Your estimated savings
Solar alone vs solar with a battery
Same solar system, first-year savings. This is where the current PG&E rules make the biggest difference.
Where your energy goes
A year of solar production and home use, in kWh.
What happens to your solar
How your home is powered
How these numbers are calculated
Your yearly use comes from your bill: the bill minus the fixed charge, divided by your average rate. Solar production is the system size times yearly output per kW for your roof, with more in summer and less in winter.
Each day, solar first powers whatever the home is using at the time. Extra solar charges the battery, which then powers the home during the 4–9 p.m. peak and overnight. Whatever is left goes to the grid for a small export credit.
Savings are what you no longer buy from PG&E, valued at the rate for that time of day, plus export credits. The 25-year figure grows with your chosen rate increase and assumes panels lose 0.5% of output each year. This is a planning estimate, not a proposal; a real design uses your hourly usage data.
Why batteries matter more now
New PG&E solar customers are on the Solar Billing Plan (also called net billing or NEM 3.0). Solar sent to the grid midday earns only a few cents per kWh, while power bought back in the evening costs several times more.
A battery stores midday solar and uses it in the evening, turning a low export credit into a high-value saving. It also keeps essentials running during outages; see the Battery Backup Planner for that side of the decision.
About this planning tool
Is this a solar proposal?
No. It's an educational estimate, not a proposal, engineering design or savings guarantee.
What changes the real numbers?
Your hourly usage, roof direction and shade, equipment, rate plan, export credit values for your year of interconnection, and future PG&E rule changes.
Why email my results?
It gives you a copy to compare against quotes you receive.
About NRG Geek
NRG Geek is Robert Kelly's independent educational platform for practical Northern California guidance on solar, battery backup, EV charging, heat pumps and home electrification.
Privacy, legal and terms
How is my information used?
The Email My Results button opens your email app with your inputs and results. Nothing is sent until you send it. If you ask for personal guidance, Robert may follow up. NRG Geek does not sell your personal information.
Is this a proposal or guarantee?
No. Results are estimates for educational planning and are not a proposal, engineering design, financial guarantee or utility bill guarantee.
Third-party brands
Tesla, FranklinWH and Enphase are trademarks of their owners. NRG Geek is not affiliated with them.
Accuracy
PG&E rates, export credit values, tax rules and incentives change over time. Verify important information before making financial decisions.
Copyright
© 2026 NRG Geek. All rights reserved.