Savings Range and Simulation
The savings range measured from historical fuel-price windows, and the separate Monte Carlo and battery tools, whose spreads are our choices.
Savings Range and Simulation
The headline comparison comes with a savings range measured from history. We take every historical window of your ownership length (up to nine years) in the stored gasoline and electricity price indexes, grow the two fuel prices by the rates each window actually saw, re-run the cost arithmetic, and report the 10th to 90th percentile of the savings. The range shows how far fuel prices alone could move the answer. It is not a forecast, and it holds every other input where you set it.
The Monte Carlo endpoint of the API (POST /api/v1/montecarlo) is a separate tool. It varies gas and electricity growth, depreciation, maintenance and price levels around your assumptions with spreads we chose, not measured ones, and the response says so. Its distribution is only as good as those choices.
Battery degradation (POST /api/v1/battery) is also an authored model with stated constants, not a fit to a published study.