Smart Meters Can Save You Money

Recently a friend of mine  has been having electricity issues.  Not issues with the electricity being available, but issues with his usage.  Despite putting great effort into making his house energy efficient, he found that his electric utility bill was far higher than he thought it should be.  After looking into the size, age, and efficiency of his house, along with the ratings of his appliances, his home's use of natural gas, and comparing his usage to neighbors, he found that his house is using around 500 kilowatt-hours (kWh) more than it should.  He was understandably very frustrated.

Pinpointing Energy Losses

After discussing the situation with him over a game of Sid Meier's Civilization V, we were able to pinpoint at least part of his energy loss, the hot water heater.  Despite using natural gas for heating, fireplaces, and the oven, his water heater is electric, accounting for 25% of all his electricity use.  This is amazing to many people for a couple reasons.  For one thing, the sheer amount of electricity a water heater uses is astounding.  It is really remarkable how much electricity is required to heat up a forty, fifty, or in this case eighty gallon tank.

Electric Water Heaters are Energy Hogs

The other thing that was really surprising to him, and was surprising to me at my last apartment, is the fact that despite having natural gas lines run to the house for heating, and living in an area where gas is so much cheaper than electricity, an electric water heater was installed when the house was built.  This was the setup of my previous apartment, and it made absolutely no sense to me.  The cost of installation is the same, the cost of the heater itself is the same, and the cost of gas is much lower than electricity.  There is absolutely no reason why a gas water heater wasn't put in.  I don't know why builders do this, but it seems to be common in many areas.  Needless to say, he is going to be replacing his hot water heater with a gas one.

Smart Meter Electricity Usage Information

While his investigation is still ongoing, this problem got me thinking about my electricity situation and smart meters (as well as a brief mental detour about my energy policy).  While my friend does not have a smart meter, I do, and I also, unfortunately, rely on electricity for everything in my house, including the water heater and central heating.  What this does allow me to do, however, is to track my electricity usage month to month, day to day, and hour to hour, with about a twenty-four hour delay.  I am not able to narrow down my usage to any one appliance, but it very easy to see when I am using the most electricity, which allows me to more easily figure out how to reduce my consumption.  It is an incredibly useful tool, and I hope that smart meters roll out quickly to other areas of the country so that everyone can make use of this information.

I also realized quickly that most people who have smart meters don't even know this information exists.  They may know they have a smart meter, but they have no idea how to access the extra data the meter is providing.  This is disappointing, because you can really see where your money is going by the hour based on this data.  Monthly data is fine for comparing month-to-month or year-to-year, but seeing your hourly usage really help you pinpoint what appliance is using how much electricity.  As a user of electricity for everything at my current home, I find this incredibly helpful, and I think my friend Josh would benefit greatly from having this data available to him.

Sample Data from My Smart Meter

Since there is a large portion of the country that either doesn't have smart meters or does not know what types of data are available to them, I thought this would be an appropriate time to gather the electricity date from my electric utility and show people what value a smart meter has.  I have been living at my house now for almost two years, and have been able to grab some snapshots of my electricity usage over a day, a week, a month, and my entire time living here.  It is really remarkable what you can glean from the data just by looking at some charts.

For some quick reference, I currently have electric baseboard heaters, a forty gallon electric water heater, a high efficiency washer and dryer, no dishwasher (unfortunately), and mostly compact fluorescent light bulbs.  In addition I have a wood burning stove that I use regularly during the winter to offset heating the house.  The house is occupied by my wife, a stay-at-home mother, me, a full-time engineer, and my son, an eight month old infant.

A chart of my electricity usage by month since I moved into my first home, overlayed
with heating and cooling degree days, which is a method used to estimate
the demand for energy based on a need for either air conditioning or heating.

What should stick out in the above chart is the extremely high electricity usage in January and February 2012.  When we moved into our new house, the wood burning stove had not yet been cleaned and inspected, so we stuck with using our electric baseboard heaters for our only source of heating.  After seeing the largest single electric bill I have ever seen in February, we immediately got the wood burning stove inspected, took a trip to my coworker's property to cut and split firewood, and started up the stove.  The results were immediate.  March's electricity usage was cut to almost one third of February's, and the heating degree days were almost identical between months.  After seeing this, I have vowed to use the electric baseboards as little as humanly possible.

This is a chart of my daily usage for the most recent full month of data, August 2013,
overlayed with the average daily temperature.

In the above chart of daily electricity usage, the weekends (light blue) tend to show lower usage because we often are out of  the house on those days, while my wife and son are generally home most days during the week.  For families with all members either working or at school all week, the data would probably show the opposite, putting the low usage days during the week, and the peak on the weekend.  Even though our house is over twenty-five years old, we are lucky to live in an area with relatively cool summers, and in a development that is buried in the woods.  This allows us to use the air conditioning sparingly, which means our electricity usage does not track with average temperature very well.  

A chart of average day-of-week usage using data from all of August, 2013.

Sourcing Electricity Usage Using Smart Meter Data

To try and get a better idea of what a full week of energy looks like, my utility also offers a chart of electricity usage data averaged by the day of the week.  This is the average from the same time period as above, again showing lower usage on the weekends and generally higher usage on weekdays.  It should also be pointed out that Fridays are usually gaming nights with our friends.  For those who run on a more normal schedule, this might be more useful, allowing them to pinpoint what day of the week normally sees the highest usage and figure out ways to reduce usage on that day.

Hourly electricity usage for August 27th, 2013 at my house.

The hourly usage data is really where the usefulness of a smart meter pays off.  Above is hour-by-hour breakdown of my electricity usage on August 27th, 2013.  What should be readily apparent is the peak at 6 AM, and the increase in usage from around 4 PM until 10 PM.  From this plot alone, I know that the first peak is from me taking a shower around 5:30 AM, and the hot water heater kicking on after that.  I also know that the increase starting after 4 PM is due to me coming home, cooking dinner, watching TV, and playing video games.  Seeing this plot hit 7-9 kWh in the morning at my previous residence prompted me to lower my water heater temperature and take cooler showers.  The energy savings were immediate.

Hourly electricity usage for August 27th 2013, overlayed with usage from the peak day
in all of August 2013, along with the averages of weekend and weekday usage over the
same month.

The final chart is the same hourly data from the previous chart, but with the addition of some extra data to try and help perform a comparison between that day, the peak usage day, and the average usage per day, broken into weekends and weekdays.  From comparing the day analyzed (August 27th, 2013) with the peak and average data, it is obvious to me that August 27th is a weekday (Tuesday) based on when the water heater peak occurs, and that the peak day was a day that the family went out for the day, most likely a weekend, due to the higher and more extended morning peak, combined with lower than average usage during the midday.  The average data is only mildly useful to me since I don't run on as regular a weekly schedule as many people do.  Even so, you can see that the usage peak from the water heater is shifted four hours between the weekday and weekend.

UPDATE: Per reader request, I added a picture of my smart meter and a small blurb about what smart meters look like.

What a Smart Meter Looks Like

Smart meters come in a wide variety of shapes, sizes, and looks.  The commonly pictured smart meter contains a digital display and communicates via radio to the utility about the home's electricity usage.  These have come under some scrutiny in certain areas of the country because of privacy concerns and fears that the radio waves are causing physical harm to homeowners.  I don't exactly know how these radio waves would be different than all the other radio waves that are constantly being transmitted from cell phones, microwaves, or radio stations, but everyone is entitled to their opinion I guess.

My smart meter.  Really not much to look at, but
here it is.

Per a request from a reader, I went around the side of my house and took a picture of my meter, then looked up what information I could gather about it's capabilities.  As it turns out, the smart meter (or advanced meter as my utility calls it) is not much to look at.  It is actually indistinguishable from a "dumb meter," displaying it's analog dial gauges on the front.  Reading a little bit I discovered that PPL Electric Utilities actually uses some slightly older smart meters that communicate via the power lines instead of radio.  I am guessing they did that more for cost than customer privacy, but it is interesting that it is even possible to transmit that data through the power lines at all.