Power electronics, advanced software: Inside the digital power generator designed for the 21st century.

How Adaptive Pressure Cycle™ technology provides the three capabilities the changing grid needs most.

Transformations are difficult to see clearly while they’re happening, and today’s rapidly changing grid is no exception. Electricity demand from AI data centers, electrification, and manufacturing is surging far beyond precedent—and what existing grid infrastructure can deliver on its own.

This surging demand, in combination with aging infrastructure and transmission and distribution bottlenecks, is calling for more new, firm capacity. More broadly, it’s calling for new ways of meeting these power needs in a way that will ultimately transform the supply and operation of power infrastructure in the 21st century.

What does this mean in practical terms? It means supporting changing use cases: Powering customers independently until the grid is ready to serve them, and then working in tandem with it once it arrives. Providing firm power to support intermittent resources like solar and wind. Offering flexibility to adapt to fuel availability and fluctuating prices. And being able to meet stringent emissions standards and earn community support that can determine the future of a project.  

In 2010, Mainspring set out to redesign the power generator from the ground up, and in doing so anticipated many of the critical requirements of power generation today. That power generator is here, the Mainspring Linear Generator, and its core technology allows it to provide the three capabilities the changing grid needs most: high efficiency, low emissions, and fuel flexibility.

A different way to make power.

This core technology is called the Adaptive Pressure Cycle™, or APC. It operates on a principle that is remarkably simple and made possible by a combination of proprietary software and advances in power electronics that also enabled solar, wind, electric cars, and batteries. Inside the linear generator, picture two metal tubes, called oscillators. When the oscillators slide toward each other, they compress a mixture of fuel and air trapped between them. With enough compression, the mixture reacts, without a flame, increasing the pressure and pushing the oscillators apart again. As they move, magnets inside the tubes pass through coils of copper wire and generate electricity.

High efficiency.

The reaction that releases the fuel’s energy occurs at the point where the oscillators stop and then return. Efficiency depends on controlling exactly where that happens, to 100 micron precision, or within the width of a piece of paper. APC provides that precision, making adjustments up to 5,000 times per second. As a result, more of the fuel’s energy becomes electricity, which means lower fuel costs and emissions, regardless of the fuel used.

Low emissions.

The same precision that makes the reaction efficient also keeps it clean. Nitrogen oxides, or NOx, form when the nitrogen and oxygen reach very high temperatures. APC holds the reaction temperature below the threshold where NOx formation rises sharply, because the position of the oscillators sets how much the mixture is compressed and therefore how hot it gets. There is no flame to create local hot spots. The result: emissions low enough to meet stringent air quality standards without added aftertreatment, which can accelerate project siting and permitting.

Fuel flexibility.

The amount of compression required to generate electricity depends on the fuel, and APC adjusts for the differences in real time. Natural gas requires a different amount of compression than propane or hydrogen or biogas. This allows customers to change fuels in response to price and supply fluctuations without requiring new equipment. It also allows for the transition to lower-carbon fuels as they become available.

Simple to imagine, hard to achieve.

The concept of the Adaptive Pressure Cycle may sound simple; the execution is not. Precisely calculating and adjusting the right amount of compression depends on the fuel, the load, and even conditions like the outside air temperature and pressure, factors that can and do change from second-to-second.

To unlock the potential of producing electricity more efficiently, Mainspring has rebuilt the generator from the ground up, developing software and control systems able to provide the exacting control the linear generator needs. At its core, Mainspring created a digital generator whose flexibility and adaptability are enabled by software rather than limited by mechanical parts. 

The monumental changes reshaping power demand necessitate a new approach to generating electricity, one designed to provide high efficiency, low emissions, and fuel flexibility. That approach also has to meet today’s power needs and remain valuable over the long-term, as the grid continues to change. Mainspring has already built, tested, and deployed exactly this technology at scale.