Power beyond the battery

Stacked concrete blocks. molten salt. flywheel. compressed air. Pumping water to higher tanks. And… the good old battery. Energy storage technologies are booming. Since renewable energies are often intermittent, it is necessary to find bridges between stormy and sunny moments.

Mathieu Perrault
Journalism

batteries

Since last year, Hydro-Québec has set out to conquer the planet’s energy storage markets. The EVLO division, equipped with 0.5 megawatt-hours (MWh) batteries, has won contracts near a wind power plant in France and near a solar power plant on the outskirts of Montreal. “We have also launched a 1 megawatt hour system and are working on a system with a larger storage capacity, perhaps 1.65 megawatt hour,” explains EVLO CEO Sonia Saint-Arno.

EVLO systems have also been installed at Quaqtaq, to ​​test the solar potential at Nunavik, and in the Lac-Mégantic microgrid. according to m^I St-Arnaud, EVLO batteries’ capacity density continues to increase, with an expected 50% improvement between the 1 MWh system and the 1.65 MWh system.

Batteries are likely to be required near variable energy sources, such as wind turbines and solar power plants, to ensure storage for a few hours, said Venkat Srinivasan, director of energy storage at the US government’s Arjun National Laboratory.

“For long-term storage, such as at night when there is no sun, and for the few times in the week when it is not windy, you will need other systems,” says Srinivasan. But it is estimated that costs will be reduced tenfold until other storage systems are operational. »

Ontario

Ontario has experimented with many “exotic” storage technologies over the past decade. Grid-connected systems include flywheels, swivel inertia wheels and pneumatic. “We’re also looking at storing chemicals, like molten salt, that release energy when solidified,” says Catherine Sparks, director of innovation for the Independent Electricity System Operator of Ontario (IESO).

IESO currently has 48 megawatts of energy storage, the vast majority in the form of batteries, and plans to contract additional storage systems under public tender of 1,200 megawatt hours this year. Companies in Ontario operate on a system of rollers where cement blocks are stacked. When we need energy, we reduce it.

hydrogen

Another method is to produce hydrogen by electrolysis – hydrogen which can then be used, if necessary, in a fuel cell. “If you want to store a lot of energy, say for several months, hydrogen is probably the best solution,” says Loïc Boulon, of the University of Quebec at Trois-Rivieres, who is working on the technology.

“Think about the energy we need in the winter in Quebec, or in the summer in areas where there is a lot of air conditioning. The problem is that we have 50% efficiency with fuel cells, compared to 80% with batteries. According to Mr. Boulogne, fuel cells are On the eve of rapid technological progress, just as batteries were 10 years ago.

Switzerland

Since last year, Switzerland has had a natural battery in the form of a pumping station at the Nantes des Drances hydroelectric power station. This infrastructure is equivalent to a 900 MW battery. Nuclear power purchased in France operates at night, when costs are low. “We have had a 175 megawatt pumping station in Niagara Falls since the 1950s,” says Ms.^I sparkle;

For its part, Hydro-Québec does not plan to add a pumping station at its existing power plants because it is so far from wind farms that its current supply must be regulated, according to Frances Lappé, head of Communications for Innovation. Governmental company. In any case, Quebec’s tanks are already playing the role of giant batteries, Mr. Labé asserts.

An Australian study last year targeted more than 600,000 places around the world where storing pumped water could be profitable. Pumped storage is usually not part of the energy storage statistics because it has been a mature technology for decades, with energy losses of less than 20%.

Montreal solution

Over the past year, engineers have been testing pumping a liquid 2.5 times denser than water in a lab at the edge of the Lachin Canal. The fluid used is called R-19 and was developed by the company. Its recipe is a secret but inexpensive solid powder suspended in water. London-based RheEnergise will test its pumped-out energy storage solution this summer at Montcalm near Rawdon. Stephen Crocher, CEO of RheEnergise, explains in an interview from the UK: “With a denser fluid, you need less height or less infrastructure to store energy by pumping fluids.”

These facilities should be the size of a water treatment plant basin, and the height needed for Mount Royal, according to Tamas Bertini, chief technology officer at RheEnergise. Mr. Bertényi moved to Montreal eight years ago and has worked on sustainable energy projects with indigenous companies. “Montreal is very beneficial for hiring engineers, we have four of them and we aim to hire about ten more within a year,” says Mr. Bertényi. All engineering work is taking place in Montreal, and a pilot plant is scheduled for mid-2024 near Plymouth, England.

Underestimated cost

If you take into account energy storage needs, or the need to build and maintain a natural gas plant to compensate for fluctuations in wind power, the cost of renewable energy is likely to be twice as high as the cost of direct construction of a solar or wind power plant according to Mr Srinivasan, of Arjun Lab .

“But it’s average,” he adds. In regions where there is a lot of hydropower, the increase in cost is small, and in extreme cases, in areas that are not well connected to other electricity networks, the increase is even higher. In Hawaii, for example, each island should have its own storage capacity. »

An earlier version of this text indicated that EVLO batteries have energy on the order of GWh, rather than MWh.