Why is my electric bill so high this month? A diagnostic walkthrough

An electric bill has two moving parts: how many kWh you used and what each kWh cost. A bill can jump because usage went up, because the per-kWh rate went up, or because both moved at once. Before diagnosing anything else, pull last month's bill and this month's side by side and write down four numbers: kWh used, supply rate in cents per kWh, delivery rate in cents per kWh, and the total.

If kWh is flat but the total jumped, the cause is on the rate side and you can skip to cause #2. If kWh is up, work through the causes in the order below.

This is the single most common cause and it's the first place to look. Heating and cooling are 60-70% of the average home's electric bill in peak months. A summer where average temperatures run 5°F hotter or a winter that hits a two-week cold snap can push HVAC runtime up 30-50% without you changing a thermostat setting.

The math: a 3,500W central AC running 8 hours a day at 16.5¢/kWh costs about $139 a month. Same AC forced to run 12 hours during a heat wave costs $208. That's a $69 jump with no behavior change. How to check: compare this month's average outdoor temperature to the same month last year. Most utilities now show a degree-day chart right on the bill.

Utility rates move. Supply rates (what the power itself costs) reset every six months in many states and can swing 20% either way depending on natural gas prices. Delivery rates reset on a slower cadence but still step up annually in most markets. A 2¢/kWh rate change on a house using 1,000 kWh a month is $20 extra. On a house using 2,500 kWh, it's $50.

The 2026 baseline is moving fast. National residential average is now 18.05¢/kWh per the EIA, up 5.4% year over year and up 21% in three years. The latest hikes already on the books: Southern California Edison +12.9%, Oregon's PGE and Pacific Power both stepped up March 31, El Paso Electric added a fresh fee package in April, and PSEG New Jersey rolls out time-of-use rates June 1 with a 31¢/kWh on-peak window. If your bill jumped this spring and you live in any of those territories, the rate side alone explains a meaningful chunk of it.

How to check: find last month's supply and delivery rates on the old bill and compare to this month's. If either moved, multiply the delta by your kWh to get the dollar impact. See current rates for every state on the state-by-state rate breakdown to sanity-check whether your number is reasonable for your region, or jump straight to your state's page (e.g. California).

A national pattern sits behind the individual hikes. US utilities filed requests for $31 billion in rate increases during 2025, roughly double the 2024 total per PowerLines.org. Yale Climate Connections, Harvard Law's policy program, CNBC, Stateline, and the Environmental and Energy Study Institute have all pointed at the same primary driver: data center load. AI and cloud buildout now accounts for roughly 40% of new electricity demand growth in the United States, and utilities have received interconnection requests totaling more than 700 GW, more electricity than the entire country consumed in 2023.

That demand has to be paid for, and most of the cost flows through to residential ratepayers via the same supply and delivery rate components on your bill. Reporting from Yale and Harvard found retail electric costs in counties hosting large data centers up as much as 267% over the last five years. EIA's 2026 summer outlook calls for an additional bump in many regions, including a roughly $13/month increase across New England.

In the first week of May 2026, the New York Times, Fortune, and Reuters each confirmed the same trajectory: summer bills are headed higher. Fortune's investigation found utility CEOs collectively earned $626 million while residential rates hit record levels. State and local governments have started pushing back on the data center cost pass-through: North Carolina introduced legislation targeting data center electricity costs, Pennsylvania's Public Utility Commission launched residential protections, DTE Energy in Michigan tied a proposed 10% rate hike directly to data center demand, and Seattle's city council voted in late April to halt new data center construction.

You can't fix the macro picture from a kitchen table. What you can fix is knowing exactly what each appliance in your house costs at the new rate, so the next bill doesn't surprise you the same way. The summer bill guide covers ten specific cooling savings with dollar amounts. Use the calculator at the bottom of this page, or jump to the ranked list of the costliest appliances in a typical home and start with the top of the list.

Anything that pulls more than 1,000 watts for extended hours can visibly move a bill. The usual suspects:

• A space heater at 1,500W for 10 hours a day adds about $56 a month.
• A hot tub running year-round adds $40-100 a month depending on insulation and setpoint.
• A new EV charging at home adds $30-60 a month for a typical commute.
• A second window AC in a bedroom adds $20-40 a month in summer.

How to check: walk through the house and list anything that wasn't plugged in this time last year. Anything with a compressor, heating element, or motor is a candidate.

Appliances don't fail all at once. They drift. A fridge with a bad door seal or a dusty condenser coil can pull 30-40% more than its nameplate. An old HVAC system losing refrigerant runs longer to hit the same setpoint. A water heater with mineral buildup heats slower and cycles more. The bill moves quietly over months until you look at a year-over-year comparison.

How to check: pull your last 12 months of bills from the utility portal. If kWh is creeping up 5-10% year over year with no lifestyle change, something is drifting. Prime suspects are the oldest motorized or heat-element appliances in the house: fridge, HVAC compressor, water heater, pool pump.

A new baby adds roughly 50-80 kWh a month in laundry, warm baths, and lights. A partner switching to remote work pushes the daytime thermostat from 78°F to 72°F in summer, which is worth $30-50 a month on a central AC. Houseguests for two weeks can run the dishwasher daily instead of twice a week. None of these feel like big changes. All of them show up on the bill.

How to check: think about what changed at home in the last 60 days. Work schedule, family size, guests, a pet that needs the house warmer, kids home from school. Map each change to an appliance and estimate the extra runtime.

This is the last place to look because it's the rarest, but it does happen. A smart meter can fail in a way that over-reports usage. An estimated read (the utility guesses instead of pulling an actual number) can catch up months later with a big correction. A previous tenant's final bill can get rolled onto yours if the handoff was sloppy.

How to check: look for the word "estimated" on recent bills. Read the meter yourself and compare to what's printed. If the numbers don't match, call the utility and request an on-site reread. Most utilities will send a tech within a week and credit any confirmed error.

Once you have a candidate, plug the real wattage and runtime into the calculator below. If the math lines up with your bill increase, you've found it. If not, move to the next cause on the list.

Weather is out of your hands. Rate changes are out of your hands. The three causes you can act on are new appliances (swap or schedule), drifting old appliances (maintain or replace), and usage shifts (adjust setpoints or timing). The biggest single lever in most homes is the HVAC setpoint: every 1°F closer to the outdoor temperature is worth roughly 6-8% on the heating or cooling bill. That's a free change and it compounds every month of the season.