KQED's STEPHANIE MARTIN: Tuesday could prove to be a pivotal day in San Francisco's efforts to become a greener city.

The Board of Supervisors is set to consider whether to go forward with CleanPowerSF -- a program that, if approved, promises households and businesses the opportunity to receive 100 percent of their power from renewable sources.

A state law enacted 10 years ago allows municipalities to choose alternatives to electricity providers such as PG&E.

Marin County is the first and only one so far to do it.

If San Francisco decides to follow suit, it, like Marin, would buy its renewable power from Shell Energy, a subsidiary of the global oil giant Royal Dutch Shell.

Ed Harrington is the general manager of San Francisco's Public Utilities Commission and a lead proponent of the plan going before San Francisco supervisors tomorrow.

Mr. Harrington, we'll get into the details of how this program works in just a moment. But first, let's talk about why it's Shell specifically that would get the nearly $20 million contract.  I know it's a company that plans to drill for oil off the coast of Alaska -- not a terribly popular idea with the green-energy crowd in general, much less in this part of California.  Why are they winning contracts in Marin and here, potentially in San Francisco?
    
ED HARRINGTON: Well, you know, this green power thing with local governments is pretty new in California, and so, what happens -- we've gone out three times and tried to get somebody that is willing to go out and put their line of credit up there to actually purchase the power for us. Shell is the only one that's responded.

MARTIN: So, I'm a San Francisco resident. How do my energy options change if the supervisors approve this plan?

HARRINGTON: So the good news here is that all the same thing happens with PG&E in terms of if you move, if you have a problem with something, you get your bill, you pay your bill -- all that stays with PG&E. What this does is this allows people to choose whether they want to buy the relatively brown power from PG&E, or whether they want to have us provide power to PG&E for them, and our power's 100 percent green.

MARTIN: How much more will ratepayers pay for this program, and why can't the program be competitive and lower than PG&E's current rates, as originally envisioned?

HARRINGTON: People will pay more depending on how much they use. About 40 percent of the people in San Francisco are in what's call Tier 1, which are relatively low users of PG&E electricity. They will pay, on average, about $9.50. But if you a really big PG&E customer, you could pay more, because it's going to raise your total PG&E bill by around 20 percent per month if you want to join this program.

MARTIN: Now PG&E says it's looking at offering its own renewable power option that's similar, but cheaper. Wouldn't that undermine the project and leave San Francisco financially on the hook for the Shell project?

HARRINGTON: What PG&E is talking about offering starting next year, and we're not sure if they will offer it, isn't really generated green power. What they're going to offer is what's called renewable energy credits, and what that means is that you still provide brown power, but you've bought a renewable energy credit from somebody who might be doing wind in the Altamont Pass, but you aren't buying the actual wind power. You're just buying this asset that the state created that's called an energy credit. That's cheaper. We could have provided a program like that for about the price that PG&E is going to provide it for. We thought people here wanted real green power. Real power that was being generated that was green.

MARTIN: Another issue drawing concern is a plan to automatically enroll half of the city's residential customers. They can opt out, but since they'll be paying more, shouldn't it be an opt-in program?

HARRINGTON: Well, state law only allows us to opt out. That's the only choice we have. And so what we're doing is we're going to phase people in in San Francisco. What happens is you will get two notices before we even start to offer power to you neighborhood. Then you'll start to get power from us if you don't tell us otherwise. But then, you'll be able to opt out for the next two months for free, and after that you can opt out at any time for anywhere between $0 and $5, as our recommendation to our commission.

MARTIN: Who gets enrolled first? Which neighborhoods?

HARRINGTON: We went out and looked at people where our polling showed they were the most interested in this. That tended to be portions of Districts 6, 5 and 8. But anybody in the city -- even if we don't approach them first -- they can opt in.

MARTIN: Ed Harrington, thank you.

HARRINGTON: Thanks.

MARTIN: Ed Harrington is general manager of the San Francisco Public Utilities Commission.