The Path to Net-Zero through Ground Source Heat Pump System and Solar means generating enough extra power to have zero energy cost at the end of a year and/or provide extra energy for your neighbors.
First evaluate your energy needs for your home or for a new home making sure you have utilized passive design ideas, insulate walls, ceilings and floors, ducts in conditioned space, and air infiltration blocked 100%.
Second create your own utility by installing a ground source heat pump system. A ground source heat pump (GHP) system takes one part kWh and 3-5 kWh of free energy from the earth to yield 4-6 kWh of energy for the building giving you 400-600% efficiently. The second step is to install solar photovoltaic panels on the face of your roof toward the son to generate the balance of the electrical power needed to support the total kWh needed for your home or building. Since you have installed a GHP system you will only need half as many solar panels for your roof. The GHP system works 24 hours a day, 7 days a week, and 365 days a year, whereas, the solar panels work only when the sun is shining. We honor the earth by using the free energy under the crust of the earth which has a constant temperature of 40-70F degrees. Caves have been used by humans and animals for years to survive. Outside temperature maybe 10 to 110 degrees, but the temperature of the ground stays constant. The earth is like a giant solar battery absorbing nearly half of the sun's energy.
Third create your own utility by installing solar panels to get direct energy savings from the sun. Solar panels can be bought or rented to complete the cycle and since you will only need half as many may have to be only on one side of your home facing toward sun. Since solar panels are decreasing in cost they can be added later to complete the path to Net-Zero.