Professor Birgitte Bak-Jensen and Associate Professor Filipe Miguel Faria da Silva, AAU Energy, Aalborg University 

Denmark and the rest of Western Europe are in the middle of a serious energy crisis. Electricity prices are rising, there is a real prospect of power outages, and the crisis has caused businesses and private consumers to look very closely at their electricity consumption and cut back where they can.

We’re gritting our teeth, and we’ll get through it. It’s something we’ll just have to endure, but it feels as if it is only a phase. Not so very far into the future, an abundance of renewable energy from wind turbines, solar panels, and more awaits.

But unfortunately it’s not that simple. Even though there are good opportunities to generate all the renewable energy we need, our system to manage this abundance is not yet in place. Our electricity system is simply not built to manage the large fluctuations that will arise when we base our energy supply on green renewable sources.

Upgrading the electricity system to cope with the new reality requires investment, technological development and research. If we fail to do this, we will risk the prospect of long, uncontrollable blackouts in the electricity grid that will make the possible outages warned by the Danish Energy Agency for this winter fade into insignificance.

Traffic chaos in the electricity system

When winds blow strongly and the sun shines brightly from a cloudless sky, we have so much surplus electricity we can export it to our neighbouring countries. But when winds drop and it the sky becomes cloudy, we can have too little electricity. Today, we can adjust production by using fossil fuels at power plants, and by importing energy from neighbouring countries. However, as fossil energy sources are phased out, we will see much greater fluctuations in supply.

These fluctuations constitute a considerable challenge for the existing grid. We can illustrate this with an example.

Imagine we want to build a motorway. We know that an average of 10,000 vehicles will use the motorway every day, and we draw up plans on this basis. However, the problem arises if we forget that the number of vehicles fluctuates significantly during the day. Perhaps just 200 vehicles will use the motorway at night, while during the morning rush hour there will be 10-, 20-, 30- or even 50-times more. This means there is massive spare capacity at night and too little capacity in the rush hour. The result may be traffic chaos. The system collapses.

The same applies for the electricity grid. If there is not enough capacity for peak-load hours, the system will collapse. The result is uncontrollable and long-term blackouts. The challenge is to balance the system, so that demand always exactly fits production. Or to make the system sufficiently flexible to accommodate the large fluctuations and, for example, channel the surplus energy into storage technologies when production exceeds demand.

Invisible technology and sector coupling

Flexibility can be increased by making efforts to develop effective energy storage, for example Power2X installations. Power2X technology makes it possible to store energy for later use, the technology can also link electricity production with the production of fuels via so-called sector coupling. This requires that Power2X systems are developed at industrial scale and integrated in the overall electricity system. This is within our grasp, but it requires continued research and investment in infrastructure.

Another focus area is the electricity grid. We can see wind turbines. Perhaps we know more or less how they work.  What we can’t see is the invisible technology that ties the electricity grid together and that lies between the turbines and consumers, for example.

The technology behind today’s electricity was developed and taken into use in an entirely different reality. It was designed for stable electricity production, based on fossil fuels, and distributed evenly and steadily to consumers and businesses. Or, going back to the motorway example, it was designed for a reality in which traffic flows steadily and predictably throughout all hours of the day.

Denmark is renowned worldwide for its secure and stable electricity supply. This is a strong argument when international businesses with significant electricity needs locate their facilities here. However, the Danish system risks collapse if it is not updated.  

The electricity system of the future

Deployment of more renewable energy sources such as wind turbines and photovoltaics, and better sector coupling are undoubtedly part of the answer to ensure future energy supply and make Denmark independent of fossil fuels.

But we must not be allow ourselves to be blinded by this clear progress and forget to develop infrastructure, systems and demand regulation mechanisms for both businesses and private individuals.

There is a lot on the drawing board, for example Power2X installations and intelligent, data-based regulation of electricity demand. Energy islands as an integral part of the Danish system also have a huge potential to help solve the challenges we’re facing. However, even more development is required if we are to establish a durable electricity system for the future.

At a time when many issues are competing for priority on the desks of the newly elected Danish members of parliament, this is by no means the least important. We risk groping in the dark and falling helplessly into an unstable electricity reality if we fail to act now and increase research, upgrade the electricity grid and secure demand management.  

The development and deployment of technologies, including electrification of transport and the heating sector, as well as integration of energy islands and Power2X installations, must be in parallel with the deployment of renewable energy in electricity production. The green transition is already well underway, and there’s no time to waste.

This is no small task, on the contrary, it is one of the largest development projects in Danish history. It is the greatest revolution seen for a long time in a Western energy system. However, when we reach the objective, when we have tamed the green superpowers, we’ll have a renewable energy source that can forge endless opportunities.