That depends on where you live. In most regions, you can buy electricity that is generated using renewable sources. In PA, where I live, you can pay 7.25 cents/kwh instead of 6.5 cents/kwh and buy electricity that is from 100% renewable sources. This funds further investment in renewable sources of energy.
However, to answer your your assertion directly
"Base load electricity currently is supplied by generators using coal (50 percent), nuclear power (20 percent), hydro (9 percent) and oil (3 percent). Of the remaining electricity on the grid, 18 percent is provided by natural gas (16 percent) and the renewables (2 percent)"
Unfortunately, the original poster was in a bind, and had to get a system ASAP because they were without heat. Also, I believe, they already had oil hot water so installing new ductwork etc would have been a PITA. In their shoes, I might have gone with conventional heat pump if they had an A/C with ducting already. If they didn't? That's a tough call. I'd have to see their exact situation to make an intelligent suggestion.
I am putting my money where my mouth is. I have oil hot water and baseboard heaters and a conventional A/C. I am in the final stages of arranging to have a ground source heat pump installed and have already ordered my electricity to be switched over to the 100% renewable source.
I should add that I wasn't trying to be a wise ass in my reply. It is truly a shame that anybody has to go with oil these days because I sincerly think that their oil bills are going to go from maybe $1500 last year to $3000 next year (based on my last couple year's average consumption of about 1500 gallons/year) to $6000 in maybe 3-4 years.
In addition, I am planning some renovations to my home and will be adding a completely solar heated shop and will be using the excess heat to heat my domesting hot water supply, further reducing my overall energy impact.
I should also add that I am not any sort of radical environmentalist. I simply feel that the 10 year payback of these systems will by far exceed the expenses AND I believe that the "oil peak" will render most of the oil based items cost ineffective.
that's my 2 cents.
Cheers!