During the nights they would hide in a dark part of the church, they received electricity through the power of their solar panels which used photovoltaic cells to convert the Sun's waves to electricity.
When they were eating, they would heat the food and boil the water using a hot plates. The hot plate would heat the water and the food through the hot plate using the electricity from the solar panels.
One day they went out for too long and the guys got burned by the sun's radiation. They ran from the burning zombies wanting to eat their delicious flesh.
One night, the zombies got in and surprised them and the guys screamed like little girls and ran for their lives like scooby-doo, but tripped and got eaten.