A strange meter reading prompted questions from one National Grid customer after a solar setup pushed the display past zero and over to 99999.
In the r/solar subreddit, solar users said that kind of rollover can be normal when a home sends more power to the grid than it uses.
Here's what to know
After seeing their meter pass 0 and land on a large positive number, the original poster wrote on Reddit that National Grid "had no real answer." They were worried the utility might mistake the display for enormous power use instead of surplus solar energy exported to the grid.
Some net meters simply are not built to display negative values.
"The utility can handle the math on meter rollovers, whether happening going forward (ie, crossing over 999999) or backwards as has happened to you," one commenter wrote. "It is not particularly complex."
Several replies also argued that a 99,999-kilowatt-hour charge would make little physical sense. Using a 31-day month at 240 volts, one commenter noted that a 100-amp service running continuously would max out at 17,856 kWh, while a 200-amp service would reach 35,712 kWh.
More background
For homeowners with rooftop solar, a backward-spinning or rolling meter is often tied to real savings. When a system produces more electricity than the home uses, that extra power can generate credits that reduce future bills instead of going to waste.
Going solar is one of the best ways to save money on home energy, especially if your system produces enough to offset a large share of your usage. Homeowners who want to explore that option can try EnergySage to get free solar installation estimates and compare quotes.
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Commenters also shared examples of how much excess generation can turn into bill credits. One wrote, "Most of the year I am negative. Each month outside of the winter months I go negative by over 1000kwh."
One person added that this display behavior dates back at least to 2008, saying their digital net meter from 2008 "couldn't go below 0000."
What can be done?
The practical advice in the thread was to wait for the next statement and compare it against the meter display. If the utility ever billed the rollover as though it were massive consumption, commenters noted that a customer could challenge.
"Pulling 99 999 kWh in one month is physically impossible," one wrote. "If an issue arises, point that out and continue pointing it out until someone listens."
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Another commenter shared a simple way they interpret the reading: "Subtract the current reading from 100,000. when you consume, the meter will spin forward, when you export it'll spin back."
For people considering solar for the first time, EnergySage can be especially useful. With EnergySage's help, the average person can save up to $10,000 on solar purchases and installations.
EnergySage's solar map shows the average cost of a home solar panel system by state, along with details on local incentives. Those resources can help homeowners get the best price for rooftop solar panels.
Adding battery storage to a solar setup is also one of the best ways to protect your home during outages, save money on energy, and go off-grid. Homeowners can explore EnergySage for information about home battery storage options, including competitive installation estimates.
Where can I learn more?
For a clearer picture of how utilities handle exported solar power, there are more real-life examples of the interplay.
• In Ohio, one homeowner learned net metering may leave major utility charges untouched after going solar.
• In 20 states, the net metering rule still shapes whether adding a home battery pays off.
• In Massachusetts, one homeowner said solar, mini-splits, and net metering left him 4,100 kWh ahead.
• In South Carolina, a solar owner saw exports, then a $150 bill claiming grid use instead.
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