Smart meters: What every solar homeowner should know

A common thing we hear from solar homeowners is that going solar makes them more interested in the results from their monthly electric bill. Your bill is made up of several charges, including a charge based upon your usage. (Click here to learn how your bill is calculated). Your utility uses a meter mounted on the side of your residence to measure your electricity you use. Just as rooftop solar is changing the way we generate and consume electricity, new technology is changing the way your electricity usage is measured.

Smart meters vs. analog meters

Smart meter (left) and analog meter. Source: Analog meter via Wikipedia.

Traditional analog meters take simple, cumulative measurements of how much electricity you’ve consumed. It typically has a dial that spins when the electrons flow past it. If you are using electricity it spins one way. If your solar panels are producing more electricity than your house can use, it spins in the opposite direction. The meter spinning backwards decreases the total amount of electricity you will be billed for at the end of the month. A meter reader from your utility company takes a monthly meter reading at your home. As we move into the digital age, metering infrastructure has evolved.

While the smart meter can do many things and take a variety of forms, its core function is to measure your electricity consumption in sub-hourly intervals. It then digitally transmits this data back to the utility. Smart meters use low-power radiofrequency transmitters (of lower frequency than your microwave or cell phone) to exchange consumption data between the home and the utility. The utility then uses that data in the calculation of your bill at the end of the month.

This radio transmission has caused some people to raise concerns about “radiation” in the home due to smart meter. Research from the National Cancer Institute, World Health Organization, Electric Power Research Institute (EPRI), and countless other scientific bodies, indicate that there are no adverse health effects resulting from the low-level radio frequency emitted by smart meters. According to EPRI, the radio frequency waves from smart meters “are at the same order of magnitude as emissions from… TV transmission and WiFi routers, and far lower than [emissions] from cell phones or microwave ovens”.

Utilities have begun to invest heavily in smart meter infrastructure for their customers. As of early 2017, there were more than 70 million smart meters installed in the U.S., 88% of which are located at residential properties. To date, nearly 150 million residential customers have a smart meter at their home.

Whether or not you have a smart meter will depend on who your utility company is and how much they have invested in smart meter roll-outs to date. Seven states have smart meters installed among at least 80% of their residential customers: Nevada, Maine, Georgia, Michigan, Oklahoma, California, and Vermont. Washington, D.C. is home to the highest concentration of smart meter installations in the country, with 97% of District customers having a smart meter.

You can verify which type of utility meter you have at your property by searching for two items: meter dials and smart meter serial codes. If your meter still features physical dials to measure consumption (as opposed to a digital screen), you most likely still have an analog meter. Additionally, most smart meters come with a serial code from your utility company used to tag and identify meters in the field. For example, the Midwestern utility ComEd identifies their smart meters with a 9-digit numerical ID beginning with “2-”. Consult your utility for specific information on their serial coding they use to identify their smart meters.

Individual customers are not responsible for the purchase of these meters for their own property. Utilities who install smart meters for their customers will plan for the meter installations in advance, seek regulatory approval to charge customers for the meters via increases in their base electric rates, notify customers of the installation, and, after installing the meters, maintain them over the course of their lifetime (15-20 years). At no point must you, the customer, go out and purchase a smart meter for your property yourself. Most utilities offer an opt-out option for customers who do not want a smart meter installed on their property. In many cases, opting to retain your old, analog meter will come with an opt-out fee and/or monthly “reading fees” to cover the cost of manual meter reading.

Why smart meters?

Utilities are moving to smart meters for a number of reasons. The simplest is it allows them to reduce costs, by not having to send someone to your house to read your meter. By removing human error from the meter-reading process and measuring electricity usage in smaller time intervals, smart meters allow for more accurate electricity bills. This can save customers money while minimizing utility administrative costs and errors. Smart meters offer tremendous benefits to the reliability of our electric grid as well Smart meters allow utilities to pinpoint outages with greater accuracy because they transmit on-site electricity consumption data (or lack thereof) in sub-hourly intervals. This can mean shorter power outages and more reliable electricity for customers. Over time, smart meters have the potential to do much more by enabling utilities to dynamically control a distributed grid.

More granular data about electricity usage can benefit customers by incentivizing them to change their consumption habits. Utilities have begun exploring time-of-use (TOU) rate structure. The purpose of this rate structure is to encourage consumers to use less electricity when overall demand is high. (Click here to read about an example program from Oklahoma). This helps save money as the electricity during these peak demands is the most expensive. If done well, it could allow us all to use less energy more efficiently and enable large scale integration of renewable energy on to the grid. Enabling this integration is key to an energy system with rooftop solar at its cornerstone.

Impact of smart metering on solar customers

Despite smart meters’ many benefits, there can be downsides for solar homeowners. With analogue meters, the default is 1:1 net metering. You produce excess energy, it reduces the amount of energy measured on your bill by the same amount (the meter spins backwards). With “smart meters” utilities can measure and value your solar production any way the regulators let them. In many situations, when the changeover to smart meters take place — the new meters are not initially set up to properly measure flow going out from the house.

In addition, we have seen a growing number of cases across the country (Florida, Utah) where utilities have argued for shifting net metering to something called “instantaneous” net metering. Instantaneous net metering allows utilities to eliminate the fair compensation net metering provides to solar homeowners. It means solar owners can’t use their day time excess electricity to offset their nighttime consumption. As new energy technologies, like smart meters come online, solar homeowners and supporters will need to stay vigilant and vocal at their public service commissions to ensure these new technologies are benefiting energy producers, and ratepayers not just monopoly utilities.


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