About
An apartment, a spreadsheet, and the ERCOT grid
Why a home-backup-power site is written by someone who rents.
Charles McQuain
Engineer
Engineer in Texas, on the ERCOT grid. I size home backup power with real load math — what actually keeps a fridge, a CPAP, and a router alive through a multi-day outage — and I show the work on every number.
I don’t own a house. I rent an apartment in Texas, on the ERCOT grid, which means my “lab” is a spreadsheet and a stack of manufacturer spec sheets, not a garage full of metered appliances. I’m telling you that up front because it’s the honest answer to the question every reader eventually asks: did you actually test this?
Mostly, no. What I do instead is arithmetic nobody else bothers with — real duty cycles, inverter losses, the difference between a battery’s rated watt-hours and what you can actually pull out of it. Every number on this site is attributed to its source and computed in the open, so you can rerun the math yourself instead of taking a star rating on faith.
February 2021 is the reason this site exists — 4.5 million Texas homes lost power, and I watched most of the advice available afterward be generic, un-sourced, or written by someone who’d never seen an ERCOT conservation appeal in their life.
That storm is the design case behind every page here: what actually keeps a fridge, a CPAP, and a router alive, sized honestly, for the outages Texas actually has. Not a lab-format spec review — those already exist, done well, by channels with real testing rigs. This site’s job is the layer above the spec sheet: the math, the sourcing, and the buying decision, worked through in public. The full policy on what “sourced” and “computed” mean in practice is on the methodology page.
- 16
- pages published
- 90
- sources cited
- 2026
- publishing since
Frequently asked
- Do you test these products yourselves?
- Not in a lab — see the methodology page for the full policy. Every capacity and runtime figure is attributed to the manufacturer's own spec page and then computed in the open (real duty cycles, inverter losses included), so you can check any number with a calculator. Where a page carries a tested badge in the future, that will mean a unit was actually bought and metered — it doesn't yet.
- How do you make money?
- Some links on this site are affiliate links — if you buy through one, we may earn a commission at no extra cost to you. Picks are decided on the math first; the links get attached after. See the full affiliate disclosure for specifics.
- How often is this updated?
- Every cited claim carries the date it was checked, and citations older than 120 days block the build until they're re-verified or removed. Substantive changes — a corrected spec, a changed price, a retracted pick — are logged on the corrections page, not silently edited.