As I have often mentioned in these pages, we had an energy audit last Spring. The audit was a seminal moment in my understanding of our household energy usage.
Mission Accomplished! (Or Is It?)
I talk to a lot of people about their energy conservation measures. Naturally, not wanting to look uncaring, people talk about how they have changed and are going green. Perhaps a light bulb or two changed to CFL. Perhaps they a jacket on their water heater. Some weatherstripping on their door? A programmable thermostat?
These changes sound fine, and they may actually make a difference. But there are two ways that just making changes alone doesn’t really change things.
Perhaps your two CFL bulbs reduce your electrical use a little, but isn’t it important to know how much? (For example, the oft-repeated water heater jacket is of almost no value if you have a relatively newer one). So it’s possible that your changes haven’t improved anything. And the second way changes alone are bad: you may feel like you have “gone green” … mission accomplished.
So to my great chagrin, I realized recently that I had very little clue what my heating usage was, or for that matter what it should be. I had made lots of great changes. Mission accomplished? Not so fast.
I logged in to the National Grid website, and was able to see my last three years of bills, including how many therms of natural gas we used each month. I added it all up, and realized: I have sinned indeed. My energy use for heating has been basically flat for the last three years. I have made almost no progress.
(Of course, denial kicked in, and when another green blogger friend pointed me to a site where I could see my heating degree days for our zip code. My denial says I will find that there were more degree days each year, meaning even if my consumption was flat, it was because it was colder outside, not because I hadn’t done anything. Hope springs.)
But my darker, more realistic side kicked in. I asked myself the hard question: “Tom, what have you done, really done, to reduce your use of natural gas in the last several years?”
Mission not accomplished.
Ghost of Conservation Past
Oh, sure, we did lots of very good things … years ago. We insulated. We replaced all the old windows with good ones. And we replaced our gas burner with a new, efficient model. These are big changes. And they cost us some big change (by which I mean: a lot of money).
To be honest, our motivation was simply to be able to keep the house warm enough to avoid being raided by the local child-protective service for abuse of our babies — the damned burner could run day and night when the weather was especially cold, and still not put out enough heat to keep the place warm. Global warming had nothing to do with it — this was local warming (or the absence thereof) to the extreme.
We did our first round of conservation well before we realized that our use of energy was about more than comfort, or more than expenses.
Our profligate use of global resources, especially energy, has impacts beyond the our walls, or checkbook. In 2004, I read, The End of Oil, and that’s when we ordered our first Prius, which took 9 months to arrive. We loved it so much, we got another. In 2005, I started writing down all the other changes we made to save energy and started reading my energy bills.
Well, the truth is, I can run, but I cannot hide. Since 2005, I have written down almost everything we have done to save energy. And I have categorized and tagged my posts here, and the answer is, I have talked a lot about how important it is to be able to measure. But I haven’t done much to save on household heating.
There are a couple changes we have made that might have made a difference in heating. We insulated the ceiling of our sun room. We installed storm doors with actual working weather-stripping over our front, and back doors. We added some insulation under the floors of the kitchen and sun-rooms. But (heating degree-day data denial notwithstanding), the numbers show they haven’t made a big difference in how much fuel we use to heat the house.
The Ghost of Conservation Present
Last Spring, my denial hit a speed bump: I had an energy audit.
Fleming Lund, owner of Infrared Diagnostics did our energy audit — he came to my house on a sufficiently cold Spring morning and rendered the awful truth. Well, actually, he was very nice about it and said that our house was relatively tight and reasonably well insulated. But I know now, he was just being nice.
Missed Insulation First Time Around
We knew we had punted on insulating the whole-house fan, and, well, you could see daylight through the bulkhead door to the basement. And yes, those basement windows were, um, bad. I knew all of this, but how much could it really matter?
Or how much could the poorly caulked windows matter? Or the draft under the kitchen door (even after the storm door was replaced) on winter mornings? Would it really make any difference if we increased the existing insulation in the attic?
And yes, there was cold air leaking in through the light fixtures in the recently remodeled kitchen — why hadn’t they insulated properly when all the walls were down? And on, and on.
We don’t know the answer to all of these questions, but as the winter kicks in, I think we will.
Actions Speak Louder Than Words
After the energy audit was delivered, we took action. We have:
- Hired a contractor to insulate missing areas, seal the basement sill and other air leaks, and top off the attic with insulation ($500, with rebate)
- Caulked around leaky windows in the house as identified by the infrared photos ($15)
- Built an insulated cover for our whole house fan ($20)
- Installed an insulated cover over the attic stairs ($10)
- Installed insulation over the incredibly leaky bulkhead door ($10)
- Installed a chimney balloon to prevent leakage of air up the chimney ($56)
- Caulked the horribly leaky basement windows ($15)
- Installed pipe-insulation over our hot-water pipes ($12)
Total cost, around $650. This was greatly reduced by an excellent rebate program offered by our gas delivery service, National Grid, who paid for 75% of the expense of the major insulation and weather-sealing update we did. We will also be eligible for a small federal tax rebate on the cost of the actual insulating materials we purchased.
But then, this morning, we re-ran a part of the energy audit test: we closed all the windows and doors, removed the whole house fan cover and turned it on high. This replicated part of the test done during the energy audit: the blower-door test. That test put a specially calibrated, computer-connected fan over the front door of the house and measured carefully how much air was leaking in. Our test this morning used less scientific methods: we put our hands over the (formerly) leaky places and felt for drafts.
And what’s important is: we did find drafts. So once again the caulking gun came out, and we sealed up the spots we had missed in the first round. I ran my hand around the floor, ceiling and openings (windows, doors) of the entire house. And I found a lot of little leaks, still. Probably not anything like the ones we had found before — then again, it’s hard to find little leaks when you still have huge leaks. Having plugged all the huge leaks now, our whole house fan, taking the place of the fancier blower-door, was able to help us quickly find the remaining leaks, and plug them up.
The Ghost of Conservation Future
Given how much air was leaking in this morning, and given how much air leakage and extra insulation we had already installed, I predict that our house will need perhaps 5% or 10% less fuel to maintain the same temperature as last year. If we saved 5% through these actions, we would reduce our annual expense by about $90. However, the energy audit did a calculation saying that if we reduced our air infiltration to the degree possible, we could save $300, given our current gas rates, and other factors. This would reduce our annual bill of around $1,800 to $1,500 — almost 17%.
And what we always must remember: that number is effectively permanent. Every bill, and every year I’ll save that $300 or so.
And the other cool (warm?) thing about money saved is that it’s worth more than the same amount earned. If I got another $300 a year in income, I would pay some percentage of it to federal and state taxes, somewhere between 1/4 and 1/3 of my “raise” would go to taxes. So making these energy efficiency changes is like getting a $400 a year raise.
And the most important thing has nothing to do with money. By making small, relatively inexpensive changes, I will reduce the amount of CO2 we emit from our household. And if I leave not a dime to my children, this change, as part of a social movement made by many of us to cause significant change, will leave my children with a planet in slightly less peril than the one our current course seems destined to lead them to.
It will pay off. One way or the other.
Can you make some of these changes, too?
If you really want to conserve try switching to geothermal. Heating and cooling is the largest user of energy in a household.
Comment by Charles — September 26, 2009 @ 7:18 pm
Comment on Charles’ comment; be sure to do the math on the geo first. I have modeled several, and while they do put a nice dent in the yearly energy cost the paybacks were all 25 years or so, longer than the system life of around 20 years.
The best bang for your buck will be to get the infiltration down to .35 ACH. A good investment is to install an energy recovery ventilator, and make the house as tight as possible. More than energy benefit also; comfort, less dust & other things coming in, exactly the right amount of ACH, consistentcy.
Comment by Stan — October 3, 2009 @ 11:04 pm
Stan –
That’s the first time I have heard these two stats (25 year payback, 20 year lifespan) — I honestly haven’t done much research on geothermal, but it certainly has to depend upon where the system is installed, right? If you could point me to a source of data on payback and lifespan, that would be really great.
Charles’s company (which based on the 4 other comments that appeared within five minutes of this one) seem to be promoting his company, which is located in Florida. I live in Massachusetts, where I think payback is a bit more dodgy.
Having said this, I think it’s important that we try to internalize the cost of the fuels that geothermal or other renewable sources replace (typically coal or nat gas which both emit CO2). These costs are not baked into the amount us consumers spend … at the moment; if they were, the cost would be somewhat higher, and perhaps considerably higher. ROI calculations assume that burning things that make CO2 is costly and will continue to be the case through the lifetime of the ROI calculation. Hopefully this will be a bad assumption (soon!).
And having said that, I completely and totally support the notion that creating a tight house with low air infiltration and creating a well-insulated house have an advantage that far exceeds coal, gas, or even geo-thermal, wind, or solar: the heat or coolness that leaks out of your house is a complete loss; keeping it in is by far the least costly, most effective (and even most comfortable) solution to the problem, whose impact should not be under-estimated. The energy you don’t use is the greenest energy available.
I’ll begin to get data on my air sealing, weatherization and insulation efforts from this summer soon, as heating season has begun here in New England.
Comment by Tom Harrison — October 4, 2009 @ 5:10 pm
I use residential energy modeling systems, and model all the probable improvements that may be reasonable for each home I audit. You’re pretty serious so one you may be interested in is TREAT software. It costs $495 I think. Google it. You can download a trial copy. You can model most improvements that you’re considering, and it will give the annual btu and dollar savings as well as simple payback. It can’t be all about payback, but you can see the really long ones and put more thought into other possible solutions, or choose the better ones to implement first. Of course, you must first model the existing house to get the baseline. Another option is to have your auditor model the improvements you’re considering; assuming modeling was a part of the audit process. I know there are many types of audits, and sales approaches that are called audits. A heating system should be the last thing you do, after your home is where you want it regarding conservation. That way you install the right sized unit that is the lowest possible first cost and the lowest cost per use. The smaller system will also be the most comfortable, given that the ducting is correct. By the way, duct leakage is one of the most common issues I find, and if you have ducts located outside the conditioned envelope, leakage can be a major energy drain and comfort issue. Correcting it can also be modeled if you first measure the leakage rate with a duct blower.
Comment by Stan — October 4, 2009 @ 8:52 pm
Hi Tom,
great (but huge) topic and long dear to my heart.
First, dig out your copy of my book, The Emperor’s New Hydrogen Economy and read the sections on reducing your home heating energy use. (For those without a copy of the book, start at http://www.econogics.com/en/natgas.htm for related information.)
Second, I have looked at ground source heat pumps (not the same as geothermal), but I can’t find a commercial unit small enough for our house. Our calculations say we need a 1/2 ton unit, but 1.5 tons is the smallest we can find. Installation cost estimates suggest the unit will never pay off for us assuming a non-zero interest rate. BTW, Massachusetts is the tropics compared to our region (Ottawa, Canada).
And now, I’m off to replace the blower unit on our active solar heating system – failed after only 32 years.
Darryl McMahon
Comment by Darryl McMahon — October 5, 2009 @ 1:38 pm
Re Stan’s comment on geothermal: Tom mentions in this post that he bought a Prius. Any idea what the payback period is on that purchase? My guess is that it’s longer than the life of the vehicle.
Why do we force the HVAC system live and die by simple payback, when almost nothing else does? We just installed granite countertops in our house. What’s the payback on that?
But if you do want to talk about simple payback, I have to say that tossing out a WAG like 25 years is irresponsible. The simple payback of an HVAC system depends on a) how much you use it, b) the price of fuel, and c) the alternative you’re comparing it with. Factors a and b vary widely across the country, so you can’t quote a single number. Factor c makes a big difference too. Is Tom getting ready to replace his HVAC system anyway? What are his alternatives? What’s the incremental cost of geothermal above those alternatives?
Comment by John S. — October 9, 2009 @ 5:42 am
Hi John (and all).
I think simple payback is a valuable tool for most of us. Most of us have limited means at our disposal and have to choose between available alternatives (e.g., do I insulate the attic or replace the windows?) Simple payback gives us an easy and fairly accurate way to set priorities based on estimated savings.
In my book, I refer to this as bootstrapping your Personal Energy Plan. Start with those things with the most positive payback. Then harvest those savings to pay for additional items on your energy savings investment list.
So far, I don’t know of a tool for ranking aesthetic decisions, or how to match those up against payback calculations in a quantitative way.
Comment by Darryl McMahon — October 9, 2009 @ 7:28 am
Darryl (and John and all) –
Excellent discussion. I would just like to reiterate a point on payback, which is that it only works if the $ spent accurately and completely represent the costs.
They don’t when it comes to energy — in some cases prices under-represent the costs.
First, sentient beings tend to recognize that climate change is a large issue, primarily caused by use burning things that emit CO2. It is already costing us a modest amount — droughts, floods, fires, crop damage and so on. Nothing in our barrel of oil or ton of coal or therm of gas reflects these costs, even though they create them.
Second, our national security is costly. War ain’t cheap.
Third, our failure as a country to compete in a growing market would have untold costs for the US.
The problem is that it’s hard to know what those costs are. One could reasonably assume that the costs of climate change, left unchecked, are astronomical.
But until we make some effort at assessing that external cost and applying it to the energy source, we’re kidding ourselves because natural change, motivated by money won’t happen, or at least not at the pace required.
So to the point: whether the extra several thousand dollars I paid to get a Prius compared to a comparable all-gas car pays back over it’s, say 100,000 mile life is probably a wash if gas is $2.50/gallon and the Prius gets 20 MPG more than the alternate car getting 30 MPG (both about accurate now) — I will use 1,300 fewer gallons of gas and save $3,300. A wash.
But let’s say that gas fails to include $1/gallon of costs. Actually, it’s probably more like $3, but even at 1, my $22,000 Prius is not $5,000 more expensive than a comparable car.
How about the geothermal system? I don’t know the costs, but if coal is used to burn electricity that is not needed from geothermal, the costs over 25 years become competitive.
Internalizing these costs in a fair, effective and market-driven way is a key element of the climate change legislation now in our Congress. It won’t have any significant impact for consumers for a few years, but eventually, it’s impact will change the balance of power (pun intended).
Payback is simple, to be sure. But without capturing all the costs, it leads us to make bad choices.
Tom
Comment by Tom Harrison — October 9, 2009 @ 1:28 pm
Offhand, I’d say John S may be an HVAC salesman. The numbers I stated were not a “WAG”. They came from actual energy model projections. More than one. In Central PA. If one can afford granite, fine, but it has nothing to do with the topic being discussed here. (But since it was broached, I think it’s one of the most wasteful expenditures in a home.) Payback is payback, period, don’t make it complicated. Save that for the sales pitch (and don’t forget that all-important pitch book with the scary pictures).
Tom, I applaud you for your ability to get your points across in an interesting way.
Comment by Stan — October 9, 2009 @ 1:53 pm
Tom et al, my point about the granite countertops is that luxury items like that are felt (by some) to have an intrinsic value; the payback consists of the warm fuzzy feeling people get because they live in a house with such amenities.
Some of us get those warm fuzzies from knowing we have the most efficient HVAC system available. Our payback comes from more than just the lower utility bills.
I think if we’re going to solve energy, environmental and climate change problems, we have to start seeing energy efficiency as having an intrinsic value all its own.
Comment by John S. — October 9, 2009 @ 2:33 pm
Here in Ohio the carbon footprint of a ground-source heat pump (a/k/a geothermal) is the same or higher than that of a high efficiency gas furnace, since our grid from my supplier is 90 percent coal-fired and very inefficient.
So, geothermal may be better than resistance coil electric heat, but what isn’t? Ditto these new electric water heaters (with great tax rebates right now!) that work via heat pump technology– they cost a ton and won’t save any carbon compared to a gas fired unit. I’m better off with a tankless gas unit or else go straight to solar thermal water heating.
I’m still back at investing in conservation. 2 energy audits 4 months ago pointed me to some more insulation and air sealing. Plenty of room to improve there as a retrofit, with passivhaus as the example of what is possible with new construction.
Comment by Dave — March 23, 2010 @ 4:19 pm
Dave — I completely agree; geothermal may have a place, but there were aspects I had never really considered. Recently at the NESEA conference, I attended a workshop which discussed some of the issues with many HVAC systems. A remarkably high percentage the energy going into some systems, including geothermal, is in moving heated air or water around with fans and pumps. In marginal areas, geothermal also needs to run some fairly heavy-duty motors to extra heat out of the ground water.
No one solution is perfect, and none is always wrong.
But simple almost always seems to trump the fancy solutions.
Tom
Comment by Tom Harrison — March 23, 2010 @ 5:49 pm
I’m surprised that your insulation etc didn’t do better the first go-round; after we retrofitted our walls last Feb, our bills went down over 10% this year over last (for Jan and Feb, with avg temp slightly lower this year).
Graphing month over month is a great way to see progress. Microsoft Hohm is a decent way to do this; Xcel also has a customer portal at http://www.xcelenergy.com/myaccount which will make pretty graphs a well. Sometimes I think half the battle is getting people to look at their usage trends.
I wrote up what we did to our house, with graphs, in this Quora answer: http://b.qr.ae/i6bErz
Comment by Eric — February 9, 2011 @ 12:28 am