Mainspring Energy
Update for the turbine?
You have to hand it to the turbine. It has really managed to hang in there as the go-to generation technology over the last century. And it seems poised to be around for much longer. Even with the most frontier technologies vying to provide the baseload power of the future, it is like “we’ll use unimaginably powerful lasers to harness to forces that power the sun!! And then we’ll take that energy…. and use it to make steam and turn ye olde turbine to create electricity”. The electric turbine has been basically unchanged forever - spinning a rotor inside a coil to create an electromagnetic field. It is basically the same for fossil generators driven by steam or expanded gas, or for hydro power and wind turbines. This makes the work being done at Mainspring Energy to innovate on the turbine particularly intriguing. Their technology is particularly focussed on replacing today’s backup generators, to offer a cleaner, more efficient way to use natural gas, and then renewable fuels, as flexible, distributed resources to back up variable renewables. I tuned into Shannon Miller, co-founder and CEO, on Watt It Takes podcast to learn more.
The principles behind electricity generation with turbines have been understood for almost 200 years, first demonstrated the the Faraday disk invented in 1831:
Today’s generators work with the same principle of creating an electromagnetic field by spinning a core, or rotor, inside a stator. The rotation is created by generating steam (like with coal or nuclear) or by combusting and expanding gas like a jet engine (like with natural gas combined cycle), or indeed with hydro or wind power :
Mainspring’s technology, instead of having a core rotating inside a stator, has magnets moving back and forth inside copper windings. Short video available here:
Because the technology uses a low-temperature reaction (so no spark or combustion), even when it is run on fossil fuels it (apparently) has lower carbon emissions than it would with other fossil generation technologies. [The company seems a bit cagey about what this low-temperature reaction actually is. They have a short technical brief on their website, which is clear that the low temperatures of less than 1500 degrees C avoid the creation of NOx but doesn’t specify what the reaction actually is, so I’m assuming it still looks like combustion for hydrocarbons in that it produces CO2 and H2O.]
The company says that each of its 250kw units using natural gas saves 450 tonnes of CO2 per year when compared to using electricity from a nat gas-powered grid, and 1400 tonnes per year when using renewable fuels.
Mainspring’s software allows the technology to be flexible on the fuel type - natural gas, biogas, hydrogen (ideally of the the low-carbon variety) and are also developing ammonia compatibility.
Kroger, the supermarket chain, was their first pilot customer. The 250kw system fits into the size of a parking space and generates about the amount of power a supermarket needs.
PG&E is first utility to use Mainspring to supply energy to the grid. The utility needs to shut off power-lines during high winds to avoid starting wild fires [something they are particularly hot on now after just paying a $55mm fine], at which point they use local diesel generators and micro-grids. In this case, Mainspring’s generators were run on biogas, displacing the carbon, NOx and particulate pollution of diesel.
Pragmatic optimism - one of Mainspring’s core values - developing companies, particularly with hard technologies, will involve running into set backs and challenges and the team needs to move forward with an optimism that they will find a solution.
Excellence without Ego - another cultural principle - the people who are the best at what they do are always looking for ways to improve and have the humility to take feedback and improve. Timely tactical feedback is hugely important for learning. [This is something that resonates strongly with yours truly. I did Seth Gogan’s AltMBA program a few years back, which has tight feedback loops in a trusted environment as a core component. Really powerful.]
On innovation, The Innovation Stack book, suggests that you don’t build companies by solving a single problem, but that by solving an initial problem, you create 3 more which need to be solved, and solving those causes new problems, etc, etc, and then when you have a solved enough problems you have a viable system and a real technical moat.
White paper
"In Mainspring’s linear generator, electrically-controlled linear motion of oscillators compress a fuel and air mixture until the mixture reacts uniformly and near instantaneously without a flame or burning. Since there is no flame or burning (i.e., no combustion), the reaction occurs at low
temperatures (less than 1500 C) and, as a result, produces near-zero NOx emissions."
vs web site
"Mainspring’s linear generator uses a low-temperature, uniform reaction that maintains peak temperatures below the levels in which NOx forms (1500°C), resulting in near-zero NOx emissions. This is in contrast to the burning of a fuel with a flame, which creates high temperatures and high NOx emissions."
That still is combustion but probably using something like homogeneous charge compression ignition (HCCI).