Green / Eco-Friendly

Solar + Battery for new construction off the grid - feasible? Possible?

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  • Jul 16th, 2017 9:55 pm
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^LOL the power packs.

I can't imagine geothermal is going to require upwards of 100kWh per day though. A few people he spoke to who did similar construction with geothermal had relatively low utility costs (electric from the grid). I don't have all the info on me, but going to check.
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joey003 wrote:
Mar 23rd, 2017 8:21 am
^LOL the power packs.

I can't imagine geothermal is going to require upwards of 100kWh per day though. A few people he spoke to who did similar construction with geothermal had relatively low utility costs (electric from the grid). I don't have all the info on me, but going to check.
You need numbers to calculate with but 6000 sq ft built only to code is only going to work if your friend is made of money. I am curious how much the quotes are for geothermal though, and how its being sized for these quotes.
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Quentin5 wrote:
Mar 23rd, 2017 8:26 am
You need numbers to calculate with but 6000 sq ft built only to code is only going to work if your friend is made of money. I am curious how much the quotes are for geothermal though, and how its being sized for these quotes.
Definitely should go above code for insulating. I've pushed them on that a bit. 6000 sq ft isn't final, he was trying to bring the size down a bit, closer to 5000.

One of the quotes was upwards of $100k, which included all equipment, full HVAC throughout the house and all floors heated, which was overkill. Didn't have a breakdown to see which costs were which specifically.
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joey003 wrote:
Mar 23rd, 2017 8:30 am
Definitely should go above code for insulating. I've pushed them on that a bit. 6000 sq ft isn't final, he was trying to bring the size down a bit, closer to 5000.

One of the quotes was upwards of $100k, which included all equipment, full HVAC throughout the house and all floors heated, which was overkill. Didn't have a breakdown to see which costs were which specifically.
What is his total budget on this house?
100K is less then i would expect, and with geothermal you can expect cost overruns and complications. The concept is great but the execution can be very tricky if you get unlucky. Also how was the 100K quote sized?

I would highly recommend hiring someone who can do not only a load calculation and cost but has experience in above code construction practices. Basically you want someone who does net zero calculations. You may even consider speaking with a Passivhaus consultant, i would not build to that standard because its not cost effective in our climate but it can be very enlightening to see how different approaches stack up. Don't fall for Passivhaus hype.

I do think 5000 sq ft is far beyond what is necessary, but if your friend is a multi millionaire then thats a different story.
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Quentin5 wrote:
Mar 23rd, 2017 8:42 am
What is his total budget on this house?
100K is less then i would expect, and with geothermal you can expect cost overruns and complications. The concept is great but the execution can be very tricky if you get unlucky. Also how was the 100K quote sized?
It was actually when the tentative plans for the house were at around 6500 sq ft. But it was full mechanical design throughout. I was kind of shocked when I saw 100K at first.
I would highly recommend hiring someone who can do not only a load calculation and cost but has experience in above code construction practices. Basically you want someone who does net zero calculations. You may even consider speaking with a Passivhaus consultant, i would not build to that standard because its not cost effective in our climate but it can be very enlightening to see how different approaches stack up. Don't fall for Passivhaus hype.
Fully agree here. I think a lot of this is important.
I do think 5000 sq ft is far beyond what is necessary, but if your friend is a multi millionaire then thats a different story.
Why is 5000 sq ft far beyond what is necessary? Because you say so?
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joey003 wrote:
Mar 23rd, 2017 9:59 am
It was actually when the tentative plans for the house were at around 6500 sq ft. But it was full mechanical design throughout. I was kind of shocked when I saw 100K at first.
Minisplits and a low load can come in at more then 75% less then that 100K quote.
Fully agree here. I think a lot of this is important.
I'm a numbers person, one can maximize value when one has accurate figures to crunch.
Why is 5000 sq ft far beyond what is necessary? Because you say so?
For an average family yes.
What is your friend's house budget?
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Is your friend putting in a gas line? It's vastly cheaper to go hydronic in-floor heating and have a gas boiler system. Then, put in an HRV/ERV for air movement, air tight home, and over spec insulation. Challenging for such a big space tho, I did all of that for only ~ 3000 sqft (incl basement).
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Bawler wrote:
Feb 23rd, 2017 9:50 am
Rural person here with a 3 year old geothermal system here. I use about 100kW per day during the winter and 60kW per day during the summer.

I pay about $6k a year in hydro so my repayment is around 10 years given hydro costs will just keep going up.
What is your sq.ft including basement & are you on a well?
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paullyn59 wrote:
Mar 25th, 2017 5:03 pm
What is your sq.ft including basement & are you on a well?
Including the basement my house is ~5,400 square feet and yes I'm on a well.
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Mine is only 3500sq.ft & use 72KW average @ 72 degrees from December - March since 2006 install. Have you ever compared your before Geo & after Geo hydro usage?
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paullyn59 wrote:
Mar 26th, 2017 11:50 am
Mine is only 3500sq.ft & use 72KW average @ 72 degrees from December - March since 2006 install. Have you ever compared your before Geo & after Geo hydro usage?
Just to clarify - that's a daily average of 72kWh?
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Yzord wrote:
Mar 23rd, 2017 7:59 pm
Is your friend putting in a gas line? It's vastly cheaper to go hydronic in-floor heating and have a gas boiler system. Then, put in an HRV/ERV for air movement, air tight home, and over spec insulation. Challenging for such a big space tho, I did all of that for only ~ 3000 sqft (incl basement).
Definitely agree about HRV/ERV, air tight and over spec insulation.

No gas service in the area at all unfortunately. Unless you were referring to using propane or something else?
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Yzord wrote:
Mar 23rd, 2017 7:59 pm
Is your friend putting in a gas line? It's vastly cheaper to go hydronic in-floor heating and have a gas boiler system. Then, put in an HRV/ERV for air movement, air tight home, and over spec insulation. Challenging for such a big space tho, I did all of that for only ~ 3000 sqft (incl basement).
When OP said it was "somewhat rural" I assumed that gas was not available. If gas is available that is the way to go for heating. It is way cheaper than geothermal even over the long term. Rural electricity is substantially more expensive than urban electricity.
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JWL wrote:
Mar 26th, 2017 6:19 pm
When OP said it was "somewhat rural" I assumed that gas was not available. If gas is available that is the way to go for heating. It is way cheaper than geothermal even over the long term. Rural electricity is substantially more expensive than urban electricity.
Yeah - no gas service at all.

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