Susan Nolan
Air conditioning is not something most Humboldters think about, but statewide, it’s a big driver of electricity demand, pushing up need in afternoons and evenings through summer and fall. That affects everyone in the grid, including us here, because it creates a mismatch between available green energy and demand.
Solar energy output begins to trickle in at dawn, rises to a peak at noon when the sun is highest (i.e, 1:00 p.m. during Daylight Savings Time) then gradually declines. Wind in California is strongest during afternoons and evenings. Biomass burning, geothermal, and hydropower run steadily through the 24 hours, but output can vary by season.
Besides a misalignment with time of day, there’s another discrepancy over time of year. The state’s many solar arrays turn out a surplus of solar power in spring, when the sun is just as bright as summer, but the heat hasn’t kicked in yet. California utilities can end up giving it away or even paying out of state networks to take that extra solar power, to avoid a damaging overload of our grid.
To fill the gaps when renewable energy is not available, utilities rely on “peaker plants.” which can start up and slow down easily, unlike the energy sources mentioned above. They typically burn fossil fuels, especially natural gas, sometimes diesel. Nuclear and coal plants take longer to power up and wind down, and aren’t useful as peakers.
So the available green power is out of phase with demand. In order to nudge us toward using electricity when the most renewable energy is on line, PG&E has come up with “time of use” (TOU) pricing.
The pricing schedule is complicated, but just to give you a rough idea, the rates this summer are about 49 cents per kilowatt hour for peak usage (4-9 p.m.) and 36 cents for off-peak. Winter rates tend to be lower, despite increased heating demand, because in most of the state cooling is actually a bigger draw than heating.
How can you play this to your advantage? PG&E offers these suggestions:
- Turn it off: turning lights, appliances, TVs and computers off while not in use is one of the easiest ways to conserve energy.
- Pre-cool your home: If you have air conditioning, cool your home during lower-priced times. Then, nudge it up to 78˚ F or higher (health permitting) during peak times.
- Load first, run later: During peak times, get your dishes loaded and your clothes ready to wash or dry, then wait until lower-priced off-peak times to wash them. After 9 p.m. press the start button.
- Set your thermostat to 68°F or lower, health permitting. Your home uses 3 to 5 percent more energy for every additional degree that it’s raised. When you leave the house, set your thermostat to 56°F or shut it off. You can save 5 to 15 percent on your annual heating bill by keeping your home at this temperature eight hours per day.
- Recharge batteries, from phones to cars, at night.
- Big energy consumers include washing machines and dryers (including at the laundromat), electric water heaters, electric ovens and power tools—anything that generates heat or has a big motor.
TOU is a voluntary program. Most customers were automatically enrolled in it, so you’re probably already set up to benefit from it and help the shift to green energy by avoiding electricity use between 4 and 9 p.m. You can check or change your status by creating an account here: m.pge.com
More about Time of Use plans here: pge.com/en_US/residential/rate-plans/rate-plan-options/time-of-use-base-plan/time-of-use-plan.page?
A bright spot on the horizon: ocean wave energy, not yet ready for commercial development, has great promise for steady, 24/7, year-round output. It’s a natural fit for Humboldt and preliminary research is already underway.