When will we be able to start storing wind and solar energy?

Published on: 28 April 2022

Current issues related to economics, (responsible) investment, pensions and income: every week an APG expert gives a clear answer to the question of the week. This time: Jan-Willem Ruisbroek, head of infrastructure investment strategy at APG, on when renewable energy can be stored for later use.

Last weekend it happened both days: the Netherlands produced more solar and wind energy than was used, weatherman Gerrit Hiemstra tweeted. The energy surplus went abroad, because storage of wind and solar energy is still difficult. This raises the question of when we will be able to start storing it.

Solar energy
“Solar energy storage is already happening,” Ruisbroek says. “For example, APG is investing in some solar parks in Nevada and California, where there is a predictable pattern of solar power generation and consumption. At the solar farm, there are a number of large batteries that store the excess energy. Such a battery is the size of a shipping container and looks like a kind of server room. During the day, energy is stored in them that people can use in the evening when they come home and the sun is no longer shining. The challenge lies in scaling up the use of these kinds of batteries. They are still relatively expensive, but they are rapidly becoming cheaper. In about five to ten years, they may be so cheap that you can put a small version in your garage. Then the excess energy generated by your solar panels will not be fed back into the grid, but can be stored in your own battery. That consumer product is going to come anyway. At present, there is a huge hype about solar panels, and in five or ten years' time there will be a hype about batteries. So, we can already store solar energy, but it is not yet being done on a large scale and the costs are still relatively high.”

Wind energy
It will also be possible to store wind energy within about five years, Ruisbroek expects. “But it is likely that with wind this will be in the form of large-scale hydrogen projects. Large offshore wind farms are being built now. These consist of gigantic turbines, about as tall as the Eiffel Tower. They produce an enormous amount of energy. When that comes ashore, it has to be stored when there is an excess of energy. And wind is a very good source for turning water into hydrogen, which can store energy and be released as energy again after combustion. Shell and Gasunie are currently building a hydrogen power station in Groningen. It will use energy from wind turbines to produce hydrogen. This is done on an industrial scale and, unlike a battery for solar energy, is not suitable for private use. The big challenge for hydrogen is that there is not yet a large infrastructure for transporting it, although the existing pipelines for natural gas may be a solution.” 

A lot of solar and wind farms still need to be built to meet the total demand for energy

Last weekend, the Netherlands had more than enough generated solar and wind energy. The question is whether that is the rule or the exception. “It didn’t surprise me that the days with excess energy were on the weekend, because a lot of industry is closed then so demand is lower. A lot of solar and wind farms still need to be built to meet the total demand for energy. Currently, only a small percentage of the total energy supply consists of renewable energy. In addition to the development of battery technology, many more wind turbines and solar parks will have to be built in the Netherlands. There are presently a number of large offshore wind farms that supply some 4 gigawatts of energy. By 2030, an additional 20 gigawatts will be generated and by 2050 the total should be 70 gigawatts. There are plans to build more as quickly as possible, but these are also needed to meet demand. Because a great deal of energy is needed.”

European network
In addition to investments in battery technology and hydrogen power plants, a lot of money is currently being invested in so-called interconnectors. These are connections between countries through which excess sustainable energy is transported to neighboring countries. “The Netherlands has these connections with England and the Scandinavian countries, among others. In order to ensure that the surplus of energy generated in Europe arrives at the place where there is a demand for it, many connections are needed between the national high-voltage networks. There is already a European network in place, which enabled the Netherlands to export its energy surplus last weekend, but it is now being further expanded.”

Larger scale
The storage of solar energy in a battery is already possible on a small scale, as the solar parks in America show. According to Ruisbroek, it is now mainly a question of applying it on a larger scale, so that the batteries become cheaper and eventually also affordable for private individuals. Conversion of wind energy into hydrogen for storage purposes, on the other hand, is still in the start-up phase. “For now, that is a matter of making it work in practice before it can be rolled out further. So actually, the development towards storing wind energy is a step behind the development towards storing solar energy.”