Comments on: Geothermal: flourishing under the shadow of solar

By: Anonymous

Anonymous — Sun, 20 Jan 2008 22:50:00 +0000

CMHC has a series that looks at different types of Canadian Homes, and how they typically waste heat energy, and what are the most important things that can be done to reduce these losses. I found them through a design firm in Nova Scotia, abridesign.com, Publications, found here:

http://abridesign.com/pubs.htm

There is also a book published by Fine Homebuilding that is a collection of their articles, some on retrofits, some on new construction, that seems very good. I have found very few books on retrofitting to high efficiency standards, and even of these found, most are in the Build Your Green Dream Home and not the Fix Your Seive category.

CMHC also has a book Tech Guide for Renovators, I think its called, that has Healthy Home tips throughout.

There is now also a Greening-Up A Home (not the correct title) series put together by the Holmes on Homes tv-show crew, but it is a house in the US, so is likely wooden not brick, as most homes in Canada are brick. I believe this series is beginning this season.

By: Anonymous

Anonymous — Mon, 12 Nov 2007 01:31:00 +0000

This is very interesting point you are making. I am considering building a home. Is there a good reference you can point me to that can show me how to reduce my heating and cooling requirements by 90%. Can that reduction be achieved versus a recently built home or is it versus a home built in the 1950s?

Thanks

By: Anonymous

Anonymous — Thu, 08 Nov 2007 21:30:00 +0000

Retrofit is a bit more difficult than new construction. But we do it in new construction every day. With retrofit it takes more creativity. But, yes we’ve done retrofit projects for close to that.

In new construction we try to offset efficiency costs by reducing HVAC requirements. I’m not usually not too choosy about HVAC efficiency, and usually go with a low cost solution, because going from 85% to 95% efficient furnace with a house that only needs 10% of the heat, is not usually worth it.

It all take looking at the house as a system, to determine what makes sense.

By: Anonymous

Anonymous — Thu, 08 Nov 2007 18:26:00 +0000

That’s a very good point, thanks for raising it. Does your scenario include conventional HVAC under that $15,000? Just wondering, because you’d have to subtract the HVAC costs from the geothermal costs and work with that figure. There is also a comfort premium — I hear, anyway — with the geothermal stuff. But I agree, if you can achieve 90 per cent with the same money it’s definitely a better way to go. That said, can you back up that figure? I mean, I’ve been looking at doing some retrofits for my house and $15,000 gets you nothing…

By: Anonymous

Anonymous — Thu, 08 Nov 2007 18:14:00 +0000

As a energy engineer that works on designing “whole-building solations” for ultra-efficient houses, I’ve never been able to justify a ground source Heat-Pump (GSHP) in a residential application.
Given the same $15,000, I can make a house 90% more efficient that code using passive solutions (insulation, windows, passive solar methods, etc). After addressing the quickest payback improvements, and lower the energy profile by 10 times, a GSHP typically has a payback period in the hundreds of years.
Another nail in the coffin is the development of air source heat pumps suitable for cold climates that get a COP values of approx 3. GSHP typically only achieve a COP of 3-4, negligibly better at a $10k premium – which is not good payback.
And, unless your buying renewable sourced electricity for your system, lets not forget that a heat pump with COP of 3 sourced from fossil fuel electricity (which is only 30% efficient by the type it reaches your house), is no better than a standard high efficiency furnace running off of natural gas – cost wise or carbon wise.

By: Anonymous

Anonymous — Thu, 08 Nov 2007 14:21:00 +0000

I understand your point, and while I am only guessing here, I’m thinking the “payback” is on the difference between the cost of a typical HVAC installation/system and the cost of the geothermal. The question is whether the $10,000 to $12,000 premium I mention takes this into account, or is the cost of just the geothermal installation.

That said, even if the payback is 10 to 15 years, it’s still way more favourable than solar PV, which — as my posting points out — seems to get much more attention and investment. Your point about poor design and reliability is a good one, based on the industry’s track record in the 1980s and 1990s. But the goal of companies such as Clean Energy Developments is to address quality and reliability issues, emphasize proper training, and bring standards and consistency to the business. On top of that, The Canadian GeoExchange Coalition has introduced a certification program to address quality control. So I think your comment about “continuing poor design” may be a tad exaggerated, at least within the context of all renewables. The fact that Reid’s Heritage is taking this route shows that it is satisfied that reliable issues have been addressed.

By: Anonymous

Anonymous — Thu, 08 Nov 2007 13:39:00 +0000

Unfortunately, the numbers in your article don’t add up. A cost premium of $10,000 to $12,000 for geothermal systems with a 4.7-year payback implies annual energy savings of $2100 to $2600. Total energy cost for my typical 80’s-style detached home is only $1700/year! Of that, space heating and cooling account for about $900. An “average” house with less energy-aware occupants would still use less than double the amount. So real savings from geothermal is probably less than a third of the claim.

Further, as I understand it the “real” problem holding back the geothermal industry is not so much the cost factor, it’s continuing poor design and reliability.

While the technology is promising, a more critical viewpoint would be much more valuable to the industry (and the environment) than extravagant claims by salespeople.

By: Anonymous

Anonymous — Thu, 08 Nov 2007 12:16:00 +0000

Yes, but this case is not about incentives. Federal and provincial incentives for geothermal are for retrofits. I don’t believe Reid’s Heritage or the buyers of its homes benefits from incentives, other than the energy savings that result. Obviously a home developer can’t embrace every technology. I think the fact that it’s embracing one is terrific.

By: Anonymous

Anonymous — Thu, 08 Nov 2007 03:18:00 +0000

We just have to be careful about the policy structure we set in place. I don’t think we should be rewarding certain technologies with rebates to their purchasers while others are left without. If it is all about conservation and efficiency then let those two be the deciding factors, not the type of tech we support. For example; in one atlantic province, ground-source heat pumps are granted a higher rebate than air-source heat pumps. What incentive is there for air-source manufacturers to increase their efficiency levels now? And what of inventors of altogether new concepts -since they aren’t included in the government’s list; they are left high and dry. One manufacturer in Maine, Hollowell, makes an air-source pump that is as efficient as the ground source variety, without the digging or trenching -but only receives the air-source rebates, so is hampered by this technology-focused approach. Government should instead hold out the conservation and efficiency bar, and request industry jump over it. Whoever can do so gets the rebates, the higher you can jump the more you get. This way government is not having to be always knowledgeable of what is the best tech out there; they just need a peripheral understanding and leave it to the industries to sort it out and brainstorm their way to the prizes, in whatever way they can. This is what they do best and the proper roles of both industry and government. In the case of Hallowell, they manufacture in Maine, so are right next door, and this kind of performance should also be included in the calculations, but again, the regulators are focusing on other issues. They said they will address this in their next round of talks, so I hope there has been some movement on it. All provinces and the feds should consider not using the stick to divide the industries into winners and losers, instead holding it out to see who jumps highest.