Energy question of the week: How will energy provision change over the next few decades?
Several studies forecast that by 2050, it will be possible for Germany to obtain a high proportion of its energy from renewable sources. DLR also has significant involvement in the expansion of wind, hydroelectric and solar power stations. But what specific changes can be anticipated here? The DLR Executive Board Member responsible for Energy and Transport research, Ulrich Wagner, provides insight into future prospects.
In June 2010, DLR, along with 30 other experts, presented a global energy scenario commissioned by Greenpeace International and the European Renewable Energy Council (EREC). By 2050, up to 80 percent of energy needs could be covered by renewable sources, and this could cut emissions of carbon dioxide, the greenhouse gas, massively. "The important thing is not just to build renewable energy power stations as we go along, but also to raise the efficiency levels of conventional power stations," says Wagner. In parallel with the expansion of renewables, these coal and gas-fired power stations are scheduled to remain in service for many years.
Solar thermal power as an export star
Wagner says that a broad spectrum of technologies will be harnessed to cover future energy needs. Wind farms in the North and Baltic Seas could be augmented by solar thermal power stations. "Because these plants need direct solar radiation, they would not be very efficient at our latitudes," says Wagner. Nevertheless, it is extremely important to further improve these relatively mature technologies because they constitute an important export asset for the domestic industry in Germany.
Offshore wind farm of Middelgrunden, Denmark, two kilometres from the coastline East of Copenhagen. With a total power rating of 40 MW, this wind farm can generate 90 GWh per annum, and is able to supply electrical power to 20,000 households. Photo: Bundesverband WindEnergie e.V. [German WindEnergy Association]
"I believe that there is great potential for the expansion of wind power on the open sea," says Wagner. However, to make efficient use of the strong and steady winds out at sea, the power generation infrastructure needs to be redesigned completely. It is not sufficient to simply copy the wind turbine technology used for infrastructure on terra firma if the full potential of offshore wind power is to be harnessed effectively. "For these new systems, we will have much to learn from our DLR colleagues, with their extensive experience in aerospace," says Wagner with conviction.
The challenge of heat storage facilities
Solar thermal power stations have an important role to play in the electrical power mix of the future and some are already under construction in southern Spain, with plans for more in North Africa as part of the Desertec initiative. "These power stations are already operating with heat storage units which means that they are able to contribute electrical power to the mains grid in the evenings or even at night," says Wagner, while also admitting that a great deal of research still needs to done in this area. "We have to drive forward heat storage at the highest possible temperatures to enable these storage units to operate efficiently as well as cost-effectively. It would constitute tremendous progress if we were able to come up with a solution here."
Reinforcement of the European electrical power grid is a key factor driving the development and construction of these new power stations. To transport electrical power from the generator to the consumer with minimal transmission losses, network operators are already demanding 40,000 kilometres of new power lines for Europe. While DLR is not involved with the technology for these electricity highways, DLR researchers are hard at work on detailed system analyses to establish where it makes most sense to expand performance capacities.
The future of electric mobility
Fossil energy sources will be replaced more slowly in transport than in the electricity sector. "Nevertheless, by 2050, I can well imagine that electrically powered cars will account for somewhere between 20 and 25 percent of the vehicles on the road," says Wagner. Certainly there is no reason why passenger cars and smaller commercial vehicles should not be taking to the roads powered by electricity, or with hybrid or hydrogen drives. The third of these options calls for stable fuel cells with long service lives, and things have recently gone quiet in discussions about the future of transport. "Nonetheless, the fuel cell has always been, and remains, an interesting option," states Wagner.
A further boost for electric mobility is expected to come from mobile power storage units (or batteries) with high charge capacities. "For this vision of the future, we are currently setting up a battery research centre in Ulm with our partners," says Wagner. The green light will be given in January 2011, when a large number of storage technologies not yet ready for the market — the lithium-air battery for example, will start to receive serious attention. In the years to come, DLR will further reinforce its activities associated with solar power stations, energy and storage systems, and mobility technologies for the future. "Energy and transport, building on the successes already achieved, are set to become an even more important focal area for DLR," adds Wagner with conviction.
Top image: Ulrich Wagner, Member of the DLR Executive Board responsible for Energy and Transport research. Photo: DLR.