Batteries & Backup

Sizing a battery from your own load profile, the difference between backup and self-consumption, and the codes that decide where it can go.

Batteries & Backup August 18, 2026 Backup or Bill Savings: Two Battery Jobs, Two Prices A backup battery earns nothing and a self-consumption battery protects nothing. Separate the two prices on your quote before you accept one payback number. 9 min read
Batteries & Backup August 17, 2026 Size a Home Battery From Your Load Profile, Not a Brochure Pull your own interval data, then size a battery on it: why nameplate, usable kWh, depth of discharge and round-trip efficiency are four different numbers. 10 min read

About this section

Three quotes for the same roof came back with three different payback figures — seven years, nine, and fourteen. Priya Raghunathan rebuilt all three in a spreadsheet to find where they diverged, and the spreadsheet turned into this site. She does not work in the energy industry and has never sold, financed, or installed a system. Every number here is traced to a utility tariff sheet, a regulator's decision, or a published standard, and the arithmetic is written out so you can redo it on your own bill.

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Every guide cites the agency, statute, or document it was checked against, and carries the date it was checked. Rules change — if something here is out of date, tell us and it gets corrected.