# Solar Halowerk Low-Wattage Cooking Energy Calculator

> Solar Halowerk Low-Wattage Cooking Energy Calculator is a paid API for AI agents from solar.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Computes thermodynamic heating time estimates for low-wattage cooking appliances given user-supplied device power, food mass, temperatures, specific heat, and efficiency range.

## Facts

- Endpoint: POST https://solar.halowerk.com/low-wattage-cooking
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/solar-halowerk-low-wattage-cooking-energy-calculator-8e1db8ab
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1mnkti-S-9nUox-6Nspp4

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability solar-halowerk-low-wattage-cooking-energy-calculator-8e1db8ab -d '<json body>'
```

Example prompt: How long will my 250W solar cooker take to heat 1.5 kg of rice (specific heat 1.8 kJ/kg·K) from 18°C to 95°C, assuming an efficiency range of 40% low, 60% expected, and 75% high, with a 1 kg aluminum vessel (specific heat 0.9 kJ/kg·K)?

## When to prefer this

Choose this endpoint when you need a transparent, physics-based estimate of heating time and energy for a specific low-wattage electrical device — especially in off-grid, solar, or van/boat contexts — and you want to supply your own efficiency assumptions rather than relying on a black-box recipe database. Prefer this over generic cooking apps when the user needs to plan energy budgets or compare device wattages for off-grid scenarios.

## Known failure modes

- Missing required fields (device_power_w, food_mass_kg, temperatures, specific_heat, efficiency) returns a validation error
- Target temperature below start temperature may return an error or zero/negative result
- Efficiency values out of order (high < low) may cause a validation or logic error
- Extreme parameter combinations (e.g. 10000W, 0.001 kg) may return implausibly short times without error
- Network or payment (x402) failure returns a 402 or connectivity error

## How this service works

Uses rated electrical power, food mass, start and target temperature, specific heat and an explicit efficiency range supplied by the caller. Optional vessel heat, evaporation and a caller-defined hold phase can be included. It contains no recipes, recipe text, food-specific cooking claims or hidden food database; the output separates the thermodynamic lower bound from the practical range and is not a food-safety clearance.

## Output

Returns a separated breakdown of the thermodynamic lower bound heating time and the practical heating time range (low, expected, high) in minutes or similar units, along with energy requirements in kJ or Wh, accounting for vessel mass, evaporation losses, and an optional hold phase. Explicitly notes this is not a food-safety clearance.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "hold": {
   "type": "object",
   "required": [
    "minutes",
    "power_fraction"
   ],
   "properties": {
    "minutes": {
     "type": "number",
     "maximum": 1440,
     "minimum": 0
    },
    "power_fraction": {
     "type": "number",
     "maximum": 1,
     "minimum": 0,
     "description": "Average fraction of rated input power during the hold phase."
    }
   },
   "additionalProperties": false
  },
  "vessel": {
   "type": "object",
   "required": [
    "mass_kg",
    "specific_heat_kj_kg_k"
   ],
   "properties": {
    "mass_kg": {
     "type": "number",
     "maximum": 100,
     "minimum": 0
    },
    "specific_heat_kj_kg_k": {
     "type": "number",
     "maximum": 10,
     "exclusiveMinimum": 0
    }
   },
   "additionalProperties": false
  },
  "efficiency": {
   "type": "object",
   "required": [
    "low",
    "expected",
    "high"
   ],
   "properties": {
    "low": {
     "type": "number",
     "maximum": 1,
     "exclusiveMinimum": 0
    },
    "high": {
     "type": "number",
     "maximum": 1,
     "exclusiveMinimum": 0
    },
    "expected": {
     "type": "number",
     "maximum": 1,
     "exclusiveMinimum": 0
    }
   },
   "additionalProperties": false
  },
  "evaporation": {
   "type": "object",
   "required": [
    "mass_kg",
    "latent_heat_kj_kg"
   ],
   "properties": {
    "mass_kg": {
     "type": "number",
     "maximum": 100,
     "minimum": 0
    },
    "latent_heat_kj_kg": {
     "type": "number",
     "maximum": 5000,
     "minimum": 0
    }
   },
   "additionalProperties": false
  },
  "food_mass_kg": {
   "type": "number",
   "maximum": 100,
   "description": "Mass being heated in kilograms.",
   "exclusiveMinimum": 0
  },
  "device_power_w": {
   "type": "number",
   "maximum": 10000,
   "description": "Caller-supplied rated electrical input power in watts.",
   "exclusiveMinimum": 0
  },
  "start_temperature_c": {
   "type": "number",
   "maximum": 200,
   "minimum": -50
  },
  "target_temperature_c": {
   "type": "number",
   "maximum": 300,
   "minimum": -49
  },
  "specific_heat_kj_kg_k": {
   "type": "number",
   "maximum": 10,
   "description": "Caller-supplied effective specific heat of the contents.",
   "exclusiveMinimum": 0
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/solar-halowerk-low-wattage-cooking-energy-calculator-8e1db8ab/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from solar.halowerk.com](https://www.zero.xyz/host/solar.halowerk.com/llms.txt)