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California’s guiding light to 100% renewable energy

7 min read

03 Nov 2020

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Lorelei Yang

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123RF

7 min read

03 Nov 2020

Text:

Lorelei Yang

Photo:

123RF

Wärtsilä’s Path to 100 initiative is helping California plan its transition to renewable energy. Read on to find out what this entails. 

California’s role as a global clean energy leader with a vision for a future powered by renewable energy is well known. The state has a lofty goal of generating 100% of its electricity needs from clean sources by 2045, but meeting that target requires careful planning.  

Wärtsilä’s Path to 100 initiative has analysed the situation in California and offered suggestions on the best way forward. Path to 100 released its recommendations for California’s decarbonisation in spring 2020, and since then the suggestions have captured the interest of both regulators and policymakers.

Becoming ‘part of the solution’

According to Jussi Heikkinen, Director of Growth & Development, Wärtsilä Energy, the Path to 100 initiative stems from Wärtsilä’s vision that the shift to renewables is inevitable and that companies should be part of the solution helping to lead this transition.

The Path to 100, which looks at different utility systems in a broad range of countries to help develop tailored plans for reaching 100% renewable capacity, is an important part of Wärtsilä’s commitment to lead the renewable energy transition. 

“We use sophisticated computer modelling to figure out how the power system should be developed, and we do not just present the optimal end solution, but how they would execute the plan through the years,” Heikkinen explains.

Outside-the-box solution

A detailed plan like the one proposed by Path to 100 is critical for California’s success, according to Jesus Arredondo, Principal and Founder of Sacramento-based Advantage Consulting, a governmental and regulatory affairs consultancy. Arredondo contends that California’s enthusiasm for a “very aggressive approach to renewable power” is not currently backed by sufficiently detailed executional plans for achieving its goal.

In particular, Arredondo notes that California’s reliance on mandating batteries to offset shortfalls in energy availability in the evenings and when the wind doesn’t blow is inadequate to meet the challenge of powering the entire state. This is particularly true considering that other Western states have enacted their own renewable portfolio standards, limiting the amount of excess capacity they can provide to California.

“Coal, which used to be the most common source of surplus energy in the West, is being shut down,” says Arredondo. “That electricity is no longer available, so the excess capacity in the rest of the West is dwindling and is being consumed at home, and not being exported to California.”

With this in mind, the Path to 100 plan proposes using the oversupply of renewable energy – which would otherwise be dumped or wasted – to provide energy for the power-to-gas process. In power-to-gas, CO2 captured from the air is combined with hydrogen produced from water using electrolysers, to form synthetic, renewable methane. When burned, the resultant fuel emits CO2 that was originally taken from the air, making the process carbon neutral.

By transitioning to synthetic renewable methane, which can be inserted in the existing natural gas grid with large storage capacity, California can use flexible thermal generation capacity built today as part of the plan for balancing renewables in a 100% renewable future. This thinking allows the state’s utilities to invest in flexible thermal capacity to ensure security of supply at all weather conditions, without concern that the assets will become stranded as California’s renewable energy commitment target dates approach. It also allows for thermal capacity for reliability purposes at a dramatically lower cost than alternative pathways.

Additionally, power-to-methane would allow California to avoid overbuilding renewable generation and battery storage. Because wind, solar and batteries have very low load-carrying capacities for capacity reserve margin purposes, each megawatt of thermal capacity retained in a 100% renewable system offsets the need for multiple megawatts of solar or wind capacity that would not be used continuously. This of course would lead to excessive cost of electricity for consumers. Finally, because the power-to-gas process absorbs overgeneration, the Path to 100 proposal would maximise the utilisation rates of wind and solar, making sure these assets are used to their fullest extent, and ensuring competitive cost of power.

This plan would cut the amount of land needed for solar panels and wind turbines by hundreds of square miles, thereby lowering costs, alleviating land-use conflicts, and mitigating habitat loss concerns. In sum, power-to-gas could help California reach its clean electricity goal by 2040 –five years ahead of the 2045 deadline.

Interest in the initiative

The California Independent System Operator (CAISO), which oversees the operation of California’s bulk electric power system and its electricity market, is interested in the Path to 100 initiative. CAISO recently requested that Wärtsilä advise them and provide guidance to independently validate the Path to 100 study findings.

Thanks to active participation in the Path to 100, Wärtsilä is “getting a lot of positive traction from the industry,” Heikkinen says. “People are contacting us to find more information, and think, ‘these guys are offering unique and workable solutions for decarbonizing the power systems,’ and that interest opens many doors for us elsewhere.”

Arredondo is similarly positive about the Path to 100’s reception in California.

“The Wärtsilä study is something positive for the state to consider. What we’re realising from a policy, regulatory, and political perspective is that there’s no single silver bullet that will keep the lights on in the future if we’re going to maintain a reduced carbon intensity goal and a goal to go green. Everything that’s viable has to be considered,” Arredondo says.

Looking ahead, there is a real possibility that the Path to 100 study – and in particular, its way of approaching renewable energy modelling – may become a valuable input in the development of California’s path to 100% clean energy. CAISO scientists and engineers are already conducting a simulation review of the plan and soliciting Wärtsilä’s guidance with regard to the setup of its own model. Meanwhile, policymakers, Wärtsilä, renewable fuel trade organisations and gas utilities are working together to expand California’s definition of “renewable fuel” to include synthetic renewable methane and other renewable fuels, such as hydrogen.

If all goes well, California may adopt the Path to 100 within the next three years. Should Wärtsilä succeed in California, it is possible that renewable methane will gain traction with other US utilities, including giants like Duke Energy and Southern Company, which are closely monitoring the adaptation of the Path to 100 plan in California.