Which statement about passive solar heating systems is true?

A they do not work in enclosed areas

B they generate electricity

C their heat cannot be stored

D they do not produce electricity

D. They do not produce electricity.

Passive solar heating is a technique where the sun's energy is used for heating spaces. It does not generate electricity but can save substantial electricity by making use of thermal mass. Materials that have a high density such as concrete and bricks absorb and store electricity. Along with operable windows and thermal chimneys, thermal mass is being utilized to take advantage of sun exposure.