What I learned from my smart meter – so far

DISCLOSURE - I work for and buy my power from Reliant Energy.

Local electric distribution utility Centerpoint installed my smart meter sometime in July or August, I think. I don’t know the exact date because I must have missed the notice or doorhanger telling me when it would be installed. I knew something was up because the digital clock on my microwave was flashing ‘12:00’ one afternoon. That weekend I noticed the new meter and figured it out - they have to cut the power briefly to swap the meters. I admit I was a little excited, but, then, I’ve been tracking how much power I use every month since we moved to Texas in 2001.

So I wrote down all the pertinent information – the ESI ID and meter number – an headed to smartmetertexas.com, the web site sponsored by a consortium of electric transmission and distribution service providers (TDSPs) doing business in the state of Texas that lets you see how much electricity you use - in 15-minute chunks. Unfortunately (at least for me) it takes time – like 4-6 weeks – for the data from the meter to start showing up on the website.

So, several weeks later I registered, and could see a 24-hour chart showing how much electricity my house used every 15 minutes. Unfortunately there is no easy way to compare one day to the next, or one week to the next, and it doesn’t have anything about cost. But it does give me an idea of when we use the most power, even if it is delayed about 48 hours.

Once the data started showing up there, I was able to sign up for Reliant’s Weekly Summary Email. This free service for Reliant customers with smart meters has three things that I really like.

First, it estimates my monthly bill based on how much power I’ve already used. I’ve got average billing, so the amount I pay each month doesn’t change much, but knowing that month-end amount early on let’s me decide if I want to change something – like raising the AC a couple of degrees – to cut my use and save some cash.

Second, it gives me a graph that shows three different bits of information – the high and low temperature for each day; how much electricity I used and when during each day compared to the same day the week before; and our daily electricity cost.

Third, each weekly email has a tip on how to lower my bill – dropping the temp on the hot water heater, keeping my AC filters clean, etc.

I’ve gotten four of these emails so far – what have I learned?

1. I use almost twice as much electricity on a weekend day as on the other days of the week.
2. The outside temperature makes a difference.
3. Doing the laundry costs $3 - $5 in electricity.

Number one is easy to understand and makes sense. I’ve got programmable thermostats set to raise the AC temperature on weekdays when no one is home. It probably has the same setting on the weekend, but since there is usually someone in the house we use the over-ride to keep it cooler.

Number two makes sense as well – when it’s hotter outside your AC has to work harder to keep the same temperature.

The third took a little longer to figure out. I noticed that every Tuesday we used about $3 - $5 more in power and there was a morning and an afternoon spike. After a few weeks I got it – laundry day. My wife usually does the family laundry on Tuesday. She starts in the morning, does errands around mid-day, and finishes in the afternoon. One note – I do offer to help with the washing, but I’ve been judged incompetent in that area.

What have I learned? A few things:

o For what it does for us, power is pretty cheap. My average cost with the temperature in the upper-80s was $8-$9 each day. Even though that adds up to a lot for a year, it isn’t much for comfort and security at home.

o Change the temperature. Running the AC can make up as much as 50-60% of summertime electricity bills in Houston. Keeping the system well-maintained (change those filters) and cutting back on the amount of time the system runs will have a bigger impact that just about anything else. I tweaked the schedule on the programmable thermostat - we’ll see if that makes a difference.

o Time-of-use might make sense. Looking at that Tuesday laundry spike, I thought that shifting laundry to off-peak times – usually after 8 or 9 at night and all weekend long – might make sense. Reliant’s off-peak TOU price is about 14% lower than the peak price, so I could theoretically save fifty to seventy cents each laundry day.

What do I want to learn? A few more things:

o What does each appliance cost? A friend tells me that his pool pump costs him about $1000 (that is a thousand) each year. If I can measure that and cut it by just 10%, that would be worth it. If I know what each energy purchase decision (that’s what we do when we turn on something) costs, I’ll be able to make more rational and effective choices.

o What’s my ‘baseload?’ It would be cool to know how much power my house uses when we’re not doing anything – like at 3 in the morning. Maybe not all that useful, but still interesting.

o What are the trade-offs? If I know my clothes washer costs $1.00 of power per load (just guessing here) and I can buy one that claims to be more efficient, I can better make the decision if it is worth the expense of the new machine.

For those I’ll have to wait for the next device – a home energy monitor, hopefully coming soon.