Storage is part of the solution to our energy security woes, not coal
An Adelaide-based start-up may have solved the problem of renewable energy’s intermittency — with very hot silicon.
The company’s name is 1414 Degrees, which is the temperature at which silicon melts, and it’s just an ironic coincidence that it’s based in South Australia, which has become ground zero for renewable energy controversy.
The patents for the process were bought from the CSIRO by a group of SA investors and they have spent about $3 million building a pilot plant at Tonsley Park, in the old Mitsubishi factory. The company is preparing to do an IPO to raise another $10m this year to build a commercial plant, but it says the viability of the process has been proved.
Part of the money for the pilot plant has come from the Federal Government, via an AusIndustry grant — but don’t tell the Prime Minister or Treasurer. They’re dead against renewable energy, and are big fans of coal.
Using hot silicon to store energy was a world-first invention by the government’s CSIRO, which took out global patents. The Adelaide company has modified the original patents and the details of those modifications are a closely guarded secret.
There’s apparently only one other company in the world working to use silicon to store energy — a Spanish firm that is using the brightness of molten silicon to power photovoltaic cells, as a sort of continuous solar power.
The CSIRO/1414 Degrees process is beautifully simple: an insulated container of silicon is hooked up to a wind turbine or solar generator and the energy used to heat the material to 1414 degrees. The insulation keeps it at that temperature — “like an esky”, says executive chairman Kevin Moriarty.
The heat itself drives a turbine to generate electricity directly, rather than heating water to steam, as with coal and gas fired generation.
As Moriarty told me last week: “We heat it up just with elements, much as you would something on your stove. … The silicon stays put, doesn’t go anywhere and we have essentially a heat exchanger which extracts the heat and pushes it into a form of heat engine or turbine, something like a jet engine or something like a gas turbine, but we’re not using gas, we’re not burning anything. It’s just simply the high temperature is sufficient to drive these turbines.”
Kevin Moriarty says they have calculated what it would cost to use the company’s processes to remove all the intermittency from the South Australian electricity grid. The answer is $3-4 billion.
“That could remove the need for expensive interconnectors to the East coast and … the state could have more renewables and have energy security.
“It potentially can pay for itself. We worked on the premise that it will be paid for because the fact is your cost of generation is going down. The cost of wind and solar is zero once you’ve amortised your capital, so we’ve allowed for that, and so you basically could end up with a situation where you’ve removed the intermittency, about 90-95 per cent.”
He added that there would need to be some gas generation as a backup, since there are occasionally times when the wind doesn’t blow for a couple of weeks, but that doesn’t happen often. But no coal, and no interconnectors.
Storing energy as heat in silicon looks like it could be one solution to the problem of renewable intermittency; the other is lithium ion battery storage. The advantage of the hot silicon process is that it can be used on a large scale, as part of the state or national grid.
Although Tesla is building what it called a “gigafactory” of large-scale lithium battery storage in the United States, batteries are more likely to widely distributed, as an add-on to household rooftop solar.
But distributed storage can also be part of the solution to renewable intermittency — storing power and feeding it back into the grid when there’s a surplus.
Co-ordinating a push of storage solutions is the sort of work that the Federal Government should be doing as part of a long-term energy plan, rather than try to prop up coal.
