Sunday, June 08, 2008

Real-time Electricity Pricing - 1 Year Later

So last May, we signed up with ComEd's Residential Real Time Pricing (RRTP). This is a relatively new program that allows consumers to pay variable rates for their killowatt-hour usage instead of the standard fixed rate that most residences are on. This is in addition to ComEd's Nature First program that ANYONE can sign up for now and get $10 per month back from ComEd.

To briefly recap the RRTP program, the idea is basically that during times of the day where there is high demand on the electrical grid (such as during the day), rates are higher than the fixed rate, and during times of low demand (at night) rates are much cheaper. The idea is to get people to shift behavior to times when electricity is cheaper, thereby reducing demand on the electrical grid at the macro level, and saving individual consumers money on their utility bills.

In practice, I've found this mostly to be the case, but the window for cheaper electricity is smaller than I would like. Like most families, we use most of our electricity in the early evening hours, and frequently into the late evening hours too. Generally, rates aren't dirt cheap until after midnight, but since appliances like dishwashers, washing machines have delay-start timers on them, we can delay running them until 3 am when we pay 2 cents per kilowatt hour, as opposed to running the dishwasher right after dinner which would cost on average around 8 cents / khw.

Anyway, ComEd has a third party group manage the program, and they have a nice website that allows enrollees to check what the predicted prices are for the day so we can plan activity accordingly. But sometimes actual prices (in red below) are much different than the expected prices. Here is today's graph:

Now, the actual price (in red) doesn't normally have the large trough - this is quite unusual, but reflects the lack of grid demand we had after a thunderstorm and cold front moved through Chicagoland around noon today. Temperatures aren't the only indicator of cost.. there are all kinds of factors, and sometimes the rates get very screwy. At one point last week, the hourly rate was up to 23 cents / kwh! There is an online group of ComEd RRTP customers that have all kinds of thoughts, opinions, and tips on the program, and the price spikes and service fees are a favorite topic of discussion.. Some have even been driven out of the program by them.

But what about Humphrey House? Well, compared to the average family, we're relatively high consumers of electricity (an ongoing battle), but one of the other neat things on the website is a monthly comparison that shows your bill on RRTP vs the standard rate and shows. So now that we have been on the here's how we have done for the entire year we've been on the program:

Some months we saved more than others, and some months we actually spent more by being on the program, but overall, we've saved a total of $167 over the entire year with the real-time pricing program. In thinking about the way energy is shaping up in the future (costs keep rising), I'm tempted to think the RRTP program will be sensitive to fluctuations and it may make sense to cancel out of the program, but I think for the time being we'll keep on it and keep trying to curtail our use during the peak hours.


Jennifer said...

Sounds like a unique idea.. I wished they offered it here for us to try!

denise said...

This is good to know—we signed up for it just last month, so I'm anxious to see how we fared. At this point we really didn't alter how we use electricity, so I'm interested to see if there is any price difference by doing nothing, and then making real adjustments from there.

jay said...

Of course, there is a big downside to this program. Like when electricity prices topped $0.49 per kwh today at 3pm.