I once stood in my kitchen at high noon, under thirty working solar panels, with no power.
The panels were fine. The inverter was fine. The system was doing exactly what it had been designed to do.
My mental model was the broken part.
“Solar” does not describe the outage plan
We had installed a grid-tied system. When the grid was healthy, the panels produced electricity and the interconnection reduced how much power we bought over time. On the bill side, it worked very well for our house.
When the grid went down, the inverter disconnected.
Mexico's published technical specifications for distributed generation include anti-island protection. In plain English, the system must detect an unintended island and disconnect from the distribution circuit instead of continuing to energize that circuit as though the wider grid were still present.
The U.S. Department of Energy describes the same basic distinction another way: traditional grid-following inverters depend on an outside grid signal, while a solar-plus-storage system can operate without the grid only if it is designed to do so.
“The bill and the blackout are two different problems. Buy the answer to each one on purpose.” — From Vacation to Owner, Chapter 13
The battery is not the whole answer either
People often hear this story and jump straight to “add a battery.” Storage is part of the answer, but the complete answer is a system: compatible inverter behavior, safe isolation from the grid, transfer controls, correctly selected backed-up loads and enough usable storage for the outage you are planning around.
A battery quote without a load plan is still guessing. Keeping a refrigerator, internet equipment and a few lights alive is a different assignment from running every bedroom air conditioner and the pool through the night.
The installer should be able to show you which circuits remain powered, how the system isolates from the grid, what happens when the battery reaches its reserve, and how the system returns to normal operation.
Two houses can make two correct choices
On our current home, we lived with grid-tied solar first and later added batteries after we understood the local outages and the loads we actually cared about.
At Casa Arroyo Blanco, we installed grid-tied solar without pretending it was backup power. The system was designed to address electricity consumption. A future owner can decide whether outage backup is worth adding and size it to the way they intend to use the house.
Those choices are different because the assignments are different. Neither should be disguised by the single word “solar.”
Friction Point: “Does the house have solar?” is incomplete. Ask, “What still works when the grid is down, and show me why?”
Questions to put in front of the installer
- Is this system grid-following, grid-forming or capable of both?
- What equipment disconnects the house safely from the grid during an outage?
- Which exact circuits and loads remain powered?
- How long will those selected loads run under realistic conditions?
- What interconnection approvals, settings and maintenance records come with the system?
- Who is qualified to service it locally after the installation crew leaves?
Have a qualified installer or electrical professional design and verify the actual system. The owner's job is not to engineer it. The owner's job is to ask a precise enough question that the quote cannot answer the wrong problem.
Sources checked August 18, 2026: Mexico's published distributed-generation interconnection and anti-island specifications and the U.S. Department of Energy's inverter and grid-services overview. System design is property-specific; use qualified local professionals and current interconnection requirements.