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[blgentry]

I believe that electric heating (including water) and electric cooking are 100% efficient.  Essentially all the energy is converted to heat

That's vastly over simplified.  Have you ever run "heat strips" for electric heating?  Have you compared those to a heat pump?  Both are electric.  Heat strips consume enormously more electricity to get the job done.

I still say you are spinning your wheels looking at devices that consume 40 and 50 Watts.  How much energy does your air conditioner use?  But do whatever makes you happy.  Saving any amount of electricity is good I suppose, as long as it doesn't interfere with other things (your life, your work, etc).

Brian.

[JimH]

That's vastly over simplified.  Have you ever run "heat strips" for electric heating?  Have you compared those to a heat pump?  Both are electric.  Heat strips consume enormously more electricity to get the job done.

I should have said resistance heating.  A heat pump can be more efficient, but it won't work well in some climates.

http://energy.gov/energysaver/heat-pump-systems

[glynor]

I should have said resistance heating.  A heat pump can be more efficient, but it won't work well in some climates.

http://energy.gov/energysaver/heat-pump-systems

We're actually in the process of deciding on all of this right now for our new home. Electric resistance heat is very efficient when used with hydronics (heating water) because water is a good conductor of heat. It is slow, which is why electric coil ranges are terrible, as anyone who likes to cook knows, but very efficient (slow and steady wins the race, in this regard, certainly).

Unfortunately, air is a particularly good insulator and so "coil heat strips" are terribly inefficient (well, good because otherwise we'd all die from a single lightning strike across the planet, bad for resistance heating). The main problem with air-source heat pumps in cold climates, like you have there in MN and as I have here in ME, is that they have to supplement the heat when the outside air temperature drops. They generally do this with coil heat strips, and so the efficiency of the heat pump (which is otherwise absolutely splendid) plummets like a stone below around the freezing point of water. Hydronics is good, though. You can do it instead with a Rinnai on-demand hot water heater and an itsy-bitsy little forced hot water heat system strapped to the outside of your heat pump, but that's no longer electric.

If you can stomach the cost of digging a deep well, you can use groundwater source heat pumps, and then your heating is almost completely free (other than running the fans and pumps to move the liquid around). Unfortunately for us, we're building our house on a giant granite rock...  

So, we're going with a "traditional" propane boiler. All in all, for our area, that's just more efficient. We might, if we can stomach the cost, put a couple mini-split heat pumps upstairs in the bedrooms, and use them only in the spring and fall (and get "free" air conditioning up there for the 2 weeks of actual hot summer we get each year). But we'll see. That might have to come later.

We're planning to wire it for photovoltaics on the roof though! And I'm absolutely putting two 220v outlets in the garage for a future all-electric car or two.

[cncb]

If you can stomach the cost of digging a deep well, you can use groundwater source heat pumps, and then your heating is almost completely free (other than running the fans and pumps to move the liquid around). Unfortunately for us, we're building our house on a giant granite rock...  

You might want to check out the current season of This Old House which covers a new build in North Shore, Boston.  They have a lot of land but where they wanted to position the house was a huge slab of stone.  They hired someone to literally blast it away with hundreds of explosive charges.  They also drilled two very deep geothermal wells.  They mention "budget" a lot on that show but it never seems like they really have one (at least not even close to the range of most of us).

[jgreen]

I have 830 watts of solar and ~800ah of batteries.  I am 100% LED lighting, not for the small energy savings but for the large heat savings. 

I save energy with my computers by turning them off at night.  I save energy with my drives by not plugging them in unless I need them.  I can't unplug my sat system because that forces a 20 minute reboot.  If the hardware industry wants to save energy all they have to do is bring back "off" buttons that cut power and eliminate "sleep" modes.

If electrical rates were $10 per kwh instead of ten cents per kwh (typically), energy conservation would make economic sense--and we'd be doing it in meaningful ways. 

[glynor]

They also drilled two very deep geothermal wells.

It drives me crazy when they call groundwater source heat pumps "geothermal". That isn't geothermal heat, and it isn't "renewable". If that's renewable energy, then every refrigerator is also "renewable"!

They have geothermal heat in Iceland and Hawaii (ok, lots of other places too, but not in Beantown). Groundwater source heat pumps are incredibly efficient, but they aren't "geothermal" and they still use electricity. The difference is that the ground water stays at a constant temperature year round, so you can tune the heat pump for maximum efficiency and it never needs a supplemental heat source.

They're only renewable if they're hooked up to a PV system or you have 100% hydroelectric power or something.

[DJLegba]

If electrical rates were $10 per kwh instead of ten cents per kwh (typically), energy conservation would make economic sense--and we'd be doing it in meaningful ways. 

We'd be running wood-burning computers.

[rudyrednose]

@glynor: you are mistaking with thermal sources in Iceland.  Geothermal is actually taking the temperature of the ground, be it 6C or 75C for your heat pump.  It is incredibly efficient for two reasons, the solid ground is a good medium to exchange heat with, and below 10' temperature is fairly constant (6 to 9C here).

Don't rule out geothermal heat pumps.  You could consider a closed loop one. Especially if you plan to stay there long enough to recoup (5-7 years)

We live in Canada, with our year typically going from -30C to +35C.  We have to heat our houses 6 months a year and AC another 2.

We designed and self-built our house 10 years ago.  At the time, I wanted two things:
- insulated forms concrete construction.  All external walls are 2.75in styrofoam each side of a 6.5in reinforced concrete core.
- geothermal heat pump for heating and air conditioning.

geothermal heat pump primary stage have two basic forms, closed and open loop.
in open loop, you take underground water from a well and reject it in a second well 70'+ apart.
in closed loop, you have one or more well with a U-shaped pipe, exchanging heat with the ground through the water-glycol liquid you pump into the closed loop.

The thermal mass of the concrete walls averages the daily variations, and insulation is excellent.  Combined with geothermal HVAC, our 4600 sqft house total energy bill is less than C$2000 (U$1575)a year!

The concrete construction would be around 15% costlier than a standard concrete full basement and wood framing house.  the difference to go geothermal, in our case was two 140' wells ($5000) and about $10000 more on the heat pump vs standard central electric furnace.

Being green can be very cost effective if you have time to pay off initial cost.

[glynor]

@glynor: you are mistaking with thermal sources in Iceland.  Geothermal is actually taking the temperature of the ground, be it 6C or 75C for your heat pump.

The term has been signifigantly muddied in recent years, but geothermal power is quite different than ground-source heat pumps. True geothermal power generates power from heat in the ground, and is generally used to drive a turbine (you pump water into the ground, it flashes to steam, which pressurizes the pipe and drives a turbine, which powers the pump, and you get excess energy).

Groundwater source heat pumps exchange heat from the groundwater, yes, but are run via pumps driven by electricity which comes from another source. They're air conditioners run in reverse. Don't get me wrong. They're not bad in any way. My brother has one at his home and it is fantastic! But it isn't renewable power because it uses energy, it doesn't generate it (and it isn't net-zero).

Unfortunately, this does not apply to me here:

Don't rule out geothermal heat pumps.  You could consider a closed loop one. Especially if you plan to stay there long enough to recoup (5-7 years)

I'm building on an extinct volcano which has been worn down for eons and all we have left is granite veined with bits of igneous rock covered in a veneer of rich soil. You don't dig here. You blast. As often as not, even for drinking-water wells when the third drill bit fails. Prices here for groundwater-source heat pumps are usually $30-40k, and that assumes you don't disrupt your neighbor's well, which causes a whole other thing.

I'll have enough expense in dynamite just to dig the foundation.