We went out for a very early walk yesterday. The humidity was a bit high and the temperature was in the 20s, a clear day. I noted a grid-like pattern on several new houses as we walked. I took a picture of one, and you’ll find it below.
This is a very new well-built home employing conventional construction. What you are seeing on this south-facing exterior wall are patches of frost separated by vertical lines where the wall’s 2×6 studs lie behind the siding and sheathing. Warmth from the interior of the house is flowing through the continuous wood structure and melting the frost on the outside. Where insulation is placed in voids between the studs, less energy flows through, not enough to melt the frost. This is a really good demonstration of thermal bridging, (1) and why employing construction methods that reduce bridges (like the SIP walls on our Legacy House) can save a lot of energy.
In other parts of the world where some degree of environmental rationality still exists, things are different. The Cooling Project goal is to to develop technology that will provide equivalent residential cooling for one fifth of the present power requirement. That improved efficiency can save up to 5,900 TWh/year in avoided demand in 2050, equal to 2X the annual generation of electricity within the EU, and it has the potential to potential to mitigate up to 0.5˚C of global warming by 2100.
Because our Legacy House is largely solar powered, our air-conditioning CO2 contribution is very low. We are probably doing better than the Cooling Project’s 2050 goals even today. Many people, particularly those in crowded urban environments or those lacking sufficient financial resources cannot go out and build solar houses. But if they can buy a window or house air-conditioner that is five times more efficient to run, that’s a winner from personal economic and global environmental perspectives.
Today’s New York Times reports that GM has reversed course on emissions standards and now favors Donald Trump’s proposal to relax automobile emission standards. (1) I don’t suppose that’s a surprising flip coming from the company that gave us the Corvair and the Vega, and killed the electric car (for a while, anyway).
The Times says that Trump’s plan would roll back the 2025 fuel consumption guideline from 54.5 mpg to 37 mpg resulting in about six billion more tons of CO2 over the life of those vehicles with which to smother our grandkids and help burn California to the ground (probably more important to Mr. Trump). It should be noted that Toyota and Hyundai/Kia already have nice hybrid small cars that can achieve the 2025 fuel economy target. There is no reason why GM can’t do that too.
In our garage, we have a Tesla Model 3 and a five year-old Honda CR-V. The 30-odd mpg Honda is probably our last combustion engine powered car. Even if a 54 mpg replacement SUV came along that we could buy to replace the Honda, the CO2 emissions generated in building any such new car would offset anything we could save by driving it as infrequently as we do. Unless something weird happens with respect to the CR-V, we’ll use it up, wear it out, and do without.
What we (or you) can do with respect to GM, if we must buy a new car, is to buy it from a company that gives a shit about planet Earth. Clearly, GM does not. We now place GM vehicles near the top of our automotive manufacturer shit list, just below the German Diesel makers. Just below, because GM is not lying about their immoral act. At least not yet. The lying will probably come later as they try to justify what they’ve done. Then we can move them up to the pinnacle with Mercedes Benz and Volkswagen.
We have bicycles in our garage, and in our New Urbanism community we think we will have an opportunity to make more use of them than we used to do. They won’t be just for recreation. We can ride to local shops, get the mail, or visit a neighbor a few blocks away. Good for the body and less car use — even if ours is largely solar powered.
But there is a problem with bicycles that complicates the situation, and that is keeping air in the darned tires. If one does not ride often, the first thing that has to happen before each run is to pump up the tires. That’s particularly true if the bike is one with 700×35 high pressure tires that leak down like helium balloons. Like ours did. It’s often easier, cleaner, and faster just to jump into the car. Having a bike that can’t be ridden when it’s needed just takes up garage space.
For other reasons we recently replaced one of our bikes with a low-maintenace Specialized Alibi. (1) It came with airless tires made by Tannus. The riding experience is good. This bike is ready to go at a moment’s notice without the need for a pit stop to get under way. So, after a little thought and research we decided to change out the pneumatic tires on the perfectly good second machine (Trek) with Tannus tires. A lot cheaper and more ecologically responsible than replacing the whole bike.
We did not take pictures of the replacement process and did not plan to write about bike tires as we were doing the job. Sorry. The replacement task is tedius and somewhat difficult. There are several Tannus and Youtube videos on the process. If you decide to do this, watch them all. Pay attention. Take notes. Do what they say to do. Have a helper. Have cold drinks at the ready. Don’t waste money on the special installation pliers. They don’t work well and the standard tool that comes with each tire will get the job done if you use it correctly. An important point is to push the standard tool into the center area of the tire as the retainer clips are being pressed down. That makes things go much easier. If you watch the videos, you’ll see what this meaningless important point is all about. Don’t forget it.
Anyway, we got it done. We have two emission-free vehicles that are ready to go when we are and can’t have flats. How cool is that?
The Legacy House got its U.S. Department of Energy Zero Energy Ready Home (1) certification (dated August 1, 2019). That’s a recognition of the quality of the work done to build an efficient home. A standard new home has an HERS Index (2) rating of 100 or thereabouts. The Legacy House came in at 17. Lower is better, of course.
The certificate projects an annual energy cost of $950 and annual electricity savings of 27,934 kWh. Estimated CO2 reduction is 24.9 tons. We will watch it and see how accurate this information is.
We have four months’ data to give us some idea how the Legacy House solar plant, seen above just after installation, is working.
May 2019 — $46.48, 731 kWh delivered, 416 kWh to grid, 315 kWh net. June 2019 — $20.40, 617 kWh delivered, 544 kWh to grid, 73 kWh net. July 2019 — $9.50, 488 kWh delivered, 536 kWh to grid, -48 kWh net. August 2019 — $16.48, 619 kWh delivered, 577 kWh to grid, 41 kWh net.
It appears that we are getting a bit less than 85% of our power from the garage roof panels. That’s great, but a bit more than we really want. Unless one builds off-grid, AEP Ohio expects net-metering users like us to buy some power to pay for grid maintenance. That’s fine.
Keep in mind that the numbers above relate to the house and the electric car in the garage.
It has been over a year since I last posted on this blog. There are two reasons for that.
First, I was really getting down over the stuff I was constantly writing about Donald Trump and his henchmen and henchwomen. See what I mean? Just thinking about those folks drives me right into an intellectual quagmire that sucks the hip-boots of reason clean off my body.
Second, this blog is supposed to be about doing stuff that’s good for something, not fuming and writing about stuff that’s good for nothing (which isn’t actually doing anything, is it now?). Well, we have just finished a busy year of doing good stuff, and it’s time to clear out the bad vibes. Start over.
A bit over a year ago, June 20, 2018, we had finished digging a hole in the ground at Evans Farm (1) in central Ohio.
We would plant a house there. They take about a year to grow, it seems, and we are now at harvest time.
Evans Farm is a New Urbanism (2) community, or will be when it fills in around us. It was the best place we could find to put our Legacy House. We wanted a site that would permit us to walk to shops, recreational facilities, the post office, schools, and the like. We wanted something closer to our neighbors. In the long-run, a community is not sustainable if it’s made up of nothing but quarter acre patches of grass upon which are planted ticky-tacky houses serving as a motels for the folks inside. It’s not a community if you have to jump in the car to access all your services, if you never see the folks next door. It’s not emotionally healthy nor environmentally nor economically sound. We did not want to leave a quarter acre legacy to our family when times are-a-changing. So, we did something about that, and here is what grew in the hole we dug:
There is still a bit of work to do, but we are happily ensconced here and all systems are go. The Legacy House is a 2500 square foot modern farmhouse. It’s big enough to live in, functional, practical, and pleasant. Just what it needs to be, and not more. It is not a wasteful nor pretentious home, and it is ready for the 21st century.
The all-electric house stands over a ten foot Superior Walls (3) precast wall basement. The envelope is a SIPs (4) system. The walls are made of eight and six inch panels, and the roof is made of ten inch panels. The triple pane windows are by Marvin. Primary HVAC is a Mitsubishi two zone air-sourced heat pump. (6) The garage roof supports 20 LG360Q1C-A5 solar panels with Enphase IQ7+ inverters (7200 Watts). (7) Electricity costs for the last quarter came to $76.38 (including the Tesla Model 3 in the garage).
The Legacy House builder was Dan Troth of Greentech Construction. (8) He is presently rebuilding his web site, so be patient.
There will be many more posts about this building in the future. It’s great to be writing about doing things.