Stackable energy storage start-up rebooting coal plant to run emissions-free
Roughly the shape and size of a brick, the energy storage blocks developed by Australian research start-up MGA Thermal can be stacked and scaled to store millions of kilowatt hours of energy. The company has partnered with Swiss company E2S Power AG on a pilot demonstration to retrofit coal-fired plants in Europe with MGA storage, which could see coal plants running fossil-fuel free.
The MGA solid metal storage system is a large-scale solution to enable reliable renewable baseload power and transition away from coal-fired power generation. The founding researchers from the University of Newcastle see MGA technology as a “paradigm shift in the way that we create energy”.
“We definitely need to have some way of transitioning between the traditional way of burning fossil fuels into the completely renewable technology that everyone wants to see,” Chief Technology Officer Dr Alex Post told the ABC in September. “And that’s where we see ourselves, helping that transition take place.”
The compact blocks are made of the patented Miscibility Gaps Alloy (MGA), a blend of metallic phase change material and non-metals such as carbon. Lead Researcher Professor Erich Kisi and Dr Post describe the energy storage system as a “choc-chip muffin heated in a microwave”.
MGA blocks consist of two components: particles which melt when the alloy absorbs heat (the “choc-chips”), interspersed in a material that remains solid (the “muffin”). The particles absorb energy upon heating and release it when cooled, melting and solidifying without disrupting the outwardly solid block.
Highly versatile, MGA blocks can absorb energy from various heat sources, including solar energy and waste industrial heat. They can rapidly deploy energy to help to alleviate the gap between energy supply and demand, while the modular design means they can be stacked to meet market demand for electricity.
MGA Thermal’s partnership with E2S will retrofit a retired coal-fired plant, replacing the coal furnace with a large MGA energy storage system. The system will be charged using excess renewable energy from the grid. In turn, this energy will be used to power the existing steam turbines emissions-free.
MGA Thermal says that the high energy storage capacity of its system means the plant will be able to run entirely on stored energy. It is currently working with E2S to prove this in a commercial setting, with the 55MWh demonstration plant in Europe planned for completion in late 2021.
The project will repurpose existing machinery that would otherwise be decommissioned, saving billions of dollars in assets. “MGA blocks are an opportunity to re-deploy retired or stranded plants, turning a liability into a high value asset,” Professor Kisi told the ABC.
MGA Thermal was founded in 2019 and has its roots in the CSIRO’s innovation programs, ON Prime and ON Accelerate, which aim to fast-track research commercialisation. Dr Post, interviewed in 2017, described the pre-accelerator stage project as “a pleasant diversion” from his PhD thesis.
The company has since gone from strength to strength. It will begin producing commercial quantities of MGA blocks over the coming months, with investment from Sydney firm CP Ventures and an Accelerating Commercialisation Grant from the Australian Government. An initial demonstration on a solar tower is planned for later this year.
The researchers have shown that MGA blocks are a competitive storage solution. They are 10 per cent of the cost of a lithium battery of comparable size, yet produce the same amount of energy. When it comes to filling spikes or dip in energy supply from intermittent renewables, MGA blocks have a slower response time than batteries, but a much longer storage capacity.
The unique thermal properties of MGA mean the blocks can essentially be cycled indefinitely (thousands of cycles have been tested with no loss of energy storage capacity). Unlike thermal storage options such as molten salts, they are compact, non-corrosive and have very fast charge/discharge characteristics. The blocks are even fully recyclable.
MGA also shows potential for use in heating electric vehicles and coupling with solar thermal power using advanced power cycles such as supercritical CO2. “We know our technology can help make meaningful change and a sustainable future; we look forward to making this happen,” says Professor Kisi.
