We explain how using a chain of diodes instead of a resistive heater extracts more energy from a solar panel over a variety of solar intensities and also acts as a rough, inexpensive voltage regulator to charge batteries and power appliances. We show how a diode heater produces more heat from a solar panel than either a DDS resistive heater or a PWM/battery-connected resistive heater, averaged over a wide variety of solar intensities. The resulting cost of electricity is already cost competitive with biomass cooking in many areas.