What do you mean when you say net-zero energy?
The net-zero energy is achieved when the EnerGuide for Houses (EGH*) gives a house a 100 rating. It means that the house generates its own electricity and heat per year on its own.
How do you get an EGH* rating of 100?
It all begins with an efficient house design. You have to do it so that it won’t produce as much energy as it consumes per year.
To get this done, you have to equip your house with low-energy equipment, lighting, and appliances. You have to include the use of passive solar heating in your highly insulated and airtight structure. Your house must be connected to a grid through your solar electric power system for its electrical needs. For home heating and water, you need to have a backup electrical heater along with your active solar heating system.
Why is a geothermal heat pump not included?
It is still being studied how to make the solar heating system more efficient by integrating a heat pump. This can also help provide a bit of cooling down from the ground during the summer heat.
As of now, the installation and maintenance of a heat pump would cost a lot. Adding more solar panels is currently more cost-efficient. This is why it is necessary to develop a configuration that will integrate even a small geothermal heat pump in the solar energy setup.
What happens to our excess solar electricity?
Any excess or surplus electricity that your panels will produce will get exported to the grid. You will be given different meters for measuring how much of the electricity is exported to the grid and how much electricity is imported from the grid to the house.