Heating Cost Compare

{
  "asOf": "2026-10-11T14:31:35.911Z",
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "heatPumpBreakEvenElectricityPerKwhVsGas": 0.1616,
  "notChecked": [
    "equipment cost, maintenance, installation and duct losses",
    "heat pump performance falling in very cold weather: the COP is a seasonal average you must choose for your climate",
    "…2 more"
  ],
  "reasons": [
    "Cost per delivered MMBtu = fuel price per MMBtu of energy content / efficiency (or COP).",
    "Heat contents: 1 kWh = 3,412 BTU; 1 therm = 100,000 BTU; propane 91,452 BTU/gal and heating oil 137,381 BTU/gal (EIA). A heat pump at COP 3 beats the gas furnace while electricity costs under 0.1616 p…"
  ],
  "source": "computed locally",
  "summary": "Cheapest delivered heat: heat pump at 15.63 per million BTU (938 a year for 60 MMBtu); most expensive: electric resistance at 46.89.",
  "systemsRankedCheapestFirst": [
    {
      "assumedEfficiency": 3,
      "costPerMMBtuDelivered": 15.63,
      "note": "seasonal COP 3",
      "relativeToCheapest": 1,
      "system": "heat pump",
      "yearlyCost": 938
    },
    {
      "assumedEfficiency": 0.95,
      "costPerMMBtuDelivered": 15.79,
      "note": "AFUE 0.95",
      "relativeToCheapest": 1.01,
      "system": "natural gas furnace",
      "yearlyCost": 947
    }
  ],
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://home-energy-calc.x402tookit.com/heating-cost-compare?annualHeatMMBtu=60&electricityPerKwh=0.16&gasPerTherm=1.5&oilPerGallon=4&propanePerGallon=3.2'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://home-energy-calc.x402tookit.com/heating-cost-compare?annualHeatMMBtu=60&electricityPerKwh=0.16&gasPerTherm=1.5&oilPerGallon=4&propanePerGallon=3.2' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fhome-energy-calc.x402tookit.com%2Fheating-cost-compare
const res = await pay("https://home-energy-calc.x402tookit.com/heating-cost-compare?annualHeatMMBtu=60&electricityPerKwh=0.16&gasPerTherm=1.5&oilPerGallon=4&propanePerGallon=3.2");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://home-energy-calc.x402tookit.com/heating-cost-compare?annualHeatMMBtu=60&electricityPerKwh=0.16&gasPerTherm=1.5&oilPerGallon=4&propanePerGallon=3.2")
    print(res.status_code, res.text)