California Democratic leaders want their state to commit to a future of 100 percent renewable electricity, a goal approved so far by only one U.S. state—Hawaii.

Top officials in both places hope their policies will serve as a model for others as the Trump administration rejects actions on climate change.

California and Hawaii offer very different models for committing their power sectors to clean electricity. They differ on everything from mandate deadlines to what's considered renewable.

"For the country as a whole it shows the laboratory effect of having states take the lead on this issue," said Ethan Elkind, director of the climate program at the University of California, Berkeley, Center for Law, Energy & the Environment. "As Hawaii and California take the lead, it will provide examples of how it can be done for other states, both good and bad."

Hawaii passed its 100 percent renewable electricity mandate with a 2045 target two years ago. The Aloha State at the time had no blueprint for how to make it happen. Much of it remains in the planning stage, though leaders argue it's achievable.

"We are ahead of schedule on our path to 100 percent renewable energy goal," Hawaii Gov. David Ige (D) said at a clean energy summit this summer. "We are making significant progress toward getting off of fossil fuel and into clean energy, more aggressively than any other community in the United States."

In California, legislation offered by state Senate President Pro Tempore Kevin de León (D) provides a two-tiered approach to hitting the 100 percent mark. S.B. 100 mandates that utilities make 60 percent of their energy from renewables by 2030.

The remaining 40 percent of power falls under a "zero-carbon" requirement, with a deadline in 2045. Electricity sellers could meet the mandate with large-scale hydroelectric power, which isn't allowed under the renewable portfolio standard rule. It also allows room for future technologies, supporters said.

"We do 100 percent clean energy, we do it right, we quantify positive results," de León said in a recent call with reporters. "This is a very wonderful opportunity that we have, to send a very clear message to Washington that with or without their help, California will continue to lead on this critical issue.

"It's an ambitious goal; there's no doubt about that," he added. "I want to be very clear, it's also achievable. It's within reach."

De León recently traveled to Hawaii, where he met with Ige and others.

Goal creates momentum—supporters

Hawaii's effort took an important step this summer. The state Public Utilities Commission accepted a power supply improvement plan (PSIP) from Hawaiian Electric Co., the utility that provides power through subsidiaries on Oahu, Maui and the Big Island.

The document was the company's third iteration of that plan after the state agency rejected earlier ones. Because the PUC accepted, yet did not approve, the plan, renewables projects henceforward must gain clearance.

"When they passed the law, they definitely had no idea how it was going to work. Even today, we're still trying to figure it out," said Isaac Moriwake, an attorney with Earthjustice in Hawaii. "The magic of the RPS is you set the goal. You send a clear signal to the market that we're headed for that destination, then the market and the technology does the rest."

Hawaiian Electric Co. said in its PSIP that it would maximize distributed energy resources, make "high use" of demand-response programs to get people to reduce consumption when needed, "aggressively seek grid-scale renewable resources," and "preserve long-term flexibility to use emerging technologies and accommodate changing circumstances."

It said that "increased energy efficiency, the willingness of communities to accept projects, supportive and adaptive public policies, and partnerships to take advantage of new and improved technology are critical."

Hawaii's passage of the 100 percent RPS followed a rooftop solar boom driven by high electricity prices. The state burns fuel oil to make electricity, and costs spiked after the Fukushima disaster in Japan, when that country curbed nuclear power.

Hawaii residents added so much rooftop solar that the utility on Oahu severely limited new connections for months. The state revised its rooftop solar benefits by eliminating net energy metering, where residents earn bill credit for excess power sent to the grid. That led to a new trend of people adding energy storage with solar, Elkind said.

New technologies and cheaper costs on existing ones are now needed to reach the 100 percent goal for both states, Elkind said. Hawaii and California also need to work out a number of issues on land use, existing and emerging technologies, grid integration, and costs, he said.

"They are still both basically aspirational," Elkind said of the states' goals. "They're both still far enough off into the future, it's a bit of a leap of faith that this can be done economically. We know the technologies are there, but there's huge question marks around the cost of transitioning to solely 100 percent renewables."

That's why both states are aiming for "relatively far-off dates," Elkind said. That gives time for technologies to develop.

"If we did the transition right now, the costs would be really high," and that would jeopardize political support, he said. As well, "it would create serious operational challenges for the grid."

What's renewable?

Hawaii and California define renewable power differently.

California under S.B. 100 for its RPS allows solar; wind; geothermal; biomass; small hydropower; renewable gas such as biomethane; and wave, ocean current and waste conversion technologies, though none is commercially available.

Retail electricity sellers can buy a small number of renewable energy credits tied to rooftop solar systems. That number is limited to 10 percent of their compliance obligation. Electricity generated by rooftop solar helps utilities indirectly by reducing the amount of electricity—potentially fossil-fuel-generated—that those companies have to make.

Hawaii allows a slew of technologies to count as renewable: solar, wind, hydroelectric, biofuels and geothermal. It also includes biomass crops, agricultural and animal residues and wastes, and municipal solid waste; biogas, including landfill and sewage-based digester gas; ocean water, currents and waves; and hydrogen produced from renewable energy sources.

Additionally, it allows part of a sector known as combined heat and power. A commercial business can use a generator—powered by a mixture of liquefied natural gas and synthetic natural gas—to make electricity, for example. The affiliated utility can count the on-site heat the system produces as renewable, said Henry Curtis, executive director and vice president at Life of the Land, an environmental and social justice activist group.

Residential rooftop photovoltaic output also is counted in the RPS. The energy is added to the amount of green power utilities say they generate, and the generation amount gets subtracted from the total electricity sales utilities report.

That means the RPS isn't actually 100 percent, Curtis said, as a utility theoretically could claim more than 100 percent.

"It's absolutely inaccurate to say that Hawaii has a 100 percent RPS law," Curtis said. "It's simply a statement that you can throw out to say in the international press."

There are bills in the Hawaii Legislature "to close that loophole," Moriwake said. Curtis, however, said that so far, there hasn't been any push to pass one of the measures.

Greenhouse gas impacts

Hawaii's PUC in approving energy systems has said it doesn't need to look at greenhouse gas emissions, Curtis said. He said there is a proposal on the Big Island to create biomass that would burn eucalyptus trees.

"We're in a period of enormous turmoil, so many people have proposed many ways to get there," Curtis said.

Life of the Land is looking for a lawmaker to carry a measure that would require state agencies to track and seek reductions in greenhouse gas emissions. Hawaii's Legislature will return to session in January.

California, in contrast, must meet its strict greenhouse gas emissions goals at the same time as it's seeking to ramp up green power production. Under S.B. 100, zero-carbon electricity sources cannot increase carbon emissions anywhere on the Western grid.

Robert Harris, spokesman for the Alliance for Solar Choice, an advocacy group with Sunrun Inc. and others, said market forces eventually will push all states toward 100 percent renewables "or close to it."

"Solar and wind are the cheapest sources today," Harris said.

He noted that Texas, a politically conservative state, gets a large share of its electricity from wind because it's less expensive.

On one day last November, wind served more than 46 percent of the load and averaged 41 percent throughout the day in Texas. However, natural gas made up 48 percent and coal 28 percent of the Lone Star State's electricity production in 2015, according to the Electric Reliability Council of Texas, which operates the electric grid for most of the state.

Currently, 1 in 3 single-family homes in Hawaii has solar power, and "you can expect that to increase as the price drops," Harris said. Energy storage prices also are falling.

Sunrun has offered solar, plus storage leases, on the Big Island starting at 19 cents per kilowatt-hour, versus utility rates of 32 cents per kWh, Harris said.

"The energy future everyone has talked about is going to be happening in Hawaii in real time, and hopefully is going to become an example for the rest of the world, what can happen if you allow it to happen," Harris said.

Right now, there's a push to get as much utility-scale solar and wind online as possible while federal tax credits remain in place. Hawaiian Electric Co. has requested proposals for projects from renewable companies and landowners.

Meanwhile, Hawaiian Electric has submitted a grid modernization plan to the state PUC. It proposes adding the cost of upgrading the grid to electricity rates.

Calif. on track to 45% renewables

California's Legislature is expected to shortly take up S.B. 100. The Senate Appropriations Committee recently passed the measure and sent it to the chamber floor.

California's largest utilities already are slated to generate enough renewable power to get close to meeting the state's current mandate of 50 percent from renewables by 2030.

San Diego Gas & Electric Co. has contracts that should hit 45.2 percent from renewables by 2020. In that same year, Pacific Gas & Electric Co. could reach 43 percent green power, and Southern California Edison is expected to hit 41.4 percent.

S.B. 100, if passed, would apply to three large investor-owned utilities, municipally owned providers, and community choice aggregation (CCA) programs, groups that receive electricity procured by local governments and delivered by the incumbent utilities.

The measure is considered relatively noncontroversial, but that could change easily. The bill is expected to move forward, given that its sponsor, de León, controls the Senate. That means legislators likely will try to add amendments, according to observers, though it's not clear if de León will allow any on the floor.

Some want the measure to open California's grid to other users, so Western states could take California's excess solar energy and the Golden State could import wind or other renewables from Wyoming, Iowa or other states. That could help build support for renewables in politically conservative states, Elkind said, while spreading the environmental and economic benefits.

There's some resistance to that idea, since it would invite oversight from the Federal Energy Regulatory Commission. However, Laura Wisland, a senior energy analyst at the Union of Concerned Scientists, said it's "really an up-or-down decision" for FERC and that the agency would be unlikely to meddle with the marketplace.

The fight over counting rooftop solar as part of the California RPS is considered settled. It was fought as part of S.B. 350, the de León measure that hiked the RPS to 50 percent by 2030.

"We want to make sure that what we're getting is replacement of existing gas-fired energy by renewables, and efficiency, and demand response, and battery storage," said Kathryn Phillips, director of Sierra Club California.

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.