PGE: Time to Pay More

Earlier this year, I posted an article showing how we optimize our electricity usage so there's no grid load during peak hours. This both reduces stress on the grid and reduces our electricity bill. 

One of the key features of our optimization strategy was the rate schedule that we used. The default rate schedule here is called Basic and it's a flat rate; you pay the same amount per kilowatt-hour during a heat wave as you do on a winter night when there's surplus wind. We've opted out of the Basic plan; instead selecting the time-of-use (ToU) billing schedule. ToU gives us cheaper rates overnight than the basic plan, but it costs more during peak times. The other components of our optimization plan are charging our EVs overnight, plus solar and batteries which reduce or eliminate our electricity usage during any time other than the overnight off-peak rate hours.

We were just informed that our highly optimized plan will be disrupted at the start of 2025. Here's the letter we received message from our utility:

So ToU is going away and being replaced with Time-of-Day (ToD).

Let's look at the ToD plan. 

PGE Time-of-Day Rate Schedule (Nov 2024)

Here are a couple things I liked: 

• It doesn't have multiple seasons like ToU
• Saturday and Sunday are all off-peak; whereas on ToU Saturday is a mix of mid-peak and off-peak

But there's one important thing I don't like: it's more expensive. Both the off-peak and peak prices are higher than ToU. The off-peak price is 63% higher and the peak price is 48% higher. The mid-peak is 25% cheaper. The off-peak increase is the most important factor in our situation (more on this later).

The utility has a tool to run your energy usage data from the last year through each billing option. Here are our results:

As you can see, ToD will cost us about $400 more annually; we'll still save compared to the Basic plan. We spent a lot of money on our solar panels and batteries. Part of the justification for that expense was that we'd save on our bills going forward. With this change, the utility has delayed our breakeven by $400 per year.

ToU and ToD have different time schedules and pricing. Here's a comparison graph of all 3 plans for a weekday.

You can see in the graph above that ToD stays on off-peak for an hour longer in the mornings, and off-peak starts an hour earlier in the evening. 

When last year's data was run through the comparison tool, it examined a usage pattern optimized for ToU. So, it is not surprising that ToU had the best result. I may be able to reoptimize our usage to better fit ToD; to shave some cost off the increase from ToU to ToD. However, since the bulk of our grid usage is during off-peak, there's not much we can optimize. The increase in the off-peak price will directly impact our costs. Whereas, for our use case, the changes in the mid-peak and peak prices are nearly irrelevant.

The utility should encourage off-peak usage. This is when the wind blows in the Columbia Gorge and the industries are not there to soak up this abundance. This is when they have surplus zero-carbon energy on the grid. Raising the off-peak price by 63% is incongruous with the reliable grid and low-carbon energy goals.

I'll certainly post more about this in 2025 after we've been on the ToD plan for a while. A before and after comparison will be interesting to see if the tool's projections were accurate or if we could find some tweak that allows us to optimize in some way that's not immediately obvious. See you then.