California homeowner's solar spreadsheet shows electricity bills drop by nearly 98% in three years

One homeowner's simple spreadsheet is turning heads after showing how lucrative solar panels were for them, slashing their electricity bills by roughly 98% from 2022 to 2025.

After years of paying SDG&E hundreds of dollars a month, averaging nearly $280 a month in 2022, the homeowner shared their "happy solar math": during the entire year of 2025, they paid the utility just over $71.

What happened?

The Reddit post laid out several years of SDG&E data, including electricity use, net grid imports, and total yearly payments. 

In 2022, the annual total reached a high of $3,349.09 as household use rose to 7,148 kWh, after 2021 recorded 6,685 kWh consumed, 6,685 kWh imported from the grid, and $2,557.35 paid.

The 2023 entry looked dramatically different: 6,139 kWh of use, negative 2,376 kWh in the import column, likely meaning excess power was sent back to the grid, and just $5.79 paid to SDG&E for the year.

The homeowner said the system was already paid off, responding to a commenter who asked, "What's your system costing you over 20 years? These solar companies are making a killing on the interest for the systems," 

The original poster responded, "It's paid for already. About 38-40 months until the savings exceeds the final cost."

What can I do?

Comparing several installer quotes can help identify pricing differences. If you're interested in lowering your electricity costs with solar panels, consider checking out EnergySage's free tools, which let you compare quotes from vetted installers and save up to $10,000 in the process.

If you can't afford the upfront costs of buying solar panels, consider a solar subscription program. The LightReach leasing program, for example, can help you lower your utility rate by up to 20% and for no money down.

Pairing solar panels with efficient electric appliances can also reduce overall utility costs, allowing solar production to cover more of a home's needs.

Get TCD's free newsletters for easy tips, smart advice, and a chance to earn $5,000 toward home upgrades. To see more stories like this one, change your Google preferences here.