News item | 2011-08-24 | 17:30 PM

Can nuclear power plants be used to balance load?

In the future, increased use of renewable energy will necessitate increased load balancing to avoid fluctuations in the supply. Nuclear power plants may acquire a new role in this respect, and an R&D project will investigate the technical possibilities and limitations.

Nuclear reactors are traditionally run in such a way that they produce a stable output. The new R&D project will investigate what happens if output is reduced at times when load is low – for example, at night.

“The idea is a bit controversial in the nuclear business, but still very possible,” says Jonas Persson, at Power Technology, Vattenfall Research and Development, one of two project leaders.

“For example, France is already balancing its nuclear power output. We will investigate a number of aspects such as operational impact, safety issues and nuclear fuel issues, and analyse risks such as the potential shortening of the lifetime of nuclear plant equipment that could result from balancing operations.”

Maintaining equilibrium

In a power system, generation must always be balanced with load, or else the power frequency is affected. In Sweden, equilibrium is traditionally maintained by balancing the output of hydropower plants.

But in the future, increasing use will be made of intermittent renewable energy sources such as wind power and solar energy. The Swedish government has set a goal that, by 2020, 25 TWh more electricity will be generated from renewable resources than was the case in 2002. It is envisioned that this will include 10 TWh of wind power, meaning that merely balancing the output of hydropower plants may be insufficient.