How to read your power bill in Puerto Rico
The electric bill has more line items than almost any other household account. Understanding three numbers — kWh, price per kWh and fixed charges — is enough to know why it went up and what you can do.
The number that rules: kWh
A kilowatt-hour (kWh) is the energy unit you're billed for: using 1,000 watts for one hour. A 1,200-watt air conditioner running 8 hours burns 9.6 kWh in a day.
The bill shows the previous and current meter readings; the difference is the period's kWh. That consumption is the only thing you directly control.
The price per kWh is not fixed
The cost per kWh combines the base rate plus adjustments that change quarterly, mainly fuel cost and purchased power. That's why two bills with identical consumption can arrive with different totals.
To find your real price, divide the bill total by the kWh consumed. That's the number to use in the consumption calculators.
Fixed charges and the other lines
Beyond consumption there are charges that arrive even if you turn nothing on: customer charge, contributions and subsidies required by law. At low consumption, these fixed items can be a large slice of the total.
If your bill looks high with little usage, check the fixed charges and adjustments before blaming the fridge.
Finding the guilty appliance
The practical rule: power (watts) × hours of use ÷ 1,000 = kWh. Resistive-heat appliances — dryer, water heater, electric stove — and air conditioners dominate almost every bill.
Use the electricity calculator with each appliance's label wattage and your real price per kWh, and you'll see in dollars who takes your money each month.
Your real price per kWh is not the published rate
The bill shows a base rate, but what you actually pay includes adjustments that move period to period. To find your real price there is one operation: divide the bill total by the kWh consumed.
That is the number to use in any consumption calculator. Using the base rate understates the cost, sometimes by a wide margin, and it is the most common reason an estimate lands far below the bill.
What to check when the bill rises for no clear reason
Before hunting for a guilty appliance, compare kWh, not dollars. If kWh held steady and the total rose, the change came from the rate, not your usage, and there is nothing at home to switch off.
If kWh rose, the next figure is how many days the cycle covered: a 35-day period against a 28-day one explains a 25% jump on its own. Only once kWh and days line up is it worth hunting the appliance.