The purpose behind When Grid Fails
When Grid Fails helps you plan backup power around the devices that matter to your household. Start with what needs to keep running, then work through power demand, operating time and equipment requirements.
Start with your essentials
A refrigerator, a few lights and a Wi-Fi router create a different load plan from a home that also needs a sump pump or furnace equipment. Our starting point is your device list, with the ratings and operating conditions that apply to your equipment.
Use Backup Power Map
Our Backup Power Map calculator is available now. It separates running watts, device energy and startup scenarios. Missing information stays visible: it does not invent startup ratings or apply a universal battery-efficiency percentage.
How we approach technical content
- Sources first. We use original technical sources, including U.S. public agencies and equipment manufacturers, and link them alongside the relevant explanation.
- Conditions matter. We distinguish physical formulas, simplified estimates, product-specific data and electrical-code requirements.
- No invented credentials or tests. We do not present a calculation as a certification, or describe equipment as hands-on tested unless that testing has actually been performed and documented.
- Corrections are welcome. If you find a problem, send the page URL, the statement or inputs in question, and a supporting source so we can investigate.
Who is behind the site?
When Grid Fails is operated and edited by Tony Pham, an independent publisher based in Vietnam, serving readers in the United States and other international markets. The site focuses on clear explanations and practical planning tools. It does not offer licensed engineering or electrical installation services.
Use the results in context
Check your device manuals and the specifications of the exact backup system you are considering. A load estimate alone does not establish compatibility, runtime or code compliance. Household wiring and hardwired loads need a qualified installer.
As of September 12, 2026, this site has no active affiliate partnerships or paid advertising.