Hyme Energy Advances Molten Salt Battery Technology

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Hyme Energy in Denmark has a new take on how to store renewable energy for use later using molten salt. It’s really a variation on the concentrated solar power idea. Remember when your counselor at summer camp used a magnifying glass to burn your initials into a piece of wood? That’s the basic idea behind CSP. Set up an array of mirrors, orient them all so they reflect sunlight in the same direction and you get some seriously hot temperatures at the convergence point.

That is where we encounter the age old problem of theory versus reality. Concentrated solar sounds good in theory, but it is beastly hard to get all those mirrors installed and pointed in the right direction. Not only that, in the end the electricity created is more expensive than electricity from good old reliable solar panels. Steam turbines don’t care where the steam comes from. It can come from burning wood, trash, methane, or oil, or it can come from smashing atoms. All a generator cares about is whether the steam is of the correct temperature and pressure.

Hyme Energy has a better idea. Instead of going to all the expense of a CSP system, why not use the excess renewable energy available during the sunniest part of the day to heat salt, then let that molten salt create steam later after the sun sets? It’s a potential solution to the “dispatchability” of renewables. Today’s grid-scale storage batteries can only send power back to the grid for about 4 hours. Hyme Energy claims its technology can do so for ten hours or more as the captured energy is discharged when molten salt is pumped from a storage tank to a heat exchanger, producing steam for industrial use. This offers a cost competitive, green, and reliable solution for industrial heat electrification that supports the decarbonization of process heat.

In 2024, Hyme Energy and Swiss fluid engineering specialist Sulzer collaborated to create a molten salts (MOSS) demonstrator plant in Esbjerg, Denmark. That facility validated the concept of storing renewable energy in molten salt at temperatures up to 600°C (1,112°F). “Our technology is designed to integrate with existing infrastructure, making adoption easier for industries looking to transition to sustainable energy,” said Ask Emil Løvschall-Jensen, CEO and co-founder of Hyme Energy in a press release.

Sulzer has taken a leading role in molten salt pump development over the past 20 years, fostering close technical partnerships to unlock new advances in the field. Its work on Generation 3 Concentrated Solar Power (CSP) systems, proven range of molten salt pumps and ability to rapidly prototype precision engineered components will work with Hyme Energy in commercializing its innovative energy storage technology.

Now the two companies plan to take the lessons learned from that demonstration project to develop a 1 GWh molten salt storage system capable of powering approximately 100,000 homes for 10 hours with an efficiency of up to 90%. “Energy storage with molten salts is a tantalizing opportunity to help decarbonize industry and accelerate the energy transition, whether in terms of heat recovery, renewable energy storage, or small modular reactors (SMRs),” said Benoît Martin, advance engineering manager at Sulzer. “It’s exciting to be working with Hyme Energy to further validate this innovative technology for the benefit of all.”

 Molten Salt Energy Storage

The technology utilizes molten hydroxide salt, an inexpensive byproduct of chlorine production, to store energy captured from renewable sources. It can store electricity from renewable sources in molten hydroxide salt for up to two weeks by utilizing a two tank storage design and proprietary hydroxide salt corrosion control technology. That last part is critical. Superheated salt is highly corrosive, which makes it hard to manage over long periods of time. Sulzer’s extensive experience in molten salt pump development includes supplying pumps for a 100 MW CSP project in China. “With the MOSS plant providing good results since its inauguration in April 2024, we’re now working with Hyme Energy to further optimize the system, improve the competitiveness of the solution, and establish a strong supply chain,” Martin added.

Hyme Energy says the system achieves efficiencies of around 90% for industrial heat applications and between 80% and 90% for co-generation. Power generation alone is estimated at 40% efficiency. “Our reliable solution converts intermittent renewable energy into consistent, flexible green heat-making decarbonization possible without compromise,” the company says. It is now developing what is touted as the world’s largest industrial thermal energy storage system, a 200 MWh site in Holstebro, Denmark. When completed, it is expected to save Arla Foods, a Danish-Swedish dairy co-operative, €3 million ($3.1 million) annually in process heat costs. “For us at Hyme, it is key to work with established partners like Sulzer. By combining our strengths, we can accelerate progress and bring this solution to market faster,” said Løvschall-Jensen.

The Future Is Not The Past

The fossil fool fuel industry is in love with the technologies developed decades ago. James Watt was one of the first to perfect the process of burning coal to make steam. The latest US energy secretary, Chris Wright is running around extolling the virtues of coal and telling people how it has made the modern world possible. He is right, of course, but that does not alter the fact that burning the stuff has also pumped trillions of tons of carbon dioxide into the atmosphere and left behind millions of tons of toxic sludge that pollutes the land and water nearby. Wright and his ilk act like it is an offense against God to not continue using coal and that those who oppose using it are infected by some sort of “woke mind virus.”

In fact, the true offense against God is treating the Earth as a communal toilet where the waste products of human activity continue piling up primarily because capitalism assigns no costs to those pollutants. How utterly selfish and stupid it is to continue harming the planet when there are non-polluting alternatives like molten salt energy storage available. The fossil fuel crowd would happily kill every man, woman, and child alive today or yet to be born in order to protect their wealth. What good all that money will do them after humans are largely eliminated from the face of the Earth is one of life’s great mysteries.

The state of Texas is considering legislation that will mandate all wind and solar facilities include methane-fired generating stations to provide electricity when co-located storage batteries are exhausted. And yet, there are many new forms of long term energy storage in development that will solve the problem without adding more pollution to the environment. Ignoring them and relying on century old technology instead is not only more expensive, but just plain dumb as well. We learned to live without asbestos and Freon. We can learn to live — and thrive — without fossil fuels as well.