Yes, this is my Tesla Model 3, and yes I am (generally) an introvert.
Let me tell you how this idea was born.
Not long after the summer solstice, I came across a news story about a group of meteorologists who all wore the same ties on the summer solstice.
They did this to raise awareness of a trend in our atmosphere that has been going on for well over a century.
What has been happening is that the average temperature on our earth has been increasing. Some areas faster than others, globally though, it has been about 1.35 degrees Celsius, or 2.43 degrees Fahrenheit. Just for comparison, the difference in the global average temperature between the last ice age and the beginning to the industrial revolution is only about 5 degrees Celsius.
Professor Ed Hawkins at the University of Reading in Great Britain came up with this wonderful visualization (actually he has a lot of really interesting visualizations, I highly recommend go checking them out). The full data with references are available at this link.
Professor Hawkins also has graphics showing the temperature changes of different geographical areas, such as central England, the lower 48 states of the US, and the city of Toronto.
He also includes links to all the data and references if you are interested in the nitty-gritty details.
While the specifics can change somewhat, the general trend is all in the same direction, cooler to warmer.
So this brings me back to my car :)
After seeing that story about the meteorologists and the graphic, I though that was a wonderful way to raise awareness as well as starting conversations.
I reached out to Triet Nguyen at Tint Pros - Platinum Auto Wraps. I shared with them what I wanted to do and they were very excited about the project.
Working with their designer, and Professor Hawkins graphic (after asking for and receiving his permission) we came up with a plan.
Triet sent me photos of the process, which took a few days.
Putting a two dimensional graphic on a three dimensional object, with lots of curves and corners is very impressive. Triet's crew did a phenomenal job keeping the stipes straight, and all lined up whenever a stripe crossed from one body panel to another.
As for my goal of raising awareness and starting conversations, it appears to be working!
Below are photos of two of the events I was at this weekend. I want to give a shout-out to the Minnesota Plugin Electric Vehicle Owners Circle (MNPEVOC) group, as well as all of the other EV owners that helped organize these events as well as sharing their experiences with people at the events.
I have had more conversations in the last 10 days than I have in a very long time. At one of the events, I heard a woman using the 'warming stripes' design to show her daughter how the earth's temperature has been changing :)
Besides events such as the above, I have had conversations in parking lots, while eating lunch, and almost anywhere. Some of them about the Tesla Model 3, some about the car wrap and many about both!
I want to, once again, thank the team that really got this introvert out of his shell:
Mr. Elon Musk, for building my own personal spaceship.
Dr. Ed Hawkins, for creating such a wonderfully concise graphic that relays over a century of data so simply.
Mr. Triet Nguyen and his crew for such phenomenal work.
AND all the people that have taken time to stop, and talk to me.
It took a lot longer than anticipated, we now have a backup system for our all electric house!
When we were preparing to move in, we had planned to have a battery backup system made by Tesla called the Tesla PowerWall.
This backup would allow us to run part of the house during a grid outage. Primarily the HVAC system, our refrigerator, network, a TV and a couple of outlets.
Welllllll.... with cutting edge products and such, there were a few delays.
Tesla canceled the first gen PowerWall before we got ours, replacing it with a second generation PowerWall with lots of really great improvements. This involved the first of our delays.
Then, as we got closer, a really nasty hurricane hit Puerto Rico, and Elon Musk sent a bunch of PowerWalls and solar panels to a hospital to get it up and running, with or without a local grid.
Seriously, how could I possibly be frustrated with that?
And of course, the normal delays involving shipping an extremely high demand product.
We need what?
Because of the way our system is set up with three inverters and a production meter, it worked best to have three PowerWalls. This was more than we planned for, but gave us some opportunities as well.
Additional room in our mechanical room was also needed, so we combined two of our three electrical panels.
Of course, this shows one of the advantages to knowing all the details when you are designing the electrical system in the first place. If we had know then, what we know now, it would have gone much more smoothly. We weren't willing to wait to build until the batteries were finalized, so I have no regrets about this.
With the advances in the second generation PowerWall, and the fact we were getting three, we made some adjustments to make our plan a little better.
First, the app that controls the PowerWalls allows you to set the system as either backup power, or "sustain" mode.
Sustain mode means the batteries will soak up all the solar energy they can, and then discharge it overnight, or any time the house needs more power than it is generating.
The masterful part of this, is the two can be mixed. For example, you can run in Sustain mode, but tell the system to reserve 20% of the batteries in case of a grid outage.
After running this for a few weeks, I expect to run with a very small reserve for grid outages in the summer, perhaps 10%. During the winter, when it is much more critical that we have power for our heating, we will run with a reserve of 50% or more.
Here is an example of what the App shows. In this image our PowerWalls are charging in the morning. In addition to charging from our solar panels, the solar is also supplying power to the house and even some to the grid.
This can be seen in the image below.
Details Details Details.
Unfortunately, there are always more details. We found an issue with one of our eGauge systems. We have a temporary one it place and are waiting on our original one to be fixed or replace. In the meantime, with the new PowerWalls and some rewiring, eGauge needs a few corrections to get it back to how it was working before.
Although it was a bumpy ride, we got here!
Our PowerWalls are in place doing their job. The install (Thanks to All Energy Solar) was fairly quick, once they got the delivery of PowerWalls from Tesla.
The ease of use of this system, capabilities and speed it cuts in if the power cuts off is amazing! My computer monitor doesn't even flicker!
We were never terribly worried about a day long power outage at our house, but things like that can happen. We are now completely confident in the ability of our house to maintain heat even during a week long power outage in the coldest winter in Minnesota delivers!
We now have a year of data collection in the books!
The summary of the final results are as follows:
Below is a graph showing the Modelled vs Actual energy use and production. As well as a graph showing the difference between the monthly average temperature between 1980 and 2010 compared with last year's average temperatures.
You can see the modelled (striped bars) energy use was much more than the actual energy use throughout the year. It was a little closer in the winter than during the summer months. I'll dig into that, but off-hand I believe part of that is that we used power to preheat the cars in the winter. I had not taken that into account in my original estimates.
The modelled production (green striped bar) was less than the overall actual energy produced (solid green bar). During the first couple of quarters we were having trouble with our solar array. Once that got resolved in late March, our actual production was higher than the modelled production.
Two big factors went into us using less energy than expected. First, we had a warmer winter than normal. Especially the months of November and February.
Second, and the bigger factor, we drove our cars much less than expected.
Before we moved, we drove a total of about 36,000 miles/year. We calculated we would drive about 8,000 fewer, or 28,000 miles/year. We actually drove only 13,266 miles! It turns out our car efficiency was less than I expected, especially over the winter.
This was due to the energy used to preheat the car (it is so nice to be able to be able to warm the car up in a closed garage without worrying about a tailpipe). In addition, most of our trips were short trips which are less efficient than longer ones in the cold.
So while we drove under half of the miles we had planned for, our actual energy for the cars (5800kWh) was a bit above half the energy we had estimated (10,000kWh). Still a great savings:)
Many of these variables will change from year to year. For example, we could have a colder than normal winter (less and less likely). We may drive more next year. We could have more cloud cover. However, I am confident we can meet our Net Zero goal in years to come.
Saturday October 7th (2017) the Minnesota Renewable Energy Society (MRES) will have a sustainable home tour. Our home, along with many others from Lacrosse to Alexandria, up towards Bemidji over to Duluth will be on tour. There are about five in the Metro area and Insight Brewery is offering a buy a pint, get a pint free to people on the tour. Details can be found by clicking here.
As always, if you have any questions or want to see any graphs of more detailed data (I have LOTS of them) just add a comment here, or on the Ohm Sweet Ohm facebook page and I will be happy to oblige.
We have been in our Net Zero home for a year now, and have learned a lot, both through the experience of designing the house and the time living in the house.
Our data tracking started on the 30th of September, 2016, so we have a month to go before we have a full year of data. I'll be posting another blog when the final numbers are in.
We also have the approval of much of the local wildlife;) We have had various visitors, and I have to say, I think the rabbits are the happiest and most well fed!
One of the really interesting things in our neighborhood is the number of black and albino squirrels. And they both love exploring all the nooks and crannies in our stack of boulders.
We have seen deer and turkey as well.
We also have completed a number of certifications, including GreenStar Gold and LEED Platinum!
Our Living Building Challenge is still in process. The last piece of that particular certification is a year's worth of data tracking. That will be complete in a month. So far, we are well ahead of our goal so I am very confident we will reach that.
More about what the LEED certification is can be found here.
Additional information about the GreenStar certification can be found here. Our home along with details and the GreenStar and LEED checklists can be found on their site here.
While we strived to reach LEED Platinum, we originally expected to reach LEED Gold. A lot of work was done by our team, and we were thrilled to get the news this summer that we had indeed reached Platinum :)
Our solar array continues to work flawlessly since the final fix last spring. We also have done some preparation work to get ready for three Tesla Powerwalls! If you ready some of our early posts, you may remember we wanted to have one or more in place last winter.
It looks as if we are getting those within a couple of months (we have a signed agreement with an installer).
This was long awaited, but will be worth it once we have them in place.
ProudGreenHome did a piece on our house and posted a video produced by Geocomfort (makers of our geothermal heat pumps). Click here to see it.
Greenhome institute also made a live video earlier this summer.
Each video includes many members of the team, including our architect, builder, HVAC wizard, interior designers, landscape designer and a representative from our solar installers.
Part 1 can be seen at https://youtu.be/NjSwoB8f8Ok
Part 2 is at https://youtu.be/94YlOp_SXZE
Well, we have now lived in our house for seven months and have six months of detailed data.
As of April 1st we have just over 1000kWh surplus. Our modeled energy use for these first six months is about 11,600 kWh. Our actual power use has been just over 7,700 kWh!
Now that the heating season is basically over, we expect that surplus to grow even more over the spring and summer.
With our first winter "in the books", we have learned a lot about how we use energy.
Here are a few of the highlights...
When I created this blog, I had calculated that we would drive about 24,000 miles annually between both of our vehicles. This was 8,000 miles less than before we moved.
In the last six months, we have driven a total of 7487 miles. We expect to drive more in the summer, but not all that much more. Taking that into account, if we drive another 10,000 miles in the next six months, that puts us at about 17,500 miles annually.
What I didn't take into account was just how much we enjoy our house! I find myself leaving the house less often. I used to run errands or trips just because I was bored. Our new house is a much more comfortable, inviting place to be. And so, I have found I drive less.
In addition to Kate's work being much closer, our errands to places such as Target, Best Buy, bookstores, etc are also much closer. In general, a third to half the distance they used to be.
Recently I started looking at how much power we use at different times of the day.
Just above you can see a graph showing how much power we used each hour. This combines all days between October 1st and April 1st..
The blue line is our total power use except for the cars. Up until March, I was charging a car many times during peak sunshine hours to allow our solar array to work at 100%. Because of this, we had an artificial peak around 11am-2pm that doesn't represent what will be our typical use. As such, I have excluded the power for the cars from this graph.
The orange line is the HVAC power. The green line is for our major appliances.
The heating tends to reach a peak in the early morning, than falls off during the day when we get free passive solar heating. The stored heat lasts into the night, but needs some help from the mechanical system. More and more power is used by the mechanical heating system until the peak around 6am.
Dinner time gives us a peak for appliances which makes sense. It is our main meal and the one we most often have the cooktop, oven, microwave running.
We also tend to run the dishwasher after dinner.
Another thing to keep in mind is that we had a relatively warm winter. In a more typical winter more energy would have been needed.
Final approvals for the rest of our LEED and Greenstar certifications are due soon. Lots of paperwork involved, but we can see the light at the end of the tunnel!
Happy Earth Day everyone!
Mark really doesn't like to talk about himself, the house is much more interesting.