UPDATE September 10, 2018: As expected, Gov. Jerry Brown has signed SB 100 and it is now law.

California is one signature away from committing to 100 percent clean electricity. If it does so, it will become the most significant political jurisdiction in the world to take that step, by a wide margin. (It is the world’s fifth-largest economy!) The state is on the verge of making history — again.

SB 100, the bill sponsored by state Sen. Kevin de León, would set a target of 100 percent carbon-free electricity by 2045. It passed the California Senate last year, passed the state Assembly on Tuesday, and was reconciled by the Senate on Thursday. All that remains is a signature from Gov. Jerry Brown, which is expected soon (though there’s a bit of fuss around that — more on that in a second).

How big a deal is this?

Very big. For one thing, there’s enormous power and symbolism in “100 percent.” This instantly sets a new marker for others to match. I guarantee, before this time next year, there will be news of ambitious states, provinces, or countries following California’s lead.

But it’s also important to understand that SB 100 is not some big leap for California, or a flash out of the blue. It’s another step in a path — toward less pollution and more clean energy — that the state has been walking steadily for more than 15 years.

Its critics try to cast it as a bastion of heedless, irresponsible liberalism, but in fact, California’s transition to clean energy has been careful and deliberate. SB 100 is the logical next step.

I am endorsing #SB100. To the Legislature: We are Californians. We don’t wait. We build the future economy here. https://t.co/ksZJsglBbt — Arnold (@Schwarzenegger) August 28, 2018

In a sense, the SB 100 story is quite simple: It’s smart, well-crafted policy, with broad support (from almost everyone except a few energy-intensive industries like agriculture and petroleum), that passed by a fairly comfortable margin. For a critic like me, there’s not much to criticize!

There are a few interesting aspects and tidbits worth noting, though. Here are a few things about the bill that might help at your next cocktail party.

Brown is making veto noises because he really wants regionalization

Rumor has it — though he’s made no public statement to this effect — that Gov. Brown is threatening to veto SB 100 if legislators don’t also pass AB 813, a bill that would set California on the path to joining a larger regional Western power market.

California Gov. Jerry Brown is apparently withholding his signature from historic #SB100 bill legislators passed last night, to "persuade state lawmakers to back his own priorities, including a measure to create an expanded Western electricity market."https://t.co/PZolVACPZb — Alexander Kaufman (@AlexCKaufman) August 29, 2018

Joining a regional market, i.e., “regionalization,” is controversial (I did a deep dive on it if you’re interested). AB 813 has been amended several times in response to criticisms; opponents of regionalization still contend that it’s powerless to prevent the feds or other states from interfering with California policy.

Those disputes are very much unresolved, and the legislative session ends tonight (Friday) at midnight. Barring some miraculous last-minute dealmaking, AB 813 probably won’t pass, and so Brown’s bluff will get called.

[UPDATE Sep. 1, 2018: AB 813 did not come up for a vote — so the ball is in Brown’s court now.]

#AB813 will not be moved to the Senate Floor for a vote this year. We will continue this important discussion next year. — Senator Toni Atkins (@SenToniAtkins) September 1, 2018

In the end, most people I’ve spoken to expect him to sign it. It would certainly be seen as a massive, petulant self-own if he doesn’t — a black mark at the end of an otherwise remarkable climate legacy.

This is de León’s baby, and he has cared for it skillfully

There’s interesting backstory on these two bills.

Last year, SB 100 and AB 813 were before the legislature, but they were linked, part of a package (in part at Brown’s insistence). And the controversy over regionalization brought SB 100 down with it. [Clarification Sep. 1, 2018: This language is somewhat misleading. The bills were not part of a formal legislative package. Rather, backers of 813 (with Brown’s support) refused to let 100 go forward unless 813 did too — and vice versa. So they fell together in 2017. This year, 100 was allowed to move on its own.]

After that, the bill’s backers worked to keep the coalition behind it — environmentalists, cleantech, Indivisible, faith groups, business groups — together. De León (who is currently running for Senate against Dianne Feinstein) refused a range of amendments from both union and utility lobbyists, keeping the bill simple and direct enough to command broad support. And the coalition showed up in force when the bill went through the Assembly Utilities and Energy Committee, ensuring its passage on a party-line vote.

Over the summer, there was talk that Brown would again try to sandwich SB 100 together with regionalization (and possibly SB 901, a bill on utility liability for wildfires), but de León insisted on a separate vote.

“I’ve always made quite clear,” de León told me when I asked about the connection between SB 100 and regionalization, “that each measure needs to move forward on its own merits. Any attempt to link them undermines our climate leadership and sends a horrible message to the rest of the world.”

Clear enough!

So SB 100 got its separate vote, and passed. It is now legislatively “severable” from regionalization, in the lingo. “Decarbonizing our grid,” de León told me, “is easily within reach.”

Through all this, Brown scarcely lifted a finger to help SB 100. He shopped around some destructive amendments in committee, which were not adopted, but otherwise has not expressed a position on the bill or done much of anything to support it. Now he might get stuck with it, and not his beloved regionalization bill.

But still. Vetoing it? That would be ridiculous.

By remaining flexible, SB 100 created the coalition climate policy so badly needs

Climate policy is notoriously fractious, with warring camps fighting over carbon taxes, nuclear power, renewables, and just about everything in between. Divisions in the climate coalition helped bring down the Waxman-Markey cap-and-trade bill back in the day and, more recently, a carbon tax initiative in my home state of Washington.

Yet somehow, everyone saw themselves in SB 100. Labor and business, nukes and renewables, markets and mandates, cats and dogs — somehow the bill hit the sweet spot. It contained enough substance to matter, but not so many bells and whistles that everyone found something to hate.

A great deal of its appeal (though not all) can be traced to its flexibility. SB 100 actually sets three targets for California:

50 percent renewables by 2026

60 percent renewables by 2030

100 percent carbon-free energy by 2045

Note the difference between “renewables” and “carbon-free.”

The first two targets are simply amendments to the state’s existing renewable portfolio standard (RPS), which has been creeping up for a while.

The California RPS was established in 2002 with the goal of 20 percent renewable energy by 2017. In 2006, it was bumped up to 20 percent by 2010. In 2008, then-Gov. Arnold Schwarzenegger set a target of 33 percent by 2020. In 2015, the legislature passed SB 350 (also sponsored by de Leön), which set a new target of 50 percent by 2030.

The state’s utilities have met these escalating targets easily, in advance, which is why they keep getting raised. Today, most utilities have met their 2020 targets, and many are closing in on their 2030 targets.

So SB 100 bumps up the RPS targets again.

Despite what the fossil fuel industry would tell you, the targets have never been super ambitious. They’ve actually been quite conservative, just an increment above the trajectory utilities are already on. That’s why they’ve been so easy to meet.

But people who take this as a criticism of the program miss the point. California is steadily raising its floor, looking higher, moving in a consistent direction. That provides a stable, predictable long-term business environment, which draws innovators and market risk-takers. Market dynamism eats targets for breakfast.

In California, you can be quite confident that if you invent or design something that helps decarbonize electricity, it will find a market. That is the “regulatory certainty” Republicans claim to support (and are now destroying at the federal level). The way California got it is by electing lots and lots of Democrats.

It’s the beyond-60-percent target that’s interesting: It must be met with “zero-carbon resources.” Those include renewables (along with “baseload” renewables like geothermal and some biomass), but they also include large hydro, nuclear power, or natural gas with carbon capture and storage (CCS).

This broader language neatly moots a raging argument within the climate community.

On one side are renewable energy fans, who believe that wind and solar (coupled with lots of energy storage) can eventually cover all, or very close to all, of our energy needs.

On the other side are those who believe that getting past 60 percent variable renewables will be difficult and expensive, and help will be needed from other carbon-free resources less popular with the environmental community. (I examined the controversy with a primer here and a deeper dive here.)

SB 100 sidesteps that debate by simply stipulating “zero-carbon resources.” That excludes coal, oil, and (uh-oh) natural gas, but everything else is free to fight it out.

“I want to make sure we allow for flexibility,” de León says, “any creative, innovative technologies that have yet to be invented.”

Renewables fans are free to see SB 100 primarily as a renewable energy bill. They believe that even beyond 60 percent, wind and solar will continue their march to dominance, as storage flourishes.

Renewable energy skeptics are free to see SB 100 as a uniquely flexible “clean energy standard,” which makes room for other clean energy technologies. They believe the state will end up drawing heavily on hydro, CCS, and (who knows, maybe someday) nuclear.

There’s no need to settle that now (2045 is a long way off). SB 100 keeps its focus where its focus belongs, on the goal: reducing carbon. It turns out that lots of people support that goal!

It’s not a transportation bill, but it’s not not a transportation bill

As grid decarbonization proceeds in California, the electricity sector’s carbon emissions decline relative to other sectors. In particular, it is becoming more and more clear that transportation, which represents roughly 40 percent of California’s greenhouse gas emissions, is now the state’s biggest carbon problem — and, realistically speaking, likely a much more difficult problem than cleaning up the grid.

“Twenty-nine million individual California drivers!” de León says. “There’s no question that’s going to have to be tackled in the immediate future.” What’s that going to look like? “I don’t want to get ahead of myself.”

Still, SB 100 is not entirely unrelated to transportation.

Remember: Every vehicle that operates using power from the grid is, in terms of carbon emissions, only as clean as grid electricity. As the grid gets cleaner, every single electric vehicle that draws from it gets cleaner, automatically. SB 100 is a signal to businesses and consumers that every EV purchased in California will get cleaner throughout its lifetime.

The state’s ambitions in the near future are to get lots more electric vehicles on the road. Via executive orders, Brown has not only established a target of 5 million zero-emission vehicles on California streets by 2030, he’s also targeted 250,000 zero-emission vehicle chargers, including 10,000 DC fast chargers, by 2025.

If there is a wholesale shift of transportation to electricity, it could bump up state electricity demand by 50 percent or more. (No one, including the California Energy Commission, is sure exactly how much.)

And that’s to say nothing of what might happen if there are similarly vigorous efforts to transition building heating and cooling and industry over to electricity.

Impending electrification means that the electricity sector is significant far beyond its direct emissions today. It will soon carry a much heavier load, and SB 100 will come to seem far more significant than it does today.

California has cemented its role as US climate champion

It has been repeated so often that it is clichéd, but in what is effectively a climate Dark Ages in the US, California is carrying a torch. It has systematically and deliberately bet on renewable energy, and that bet has paid off for its economy, making it home to a dizzying diversity of clean energy businesses and jobs.

“In 2017, $2.5 billion was invested in clean energy technology in the United States,” the nonprofit research organization Next 10 reports, “with 57.2 percent ($1.4 billion) going to California companies.” And it is already responsible for “about 47 percent of all electric vehicles ever sold in the US.”

Meanwhile, the state’s cap-and-trade system is chugging away in the background, working toward its long-term carbon reduction goals.

Someday, one hopes, the federal government will once again be run by people at peace with modernity, respectful of science, and concerned for the future. When (if?) they do take power, they will have much to learn from California.