The Oil Drum

Are you in PG&E's service territory?  I understand they're installing time of day meters in the next year or so - are they going to do that for you?  I would think that would help with making PV pay, as you would be able to sell power to PG&E at a high rate during the day, and charge an EV at night at much lower rates.

"However, the spare capacity, as I understand it, includes hydro, natl gas and other generation that really can't sustain an all out 24/7 production."

As I noted previously, I don't believe there's a real danger of the lights going out Mad-Max-wise, as there's always coal (and nuclear in the longer-run) as a last resort.  California is an interesting case, as it has made a policy decision not to use coal, and therefore uses gas for about 50% of it's power generation.  It does have a little nuclear, which gets more important at night. In the following discussion we have to keep in mind that during all the acrobatics CA will go through to deal with electrical generation that coal will still be there as a last-resort - I don't think anyone can realistically believe that CA would not use coal & nuclear if they were the only choices to prevent serious, long-lasting blackouts.

As far as off-peak energy production goes, you're right, nat gas turbines aren't really meant for base-load production.  Wind is the clear answer.  Texas just passed CA for windmill installation, but I expect CA has a fair amount in the planning process, including a lot of replacements of older, small inefficient turbines.  Altamonte is an important site, which unfortunately has real bird problems (realistically the only site in the country to have such problems).  I suspect some wind power from mid-west states, and West Texas might go all the way to CA.

One possibility for CA are offshore floating windturbine structures , which are based on proven oilrig technology but still in development.  They'd reduce costs, raise reliability, take care of visibility problems, and I suspect could be sited to solve the heatwave peak output decline problem.  Another is kite-based windturbines, which I believe will be faster to install, can take advantage of stronger & more reliable high winds, and have reduced structural costs - they're still in R&D, though, and more speculative.

Peak power is a little more difficult.  On-shore wind in CA may only provide about 15% of it's normal output during serious heatwaves.  In the longrun solar is the obvious complement, as it's at it's best during such heatwaves.  I understand that CA is hoping to get about 5-6% of it's peak power from PV over the next 10 years (3GW vs 50GW peak capacity).  Here it's important to remember that PV prices are artificially high right now due to soaring demand and subsidy programs; that underlying PV costs are falling quickly; supply is ramping up; and building integrated PV will slash Balance of System costs, so eventually PV consumer pricing will fall sharply.  .  Also, there's pretty good indication that the A/C peak demand is pretty artificial, and could be seriously reduced by time-of-day metering and other demand management programs.  Electric vehicles will help a great deal here, with planned charging and even Vehicle-to-grid peak supply.

CA is likely to have some difficult times coping with nat gas depletion, especially without using coal. The energy is there, but they'll have to move fast to take advantage of it.  In the meantime I suspect electicity imports to CA, and rates, will go up.