battery – n. object that provides and stores electricity for things
density – n. the relationship between the weight of a substance and its size
abundant – adj. existing in large quantities
cheap – adj. not costing a lot of money
solar – n. relating to or involving the sun
kilowatt – n. a unit for measuring electrical power
roof – n. the top or covering of something
ion – n. an atom or atomic group that carries an electric charge