Script to calculate payback time for an iBoost device

iboost.py

#!/bin/env python3

# Script generated by Gemini
# https://gemini.google.com/share/b46c488b3399

def calculate_iboost_payback():
    print("--- Solar iBoost Payback Calculator ---")

    # User Inputs
    cost_of_iboost = float(input("Cost of iBoost + Installation (£): "))
    gas_price_per_kwh = float(input("Cost of gas per kWh (£): "))
    export_price_per_kwh = float(input("Export tariff (SEG) per kWh (£): "))
    boiler_efficiency = float(input("Boiler efficiency (e.g., 0.85 for 85%): "))

    # Estimates for energy diversion
    diverted_energy_per_year = float(input("Estimated kWh diverted to hot water per year: "))

    # Calculation logic:
    # 1. The 'Effective Cost' of the gas you're replacing.
    # Since boilers aren't 100% efficient, you save more than 1kWh of gas for every 1kWh of immersion heat.
    effective_gas_saving = gas_price_per_kwh / boiler_efficiency

    # 2. The 'Net Saving' per kWh.
    # You save the gas cost but LOSE the export payment you would have received.
    net_saving_per_kwh = effective_gas_saving - export_price_per_kwh

    if net_saving_per_kwh <= 0:
        print("\nResult: Based on these figures, the iBoost will never pay for itself.")
        print("Your export tariff is more valuable than the gas you are saving.")
        return

    # 3. Annual and Payback calculations
    annual_savings = diverted_energy_per_year * net_saving_per_kwh
    payback_years = cost_of_iboost / annual_savings

    print(f"\n--- Results ---")
    print(f"Net saving per kWh: £{net_saving_per_kwh:.4f}")
    print(f"Total annual savings: £{annual_savings:.2f}")
    print(f"Payback period: {payback_years:.2f} years")

if __name__ == "__main__":
    calculate_iboost_payback()