Reaching 100 percent renewable energy poses a big challenge for power grid contractors: what to do with inertia. Reactive Technologies claims it will help them identify answers with its innovative technology for calculating this crucial feature of grid stability. For over the past couple of years, global grid operators such as the Australian grid operator AEMO, U.K. National Grid, Italian grid operator Terna, and Tokyo Electric Power Company of Japan have taken up Reactive’s technologies to gain insight into the grid inertia. An undisclosed investment was landed this month from global utility infrastructure supplier Accenture to extend to broader markets.

The GridMetrix platform of Reactive metrics inertia- the standard of frequency stability offered by the rotating generators that have been the cornerstone of power systems for over a century. Such large spinning devices’ kinetic energy helps prevent the frequency from decreasing too rapidly when demand overruns supply or increases too quickly when supply overruns demand. For grid operators, frequency control is a significant challenge that constitutes a primary part of ancillary services that they lease from the power plants, batteries, and fast-responsive loads. If it’s not regulated, it can force rippling outages, even on the power grids with lots of moving mass, even during the year 2003 blackout that affected over 50 million residents in the Northeast U.S. as well as in Ontario province in Canada.

But as inverter-based solar energy increases as a share of grid electricity, and as conventional frameworks for understanding and maintaining inertia continue to break down, Chris Kimmett, director in charge of power grids at Reactive, stated in an interview, the problem is growing. A low-inertia grid implies that the frequency is much more unpredictable and he noted that the almost immediate measures that need to be done to handle it are more difficult to predict and implement.” For instance, when wind turbine safety systems failed amid severe weather, the September 2016 blackout throughout South Australia, which ultimately cost around $360 million in costs, came around a revelation that was only discovered after six months of testing. Another outage that impacts about 1 million U.K. individuals. It was also triggered by the wind farm safety scheme last year.

“It’s possible to manage a low-inertia program,” but it’s pricey, Kimmett stated. Any alternatives provide tools such as synchronous condensers or flywheels that effectively replace “one rapidly rotating mass in a box with yet another large spinning mass in the box.” Another alternative that has been sought in many countries is faster frequency response from the batteries. This is how the reactivity of generators, heaters, motors as well as other grid loads is tapped, as Reactive did in the United Kingdom. The pilot project and, like many other manufacturers of technology, are following.