A SunPower customer's complaint online is drawing attention to a frustrating reality: even when an app's data looks precise, the numbers can be wrong for years.
In a post to Reddit's r/SunPower forum, the homeowner described a monitoring problem that got worse after a 2023 service call meant to resolve a mismatch between SunPower's data and the utility's readings, with the system reporting "negative consumption."
Here's what to know
According to the post, the homeowner's solar system was installed in 2022, and the problem emerged in 2023 when the utility numbers did not match what appeared in SunPower's monitoring.
The original poster explained that a technician found that a basement electrical panel serving the HVAC and kitchen had not been tied to a current transformer. OP wrote, "That's when negative consumption started."
OP explained that the error persisted for two years despite multiple appointments, with each visit allegedly ending in assurances that the problem had been fixed. The homeowner also wrote that eventually, the matter escalated, but then there was "no more SP," referring to the company's Chapter 11 bankruptcy filing in August 2024.
In the comments, several users focused on the current transformer setup as the most likely source of the problem rather than the solar equipment itself.
Some said the sensor may have been installed in reverse or linked to the wrong circuit, with one user writing, "Try reversing the wires." and another saying, "If the CT is connected backwards Home Assistant won't help because it will see the same erroneous data."
Another commenter noted that homes using several CTs may need more than one correction, adding, "But if you have multiple CTs to capture all your consumption and some are reversed and others are not you'll need to fix those. That can be done DIY or cheaply."
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More background
CTs are small sensors used in solar monitoring systems to track how much electricity a home produces and uses. In homes with more than one panel, like the one described in the post, the setup can become more complicated because every relevant circuit has to be measured and assigned correctly.
Unfortunately, faulty monitoring data can make it harder to tell whether solar savings are matching expectations, delay repairs, and push homeowners toward unnecessary upgrades when the real issue may be a relatively simple sensor correction.
Rather than immediately paying for a replacement monitoring system, commenters suggested first checking the app against the utility meter and seeing whether the existing software can correct CT direction.
As one commenter wrote, "In Sunflower solar you can flip the CT direction if yours are installed backwards. If yours are reversed you can fix it and your consumption will make sense."
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What can be done?
The homeowner's frustrating SunPower experience shows how important it is to go with an installer you trust.
For homeowners still considering the switch, going solar remains one of the best ways to save money on home energy. It can be worth exploring EnergySage to get free solar installation estimates and compare quotes from vetted installers. Those who do can find techs they actually can trust and save up to $10,000 in the process.
Readers can also use EnergySage's solar map, which shows the average cost of a home solar panel system on a state-by-state level along with solar incentives for each state, to help get the best price for rooftop solar panels and access available incentives.
Where can I learn more?
The Reddit complaint is about faulty monitoring, but it points to a bigger issue for solar owners: whether a system is actually delivering the savings they expect.
• In California, solar power saved consumers $2.3 billion in 2024 as rates climbed.
• After Washington's policy shift, many buyers found solar still makes financial sense in 2026.
• Environmental Protection Agency-backed households saw solar incentives at risk after a sweeping federal freeze.
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