Electricity tariff reform is an essential part of the clean energy transition. Existing tariffs encourage the over-adoption of residential solar systems and the under-adoption of electric alternatives to fossil fuels. However, an efficient tariff based on fixed charges and marginal cost pricing may harm low-income households. We propose an alternative methodology for setting fixed charges based on each household’s willingness to pay to consume electricity at marginal cost. Using household-level data from Colombia, we demonstrate the short-run and long-run distortions from the existing tariffs and how our new methodology could provide the economic, environmental, and health benefits from adopting clean energy technologies while still protecting low-income households from higher bills.