Compare electricity plans over a full year of real usage
Build a month-by-month electricity comparison that handles seasonal consumption, fixed fees, one-time costs, and uncertainty.
A useful annual electricity comparison applies each plan's prices to each month of your own usage, then adds recurring fees and one-time costs. Multiplying one recent bill by twelve can miss seasonal heating or cooling, a temporary credit, or a rate change. Use the same assumptions for both plans and show uncertain future prices as scenarios. This method estimates costs; it does not turn a variable contract into a guaranteed annual price.
Collect a clean twelve-month baseline
Download the billed kWh for twelve consecutive billing cycles and record each cycle's dates. Use billed energy rather than payment amounts, especially if you are on budget billing. Separate electricity from gas and remove unrelated account balances from any cost benchmark. Note estimated readings or later corrections that could distort the apparent month-to-month pattern.
List meaningful household changes beside the history: an added resident, electric vehicle, vacant period, changed work schedule, or heating equipment replacement. Historic usage is a baseline, not destiny. If an upcoming change is material, build a second scenario rather than selectively adjusting only the plan you prefer. Retain the original data so you can explain how the adjusted case differs from actual past consumption.
Make each month a row
For a simple flat supply rate, monthly supply cost equals kWh multiplied by the dollars-per-kWh rate plus any supplier fee. Add delivery consistently and follow the actual tariff for seasonal changes, taxes, riders, and conditional credits. If a threshold credit applies, evaluate the condition in each row instead of applying the credit twelve times automatically.
| Illustrative month type | kWh | Plan A: 10 cents + $5 | Plan B: 11 cents, no fee |
|---|---|---|---|
| Low use | 300 | $35 | $33 |
| Moderate use | 800 | $85 | $88 |
| High use | 1,400 | $145 | $154 |
These supply-only examples exclude delivery and taxes. They demonstrate that a fixed monthly fee can make the winning plan depend on usage. Do not call the table an annual estimate unless you include all twelve actual or explicitly modeled months. A high-use month should not stand in for an entire season without a stated assumption.
Reconcile an annual fixed-fee effect
Illustrative annual example: consumption totals 9,000 kWh. Plan A charges 10 cents plus $5 monthly; Plan B charges 11 cents with no supplier fee. A's annual supply cost is 9,000 × $0.10 + 12 × $5 = $960. B's is 9,000 × $0.11 = $990. A is $30 cheaper before other differences.
At 5,000 kWh, A would cost $560 and B $550, so B would be $10 cheaper. For these simplified constant-rate plans, the equal-cost annual usage is 6,000 kWh. Monthly allocation is still needed when prices, credits, or fees vary with season or usage. Keep those distinctions explicit rather than claiming every annual comparison can be reduced to total kWh.
Add switching and renewal costs
Include a nonrefundable enrollment fee, any applicable fee to leave the current agreement, and other genuine incremental costs. Keep refundable deposits separate because their cash-flow effect differs from a permanent expense. If the new plan's term ends before your twelve-month comparison period, identify what rate you assume afterward and why it is uncertain.
Compare equal horizons. A six-month promotional offer should not be compared with a twelve-month fixed price using only its first six months and calling the result annual savings. You can compare the common six-month period or model a stated renewal scenario for the rest. If the future terms are unavailable, report the unresolved portion rather than filling it with the initial rate by default.
Stress-test what you cannot know
For variable prices, create clearly labeled lower, middle, and higher hypothetical paths without assigning invented probabilities. Test a heavier-use year separately. A household may tolerate one uncertain input but not the combination of a rate increase and a severe heating or cooling season. A range of modeled totals helps make that exposure visible.
After enrollment, compare modeled and actual current charges, not just the amount due. Investigate differences in usage, rates, fees, and dates. A forecast is useful partly because it provides a record of assumptions that can be corrected. Do not rewrite the earlier estimate to make it appear accurate after the fact; keep the original calculation and note what changed. This is a practical audit trail for your own decision, not a professional energy audit.
Keep a separate cash-flow view
An annual cost ranking does not show when money must be paid. Keep a second column for deposits, advance payments, and expected refund timing. A plan with a slightly lower modeled annual cost can require more cash at enrollment or during a difficult season. Conversely, budget billing may smooth payments without reducing actual annual charges. Compare both affordability and total cost, and do not subtract a refundable deposit permanently from one offer while ignoring it in the other. Retain all assumptions so another household member can reproduce the comparison without relying on a headline saving.
FAQ
Can I just use annual kWh?
For constant flat rates and constant fees, often yes. Seasonal prices, threshold credits, time bands, and changing terms require more detailed allocation.
Should taxes be included?
Include applicable taxes on their actual basis if known. If excluded, label totals before tax and do not compare them with tax-inclusive offers without adjustment.
Does last year's cheapest plan remain cheapest?
No. Usage, offers, delivery tariffs, and renewal terms can change. Recalculate using the current written offers and a defensible usage forecast.
Related reading
Sources
- PAPowerSwitch — price disclosure and contract guidance.
- EIA: electricity price factors — seasonal and cost context.
