The advent of inexpensive solar electric combined with the goal of many local governments and home builders to achieve net zero energy, has increased the demand for efficient forms of electric HVAC and DHW systems. Over the years MEG has designed many geo exchange systems. Geo exchange systems are can be very complicated, expensive and require experienced installation crews. With our mild California temperatures, air source heat pumps are not quite as efficient but significantly less complicated and expensive. The slight difference in efficiency can easily be compensated by adding more solar electric production. We offer a complete economic analysis that compares all sources energy and mechanical systems. Our goal is to inform the home or business owner and help them decide what is the best solution.