Several methodologies exist to calculate the Levelized Cost of Electricity (LCOE). We adopt two methods in genGEO: the simplified LCOE model (Section S2.1) and the balance-sheet LCOE Model (Section S2.2). The simplified model calculates the LCOE as the ratio of annualized costs to annual power generation, while the balance-sheet model calculates the LCOE by calculating yearly cashflows and power generation and solving for an electricity price which yields a net present value of zero. The simplified model is used by GETEM, GEOPHIRES, and NREL models in various forms. The balance-sheet model is more realistic in terms of actual cashflows and is used by Lazard (2019).