Variable Electricity Rates

It’s been awhile since I wrote a post, mostly because I’ve already done and written about most of the consequential and readily available individual choices that reduce my impact on the environment, or in some cases, have a positive impact. Today, however, Seattle City Light has given me something new to talk about. 

My very first post on this site was about renewable energy. I still use the Green Up program. Renewables result in vastly lower carbon emissions. They are also cheap, rapidly getting cheaper, and economical to scale up. Dealing with our climate disaster is going to require making extensive use of these things.

The challenge that comes with solar and wind is that they are variable and not dispatchable. You get solar during the day (provided it’s not too overcast) and you get wind when the wind is blowing. You want to use your refrigerator all the time, and your heat when it’s cold, and your computer in the evening. The mismatch between supply and demand produces something called the “duck curve,” which is the shape of the difference between total energy supplied by renewables and demanded by consumers throughout the day. I wrote about it in th renewables post in 2019. 

Notice I called this a ‘challenge,’ meaning that it’s a problem that you can address with economics, investment, and technology. There are rather dishonest people out there (in say, the Trump administration) that contend that renewables are useless because they are not dispatchable, but such corrupt and / or stupid people are not worth listening to.

This post concerns the economics part of the equation. It looks like this:

Note that Seattle City Light is almost entirely hydropowered, though wind makes up an increasing share.  

Hydro is always on but produces a fixed amount of power, and it tends to be seasonal. As the climate warms and we get less snowfall, we’ll get less and less water in the dams in the summer and need to supplement this with other sources. That’s a problem for SCL – I’m not going to solve it on my blog. What I am doing is opting into my variable rate plan and shifting to using more energy during the middle of the night and the middle of the day. So how to do that? Several ways.

1. I have an EV, and I can plug it in every day when I park it and tell it to charge in the middle of the night. Easiest step of them all.
2. I have a heat pump water heater, which happens to be programmable. In my case, I tell it to heat to 120 degrees in the early afternoon (at the middle tier rate, when the temperature at home is highest) and let it cool off in the early evening. When we take our showers, we have hot water, and it’s enough every day thanks in part due to water efficient showerheads.
3. I can set the thermostat to start heating the house early, around 530am, on the weekdays. I need to get up around then anyway.
4. The only one that requires some actual daily change in behavior on my part is using the delay functions on appliances. I can set the dishwasher to run in the middle of the night, for example. Same goes for the washer, but the dryer, which uses way more electricity, does not have a delay option, unfortunately. 

That’s about what’s possible for now. At some point in the future, I’m hoping we get surge rates – super high rates when there’s some kind of weather event like a heatwave or snow, and super low rates during a windstorm when our turbines are running like crazy or after a flood when the lakes behind the dams are at their limits. If that happens, well, program the car to charge up to 80% and do the laundry, I guess.