How might your choice of the best energy source depend on your geographic location?

Answer 1

It will depend on a few things that you should consider:

solar potential in your location - you can Google for this and you'll find a chart with solar potential relative to your location. Generally, the closer to the equator, the better. If your location doesn't have a high solar potenital, then I would advise against it. But you can calculate how long it could take you to pay off a solar panel given the solar density for your location, solar panel efficiency, and how frequently it will produce energy for you throughout the year.

geothermal heat pumps - here, you should consider the variance of temperature over the course of the year. The average temperature of earth (soil that is, so the heat exchange returning to your home should be around 55 degrees) is around 55 degrees, so the more the average air temperature changes in your region with respect to 55 degrees throughout the year, the more effective this will be. For example, if you live in a stable climate, where the average temperature throughout the year is 65 +/- a few, then it wouldn't be wise. However places where there is high variance, then you can expect savings in winter and summer.