Make your next decision with clarity.
Seven questions, one engine · 2026-09-16
Your electric bill, solar panels and backup power. Find the answer you need, then explore your home’s next step.
- How much does solar cut your power bill? The monthly bill before and after solar for three households, with net metering (Puerto Rico, Act 114-2007), plus six months of a real Puerto Rico bill: the dated rate reference, what the credit bank does and what the June closing does to it. None of them reaches zero, because of the $8 fixed charge.
- How many solar panels do I need? Panels needed to cover the day for three real households in Puerto Rico, on a typical 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? Days without the grid by battery size and panel count, for three real households in Puerto Rico, 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? kWh per day for 9,000 to 36,000 BTU units by schedule and thermostat, worked out hour by hour with Puerto Rico's sun. 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.
Puerto Rico only
The filing with LUMA and your rights as a customer. The rest of the guides work for any roof.
- 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. What to do when they do not answer, and your rights when a wrong bill shows up.
Free, no card and no sign-up. Your appliances one by one, your town's sun, and the whole day hour by hour.