Adiós Factura
The answers, worked out
Seven questions, one engine · 2026-09-11
Every number on these pages is run through the same hour-by-hour engine as the simulator — the same one an installer uses to size a real roof. Nothing here is a rule of thumb, and where a single number would be dishonest, you get a range and the reason why.
- How much does solar cut your power bill in Puerto Rico? The monthly bill before and after solar for three real households, with the net metering rules of Act 114-2007. Every figure is a range between a month of clear days and a month of overcast ones — and none of them reaches zero, because of the $4 fixed charge.
- How many solar panels do I need in Puerto Rico? Panels needed to cover the day for three real households, on a clear day and on an overcast one, and how the answer moves by region. The overcast day takes 2.6× more panels.
- How many days does a solar system last with no grid in Puerto Rico? Days without the grid by battery size and panel count, for three real households, run day by day on overcast weather with no generator. Not a yearly average.
- Do I need a generator if I have solar? Generator hours during a blackout for three real households and four system sizes, on the first overcast day and on the third. The first day says no; the third says otherwise.
- How much power does an air conditioner use per day in Puerto Rico? kWh per day for 9,000 to 36,000 BTU units by schedule and thermostat, worked out hour by hour. A 12,000 BTU unit goes from 4 to 17.71 kWh a day depending on how you use it.
- How much power does each appliance use per day? kWh a day for fridges, freezers, water heaters, dryers, pool pumps, dehumidifiers and the stove, each with the schedule it assumes, run hour by hour. The inverter alone takes 1.2 kWh a day.
- How to file your solar system with LUMA in Puerto Rico The seven steps of the Expedited Registration under Act 17-2019: the account number, UL 1741 SB, the PREPAEE portal, the certified diagram, the attachments, LUMA’s 30 days, and the meter swap. Plus what to do when they do not answer.
Free, no card and no sign-up. Your appliances one by one, your town's sun, and the whole day hour by hour.