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DNAinaGoodWay
Posts: 2765
Joined: Mon Dec 17, 2012 1:43 am
Delivery Date: 03 Dec 2012
Leaf Number: 23156
Location: Central Massachusetts

Do you have a geothermal system?

Tue Dec 15, 2015 7:03 am

If so, what do you think of it?

I'm researching to see if it could work for us. Incentives are good here through 2016, but my house is at a disadvantage with hydronic baseboards, and to retrofit with ducts is getting quotes of $60k, even more with radiant. Our oil cost is less than $2k at current prices, peaked around $3.5k just a couple years ago. A 20-30 year payback is a bit long.
'12 SL last reading @ 2 yr, 22k, 260 GIDs, 62.35 Ahr

'15 SV w/QC, Mfd 5/14, Leased 8/14, 292 GIDs, 64.38 Ahr when new
@ 36 months, 34k, 270 GID, 57.49 Ahr

'17 Bolt LT



6.72 kW Array

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RegGuheert
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Leaf Number: 5926
Location: Northern VA

Re: Do you have a geothermal system?

Tue Dec 15, 2015 7:22 am

I looked in detail at one of these and concluded that it is quite difficult to recover the cost of the system when compared with a modern air-sourced heat pump system. That was here in northern VA, but the situation is likely very different in MA due to the much lower air temperatures you have.

One thing I didn't like about the marketing of those systems was the COP quoted did NOT include the electricity required to pump the liquid through the loop.
RegGuheert
2011 Leaf SL Demo vehicle
10K mi. on 041413; 20K mi. (55.7Ah) on 080714; 30K mi. (52.0Ah) on 123015; 40K mi. (49.8Ah) on 020817; 50K mi. (47.2Ah) on 120717; 60K mi. (43.66Ah) on 091918.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

User avatar
DNAinaGoodWay
Posts: 2765
Joined: Mon Dec 17, 2012 1:43 am
Delivery Date: 03 Dec 2012
Leaf Number: 23156
Location: Central Massachusetts

Re: Do you have a geothermal system?

Tue Dec 15, 2015 7:48 am

Good point, thanks. I've seen some reports that they can use a lot of kWhs, the worst from those that had 5 kW backup heaters in the duct. It can get cold here. I don't think air sourced would work as well either. Closed loop in deep bores seems to be the consensus locally.
'12 SL last reading @ 2 yr, 22k, 260 GIDs, 62.35 Ahr

'15 SV w/QC, Mfd 5/14, Leased 8/14, 292 GIDs, 64.38 Ahr when new
@ 36 months, 34k, 270 GID, 57.49 Ahr

'17 Bolt LT



6.72 kW Array

BrockWI
Posts: 652
Joined: Fri Mar 28, 2014 6:28 am
Delivery Date: 28 Mar 2014
Leaf Number: 423875
Location: Green Bay, WI.
Contact: Website

Re: Do you have a geothermal system?

Tue Dec 15, 2015 7:51 am

You could easily get a water to water system, either a well or vertical depending on your space available. A water to water system typical heats up a storage tank, think 80 gallon water heater, then that could be circulated through your existing system. You could also heat domestic hot water as well.

We really like ours, although right now Natural gas is a bit less expensive than geothermal, we are paying about 51 cents a therm for natural gas, the lowest it’s been in 10 years for us and the first time it is less than off peak geothermal, compared to 60 cents using geothermal. We also only run our geothermal at off peak rates which is 6.11 cents a kWh.

Check out this link to see what is the least expensive fuel for you to run. For geothermal you can put in your electric rate and then put 300 in the efficiency spot.

http://nepacrossroads.com/fuel-comparis ... ulator.php
3 kw solar pv - XW6048 - eight L16's
4 ton GSHP
2003 VW TDI 180k miles - 52 mpg lifetime
evse level 2 - Clipper Creek HSC-40
2013 S model with QC package Mar of 2013
@70k miles - 56.56Ahr - 86 SOH - 82.55 Hx - 245 GID

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DNAinaGoodWay
Posts: 2765
Joined: Mon Dec 17, 2012 1:43 am
Delivery Date: 03 Dec 2012
Leaf Number: 23156
Location: Central Massachusetts

Re: Do you have a geothermal system?

Tue Dec 15, 2015 10:04 am

Thanks BrockWI, when I put my numbers in geo is $0.15 less per million BTU and about $2 less per month, at current cheap oil ($1.86) and high winter electric ($.017 kWh)

We have no TOU rates and my solar just covers about 85% of our house and car usage now.
'12 SL last reading @ 2 yr, 22k, 260 GIDs, 62.35 Ahr

'15 SV w/QC, Mfd 5/14, Leased 8/14, 292 GIDs, 64.38 Ahr when new
@ 36 months, 34k, 270 GID, 57.49 Ahr

'17 Bolt LT



6.72 kW Array

BrockWI
Posts: 652
Joined: Fri Mar 28, 2014 6:28 am
Delivery Date: 28 Mar 2014
Leaf Number: 423875
Location: Green Bay, WI.
Contact: Website

Re: Do you have a geothermal system?

Tue Dec 15, 2015 10:25 am

That is the thing, at this moment with low natural gas & oil it's not financially worth it. But who knows what the future holds. At one point natural gas was over 3 times as expensive as geo was for us. In our case we have natural gas as a backup to geo so I can choose which I want to use, which ever is less expensive at the time :)

It amazes how much electricity varies across the country, I have seen mention of it from $.025 to $.55 a kWh, crazy...

I always say, insulate, insulate, insulate, then look at your energy source.

On the flip side the cost of installing geo might be lower because of low demand?
3 kw solar pv - XW6048 - eight L16's
4 ton GSHP
2003 VW TDI 180k miles - 52 mpg lifetime
evse level 2 - Clipper Creek HSC-40
2013 S model with QC package Mar of 2013
@70k miles - 56.56Ahr - 86 SOH - 82.55 Hx - 245 GID

User avatar
DNAinaGoodWay
Posts: 2765
Joined: Mon Dec 17, 2012 1:43 am
Delivery Date: 03 Dec 2012
Leaf Number: 23156
Location: Central Massachusetts

Re: Do you have a geothermal system?

Tue Dec 15, 2015 11:40 am

We paid $0.24 kWh last winter because natural gas supply is restricted due to people fighting new pipelines, also fighting the transmission lines to bring down hydro power from Quebec.

Our house is super insulated, no problem there. MassSave does it at deep discounts.

Future oil prices could very easily go back up, even more so if MA enacts carbon pricing. That's why, if I can find a way to do that I can afford, I want to do it in 2016 before the tax credit expires, plus MACEC will rebate up to $12,500, and do a 0% loan up to $25k. It's now or never.

There are lots of installers here, so I'll take a lot of proposals.

Edit: Also, our older nuclear plants are being decommissioned, taking a lot of generation with them and no announced plans on how we'll replace it.
'12 SL last reading @ 2 yr, 22k, 260 GIDs, 62.35 Ahr

'15 SV w/QC, Mfd 5/14, Leased 8/14, 292 GIDs, 64.38 Ahr when new
@ 36 months, 34k, 270 GID, 57.49 Ahr

'17 Bolt LT



6.72 kW Array

BrockWI
Posts: 652
Joined: Fri Mar 28, 2014 6:28 am
Delivery Date: 28 Mar 2014
Leaf Number: 423875
Location: Green Bay, WI.
Contact: Website

Re: Do you have a geothermal system?

Tue Dec 15, 2015 11:51 am

Also I have heard on wells to not go the pump and dump route, meaning pump it out of one well and drop in back in the well next to it, keep a closed loop. The first problem is scaling and all the build up it picks up each time as the water passes through the ground between wells, some say it is better because you will get "warmer" water directly from the well becasue the water can pick up heat from a larger area compared to a closed loop in the well. Secondly it typically uses 2 to 4 times the power to pump the water around. Our system has uses a single 140w circulation pump.

We have a horizontal field (couldn't get permits for wells), but we put in a 6 ton field with a 4 ton heat pump.
3 kw solar pv - XW6048 - eight L16's
4 ton GSHP
2003 VW TDI 180k miles - 52 mpg lifetime
evse level 2 - Clipper Creek HSC-40
2013 S model with QC package Mar of 2013
@70k miles - 56.56Ahr - 86 SOH - 82.55 Hx - 245 GID

User avatar
DNAinaGoodWay
Posts: 2765
Joined: Mon Dec 17, 2012 1:43 am
Delivery Date: 03 Dec 2012
Leaf Number: 23156
Location: Central Massachusetts

Re: Do you have a geothermal system?

Tue Dec 15, 2015 3:02 pm

What you call pump and dump, they call open loop here, and everyone advises against it for the same reasons you do.

Good point about permits, haven't got that far yet. How big is your field? We've got about 1/4 acre we could spare for that, but I think I'd rather go vertical if I can, for the constant temperature. Does your incoming get colder by the end of the winter? How deep is it?

Just got my latest electric statement. Rate went up to $0.21/kWh last month. Good for shortening my solar payback time. Utility still owes us, haven't paid a balance since February . Going to burn through my credits this month though, it's really dark and cloudy and rainy lately. The rate increase won't help that comparison link you sent, probably oil looks better than geo now.
'12 SL last reading @ 2 yr, 22k, 260 GIDs, 62.35 Ahr

'15 SV w/QC, Mfd 5/14, Leased 8/14, 292 GIDs, 64.38 Ahr when new
@ 36 months, 34k, 270 GID, 57.49 Ahr

'17 Bolt LT



6.72 kW Array

BrockWI
Posts: 652
Joined: Fri Mar 28, 2014 6:28 am
Delivery Date: 28 Mar 2014
Leaf Number: 423875
Location: Green Bay, WI.
Contact: Website

Re: Do you have a geothermal system?

Tue Dec 15, 2015 3:34 pm

We are on 1.75 acre's so we have the room. We would have really preferred going with a well. The township doesn't understand geothermal wells and kept saying 4 wells would have consumed to much water from the aquifer, we tried reasoning with them, but got nowhere and ran out of time. Our field is buried between 10 and 12 feet. We typically go from 70F in summer (cooling) to 35F in May. About 1/2 mile from us they get 45F year round well temps.

Ya at 21 cents It will take a long time to pay it back. Unless you can add a bunch more solar on that 1/4 acre :)
3 kw solar pv - XW6048 - eight L16's
4 ton GSHP
2003 VW TDI 180k miles - 52 mpg lifetime
evse level 2 - Clipper Creek HSC-40
2013 S model with QC package Mar of 2013
@70k miles - 56.56Ahr - 86 SOH - 82.55 Hx - 245 GID

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