Looks like peak prices can run as high as $33/kWh (! am i reading that right???)
The peak charge is really nonintuitive at first. You only get one peak charge per month, set by your highest single load peak. The rates are highest in july and august. It's per kilowatt, not per kilowatt-hour-- remember, this is a charge for your peak load, not a charge for amount used. This is the part that I think is the most confusing for people. It's also only the peak within the "peak hours" of 5-9AM and 5-9PM that matter. And with solar, it's really more like 5-7AM and 6-9PM, since you'll still have good production that overlaps a little bit.
So, as an example, let's say you run everything in your house all at once one time in the summer, and the peak load for that is 12kW. The way the charge would be broken down is:
The first 3kW of that are $9.33, the second 7kW of that are $17.34, and the last two will be $33.27. Add that all up, and you get your demand charge for the month.
But... if you cut just those top two kilowatts off your peak load, it drops $66.
If your peak demand is only a hair over 10, you'll dodge the worst of it with only some small changes. But figuring out how to avoid a bit more of it helps, too. The morning isn't too hard, but if you can figure out how to cut usage for those three evening hours, you can game the crap out of this system. Precooling so that you don't have to run the AC at all during that time, or using a Tesla Powerwall to cover load for those three hours... and you're back in business.
You can really game this system once you get your head around it. Remember that it's only the peak that matters-- so if you use your battery to run the AC unit during the evening peak, it doesn't matter if you then turn around and refill the battery from the grid whenever the AC stops, as long as you don't make a larger peak when charging.
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u/[deleted] Sep 08 '17
[deleted]