Carbon Buster's Handbook:
Reader Feedback
Thank you to our readers for sending in questions.
#1: Green Power
Dear Carbon Busters,
I have been reading The Carbon Buster's Home Energy Handbook and it is very helpful BUT (and it is a big but) I have been obsessing about reducing my electricity consumption until I realized today that I didn't need to go overboard given that I have switched to Bullfrog Power (a supplier of sustainable energy.)
With that in mind, I think that the book's advice to subscribe to green power (where available) should take precedence over the suggestions about conserving electricity because, having done that, all of the suggestions for saving electricity do not help save carbon. They do save money (which could be used to implement some of the other suggestions for saving carbon especially reducing consumption of natural gas.)
Further, your recommendations about switching appliances such as driers and stoves to natural gas do not make sense (once one has switched to green power) given the diminishing supplies of natural gas. In my area it will cost me an additional 4 cents/kWh for green electricity so, since my household uses around 25 kWh/day, it will cost me approximately an additional $360 per year to use green electricity.
So I have decided that I will ignore the book's recommendations about conserving electricity and concentrate on saving non-renewable resources.
What do you think?
#1: Response about Green Power
I think that the book's advice to subscribe to green power (where available) should take precedence over the suggestions about conserving electricity because, having done that, all of the suggestions for saving electricity do not help save carbon. They do save money (which could be used to implement some of the other suggestions for saving carbon especially reducing consumption of natural gas.)
I think there is a lot of truth in what you say; if everyone switched to green power, we would have come very, very far, even if we did nothing else. However, I still believe that conserving electricity makes sense, for a number of reasons.
One is the question of electricity supply and what role wind will play, both with respect to the amount and to its reliability. Even wind turbines require energy and resources to be made, and have some environmental impact (even though vastly less than non-renewable sources). Right now the numbers for commercial turbines are a break-even point between one and three years comparing the turbine's embodied energy and its energy output. From this perspective, I think saving energy almost always makes sense, provided the paybacks are reasonable.
Counted against this, of course, is the embodied energy of the efficiency device. Turning a light off in an unoccupied room obviously has a carbon footprint of zero, but purchasing a device does. I believe that in some cases the efficiency device actually has a lower embodied energy footprint in addition to a lower consumption footprint. For example, demand water heaters probably require less material due to their smaller size and greater longevity. LED lights replace 100 incandescent bulbs and probably have vastly less embodied energy, in addition to lower consumption. In other cases the embodied energy of efficiency devices may be higher than the inefficient appliance they replace, and the embodied energy of a wind turbine could conceivably be less.
Supply is another issue: when wind turbines are not running, the difference is currently made up by fossil fuels. If your consumption is high during those periods, utility companies will use this as an excuse to build more fossil fuel plants, or keep existing ones running. I think we will ultimately be able to produce electricity 100% carbon free, for example by storing wind energy in plug-in hybrid cars, but right now this is still a concern. Denmark currently produces 25% of its electricity from wind, but even they rely on the European grid to some degree to buffer power fluctuations. This is a complex issue, and one which I have not completely wrapped my head around. While I believe strongly in wind power, my gut feeling is that prevention (efficiency) is generally safer than the cure (wind power).
Finally, if an energy efficiency measure has the same embodied energy as wind, but *saves* me money rather than costing 4 cents per kWh, why wouldn't I do it?
Further, your recommendations about switching appliances such as driers and stoves to natural gas do not make sense (once one has switched to green power) given the diminishing supplies of natural gas. In my area it will cost me an additional 4 cents/kWh for green electricity so, since my household uses around 25 kWh/day, it will cost me approximately an additional $360 per year to use green electricity.
I agree with you.
The book is written for the average person, who is probably more concerned about the money than the carbon. Given our current fuel mix, electricity for heating purposes creates more carbon than natural gas. However, if you have a reliable source of green power, that is better (my reservations above about supply notwithstanding).
So I have decided that I will ignore the book's recommendations about conserving electricity and concentrate on saving non-renewable resources.
My recommendation would be to pluck the low-hanging efficiency plums with high paybacks, subscribe to green power and stop worrying.
#2: Tankless Hot Water Heaters
Hi There,
I am enjoying reading the Carbon Busters Home Energy book. I was particularly interested in the tankless hot water heaters. I contacted Home Depot and they informed me of the following prices (for a typical family of 4):
Tank $ 1,379
Vent Kit $ 379
Installation $1,700
Total $ 3,458
The book suggests a cost of $578 plus $150 for installation. There appears to be a large gap between the two numbers?
#2: Response about Tankless Hot Water Heaters
1. The short answer:
The $578 price is based on this demand (tankless) water heater:
Aqua Star 125 HX from Bosch (which, I believe, has now been replaced by the 1600H), available for $578 at the time of writing, with the improved version available for US$599.
We paid around $150 for the installation of our water heater, which is almost the same model. (One advantage of the 125/1600 over ours is that the new ones come with a micro turbine that ignites the gas with the energy produced when you turn on the tap and the water turns the tiny turbine - very cool!) Ours requires 4 D cell batteries, which had to be replaced after 6 years.
2. And here is the long answer:
US$: First, a bit of a disclaimer: I had meant to write the "Carbon Buster's Home Energy Handbook" for Canada. My publisher insisted that it be written for both the US and Canada, with focus on the US market, since that market is 10 times larger, and they have to print enough copies (4,000-5000 minimum) to justify the printing costs. Though I resisted at first, in hindsight I have to admit that the publisher was right about this.
This means we have to adjust the pricing to Canada. This also means that products are often more expensive in Canada, but so can be the cost of energy (especially gasoline!), so that there is no major difference in US and Canadian applications in most cases with respect to paybacks, or at least no more difference than among US States. (exceptions include the Prius, which is much cheaper in the US - I will probably buy my next one in the US for this reason, even with the cost of adjusting to CDN standards - and water heaters; see below.)
Water heater cost:
You mention a quote of $1,379 for the heater, plus $379 for the vent kit. Do you know how many BTU's this heater has?
The demand water heater I propose is a "whole house" water heater, but it is rated for only one major appliance (117,000 BTU). This means that you are essentially exchanging a large pipe with a limited supply of total water for a smaller pipe with an unlimited supply of water. I.e. you cannot run a washing machine and a dishwasher and a bath at the same time. However, returning from a weekend trip, every family member can take an extensive shower or bath sequentially and you will never run out of water. You should also be able to run two energy efficient showers at the same time.
The water heater that was quoted to you may be of higher capacity, or just more expensive. You can also connect two lower capacity demand water heaters in series to increase the total instantaneous hot water available. However, either option will definitely decrease the payback.
We have had a 117,000 BTU demand water heater for 17 years, and have been very happy with it. We paid CAN$999 for the unit, but it was one of the first demand water heaters in Edmonton at the time, so the price should have come down way more since then.
In December 2006, I got a quote of CAN$898 for a Richmond (the brand is unknown to me) electronic ignition demand water heater from Rona, and $939 for an Aqua Star 125 HX from Bosch at Home Depot. The US web site lists its descendant for US$500. I cannot explain the outrageous price difference. Is it because Canada has a smaller market, because we are only slowly catching up, or are there a few suppliers with a stranglehold on the Canadian market?
The daughter of an architect friend of mine bought a demand water heater in Spain for €100 (about CAN$150), got a metric to imperial conversion kit and installed it. (The lack of CSA rating was not an issue for her, as she cannot get insurance in her area anyway.) Not that I am advocating installing non CSA-certified equipment, but this clearly shows that we have an issue with artificially high prices in Canada.
Looking at European web sites, I found prices of €239/CAN$358 for (electric) whole house demand water heaters, and €1,029/CAN$1,543 for tank water heaters from the same high-quality manufacturer. :-) Obviously, the economics are reversed there, and a tank heater may be a "special order" item, indicating that there is nothing intrinsically expensive about demand water heaters.
I generally like buying locally, but for the time being you may want to consider ordering the heater from the States (though after 15% exchange rate, 12% duty, and shipping, the savings may not be that high).
Also, a friend of mine is looking into bulk-buying water heaters directly from Europe. If you are interested, I could let you know once he has them available, if you haven't bought yours by then.
Venting kit:
Some heaters require a special venting kit, the Bosch 1600 H and its predecessor do not. This means that you pay only a few bucks for standard aluminum flu pieces (if not already in place).
Installation:
Wow! $1,700 is nowhere near what we paid. I recommend that after purchasing the unit you get a trusted plumber/gas fitter to do the installation. As I mentioned our installation was around $150, but we already had venting and natural gas in place.
Still, there are indeed some issues when replacing a tank-heater with a tankless one:
Size of natural gas pipe/venting:
Tank-heaters heat water slowly over long periods of time, demand water heaters heat large amounts of water instantaneously. Therefore, it is critical that the installer follow manufacturer's specifications when doing the install.
For example, the Bosch 1600H requires a minimum 3/4" natural gas line. If your existing water heater is close to your furnace, putting in a larger pipe is usually not a big deal. (After looking at consumer feed-back/reviews on some demand water heater sale sites, I suspect that most of those who gave demand water heaters bad ratings, failed to install adequate gas supply, thereby "choking" the burners. Indeed, some who initially had trouble report that installing the natural gas pipe size specified by the manufacturer fixed their problems.)
The venting is a similar issue. Tank water heaters typically have only a 3 inch flu pipe, while e.g. the 1600H requires a 5 inch flu pipe due to the larger amount of gas burned during operation. You may be able to tie this into your existing furnace flu, especially if you have upgraded your furnace already to higher efficency. If not, installing a 5 inch flu through the roof could add a few hundred to the cost (wall venting may be cheaper, but might require a heater with a fan).
Since writing the book, I have found that demand water heaters in the US are apparently eligible for a US$300 federal rebate, which could potentially make them *cheaper* than tank heaters in the US. It would not surprise me if the Canadian government will announce similar federal incentives for demand water heaters on April 1st of this year.
So, in conclusion, demand water heaters are not as cost-effective in Canada as in the US (yet), though, under the right conditions and with the right product, you can still get pretty good paybacks in Canada. Plus, if you can wait, hold off at least until April 1st for the new Canadian program announcements, or until Ted gets his shipment in.
Hope this helps!
