# Heat pump running cost calculator

- Human page: https://happytails.ai/en/calculators/heat-pump-running-cost-calculator/
- Markdown: https://happytails.ai/en/calculators/heat-pump-running-cost-calculator.md
- Structured JSON: https://happytails.ai/agents/en/calculators/heat-pump-running-cost-calculator/index.json
- Visibility: public

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `heat-pump-running-cost-calculator` |
| Category | calculators |
| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |
| Browser execution | Use the visible action or interactive controls. |
| Browser processing | Browser; see tool notes for network behavior. |
| HTTP API | Not callable through HTTP. |
| Browser-agent interface | run_current_tool |

### Implementation notes

Calculated on your device. Use an annual estimate or up to 12 monthly periods covering at most 366 days. COP, tariffs and standing charges are your assumptions.

### Inputs and settings

No free-text input is required. Use the file inputs and/or settings below.

| Setting | Meaning | Control type | Default | Constraints |
| --- | --- | --- | --- | --- |
| `mode` | Demand input | select | "Annual demand" | Allowed: Annual demand, Monthly periods |
| `annualHeat` | Annual useful heat demand (kWh) | number | 9000 | min=0 max=1000000000 step=any |
| `scop` | Seasonal COP | number | 3 | min=0 max=20 step=any |
| `tariff` | Electricity price per kWh | number | 0.3 | min=0 max=100000 step=any |
| `days` | Days included | number | 365 | min=0 max=366 step=1 |
| `standingCharge` | Standing charge per day | number | 0.5 | min=0 max=100000 step=any |
| `periods` | Monthly periods | textarea | "January,31,1800,2.5,0.30\nFebruary,28,1500,3,0.25" |  |

### Browser-agent workflow

1. Open the human page in a browser that supports WebMCP.
2. Discover the interface exposed by that page; use its actual schema.
3. Select files on the page first when the tool requires files.
4. Call `run_current_tool` with valid input and settings.
5. Inspect the returned result or error and the displayed output. Retrieve files from the displayed download links.

Calls do not automatically copy or download results. Browser permissions still apply. Interface availability alone is not proof of successful execution.

### Planning specification

Annual useful heat from 0 to 1 billion kWh; COP above 0 and up to 20; prices and daily standing charges from 0 to 100,000 in one currency. Annual duration 1 to 366 whole days. Monthly mode accepts up to 12 named periods, 1 to 31 whole days each and at most 366 days combined, in up to 100,000 characters. Processing stays on your device. Downloads: JSON report, results CSV and period CSV.

This describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.

### Complete machine-readable capability record

```json
{
  "id": "heat-pump-running-cost-calculator",
  "category": "calculators",
  "built": true,
  "requirements": "Annual useful heat from 0 to 1 billion kWh; COP above 0 and up to 20; prices and daily standing charges from 0 to 100,000 in one currency. Annual duration 1 to 366 whole days. Monthly mode accepts up to 12 named periods, 1 to 31 whole days each and at most 366 days combined, in up to 100,000 characters. Processing stays on your device. Downloads: JSON report, results CSV and period CSV.",
  "implementation": {
    "fields": [
      {
        "key": "mode",
        "label": "Demand input",
        "value": "Annual demand",
        "type": "select",
        "values": [
          "Annual demand",
          "Monthly periods"
        ]
      },
      {
        "key": "annualHeat",
        "label": "Annual useful heat demand (kWh)",
        "value": 9000,
        "type": "number",
        "min": 0,
        "max": 1000000000,
        "step": "any",
        "showWhen": {
          "mode": [
            "Annual demand"
          ]
        }
      },
      {
        "key": "scop",
        "label": "Seasonal COP",
        "value": 3,
        "type": "number",
        "min": 0,
        "max": 20,
        "step": "any",
        "help": "Useful heat divided by electricity input over the season. Use your own seasonal estimate.",
        "showWhen": {
          "mode": [
            "Annual demand"
          ]
        }
      },
      {
        "key": "tariff",
        "label": "Electricity price per kWh",
        "value": 0.3,
        "type": "number",
        "min": 0,
        "max": 100000,
        "step": "any",
        "showWhen": {
          "mode": [
            "Annual demand"
          ]
        }
      },
      {
        "key": "days",
        "label": "Days included",
        "value": 365,
        "type": "number",
        "min": 0,
        "max": 366,
        "step": 1,
        "showWhen": {
          "mode": [
            "Annual demand"
          ]
        }
      },
      {
        "key": "standingCharge",
        "label": "Standing charge per day",
        "value": 0.5,
        "type": "number",
        "min": 0,
        "max": 100000,
        "step": "any",
        "help": "Enter only the standing charge you intend to allocate to heating. Enter 0 to exclude it."
      },
      {
        "key": "periods",
        "label": "Monthly periods",
        "value": "January,31,1800,2.5,0.30\nFebruary,28,1500,3,0.25",
        "type": "textarea",
        "maxLength": 100000,
        "help": "One row per period: name, days, useful heat kWh, COP and electricity price per kWh. Use decimal points and no thousands separators.",
        "showWhen": {
          "mode": [
            "Monthly periods"
          ]
        }
      }
    ],
    "registrationFamily": "home-heating-costs",
    "input": false,
    "live": false,
    "presentation": "metrics",
    "note": "Calculated on your device. Use an annual estimate or up to 12 monthly periods covering at most 366 days. COP, tariffs and standing charges are your assumptions.",
    "inputKeywords": [
      {
        "id": "home-heating-costs/heat-pump-running-cost-calculator/periods.header",
        "kind": "header",
        "code": "HOME_HEATING_COSTS_PERIOD_HEADER",
        "fold": "lower",
        "values": {
          "period": [
            "period",
            "Period"
          ],
          "days": [
            "days",
            "Days"
          ],
          "heat": [
            "heat",
            "Heat"
          ],
          "cop": [
            "cop",
            "COP"
          ],
          "tariff": [
            "tariff",
            "Tariff"
          ]
        },
        "describedBy": [
          "Name the columns Period, Days, Heat, COP and Tariff, in that order, or leave out the header row.",
          "Monthly periods"
        ]
      }
    ],
    "experience": {
      "automatic": false,
      "single": true,
      "inputMaxLength": 1000000,
      "inputMode": "text",
      "label": "Heating assumptions",
      "placeholder": "Use the fields below",
      "help": "This calculator uses the fields below. Monthly period rows are entered in the options when selected. Up to 1,000,000 characters. Review the settings before running.",
      "action": null
    },
    "mode": "explicit",
    "interactive": false
  },
  "execution": "Browser interface",
  "api": null,
  "browser_agent": {
    "supported": true,
    "name": "run_current_tool",
    "discovery": "WebMCP on the human page in a supporting browser",
    "verification": "See audit/API-AUDIT.md; availability is not verification"
  }
}
```

## Page guide

Estimate heat-pump electricity use and running cost from annual demand or monthly heat, COP and tariff assumptions, with the standing charge you choose to allocate.

### How to use Heat pump running cost calculator

1. Choose annual demand or monthly periods.
2. Enter useful heat demand, seasonal or monthly COP, electricity prices and the allocated daily standing charge.
3. For monthly data, enter one period per line as name, days, useful heat kWh, COP and price per kWh.
4. Review the totals and period breakdown, then download the JSON report and CSV files.

How can we improve this tool?

Report a problem or share an idea.

Please leave out private information. Your message and the tool name go to our team via PostHog.

## Useful next steps

- [Appliance electricity cost calculator](https://happytails.ai/en/calculators/appliance-electricity-cost-calculator/) ([Markdown](https://happytails.ai/en/calculators/appliance-electricity-cost-calculator.md))

- [Hot water energy calculator](https://happytails.ai/en/calculators/hot-water-energy-calculator/) ([Markdown](https://happytails.ai/en/calculators/hot-water-energy-calculator.md))

- [Insulation calculator](https://happytails.ai/en/calculators/insulation-calculator/) ([Markdown](https://happytails.ai/en/calculators/insulation-calculator.md))

## Heat and electricity

COP is useful heat divided by electricity input. A 9,000 kWh annual heat demand at seasonal COP 3 uses 3,000 kWh of electricity. Seasonal or monthly performance should include the operating conditions and auxiliary loads you intend to model.

### Monthly periods

Each period has its own heat demand, COP, price and day count. Totals cover only the entered periods; missing months are not estimated. Annual mode uses one period. Names must be different, with at most 12 monthly rows and 366 days combined.

### Cost boundaries

Energy and allocated standing charges are rounded per period to two decimal places, then added. Enter 0 for standing charge if you do not want to allocate it to heating. Prices are your assumptions, with no live tariff or climate lookup.