How to read your electric bill
Every electric bill in the country is built from the same four pieces, even though every utility prints them differently. Once you can find the four, you can tell which one a rate case moves and which one you might be able to do something about.
1. The customer charge
A fixed amount per month for being connected, whether you use any electricity or not. Usually somewhere between $5 and $25, and rising: several recent rate cases raised it on purpose because it is the one line that does not shrink when people use less. It is set in the base rate case.
2. Delivery
Charged per kilowatt-hour for moving power over the utility's wires. On most bills it appears as distribution plus transmission, sometimes as several lines. Distribution is the local poles and wires, set by your state commission in a rate case. Transmission is the high-voltage network, and its price is set by federal regulators and the regional grid operator, so it can rise without any state case at all. In every state, delivery is regulated and not shoppable.
3. Supply
The electricity itself, also per kilowatt-hour, sometimes labeled generation, energy or supply. How it is priced depends on where you live. In most states the utility generates or buys the power and passes the cost through a fuel or purchased-power adjustment that is trued up a few times a year. In the fourteen jurisdictions with retail choice, the utility offers a default supply price and you can take that or sign with a competing supplier. The supplier guide covers which states and what to watch for.
4. Riders and surcharges
Everything else, and there is more of it every year: storm cost recovery, grid modernization, energy efficiency programs, nuclear or renewable support, low-income assistance, regulatory assessments, franchise fees and taxes. Each rider has its own docket and its own rules. When a bill goes up without a rate case in the news, a rider is usually the reason. This site tracks the large ones alongside base rate cases and labels them as riders.
What a rate case actually moves
A base rate case changes the customer charge and the distribution part of delivery. It does not usually change supply, transmission or most riders. That is why an approved "4 percent increase" can show up as a smaller percentage on your total bill in a state where supply is most of the cost, and a larger one where delivery dominates. The case pages here quote the utility's own typical-bill figure when it published one, and say which kilowatt-hour benchmark it assumed.
Why your neighbor's bill is different
Usage, first of all: everything except the customer charge scales with kilowatt-hours, so a house that uses twice the state average pays roughly twice the increase. Then rate class (some utilities have separate residential heating rates), time-of-use plans, and in choice states, whoever you signed with for supply. Two identical houses on the same street can be on different supply prices for years without either household noticing.
Finding your own numbers
Your bill shows your monthly kilowatt-hours somewhere near the meter reading. Take the dollar figure from a case page here, divide by the benchmark usage the utility quoted, and multiply by your own usage. The typical bill page walks through it with real figures.