# Compare annual electricity tariffs — BillLens

Canonical: https://getecoback.com/en/workbench/billlens.html
Language: en
Method version: 2026-09-19.2

Compare first-year and recurring electricity costs using your actual tariff inputs.

## How this tool works

First year = annual kWh × unit price + 12 × monthly fee − one-time credit. Following year excludes the one-time credit.

## Input format

- Annual electricity use (kWh): `kwh`
- Tariffs, one currency: `tariff,currency,unit_price,monthly_fee,one_time_credit`

## Reproducible example

All prefilled business examples are fictional. Replace them with your own checked inputs.

```json
{
  "columns": [
    "Tariff",
    "Currency",
    "Energy",
    "Standing fees",
    "One-time credit",
    "First year",
    "Following year"
  ],
  "rows": [
    [
      "Sample A",
      "EUR",
      "960.00",
      "144.00",
      "100.00",
      "1004.00",
      "1104.00"
    ],
    [
      "Sample B",
      "EUR",
      "864.00",
      "192.00",
      "0.00",
      "1056.00",
      "1056.00"
    ]
  ]
}
```

## Limits and assumptions

Unit price is currency per kWh, not cents. Monthly standing fees are multiplied by 12. One-time credits apply only in year one.

Taxes must already be included in your inputs. This does not model tiered tariffs, eligibility or cancellation fees. No supplier switching occurs.

Browser-based tools · Your inputs stay in this browser. No account, cloud backup or paid membership is provided.

[RFC 4180 — CSV format](https://www.rfc-editor.org/rfc/rfc4180)