Coal, sun, wind, corn What the heat does with the energy

Coal, sun, wind, corn What the heat does with the energy

Coal, sun, wind, corn What the heat does with the energy

sweats. Anyone who has air conditioning in the office or in the car can look forward to ice in the freezer or drinks fresh from the refrigerator. Germans currently consume 1.36 billion kilowatt hours per day per day – a good six percent more than the average in the past two summers.

Despite the heat, the power supply is not endangered, assures the Ministry of Economic Affairs. Because of this, the price of electricity on the exchange is not climbing either, says Christoph Podewils from the Agora Energiewende think tank – the recent increase is mainly due to the increased prices for coal and gas and the increased prices for CO2 emissions in the EU’s energy sector. Nevertheless, the temperatures have an abundant impact on the energy sector:

The sun bangs all day long, so there would have to be endless solar power – one might think. But it is not like that. A good 44 gigawatts of power are installed in Germany, but the systems deliver around 24 to 28 gigawatts, i.e. around two thirds of the possible output. The reason: The efficiency of the systems decreases as the temperature of the modules increases. Solar records are therefore more likely to be measured on warm, sunny spring days, for example around Pentecost, not in midsummer.

These are not particularly good days for the wind power industry. On land and in the sea, the plants are far from delivering their theoretical maximum output of a good 58 gigawatts. According to the German Association of Energy and Water Management (BDEW), prolonged periods of heat and drought are usually associated with prolonged high-pressure weather conditions. “In these weather conditions, the wind practically comes to a standstill and with it the electricity production from these systems.”

Biogas is produced not only from organic waste, liquid manure and manure, but also from plants. They are grown on around 1.4 million hectares in Germany, mainly maize and grass. The Biogas Association points out that the harvest has not yet been completed. Failures are already noticeable. “The harvest of field and meadow grass is extremely unsatisfactory,” says managing director Stefan Rauh. “If – as feared – the drought continues, plants based on grassland will face massive problems.” In many cases, losses of more than 50 percent can also be expected with maize.

The operators of the biogas plants would have to think about how and when to use the available substrate quantities and whether alternative substrates are available. It is possible, for example, to reduce the output now and to increase it again in winter when the need for heat increases. In biogas plants, heat is a by-product of electricity generation. “But it is also clear that a throttling is associated with massive economic losses,” said Rauh. Life-threatening scenarios are possible.

Both types of power plants run into problems when the water they use for cooling becomes too warm. The Surface Waters Ordinance regulates the river temperatures above which the responsible water authorities can order throttling of power plants. “Depending on the size and type of the body of water and the respective fish fauna, this value is between 18 and 25 degrees,” says the BDEW. In addition, the temperature in a river should not change by more than three degrees when cooling water is introduced.

PreussenElektra, for example, currently has to reduce the power to protect the Elbe by around two percent at the Brokdorf power plant for one to two hours a day. The safety of the nuclear power plants was in no way affected by the heat, emphasized a spokeswoman. operates the Philippsburg nuclear power plant and has reduced the output of Unit 2 by around 10 percent. The hard coal power plant in Hamm was shut down last weekend due to problems with the coal supply. Due to the low water on the Rhine, the coal freighters cannot currently be fully loaded.

In contrast to hard coal, lignite does not have to be imported, but is usually converted into electricity close to the open-cast mine – either conveyor belts or short rail routes lead directly to the power plant. There are no problems with the cooling either, as “swamp water”, i.e. pit water from mining, is used, said a spokesman for the German Lignite Association DEBRIV: “There are no performance restrictions to be expected.” The demand is “very high” for summer conditions. .

Like the biogas plants, the biofuel manufacturers are also dependent on energy crops. A spokeswoman for the Federal Association of the German Bioethanol Industry explained whether and how the poor harvest of grain will have an impact. Because fuel is also made from sugar beet, and it will take some time until it is harvested. However, the beets need a lot of water. A scarcity of raw materials and higher prices could have an impact on biofuel prices. But it is still too early to say whether it will come that way.