The state legislature appears to have just passed what will be a game changer.
http://www.ncleg.net/Sessions/2009/Bills/House/PDF/H512v5.pdf
First, they have renewed the 35% renewable energy tax credit for active solar, PV, passive solar, and other renewables. Coupled with the 30% federal tax credit (which now thanks to the stimulus has no cap for individuals), this is now a 65% off discount on these technologies if you pay enough taxes to use the credits.
The game changer is that they have also included geothermal for the first time. There is a cap , but it's pretty high ($8400 on the credit) so many small/medium systems won't reach the cap. At 65% off, the price of a geothermal system can look a lot like the price for a high-efficiency air-source heat pump. And a geothermal system with a water to water heat exchanger to replace a boiler system powered by oil or propane can look like a fast payback. I can't really just throw out numbers because different sites will vary a lot, but if you pay taxes, geothermal should be very seriously considered for both new homes and upgrades of existing homes.
There are also Progress energy rebates if you are in their territory:
Home Advantage (for new homes)
http://www.progress-energy.com/custservice/carres/efficiency/programs/ha/index.asp
and Home Energy Improvement Program (for existing home upgrades):
http://www.progress-energy.com/custservice/carres/efficiency/programs/heip/details.asp
Monday, August 24, 2009
Friday, August 21, 2009
SEE Expo presentation
This is for everyone who came out to see my presentation at the SEE Expo today - titled "Energy efficiency on a budget". We listed all of the things everyone at the office could think of that are easy and cheap and save energy, and we categorized them by how easy they are to do (couch potato, small effort/cost, medium effort/cost) and then estimated the carbon emissions reduction. Here they are in order with estimated tons of carbon and effort. They all add up to 10.1 (although everyone can't do all of them, and some would be double dipping), but the average car creates 6.3 tons of carbon, so you can easily take the equivalent of a car off the road. The "couch potato" ones add up to almost 1/2 a car!
Rank Item CO2 reduced (tons) Cost/effort
1 Insulate attic ceilings 1.5 medium
2 Heat pump water heater 1.4 medium
3 Don't run HVAC fan continuous ON 1.05 couch potato
4 Insulate floors 1 medium
5 CFL bulbs 0.7 small
6 Don't turn AC on and off. 0.6 couch potato
7 Clothesline 0.54 medium
8 Get rid of un-needed things (xtra fridge) 0.46 couch potato
9 Air sealing 0.4 small
10 Low flow fixtures 0.35 small
11 Kill phantom loads w/ power strips 0.28 small
12 Monitor power 0.28 small
13 Blinds/shades/trees on S, E, W sides 0.25 small
14 Close windows before running heat/AC 0.2 couch potato
15 Energy star appliances 0.19 couch potato
16 Turn down water heater 0.17 couch potato
17 Programmable thermostat 0.16 small
18 Pipe insulation 0.15 medium
19 Seal/cover attic fans, window AC in winter0.1 small
20 Keep garage door closed 0.1 couch potato
21 Turn down thermostat 0.053 couch potato
22 Fix attic kneewalls 0.05 medium
23 Lock windows to get better air seal 0.05 couch potato
24 Insulate hot water tank 0.04 small
25 Insulate + w-strip attic hatch 0.03 small
26 Fix water drips and leaks 0.001 small
27 Dual flush toilet conversion 0.001 small
Rank Item CO2 reduced (tons) Cost/effort
1 Insulate attic ceilings 1.5 medium
2 Heat pump water heater 1.4 medium
3 Don't run HVAC fan continuous ON 1.05 couch potato
4 Insulate floors 1 medium
5 CFL bulbs 0.7 small
6 Don't turn AC on and off. 0.6 couch potato
7 Clothesline 0.54 medium
8 Get rid of un-needed things (xtra fridge) 0.46 couch potato
9 Air sealing 0.4 small
10 Low flow fixtures 0.35 small
11 Kill phantom loads w/ power strips 0.28 small
12 Monitor power 0.28 small
13 Blinds/shades/trees on S, E, W sides 0.25 small
14 Close windows before running heat/AC 0.2 couch potato
15 Energy star appliances 0.19 couch potato
16 Turn down water heater 0.17 couch potato
17 Programmable thermostat 0.16 small
18 Pipe insulation 0.15 medium
19 Seal/cover attic fans, window AC in winter0.1 small
20 Keep garage door closed 0.1 couch potato
21 Turn down thermostat 0.053 couch potato
22 Fix attic kneewalls 0.05 medium
23 Lock windows to get better air seal 0.05 couch potato
24 Insulate hot water tank 0.04 small
25 Insulate + w-strip attic hatch 0.03 small
26 Fix water drips and leaks 0.001 small
27 Dual flush toilet conversion 0.001 small
Energy cost comparison for different fuels and systems
My previous post shows the results we obtained when we ran annual energy simulations for the same house in Asheville, NC. Obviously the actual energy use depends on the house design, but this shows how systems perform relative to one another in the same house.
You can see that solar and heat pump water heaters are by far the most inexpensive to run. This is followed by on-demand natural gas, which is about $65 per year ahead of a regular storage tank electric water heater. Alone, that's not enough to justify the service charges to have gas in the house. At $2 per gallon, the propane tankless is barely better than the electric tank, and at $3.30, it's much worse. Usually I only recommend propane tankless for second homes where usually no one is using it, but on occasional weekends 14 people in a row need to use the shower.
In terms of energy cost, geothermal wins for space conditioning. Using a heat pump with furnace backup is less expensive than using a heat pump alone - here it was 22% better, or $100 savings. Again, it's not a compelling economic case to pay gas service charges and install another piece of equipment. With propane at $2 per gallon, the savings are smaller, and with propane at $3.30 per gallon, you'd be better off with the heat pump alone. The gas furnace is easier to justify if you want a fast recovery time, or if the home occupant is really sensitive to moving air and likely to complain about a heat pump. But most of us would do just fine. The systems that use just a furnace or boiler alone always cost more to operate. If these are augmented with solar, this could turn around, but most homes would need a lot of solar. One or 2 panels isn't likely to do it.
You can see that solar and heat pump water heaters are by far the most inexpensive to run. This is followed by on-demand natural gas, which is about $65 per year ahead of a regular storage tank electric water heater. Alone, that's not enough to justify the service charges to have gas in the house. At $2 per gallon, the propane tankless is barely better than the electric tank, and at $3.30, it's much worse. Usually I only recommend propane tankless for second homes where usually no one is using it, but on occasional weekends 14 people in a row need to use the shower.
In terms of energy cost, geothermal wins for space conditioning. Using a heat pump with furnace backup is less expensive than using a heat pump alone - here it was 22% better, or $100 savings. Again, it's not a compelling economic case to pay gas service charges and install another piece of equipment. With propane at $2 per gallon, the savings are smaller, and with propane at $3.30 per gallon, you'd be better off with the heat pump alone. The gas furnace is easier to justify if you want a fast recovery time, or if the home occupant is really sensitive to moving air and likely to complain about a heat pump. But most of us would do just fine. The systems that use just a furnace or boiler alone always cost more to operate. If these are augmented with solar, this could turn around, but most homes would need a lot of solar. One or 2 panels isn't likely to do it.
Here's the energy cost comparison that I ran for a prototype house in Asheville, NC.
Subscribe to:
Posts (Atom)
