Foto: Gottlieb Paludan Arkitekter

We must act now to achieve our goal

Friday 24 Mar 17


Søren Linderoth
Head of Department, Professor
DTU Energy
+45 46 77 58 01

Green Power Island

The energy storage work has been ongoing for many years. Back in 2009, in collaboration with Gottlieb Paludan Arkitekter, DTU made a proposal for how to store wind power by creating artificial energy islands.

The vision of the Green Power Island project is that during periods of excess electricity, sea water is pumped out of an artificial basin. When there is a need for electricity, the sea water is led back through turbines to restore 75 per cent of the electricity used to empty the basin.
Oil, gas, and coal must be phased out and replaced by renewable energy. However, to ensure we have sufficient energy to cover our future needs, we must be able to store it. We still have to develop the energy storage technologies required to ensure we have access to abundant, inexpensive energy volumes.

Describe a fossil-free society where we only have access to existing technologies for storing renewable energy. Søren Linderoth, Head of Department at DTU Energy, only hesitates for a second before replying:

“We’ll have occasional black-outs. If we don’t have permanent access to energy, things will stop working. The transport sector will become paralysed. If we cannot store wind and solar power as fuel, no planes or ferries will be in service. Except for a small number of electric cars, the roads will be car-free. Without electricity or fuel, factories will also stop running. All production may sometimes stop. And though we may all have wind turbines or solar panels, we’ll be unable to turn on a lamp, a toaster, or the TV. Before long, the phone is out of power. We will be back in the Stone Age.”

Danish politicians’ ambition is for Denmark to be independent of oil, gas, and coal by 2050. Fossil resources must be phased out and replaced by renewable energy. The challenge is, however, to facilitate and reduce the costs of storing renewable energy sources such as solar and wind energy for grey, calm days.

Energy storage is crucial—owned by the Danish Ministry of Energy, Utilities and Climate and responsible for Denmark’s energy supply—is fully aware of the situation. Hanne Storm Edlefsen, Head of Department for Research and Development at, singles out energy storage of renewable energy resources as an important element in a fossil-free society:

“All analyses show that energy storage will play a key role in future. It’s absolutely necessary if we’re to base our society on renewable energy,” says Hanne Storm Edlefsen.

Denmark to exploit position of strength

Danish companies are leaders within some of the technologies behind energy storage and conversion, and if the international community works towards achieving the COP21 targets, Denmark will have significant market opportunities.

"36 percent of Danish scientific articles on energy storage rank among the world’s 10 per cent most cited"
Analysis by DTU

Denmark is also at the forefront of research in energy storage and conversion. As for research quality in this area, Denmark ranks 2.7 times higher than the global average, and higher than both the USA and Germany—our closest competitors. 36 per cent of scientific articles published in this area in Denmark are among the 10 per cent most cited articles in the world. And together with the fact that Danish companies are considered to be leaders in the field, Denmark has a unique position of strength. Søren Linderoth, Head of Department, believes that Denmark should exploit this position of strength:

“In any event, technologies must be developed. Oil, gas, and coal are limited resources, so it’s only a matter of time before we need large-scale energy storage and conversion. If Denmark doesn’t develop solutions, other countries will—and then we must buy from them. Why don’t we make a business out of it at the same time as solving our problem?”

2050 just around the corner

Søren Linderoth, Head of Department, explains that a society which is independent of fossil fuels requires much larger volumes of renewable energy than we have today:

“It’s great that Denmark is self-sufficient in power when it’s windy, and that we can import electricity in calm weather. But the current power consumption accounts for 15-20 per cent of our total energy consumption, half of which is supplied by wind energy. The amount of wind energy must increase significantly for us to become independent of fossil fuels. This requires that wind energy can be stored and also converted into fuels and chemicals which today are based on fossil resources.”

2050 may seem to be the distant future. But to a researcher, it is just around the corner:

“We must act now to achieve our goal. Our researchers have a lot of exciting ideas for solutions. But which are the best? The only way to find out is to develop, test, and analyse them. We might get there before 2050. However, it will be difficult unless we invest more in energy research,” says Søren Linderoth.