As our energy mix becomes more sustainable and electrical, large-scale energy storage will be a vital part of our energy system. NLingenieurs prioritises the development of new forms of power storage.
Currently, the Netherlands keeps 5 million tonnes of crude oil, the equivalent of three months of Dutch demand, as a strategic reserve. In the future, double this amount in ammonia will be needed for seasonal storage of renewable electric energy. This outcome is the bottom line of the Whitepaper that NLIngenieurs published last Thursday.
NLIngenieurs is the Dutch industry association of engineering consultants. It published its energy vision towards 2050 on October 1st, 2015. The lead author is Professor Fokko Mulder from the section materials for energy conversion and storage at the TU Delft Faculty of Applied Sciences.
CO2 emissions will have to fall globally by 60 percent by 2050, and by 80 – 95 percent in Europe. This constraint means a far larger share of renewable energy sources like sun and wind energy in the energy mix. Because these sources are by nature intermittent, the match of production and demand will be a lot more difficult to make than today.
The report expects that a larger share of our energy use will be in the form of electrical power. Domains as transport or heating are traditionally fossil-fuel based. The introduction of more energy-efficient electric cars and heat pumps is changing that paradigm.
A larger share of electricity in the energy mix makes it possible to dynamically match (peak) production and demand. So when a storm passes over the wind parks on the North Sea, cars can be tempted to charge their batteries and heat pumps to do their cooling or heating when the dynamic power price is low.
However, this smart demand management will not be enough to balance production and demand in the grid, the whitepaper says. Additional small- and large-scale power storage will be needed to deal with the fluctuations.
Batteries can deal with the variations over the day, but for seasonal storage, chemical conversions will be needed. Abundant energy from the summer will need to be converted into hydrogen, which can be combined with biomass into methane (CH4) or with nitrogen to form ammonia (NH3). Ammonia is an attractive alternative, says the report because it becomes fluid at 8.5 bar and it can be used as a fuel in gas turbines.
Since current storage techniques are unsuitable for large-scale applications, the development of methods for energy storage needs to be prioritised, said NLIngenieurs. Much-needed storage technologies include cheap batteries with a large number of cycles, carbonless fuels such as ammonia and efficient and large-scale conversions techniques of electricity into fuels.
Lees ook: 'Koester onze gascentrales', De Ingenieur, 1 oktober 2015