Thanks for asking. I believe that personal energy choices are deeply important for our planet and future generations. Here are the possible energy sources, noting those that have a relatively low environmental impact:
Solar: With an amortization of 4-7 years (depending on costs of electricity), and a lifespan of 20+ years, solar panels are the lowest price, lowest impact, and easiest energy solution. You could use the electricity to power resistance-heaters or better yet, heat pumps (see below). I do not believe that battery systems make sense yet, but they will soon. And of course, one must be tied into the grid or have a battery. This is what I have.
Wind: Small turbines are very cheap, easy to install, but must be placed to one's north. Furthermore, one most pay attention to local codes and neighbors. If placed between a dwelling and the sun, flicker can drive people crazy. There is also the issue of bird strikes. If you live in a migration path, turbines should not be erected without consulting the local Audubon Society or equivalent. And of course, one must be tied into the grid or have a battery.
Geothermal: (Not to be confused with ground source heat pumps.) this makes sense in geothermal hot zones, like Iceland, or in Spain, in Santiago de Compostela. There are a few other areas in Spain that have hot spots. This is a direct heating solution, and not an electrical generation system, and therefore no grid tie in is needed.
Wood: produces carbon. The ONLY thing that will save the planet from runaway climate change is trees. Burning them works against this. Wood/pellet suppliers say this is from small branches, but burning anything: branches, logs, bark, will increase atmospheric carbon. Allowing them to break down slowly will replenish the soil and not increase atmospheric CO2.
Natural gas: Worse than wood, as natural gas is ~87% methane. Natural gas drilling, fracking, transport, and delivery releases methane, which is 25-50 times more potent a global warming gas than CO2.
Home heating oil, Diesel: All fossil fuels release CO2, but this belches out dirty, particulate-laden smoke. There are 10,000 VOCs in this smoke, but only 3000 have been classified -- and almost all of them are carcinogenic. And while car/truck diesel engines have some filters (albeit poor ones), home heating systems do not.
Coal: There’s no such thing as clean coal. There’s no such thing as permanent and effective carbon sequestration. Coal "mining" destroys local environments. Coal dust kills.
There are other sources, eg co-generation. If you live in an area that has waste energy, you already know about this option.
How to use energy efficiently:
Heat pumps win the prize for the lowest energy use. There are two types of heat pumps: air-source and ground-source. Air-source is cheaper to buy, ground source is cheaper to run (and thus lower impact). Both should be evaluated for your specific heating/cooling needs and local climate (air source can be problematic in cold regions).
There are lots of articles about all of these choices. I always recommend looking for one published by a major university, eg Yale, Harvard, MIT, Oxford, etc. But above all, I always urge people to make their decision based not solely on the economics of their choice, but on the greater issues confronting all of us.