Wind power champion

STATUS | WIND POWER

Photo: Scanpix

By Mary-Anne Karas

A hundred years ago, hardly anyone would have imagined that nature’s bountiful storehouse would come to play such an important role in a small country far to the north, where modest hills and small valleys are the only variations in an otherwise flat landscape.

Today, however, wind turbines are generously scattered throughout the country.

Over the past couple of decades, wind turbines have grown in popularity, generating anything between 0 and approx. 3 gigawatts for the power grid.

Over the past 25 years, the invisible wind has become one of Denmark’s most valuable natural resources.

Today, wind supplies 20 per cent of the electricity used in Denmark. In future, this percentage will have to increase to achieve our ambitious climate goals.

The power grid is the backbone

The range of tools to control wind power includes everything from the planning of the power grid and robust international connections, reliable wind forecasts and adequate reserve capacity for calm periods to a well-functioning electricity market in which players compensate for any imbalances and consumer behaviour comes to reflect the strength of the wind.

Transmitting wind energy from the turbine blades to consumers’ wall sockets poses a huge challenge to the electricity transmission grid.

Wind power is only of value if the power lines between the wind turbines and the end-users are up to standard. This involves more than just Danish consumers. To make the optimum use of wind energy, it is necessary to be able to transmit it to the location in Europe where it is most needed. Consequently, Energinet.dk is constantly working on expanding and reinforcing the Danish grid and the international connections.

This is a task that requires considerable planning and analysis of the estimated need for new power lines and the positioning of wind farms.

Reserve capacity for calm periods

Consumers demand electricity whether the turbine blades rotate or not. Therefore, substantial amounts of wind power require considerable reserves of other types of power generation.

In changing weather conditions, the output of Danish wind turbines may go from 0 to 3 gigawatts in just a few hours – and vice versa.

Steady and adequate supply of electricity depends to a considerable extent on access to other production facilities capable of taking over should the wind abate. One option is coal-fired power stations, but Norwegian hydropower in particular is an excellent supplement to wind power.

It is often possible to import environmentally-friendly electricity from the Norwegian hydropower plants, when the wind is not strong enough. This is often the case during the summer months when Danish power stations supply less electricity and heat than in the winter months.

Illustrations: Energistyrelsen

First priority to green electricity

To ensure as much renewable energy to Danish consumers as possible, green electricity from renewable energy sources is given first priority in the power grid. In this way, wind energy provides a base for the market, but as the amount of wind energy in the grid literally fluctuates with the weather, the price charged by other producers for electricity is subject to similar fluctuations.

“Our market model forces other electricity suppliers to produce only when it is profitable. Danish consumers, therefore, benefit from electricity generated with the least possible environmental impact,” explains Anders Plejdrup Houmøller, Director of Business Development at the power exchange Nord Pool Spot, which organises the trade in electricity between the Nordic countries.

When it comes to renewable energy, Danish and European politicians are very ambitious. The aim is that in 2025, 50 per cent of Danish electricity will come from renewable energy sources. This means many more wind turbines than today, for which reason the number of tools must also be increased.

“Managing the amount of wind energy available in the future will present quite a challenge, but we have already come a long way in developing new tools. We need to put wind energy to even better use. To use it for transport and for heating our houses. We need to integrate all energy systems and use wind energy for an increasing number of purposes. This will allow us to handle even larger amounts of wind,” says Dorthe Vinther, Head of Strategic Planning at Energinet.dk.