The large-scale flexibility of hydropower is crucial for the transition
For more than 100 years, hydropower has formed the backbone of Swedish electricity production. Today, it accounts for more than half of the electricity production and is hugely important for the stability of the power system, and the output can be regulated almost instantaneously to keep the electricity system in balance. It has proven to be decisive for the expansion of wind and solar power that has taken place so far. But is that enough?
We must make use of the unique abilities of hydropower
Hydropower is unique because it can be cost-effectively regulated over all time scales – from seconds up to several weeks or years. In the past, the ability to regulate was used to adapt production according to use, today the ability to handle large variations on the production side is becoming increasingly important. The current capacity is on the limit of being able to balance today’s volumes of wind power. However, there are several different ways to increase the hydropower’s regulation capacity.
• It is entirely possible to increase the output in the ten largest already developed rivers by almost 25% using rebuilt or new turbines while changing the water gauges to allow greater variations in water flow.
• Raised dam limits and greater permitted variations in the magazines provide increased control ability over time.
• Fortum’s two “hybrid power plants” show that batteries can increase the power plants’ ability for short-term regulation while at the same time reducing stress and wear on turbines and other mechanical equipment.
• Pumped power plants can increase the available power for regulation but are mainly used for regulation over the day. With more wind and solar power, it can become more profitable in Sweden as well.
• More predictable base power, nuclear power and/or cogeneration, makes it possible to use a larger proportion of hydropower’s production for regulation, which in turn can then make room for more weather-dependent production.
Hydropower could thus increase its regulation capacity with comparatively small efforts. At the same time, we know that the now-paused environmental review of all hydropower risked leading to a greatly impaired regulation ability and lower annual production. As a society, we therefore need to find a balance between the different needs.
A plate model of the power system
The Swedish power system has for many decades been essentially completely fossil-free, so we have a uniquely good starting point to cope with the transition. We should “just” replace the fossil fuels in all other sectors. In round numbers, this means more than a doubling of today’s production. At the same time, two-thirds of today’s production capacity will reach the end of its technical life and need to be replaced. We need all fossil-free power types to cope with this, and we need to have a balance between the abilities needed for the power system to function and to be able to provide power for the transition. We usually call it a plate model as different types of production contribute different abilities to the power system. But to build a balanced system that meets the needs, we need to get better at making use of hydropower’s unique abilities.
Fortum is a Nordic energy company. Our aim is to give power to a world where people, companies and nature develop together. We are one of the power producers in Europe with the lowest carbon dioxide emissions and we are guided by high sustainability goals. We produce and deliver fossil-free electricity and we help industries phase out their fossil fuels and grow. Our core business in the Nordics consists of efficient fossil-free power production and reliable deliveries of electricity and heat to households and businesses.
The article is produced by Brand Studio in collaboration with Fortum and not an article by Dagens industri