Too warm for power plants

Power plants heatwaves
The heatwaves in Europe have resulted in debates concerning vulnerability and dependency linked to electricity production in thermic power plants. Ill: Øyvind Lothe
By Sigrid Folkestad

8 May 2015 09:33

(updated: 2 April 2016 09:41)

Too warm for power plants

Warmer climate creates trouble for power plants. When the temperature rises, plants are forced to reduce production or shut down.

The heat waves in Europe in 2003 and 2006 claimed many lives. Several estimates show that in the summer of 2003 alone some 35,000 people died in Europe as a result of the extreme heat.

Vulnerable in the heat

The heat wave resulted in debate concerning vulnerability and dependency linked to electricity production in thermic power plants, and in particular nuclear power plants. These require cooling water to keep production steady and high. In periods where temperatures are extremely high, these power plants experience problems relating to their access to water.

Politicians and environmental organisations, especially in Germany, came forward with renewed demands that nuclear power be replaced by green energy sources, and Germany is currently closing a number of its nuclear power plants.

Dependent on power plants

One problem is that power plants must reduce production or close down completely during heat waves.

During the heat waves, 17 nuclear power plants in Germany, France, Spain and Romania had to cut back production or shut down completely. Nine of them were allowed to continue production despite the temperature of the wastewater that is returned to nature being too high according to the emissions permit.

Europe is dependent on this production.

"We should be aware of the fact that most of the electricity in Europe is generated by nuclear and coal-fired power plants. These plants are crucial to energy security", says Professor Øivind A. Nilsen, Department of Economics, and power plants

Professor Øivind Anti Nilsen
Professor Øivind Anti Nilsen.

Together with PhD student Grant R. McDermott at NHH, Nilsen carried out a study of thermal power plants in Germany.

They have collected data on power production, power prices and river temperatures during the heat waves in Europe.

"The analysis shows that higher temperatures lead to reduced production in power plants and hence higher electricity costs. Prices shoot up", explains Nilsen.

"The higher the temperature, the lower the power plant's efficiency. Prices therefore rise in line with the temperature", says Nilsen.

Coal, nuclear or gas

Professor Gunnar S. Eskeland, together with researchers Linnerud and Mideksa at CICERO, carried out a similar study, not on nuclear power in particular, but on thermal power plants based on coal, nuclear power or gas.

Professor Gunnar S. Eskeland
Professor Gunnar S. Eskeland.

Both Eskeland's and Nilsen's studies examine the supply side of the power market.

"Every kilowatt-hour lost results in additional costs. It is this cost that we measure. We are interested in looking at what costs this generates, and how it affects us", says Eskeland.

Wastewater in rivers

The challenge facing all thermal power plants - not least nuclear - is that they are dependent on a regular supply of tremendous volumes of water from the environment to cool and control production. In very hot periods the water that is to be used to cool down production has a high temperature, reducing production and efficiency.

In addition, there are restrictions governing the return of wastewater to nature.

"There is a fear that the water coming out at the other side will have a negative impact on the ecosystem. That is why the German authorities shut down some of the nuclear power plants in 2003 and 2006. The river becomes to warm to receive the wastewater", says Nilsen.

Electricity bills

The effects of climate change can also be seen to have an impact on supply and price. Lower production results in higher prices. At the same time, power requirements increase sharply when heat waves occur, for cooling of customers' premises.

Climate change on power supply

"The Impact of Climate Change on Nuclear Power Supply" is written by Gunnar S. Eskeland, Kristin Linnerud and Torben K. Mideksa.

"Electricity Prices, River Temperatures and Cooling Water Scarcity" is written by Øivind Anti Nilsen and Grant R. McDermott, forthcoming in Land Economics.

According to Eskeland and Nilsen it is not mostly the power producers who lose out when production decreases; it is the consumers who foot the bill.

Dampens demand

"These are effects that have an influence on prices. Supply is reduced due to lower production and prices are driven upward. Although the need for energy increases during warm periods, because we are dependent on electricity for cooling purposes, the price increase dampens on demand", says Eskeland.

"Many people who work on the effects of climate change have overlooked these price effects and their implications", says Nilsen.

"And this effect will continue in the future, with more frequent and even warmer heat waves", comments Eskeland.

Power line neighbourhoods

In Germany, many nuclear power plants are being shut down. There has long been a debate, and after the Fukushima nuclear disaster in Japan in 2011, Angela Merkel's government became determined to accelerate the replacement of nuclear power with green energy.

"A problem for the Germans", says Nilsen "is that the green producers are for the most part located in the north of the country, while heavy industry is located in the south. Now they are facing a "Monster Mast debate" when needing to expand transmission lines, similar to ours here in Western Norway".

Many people want to be seen as green and environmentally friendly, but also do not want power lines through their neighbourhood".

Closing nuclear plants

Despite the challenges presented by thermal power plants, Eskeland does not want to caution against building new power plants. Closing nuclear power plants, which do not emit greenhouse gases, reflects other political objectives, he says.

This issue is special to Germany, according to Eskeland, where the green movement has played a special role.

"Nuclear power is highly political", says Nilsen.

"We see two sets of identical twins. One is Sweden and Finland. Sweden closes a nuclear power plant, and Finland opens one. There is no real underlying economic difference between these countries. The same is the case with Germany and France. The French have many nuclear power plants and do not intend to get rid of them. The Germans want to shut theirs down. It is the politics that is different. Both environmental issues and nuclear power are highly political", concludes Eskeland.