Why Did My Electric Bill Double in One Month?

A bill that doubles does not necessarily mean your electricity consumption doubled. Your total charge can change because of both the amount of electricity you use and the price and other charges applied to that electricity.

Find the kilowatt-hours (kWh) on the current bill and compare them with the previous billing period. If possible, also compare with the same month a year earlier because heating and cooling can make electricity use highly seasonal.

You can estimate the percentage change in electricity consumption before investigating individual appliances.

This distinction matters because a large dollar increase can result from more than one change happening at the same time. Electricity consumption may rise while rates, fees, credits, or the length of the billing period also change.

Heating and cooling should be among the first major loads you investigate. HVAC energy use is strongly affected by outdoor temperature, thermostat settings, the home's insulation and air leakage, equipment efficiency, and how many hours the system operates.

• The month was much hotter or colder than the previous billing period.
• The thermostat setting changed.
• The air conditioner, furnace blower, or heat pump ran much longer than usual.
• A portable electric space heater was used regularly.
• Supplemental or auxiliary electric heat operated more frequently.
• An HVAC filter became dirty enough to restrict airflow.
• The system developed an airflow, coil, refrigerant, control, or other performance problem.

ENERGY STAR notes that dirty HVAC filters can make heating and cooling equipment work harder, while dirty air-conditioning coils can reduce cooling performance and cause longer run times. These problems can increase energy costs, although the size of the increase will vary by home and system.

A sudden increase in electric heating can add a substantial load because resistance heaters convert electricity directly into heat. Examples include portable space heaters, electric baseboard heating, and supplemental resistance heat used by some heat-pump systems.

• A space heater was added to a bedroom, office, garage, or other room.
• Several portable heaters were used during a cold period.
• Electric baseboard heaters were turned on after being unused.
• A heat pump appears to be relying on supplemental or auxiliary heat more often.
• A thermostat was raised significantly during cold weather.

Water heating is another major household energy use, so homes with electric water heaters should consider changes in hot-water demand when electricity consumption rises sharply.

• More people stayed in the home during the month.
• Showers became longer or more frequent.
• Laundry or dishwasher use increased.
• A hot-water faucet or fixture developed a leak.
• Hot water seems to run out faster than it did before.
• The water heater appears to operate unusually often.

When kWh rises dramatically, look for devices that are either high-powered, operate for long periods, or both. A new load does not need to run continuously to have a noticeable effect over an entire billing period.

Also consider existing equipment that suddenly started running much longer. A refrigerator, freezer, pump, dehumidifier, or HVAC system with unusually long run time may deserve closer investigation.

Electricity prices and rate structures vary by location and utility. A change in the dollar amount therefore cannot be diagnosed from kWh alone.

1. Compare the start and end dates of both billing periods.
2. Compare the number of billing days.
3. Compare the total kWh used.
4. Look at the electricity rate or rate components shown on each bill.
5. Check fixed charges, delivery charges, fees, taxes, credits, and adjustments.
6. Look for time-of-use or tiered pricing if your utility uses those structures.
7. Check whether the bill identifies an estimated or actual meter reading.

Utilities may sometimes estimate consumption rather than calculate it from an actual meter reading. A later bill can then include an adjustment when actual meter information becomes available. Whether and how this appears on the bill depends on the utility.

If the current bill contains an adjustment, estimated reading, previous balance, credit reversal, or another item you do not understand, contact the utility rather than assuming the increase came from an appliance.

A longer billing period naturally includes more time for electricity consumption. When two bills cover different numbers of days, comparing average daily electricity use can provide a fairer comparison.

1. Write down the current bill's total cost, kWh, and billing days.
2. Write down the same information from the previous bill.
3. Calculate the percentage change in kWh.
4. Compare average kWh per day if the billing periods have different lengths.
5. If usage increased sharply, check weather and heating or cooling operation first.
6. Review electric heating and hot-water use.
7. Identify any new or unusually active high-power equipment.
8. If usage did not increase enough to explain the bill, compare rates and other charges.
9. Check for estimated meter readings, adjustments, or unusual billing items.
10. Contact the utility if the bill calculation or meter information still cannot be explained.

Contacting the utility is appropriate when the consumption or billing information does not make sense after you compare the bills. The utility can explain its own rate structure, billing adjustments, meter-reading information, and account-specific charges.

• The rate or charge calculation is unclear.
• The meter reading information appears inconsistent.
• The bill includes an adjustment you cannot identify.
• Your reported usage is dramatically different without an obvious household explanation.
• You need clarification about estimated versus actual meter readings.

A high bill by itself does not prove that an appliance or electrical system is defective. Professional inspection becomes more appropriate when unusually high consumption is accompanied by abnormal equipment behavior or electrical warning signs.

The key is to separate an electricity-consumption problem from a billing-cost problem. If kWh rose dramatically, investigate the largest loads and what changed during the month. If kWh remained relatively stable, concentrate on billing days, rates, fees, credits, adjustments, and meter information instead.