller units than are typically built. Of course, we could go all the way back to the days of stokers, but I think they would be hard to find these days.
For nuclear fission, however, there are a number of very responsive units in operation today on aircraft carriers, submarines and ice breakers. Fission reactors can change the heat they produce very rapidly and if they are connected to an appropriately designed steam plant or gas turbine, the power output from those units can also be varied rapidly.
On the flip side, I see no real reason, outside of the fact that some people seem to like enormous structures of often useless machinery, to integrate wind in with a future zero emission nuclear dominated grid, but that is a separate issue.
The systemic alternative to having additional responsive generation capacity for your demand peaks is to have an element of very responsive demand instead (which will of course be charged less for the highly intermittent electricity). This could allow us to chop the rapid demand changes down to something that can be handled more efficiently with load-followers. Enough of this, and wind could be used again - but would command a much reduced price.