The energy content of natural gas is measured in therms, while that of electricity is measured in kilowatt hours. XeroHome converts both natural gas and electric energy use for a home into base energy units of BTUs. XeroHome then optimizes the energy upgrades and rooftop solar recommendations to get annual energy consumption for the home to be Zero BTUs.  

XeroHome’s optimizer will often recommend switching a natural gas space heating or water heating unit with a high efficiency electric one, where that upgrade makes sense. However, it is possible that a Net-Zero Energy home may still use natural gas for space or water heating. In that case, the natural gas energy use will be made up annually with energy produced using rooftop-solar.