I've sure been doin some research and talking to contractors (and checking with subsidy programs from my electrical supplier lately)! I have pages of notes. And I am darn near worn out just trying to combine all the possibilities.
The various contractors all promise 30% energy use reductions in just a few years. Well, if I believed them all, I wouldn't be paying ANYTHING for electricity or water in just 3 years. R I I G H T !
The electrical supplier site suggests I can reduce my bill 30-50% with 5-8 year paybacks. The Govt sites say about the same. Those seem more reasonable and trustable. So I could save $1,000-$1500 per year by spending $8,000 now. Seems reasonable.
The best savings seem to come from...
1. Attic blown insulation (gaining from R-12 to R-49).
2. Attic baffles directing outside soffit heat to the roof vent.
3. Basement blown insulation.
4. Expanding/Sealant around the the attic and basement edges.
5. Having the ducts scraped clean to improve air flow.
6. Installing a low blow attic fan.
7. Having the existing heat pump tuned.
An almost none of that was what I expected when I started to investigate this. I thought it would be all new triple-pane windows and door weatherstripping!
I've learned otherwise... Its all about proper insulation. The standard batted stuff is crap. It never fits tightly, and it never does the job. But it is cheap for the builders and looks good.
My house is totally electric. The average bill is $220 per month. Which isn't horrible. But if I stay here 10 years (and I probably will), I could save a few thousand $ in some simple ways. Items 1-4 +6 seem like the way to go for me.
But I'm still having a few geothermal companies come by for estimates. That could save LOTS in 20 years. More a selling point than an advantage I will see. But I may stay here long enough, so who knows? And I like the idea, personally and ideologically.