Path to 100% clean energy may be shorter than you think

It’s no secret that the future of energy is renewable, and California is leading the way.

It’s also no secret that the road to a 100% clean energy future could be bumpy. Reaching our state’s goal of 100% renewable energy by 2045 through wind, solar and other renewable sources while using utility-scale batteries to smooth out peaks and valleys in generation is possible, but it could prove prohibitively expensive.

The lowest-cost, shortest path to 100% renewable electricity is to add flexible generation to the mix.

But there is a way for California to reach its 100% renewable electricity goals five years ahead of schedule while saving billions of dollars. We can even do it without delaying retirement dates for large legacy plants that burn fossil fuels, as regulators recently voted to do.

World-class energy modeling has unearthed a promising solution, as experts from the global energy company Wärtsilä will detail on March 18 during  a webinar, called California’s Faster, Cheaper Path to 100% Clean Power.

The lowest-cost, shortest path to 100% renewable electricity is to add flexible generation to the mix: small, rapid-start power plants that can run on natural gas now and on renewable fuel as it becomes cost-competitive and widely available.

Adding flexible generation to utility-scale energy storage systems and expanding renewable generation can get California to reliable 100% renewable electricity by 2040 rather than our current 2045 goal. And because it avoids the need to overbuild renewable generation, energy storage, and transmission, this approach would save ratepayers $8 billion along the way.

Renewable energy is increasingly affordable, but variability remains a problem: the wind doesn’t always blow, and the sun doesn’t always shine. But you can’t tell customers to wait until the sun comes up to turn on the lights. And our grid is built in a way that requires a consistent and equal balance between electricity supply and demand.

For now, large legacy power plants are handling this balancing act. But these power plants were not built to switch on and off quickly in response to shifting weather or changing customer demand for power.

And because it can take hours and even days to turn legacy power plants off and on, they must be kept fired up at all times, ready to provide a steady flow of energy at a moment’s notice. They keep burning gas day and night, all year long, no matter how much solar or wind we add to the grid.

It doesn’t make sense to rely solely on energy storage systems which could only keep a city or the state running for a week or so.

In contrast, smaller flexible-generation plants can switch off and on in minutes, efficiently responding to changing weather conditions or demand for electricity, and keeping power flowing consistently without brownouts or blackouts. They can switch on right away when needed, and shut down immediately when they’re not.

They’re also flexible in terms of fuel. They can seamlessly switch to renewable fuels, including emerging  “power to gas” fuels created from excess renewable energy.

I’m a battery guy. I run Wärtsilä’s energy storage group, and have been part of the energy storage industry for nearly 10 years, so I’m a true believer in the role storage will play in enabling our 100% clean energy future.

But for now, utilizing energy storage as California’s only form of flexibility to ensure a steady flow of renewable power isn’t the optimal, most cost-effective solution. Given current technology and its limitations, it doesn’t make sense to rely solely on energy storage systems which could only keep a city or the state running for a week or so.

And while battery technology costs are coming down and capabilities continue to rise, scientists tell us we don’t have time to wait before drastically cutting emissions.

Almost a quarter of the electricity generated in California already comes from the wind or the sun—almost a third if you include geothermal, biomass and small hydropower. And dozens of California cities and counties are already running on 100% renewable electricity.

Expanding renewable power to every corner of California will take smart energy policy and technological innovation. Fortunately, both of those elements are already part of our state’s DNA. California can reach 100% renewable and reliable electricity faster and more affordably than you’d think, and blaze a path to 100% clean energy for the nation and the world.
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Editor’s Note:  Andrew Tang is vice president for energy storage and optimization at Wärtsilä Energy Business, a leader in smart technologies and lifecycle solutions for the energy market.