Are microgrids the answer to California’s grid woes?


Andy Tang, Vice President – Energy Storage and Optimization, Wärtsilä


Sept. 9, 2020

When all is said and done, we may look back on 2020 as the key inflection point in the global transition to a more flexible, resilient, and renewable grid. In August, I wrote in Utility Dive how the European experience during the pandemic is demonstrating how high renewable penetration, flexible electricity markets will function in the not too distant future.

The recent experience in California offers another glimpse into the emerging challenges facing utilities and grid operators as they work to keep the lights on with an increasingly climate-strained electric grid.

You are no doubt familiar with California’s recent troubles. But the synopsis is this: a heatwave that saw temperatures climb into triple digits had two compounding effects on the power grid, resulting in the first rolling blackouts in California since the 2001 energy crisis. The first was on demand. As temperatures rose, Californians cranked up the air conditioning, increasing demand for power. But the extreme temperatures had an impact on the ability of gas-fired generators to reliably deliver power, with several even shutting down just as demand was peaking. Combined with the evening decline of solar generated power, the California Independent System Operator president called this a “perfect storm” grid event.

What does this experience portend for the future of a grid increasingly threatened by extreme weather events, such as heatwaves, wildfires, hurricanes and more?

Microgrids – the ability to isolate and maintain reliable power supply to critical load centers – are a potential solution to many of the safety and reliability challenges facing utilities today. The wildfire-necessitated public power shutoffs in PG&E’s service territory in recent years offer an interesting possibility. By cutting power on high-risk distribution and transmission lines, anything downstream will lose power. With a battery-storage enabled microgrid, critical load pockets such as hospitals would isolate from the grid. Now disconnected from the grid, that isolated system would then form its own grid, managing frequency and voltage.

While the microgrid concept is not new, it has proven a challenge to materialize in the real world. This is because the energy storage technology required to form microgrids add complexity in the operation, optimization and orchestration of grid assets that does not exist with traditional centralized assets.

At Wärtsilä, our GEMS energy management software platform optimizes the performance of individual energy storage and grid integrated assets. But from the beginning, we’ve always seen our platform as more than a single power plant controller. We developed our software from the ground up to be cloud based where a single power plant or storage asset would act as a single node on a network with multiple nodes. Batteries add significant value to grid operators, but they also add complexity. A network consisting of assets from different technology providers will have different command and operation protocols. Batteries require much more active management than a traditional utility asset. Temperatures must be monitored to prevent thermal runaway. State of charge must be constantly managed to ensure long-term safe operation. Utilities already manage hundreds of thousands of data points. Managing the operation of different battery technologies, with varying thresholds for safety and discharge levels, is simply unrealistic.  

We saw that as utilities added these new distributed storage assets that there was a need for a control room tool that could orchestrate these resources in a technology-agnostic way. This was the genesis of our GEMS Fleet Director platform. Fleet Director provides centralized, real-time visibility and control into a global fleet of power plants. It is a cloud-based platform that allows for secure monitoring of equipment, operation history, and alarms from the fleet, power plant, and device level. Combining power plant data aggregation, weather forecasts, region specific market data, renewable and load forecasting, Fleet Director brings unparalleled intelligence to the operation of utility assets. 

Utilities have found particular value in Fleet Director’s ability to seamlessly take energy storage assets from grid control to microgrid control. That level of control has proven to be the missing piece of the puzzle in making microgrids truly viable. Having the capability to keep assets on the grid during normal operations and isolate and manage critical load at the local level during high risk events gives grid operators a level of flexibility and resiliency previously unavailable.   

With the control that Fleet Director offers, multiple distributed storage systems can bond together and act as one resource. This is the future that my colleagues at Wärtsilä are working toward for California and beyond as more storage is added to the grid: a flexible, resilient, and distributed fleet of assets that utilities can isolate and safely operate during high-risk weather or grid events while maintaining service to the most critical load.