To Harness Innovation In Renewables, Make The Grid More Flexible

The last day of April this year was a typical spring day in California. The sun was shining, the wind was blowing and spring meltwater was flowing. With conditions ideal for solar, wind and hydropower, the state achieved a notable first in energy: For about an hour, renewables provided 100% of California’s electricity and a tantalizing glimpse at a net zero future.

As momentous as that milestone was, the state still has a long way to go before it has enough capacity to power its grid continuously without carbon. New sources of renewable power are appearing all the time, from solar shingles to solar farms, and eventually maybe even solar roads. For these photovoltaic innovations to have the most impact – converting light into emission-free electricity – we need to build a grid that can ensure dependable, consistent power as it incorporates these technologies.

“We need novel sources of renewable energy to continually emerge, but ensuring grid reliability is critical to harnessing their promise. This tension between innovation and reliability is the fundamental challenge of the carbon transition.” – Takajiro Ishikawa, President and CEO of Mitsubishi Heavy Industries America

A more flexible grid

Adding more wind and solar power generation to the grid is essential to the transition away from carbon. But because those sources are not constant – sun and wind, by nature, are intermittent —there will inevitably be times that solar and wind generation fall short of demand. This variability complicates power delivery on a grid that must balance the energy produced with the energy consumed on a second-by-second basis without interruption.

As Takajiro Ishikawa, President and CEO of Mitsubishi Heavy Industries America, notes, “We need novel sources of renewable energy to continually emerge, but ensuring grid reliability is critical to harnessing their promise. This tension between innovation and reliability is the fundamental challenge of the carbon transition.”

When demand for electricity rises, power companies need the ability to increase supply without delay; the alternative is brownouts and blackouts. In practical terms, power providers must maintain capacity to produce more electricity than is being used at a given moment. Yet they need to fire up that capacity strategically and flexibly, because when production exceeds demand, power companies need to shed the excess load to keep the grid stable. For example, on the day in April when California provided 100% of the power needed by using renewable sources, the state wound up selling excess electrons to other electricity suppliers.

The more that renewables are introduced to the grid, the greater the risk of intermittency becomes and the more urgent the need is to balance loads quickly and seamlessly. This evolution of the grid creates a challenge for producers. Much of existing power-generation infrastructure requires too much start-up time to be dispatched expeditiously.

“Balancing reduced emissions and reliability is key to advancing prosperity while reinventing the grid for a clean energy future.” – Raul Pereda, President and CEO of Mitsubishi Power Aero

One solution is aero-derivative gas turbines. They can produce power on demand with little start-up time and the flexibility to then scale up and down rapidly, which helps to continuously match supply with demand. This enables grid operators to add more renewables to their grids without sacrificing reliability. These peaking plants are ready when needed to power up swiftly and fill gaps between demand and the production from other sources. What’s more, these turbines can run on an expanding range of fuels, such as natural gas, LNG, propane and soon a hydrogen-natural gas blend, enabling them to evolve toward low- and no-carbon solutions.

“Balancing reduced emissions and reliability is key to advancing prosperity while reinventing the grid for a clean energy future,” says Raul Pereda, President and CEO of Mitsubishi Power Aero, a leading provider of global power solutions energized by aero-derivative gas turbines.

Looking for win-wins

An increasingly flexible grid will open opportunities to capitalize on today’s wealth of innovation in renewables. For example, Project Nexus, which breaks ground this fall, will provide proof of concept for operating solar panels over the canals that move water throughout California.

It’s the first project of its kind in the United States, but the concept has been gaining momentum in the hot, dry climate of rural India. A recent study found that installing solar panels over California’s 4,000 miles of canals could prevent 63 billion gallons of water from evaporating each year while also supplying 13 gigawatts of electricity – about half what the state needs to meet its renewable energy goals.

Agrivoltaic solutions, which site solar installations on farmland, offer similar win-win scenarios. The panels provide good microclimates for shade-loving crops as well as forage for sheep, which in turn keep the grass and weeds trimmed without the need to burn fossil fuels.

The energy transition demands many such solutions. In our increasingly electrified world, they must work in conjunction to deliver clean and reliable electricity around the clock. To make California’s April 30^th milestone an everyday reality, we must act with creativity, urgency and foresight to meet today’s energy needs while building the flexible, resilient energy system of tomorrow.

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