Power-to-gas could be key to California’s long-duration storage needs, stakeholders say
Dive Insight:
California is aiming to supply all its electricity from carbon-free resources by 2045, and the big challenge is going to be meeting those goals while maintaining a very high level of reliability in a cost-effective manner, Jan Smutny-Jones, CEO of the Independent Energy Producers Association, said during the webinar.
The state’s current plan is to basically add a lot of solar and wind power, and back it up with battery storage. That strategy will likely lead to excess solar and storage which will then need to be managed, he said. Given this context, Wärtsilä’s proposal, to leverage excess renewables to produce hydrogen and methane, “is an interesting plan and worthy of further consideration as we think about our plan for meeting our 2045 goals,” he said.
Wärtsilä’s roadmap — initially presented during a webinar in March and then updated with a scenario based on hydrogen production — could help California reach its clean electricity goal five years ahead of the 2045 deadline, according to the company. It requires a quicker build out of renewables and battery storage than is currently laid out by the state’s integrated resource planning process, and then deploying power-to-gas technology to siphon off the excess renewables closer to 2045.
Any power system moving closer to 100% renewables will have huge amounts of over-generation, which will then need to be dumped somewhere, Ferrari said. But with power-to-gas technology, excess renewables can be sucked up either to electrolyze water, creating hydrogen, or power a methanizer, which produces methane. This methane is a “renewable, carbon-neutral fuel” since its production is powered by renewables, its ingredients are air and water, and any carbon released in the process was originally taken from the air, he said.
“This fuel can be put right into existing natural gas storage and distribution [networks], or be converted to [liquified natural gas],” he said.
Power-to-gas also presents a new approach to storing energy, Ferrari said. Batteries and other short-term storage technologies can continue soaking up excess renewable energy during the day to release back on to the grid at night — but after the batteries are topped off, the remaining energy can be put into renewable fuel production week after week, building up a big store that can be converted back to electricity using the fleet of thermal assets when it’s needed.
This solution enables seasonal time shifting, and would also handle multiple days of rain, which could limit solar generation and deplete storage systems with 12-hour durations or less, he added.
|
