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Sunday, August 7, 2022

Tesla's Biggest Advantage

In many ways, Tesla is unlike other car companies. It's not just that they aren't saddled with a legacy combustion business, there are EV start-ups like Lucid and Rivian that are similar in this respect. So what is it that makes Tesla different? 

We've previously written about some of these differences here Tesla's moats and here Tesla is far more than a car company. These moats certainly are important; however, this entry is not going to repeat those. Rather, this entry is about an additional advantage, one that isn't structural, and perhaps it's their biggest advantage.

A Matryoshka of Tesla Superchargers

Tesla was founded in 2003 (almost 20 years ago). Prototypes of their first car (Tesla Roadster) were officially revealed on July 19, 2006, during an invitation-only event at the Santa Monica Airport.

Just getting to this Roadster prototype phase in 2006, the company had already learned several lessons the hard way. The plan was: use a Lotus Elise body, an AC Propulsions motor, and commodity 18650 battery cells assembled into a battery pack that they'd design. The plan was simple, the execution not-so-much. 

Unknown Unknows

While creating Roadster, they ran into problems. Problems that they didn't even know existed until they tried to make something. The battery pack didn't fit into the existing Elise design. The motors controllers from ACP were hand-tuned analog devices; fine for a prototype, but not consistent nor scalable. Another unforeseen problem, there were no existing transmissions that could handle the torque that these powerful motors delivered. 

These problems were all eventually (mostly) solved and the Tesla Roadster came to the market in 2008. There was nothing like the Tesla Roadster out there. It was quick, sporty zero-emissions fun, but it was far from perfect. There were issues with hub flange bolts, 12V low-voltage auxiliary cables, and other things, but owners didn't care; they loved these cars. They were early adopters and they were willing to work through these issues. 

Tip of the Spear :: The Earliest Early Adopters 

This tolerance for quirks and imperfections is a part of being an early adopter. In fact, I'd argue that it's more than just tolerance. For early adopters, understanding these quirks and how to sidestep them to make a product do amazing things despite the quirks is part of the appeal. The earliest of the early adopters (sometimes called innovators) have a sense of wabi-sabi (侘寂), loving something because of its imperfections; not in spite of them. They are in a club that not just anyone can join, paving the way into a new future. 

Because there was nothing else like the Tesla Roadster, this little niche flocked to Tesla. Tesla's initial customers loved the products and the company and their imperfections.

The Benefit of Time and Iteration 

By building a product, the unknown problems became known. Known problems can be fixed. This is what Tesla did. The innovation-flywheel turned a little faster with each revolution. These were the first steps to scalable, affordable, vehicle production.  

When you are trying to solve a big problem (such as how to make a fast, affordable, long-range EV) you run into a lot of smaller problems along the way. The problems often have layers and you must keep "peeling the onion" to solve them. It's a recursive nest of problems until you finally solve a fundamental issue, solving this allows you to pop-the-stack; reversing back up the layers, unwinding the problems of each layer with solutions from the layer below.

Innovation Flywheel

The faster that you can move around this loop, the faster your products improve. Tesla does not restrain themselves to 'model years' because this slows down their innovation time. Instead, the vehicles have detailed computer models that let employees test things out in virtual space first. If the computer models show that this would be a better product (better range, performance, cost, build time...) then it is prototyped and tested. A small change could go from idea to rolling out the door in new cars later the same day

As changes are made, the software in the car is updated to recognize this change and self-test this new functionality as each car rolls off the line. Each car is its own unit test system. This helps ensure quality and it allows the cars to self-diagnose issues when service is scheduled. This built-in self-test provides a safety net for innovation. If a change introduces an unexpected second-order effect, one of the thousands of self-tests can catch it before the vehicle goes out the door. 

Now Versus Then

Tesla has had the advantage of time. They've had more than a decade of runaway to make mistakes. The 2012 Model S won Car of the Year when it came out. If a startup were to release a car like that today, it would be panned as slow, short-ranged, inadequately thermally managed..., compared to the Model S of today. 

Tesla's biggest advantage is that they didn't have to compete with anyone else that was a pure-play EV manufacturer for the first decade and a half of their existence. Or said another way: Tesla's biggest advantage is that during their stumbling, skinned knees, learning, ramp-up mode, they didn't have to compete with, well, Tesla. 

Tesla's biggest advantage is that they didn't have to compete with Tesla. 

New Start-Ups Have A Bigger Challenge

Today's start-ups don't have a decade-plus of runway to try things, make mistakes, and learn lessons the hard way with sympathetic, enthusiastic early adopter customers. New EV companies have to launch a product that already has a decade of learnings in its initial release. It has to compete with EVs from the legacy automakers as well as Tesla. It is not impossible, it's just much harder. For example, Rivian's truck (RT1) is coming out and going head-to-head with the Ford F150 Lightning in many ways. Looking at the electric truck market, some buyers will be more comfortable buying one from Ford since they know where they can get it serviced and they know* Ford will still be in business five years from now. The road to profit and scale is not impossible for Rivian, but it will be a bumpy ride.

Tesla's Model S was introduced to a very different world than Rivian's truck. When the Tesla Model S came out, it was in a category of one. Model S didn't have to compete head-to-head with the likes of an electric Audi A7.

When the Tesla Model S came out, it was in a category of one. 

2012 Model S compared to 2022 Model S

What is the result of this innovation-flywheel running for a decade? As stated above, if a vehicle similar to the 2012 Model S were released today, it would not receive a warm welcome. To illustrate this point, let's compare the 2012 Model S to the 2022 Model S. 

2012 Tesla Model S

2022 Tesla Model S

Model S 2012
85 RWD
2022 Long Range
Dual Motor
Price (Long Range) $115,050 $99,990*
Price (inflation adj.) $144,069 $99,990
Range (miles) 265 375
0-60 4.3 sec 3.1 sec
Autopilot/FSD None - no cameras
(AP was intro-ed
in 2014)
AP standard,
FSD Upgrade
Rate (kW)
(6.5 miles/minute max)
(11 miles/minute max)
Gaming Chess, Backgammon,
a few 80s arcade
Equivalent to modern
game console, Steam
client support planned

* price as of 5/1/2022

As you can see in the table above, the Model S has improved significantly over the 10 years of its life. The current cost (esp. inflation-adjusted) is significantly less, yet you get a quicker car, faster charging, more range, better ADAS, and better infotainment technology. 

If Tesla (or anyone else) released a car today with the 2012 S price and specs, they would not win Car of the Year or enjoy the warm reception that Tesla had in 2012. This is the first-mover advantage and Tesla was given nearly 20 years to figure it out. 

Tesla's biggest advantage is that they didn't have to compete with Tesla.


Disclosure: I am long Tesla

Sunday, July 17, 2022

Air Quality

As recently noted, summer is here. This is great for solar production but, sadly, it can also mean wildfires and poor air quality. Fires have become an annual occurrence on the west coast of the US. The only question is how bad are they going to be this year. 

Since this looks like this will be an annual occurrence, we're taking some action to do what we can to protect the air quality in our home. We bought several HEPA air filters and air-quality monitors.

The air filters that we bought are large room tower "4-in-1" models. This model has a HEPA filter with activated carbon and an air quality monitor, plus it has a UV light and an Ionizer. The built-in air monitor is a nice feature because if you set it to Auto, it will automatically adjust the speed based on the air quality. This means it is usually slow (and quiet) but, when needed, it will turn up the speed and push more air through the filtration system. 

Air Filter    

I've tested the air quality monitor feature of the filter by standing near it when, um, "answering the call of the wild burrito." Sure enough, it kicks into high gear for a few seconds. Although be warned, no air filter can remove these gases.   

This unit has an ionizer, but we are leaving that feature turned off since ionizers can cause throat irritation and other problems, especially when used in enclosed spaces.

The second item that I added to our home was a simple air quality monitor. There are a lot of air quality meters. You can get units that collect logs that you can download, there are units with graphs, some with apps, ... I opted for none of these features. 
Air Quality Monitor

Below are affiliate links for the products that I'm using: 

Saturday, July 2, 2022

Ski Trip in Tesla Model X Gone Wrong!

In February of 2022, we drove our 2016 Tesla Model X on a little ski trip and things didn't go as planned. I've waited a while to tell this story. I wanted to have some perspective and not just gripe about the things that went wrong. 

We've taken the Model X on many ski trips. Our vehicle has the cold weather package and pre-heating allows you to stay comfortable even after the vehicle sits in a cold parking lot all day. The winter tires were on; we were packed and ready for snow.

We'd rented a condo with friends for a few days at Collins Lake Resort in the little town of Government Camp, Oregon on Mt. Hood. 

One Cold Night 

On the way there we charged up in Sandy, Oregon and arrived with no problems. We unloaded, schlepped into our temporary abode, and looked forward to hitting the slopes the next morning. That night, an Arctic blast made its way into the Willamette Valley setting record low temps in the region.

It's ironic to be discussing the coldest night of the year while most of North America is currently in the middle of a heatwave. I guess we all need to get used to more weather extremes. 

As you can see in the image above, it got down to 2F (-17C) where we were staying. Unfortunately, the condo didn't have a garage, so our car was out in the cold (not plugged in) getting covered with snow. 

No problem. The battery was ~70% full and the car knows to keep its battery comfortable. The next morning, I opened the app, noting that we had not lost much range overnight. I turned on the car's pre-heat function, grabbed the ice scraper, and headed out to the car.

While pre-heating, I brushed the snow off and scraped the windows, then we loaded up the car with gear and passengers, and hit the road. From the pre-heating, the car was nice and warm as we headed to the ski area.

Things Go Bad

After about 20 minutes on the road, the front window started to fog. In response, as I've done hundreds of times before, I double-tapped the front defrost button. Why double-tap? The first tap turns on AC to defrost mode, whereas the second tap uses the heater to defrost. Since it was cold out, I wanted to use the heated defrost mode. 

The defroster set the heat to "HI" and that's when things went awry. Error tones and a string of alert messages popped up.

Tesla Error Code BMS_w035

Most disturbing among these was a message that read the "vehicle may not restart." At this point in the drive, we were nearly at the ski area. What am I supposed to do? Do I ignore it and hope for the best, perhaps stranding my family and myself on the mountain if it won't restart? Do I immediately turn around and head to the Tesla service station (~65 miles away) even though we've paid for 2 days of lift tickets and 2 more nights in the condo? Do I call roadside service or a tow truck?

We made it to the ski area and parked. I pulled out the app and made a service appointment. The app made it easy since one of the reason-for-service options was "recent alerts." I selected this option, selected the alert, and then was given several dates to pick from. The earliest was March 18th. That was 23 days later. 

Rather than call a tow truck, I decided to take my chances. Maybe the 12V was cold and the alerts would clear up. The alert text said, "Vehicle may not restart." Which means there's also a chance that the vehicle may restart. I was putting my hopes on that word may falling in my favor. So we hit the slopes and hoped for the best. It was a great day for skiing with light snow falling most of the day. However, for me, too much of my mental energy was worried about the car to actually enjoy the moment.

Luckily for us, when we got back to the car, it started. The error codes persisted, but we were not stranded. As we made our way back to the condo, the heat was not working and there was ice on the windshield wipers which made it difficult to see. I had pre-heated the car, but apparently whatever had gone wrong had taken the heating system down too. I pulled over and scraped the ice off the wipers and the windows so I could safely make the return trip.

For day 2 on the slopes, we left the Tesla at the condo. We were on this trip with friends and we were able to all squeeze into their car for the short trip to the ski area. Day 2 on the slopes was excellent. It was a bluebird ski day. There was fresh powder from the night before and the skies were clear and sunny. 

Our bluebird day on Mt Hood

We had an excellent day on the mountain and I didn't have to worry about a ride back. After day 2 of our ski fun was done, we had another night at the condo, and then it was time to head back to the real world. Leaving the condo, we packed up the Tesla Model X, all the while I was wondering if it would get us home. I performed a "two-button reboot" to see if the errors would clear up. They persisted, but (just as it had in the parking lot) it started up. 

Leaving The Mountain, Heading Home

Heading down the mountain, there was no regenerative braking. This significantly changed the feeling of driving. I'm not used to using the physical brakes for minor slow-down moments; single-pedal driving is one of the nice things about EVs and I had lost this feature. With regen disabled, it just felt weird -- it didn't feel like my car.

We made it to the Supercharger in Sandy, Oregon and plugged in. The supercharging session started out fine and then stopped with yet another error message. The battery was far from full. The in-car nav said we had just enough to make it home but I had to wonder if it was including the fact that regen was disabled in this calculation? To be safe, I assumed this edge case was not covered in the nav's range calculation and I didn't want to end up stranded just a few miles from home. So, I unplugged from the Supercharger, rebooted the car, and tried Supercharging again. Again it started charging. We finally had enough to safely make it home with a margin of safety. Just as I was getting out to unplug, we had another round of alerts.

Here are the error messages we received this time:

Tesla Error Codes: BMS_u008, BMS_w172

These were different codes, but the same gist (something's wrong, may not restart, get service). Despite these new error messages, the vehicle started and we were back on the road again. 


We made it home. Despite the "reduced acceleration and top speed," we had no problems driving at freeway speeds or taking hills. A nerfed Tesla is still more than enough performance for typical driving. After pulling into the garage, I shifted into Park and I had no intention of driving it anywhere (other than to the service center). So our X sat in the garage with the snow and ice melting off the wheel wells and undercarriage, leaving clumps of the red lava rock (used to 'sand' the snowy roads) on my garage floor.

Twenty days later it was our turn at the service department.  Even though we had to wait, the nice thing was that service was able to pull the logs remotely and, based on the specific error codes, order the parts needed for the repair (+1 for connected cars/computer-on-wheels). About a week before my appointment, Tesla service contacted me and told me the parts had arrived and if any spots opened before my scheduled appointment, they'd try to get me in early.

Since the car was going in for service, I decided to have a few other little things taken care of while it was there. It was the end of ski season and I was certainly not taking the X back up to the mountain this season, so it was the time to swap back to all-season tires; the wiper blades were worn; and my 12V battery was still the (now well-aged) 2016 factory installed battery. The 12V battery had nothing to do with these errors (according to the service center), but I had just been reading accounts of similar age 12V batteries giving up the ghost, so I wanted to replace mine before it started causing problems.

Sadly, no early slots opened, but our turn finally arrived. I dropped off the car and Uber-ed home on the Tesla provided credits.

A couple days later, service contacted me. While doing the repair, they determined that the traction battery contactors had to be replaced. This portion of the repair was covered under the HV battery warranty (so no additional cost), but it meant that additional parts had to be ordered. They offered me a loaner, so I went in and picked up a white 2017 Model S.

Seventeen days later the additional parts arrived. I breathed a sigh of relief. Given the supply-chain troubles that are currently plaguing nearly every industry, this could have been a much longer wait time.

Just 3 days after this, I was informed that my repairs were done and I went in and picked up my car. The vehicle was still dirty with mountain road grime (I miss the days when service washed your car), but I was happy to have my ride back. 

How Much Did It Cost?

Here's the snippet of the receipt: 

High Voltage Battery Coolant Heater Repair Bill

June Update

Just when I thought it was all over. Months later, a new error message popped up. 

Tesla Alert THC_w0105 (yes, I need to clean that screen)

The coolant system was just refilled as part of the coolant heater replacement in March and now, ~3 months later, it's low🙹 This is not a system that usually gets topped off. I had a leak!

My immediate suspicion is that something was not tightened down during the coolant heater service or came loose after. I hoped this simply meant tightening it down, top-up, and done. I was not so lucky. 

This happened on a Sunday and I was able to get the car in on Wed at 4:30PM (much better than last time). I picked the car up at 3PM the next day. Good news, it was a quick fix; bad news, they had to replace the 3-way valve. They said this was the source of the leak and it had nothing to do with the work that was done in March. Hmmm. 

Nothing? Coincidences do happen. The part is/was ~6 years old (same as the coolant heater that failed). Maybe they were like the proverbial old couple, where when one passes, the other is only a few months behind.

On the other hand, maybe the wrenching and pressure testing related to the work in March caused a micro-fracture that grew into this leak. It's impossible to know, so what we're left with is a car that needs to be fixed and a service center that should be paid for parts and labor. The 3-way value was $55 and the final bill was $551.50. 

I preemptively had the 12V battery replaced when the car was there in March; I wish I would've had this part replaced too. The majority of the bill for this June service was for dealing with the vacuum-sealed coolant lines; something that was already being done in March. So it would've been trivial to change this part too. I would've paid closer to the $55 part cost rather than 10 times that amount. 

Wrapping Up

In total, from the day of the failure to fully repaired (pre-leak), it was 44 days and we paid about $1100. Adding the costs in June and the total is over $1600. This is part of the 'pain' of owning a vehicle that's no longer under warranty. I've owned this vehicle for five and a half years, prior to this failure, it has performed excellently. I hesitate to call this a "major failure" since I was able to drive home (and even Supercharge). All machines break down at some point. I'm just glad that we were not stranded when this failure occurred. Time to start saving for my 2025 Model X upgrade. 

Thursday, June 23, 2022

Welcome to Summer

Summer 2022 has officially arrived in the northern hemisphere! The June solstice was the kick-off and, since that's the longest day of the year, I like to mark the occasion by sharing our solar production. 

Solar Generation On June 21st, 2022

Here in the NW corner of Oregon, the sun rose at 5:23 AM and didn't set until 9:04 PM. That's 15 hours and 41 minutes of daylight. As the graph above shows, our PV system was cranking out power from 6 AM until 8 PM. We generated a total of 76.5 kWh of energy. 

Destinations of our Solar Production

As you can see, about one-third of the energy was used to run our home. The bulk of the remaining two-thirds was sent to the grid, running our meter backwards for most of the day. 

How Much? 

On this one day, we generated 76.5 kWh of energy; just for fun, let's look at this amount of energy in several ways. 

76.5 kWh of energy is equivalent to: 

  • 2.5 days of use in a typical US household
  • 203 Million foot-pounds
  • 261 BTUs 
  • 65822 food calories (about 132 meals)
  • 306 miles in a 2022 Tesla Model 3 standard range

Obviously, this energy cannot be converted directly into food calories or meals. I'm just trying to put some perspective on the number. 

The 306 miles in a Tesla is interesting and the energy can be directly used in an EV. Looking at fuel averages, a 306-mile trip would typically use about 15.3 gallons of gasoline. At current gas prices, that's about $76 dollars. Not a bad day's work. :) 

Sunday, June 5, 2022

Tesla's Eye In the Sky

Tesla's vehicles are flush with sensors. They have 360-degree cameras, sonar, temperate sensors, GPS, accelerometers... These are intended primarily for Tesla's Full Self-Driving, but what other purposes could they serve?

What data could these computers on wheels gather? Here are a couple of ideas:

Collecting and reporting traffic is an obvious example. There are many smartphone apps that already have similar functionality. This would certainly help for route planning to avoid traffic (assuming you can't take a tunnel). 

Another suggestion that was posted on Twitter was for Tesla vehicles to collectively look for license plates associated with Amber Alerts and, if spotted, report the location to the appropriate authorities. This could save children, but it is also a little creepy to know that Tesla cars could be reading all the license plates around them.

What other ideas do you have for a massive fleet of internet-connected robots?

Friday, May 20, 2022

Saving Money with Solar


A friend said he was considering solar and batteries for his home, but the economics just didn't pencil out. The payback time would be more than a decade and that didn't seem worth it. He is looking at getting a 14 kW system. He then asked how much we saved with our 12 kW system (with 40kWh of batteries).

As you can see in the chart above, we generated $2193 worth of electricity in 2021.

The dollar amount is important, but it is far from the complete story. Before I jump into the complexity, here are some more easily digestible graphs from our solar app:  

We were 51% solar-powered in 2021. 

This included sending some electricity (about 5.2 MWh) to the grid for net metering, leaving us only 31% directly self-powered. Our solar app allows you to optimize for self-powering or lower cost. We have opted for lower cost.

We're on a Time-of-Use (TOU) electricity schedule. This means that we pay more during peak hours and less during off-peak. TOU is optional from our utility. We're on this program because it saves us money. The solar panels and batteries reduce our peak and partial-peak usage; while charging our EVs overnight shifts a major load to off-peak. As you can see above, our Powerwall home battery packs handle a majority of our home load during peak hours. The batteries allow us to time-shift our solar (primarily generated during partial-peak) to peak hours. So now the sun can power our home when it's best for us, rather than when the sun happens to be shining. 

The partial peak usage is higher than I'd like it to be, but this is just the "normal" rate (as if we were not on TOU), so the solar is primarily charging up the batteries during this time, rather than powering our home, so the batteries can then discharge during the peak hours. That's why we're primarily grid powered (58%) during this time. 

And finally off-peak. This is generally overnight, so we are not going to have any solar during these hours. The exception to this is Sunday (and some holidays). The Tesla solar app currently does not handle this very well. They only have a "weekend rate" and it does not allow Saturday and Sunday to be on different billing schedules. So this is not accurate since there should be 52 Sundays and 6 holidays worth of off-peak solar generation. They have made several TOU improvements in the solar portion of the Tesla recently; I hope this is improved soon too.   

And the last item before we jump into the exciting math of electricity bills: backup power. You can see in the list above that we had several minor outages and one big one in 2021. Having solar and batteries allowed us to keep the lights and the heat on during a cold night in February when our neighborhood lost power. 

Electricity Bills 

Call it your power bill, light bill (Eastern/Southern US), or hydro bill (parts of Canada); a lot of modern living is electrically powered. This is an essential utility that most of us pay (too much) for. Let's deep-dive into an electricity bill and see how much we really save with solar. 

It would be nice if electricity bills were easy to understand. A simple charge per kWh and perhaps a monthly connection fee, but the reality is far more complicated. As you can see, my monthly bill below has 23 line items

Let's make this bill understandable. First, we'll split things into fixed charges (items that will be there every month regardless of our use) and variable charges (items that change with use). And, just because nothing can ever be simple, a couple of the fees are a percentage, so they are variable, but not per kWh, applying to both fixed and variable fees.

Fixed charges: 

Charge Amount
Basic Charge $11.00
First Block Adjustment -$7.22
Smart Battery Reward -$20.00
Low-Income Assistance $1.04
Oregon Commercial Activities Tax Recovery
(portion applied to fixed charges)
Public Purpose Charge
(portion applied to fixed charges)
Fixed Cost Subtotal -$15.11

You can see that we're starting out each month with a negative $15 electricity bill. This is generally driven by the $20 credit that we're receiving for being in PGE's virtual power plant program. 

For the variable charges, we're going to collapse a few things. If a given kWh has a base rate, a transmission cost, a distribution cost, a regulation adjustment, ... and some are fees and some are credits, the waters get muddy quickly. To avoid this, we're going to bottom-line it; all of these will be rolled together for one per kWh rate for each TOU rate. Here are the fully adjusted rates: 

Off-peak  Partial-peak  Peak
Basic Rate 4.128¢ 7.051¢ 12.38¢
Fully Adjusted Rate   5.336¢   16.536¢  21.966¢

Looking at the table above, you can see that the off-peak price does not change much when adding in all of the adjustments. For partial-peak and peak, it's another story; each is about 10¢ more (per kWh) than their unadjusted starting rate. For Partial-peak that more than doubles the price. 

Now let's apply these prices and compare the "with solar and batteries" to the "without solar and batteries" versions of our house for all of last year's electricity usage. 

Is It Worth It? 

In 2021, we used a total of 25,400 kWh. If we didn't have solar, we'd have had to pay $3377 for this energy. As you can see in the first graph (repeated below), our solar panels generated $2193 worth of energy in 2021.

Additionally, because we have home storage batteries, we were able to join the PGE virtual power plant program. PGE pays the participants in this program. This further reduced our annual electricity cost by another $240 in 2021. So, rather than paying $3377 in 2021, we only had to pay $944. We also had some discounts for allowing the utility to control our smart thermostat, but that's not relevant to this discussion. 

If you pay twenty thousand dollars for a solar-plus-battery system and only earn $2000 in payback each year, it is going to be a decade before you break even (longer if you include opportunity cost or interest on a loan). 

You might end up selling your home before you recoup the out-of-pocket costs. However, the panels on your home also increase the resell value. So, I can see why my friend said this does not pencil-out as a no-brainer, but that does not necessarily mean it's not worth it. 

There are many more factors to consider (listed below), but before we go there, I want to finish the economic portion of this. I know that the price for energy from these panels will be fixed at zero going forward (assuming no out-of-warrantee failures). Yes, you pay upfront, but 5 years from now, when the electricity prices have gone up and up again, you'll be (somewhat) isolated from these price swings. My friend that started this discussion recently retired. Having a predictable expense is valuable, especially on a fixed income. You don't want to be deciding on buying groceries or paying for utilities that have significantly inflated in price while your retirement income has not kept pace.

More Than Just Money

For us, solar with batteries provides a level of independence. It means if the grid goes down during a heatwave, our AC can keep running. It means if the grid goes down during a winter storm, we can keep our furnace running. It means that we have little-to-no grid usage during peak hours when they're most likely to be using peaker plants (some of the dirtiest sources). Participating in our utility's virtual power plant program means that they can call on us to power our neighbors, rather than turning on a peaker plant. Having solar means that our (local monopoly) utility is not our only source of energy. 

If you want solar on your home (with or without batteries), you can use my referral code to get $300 off a system from Tesla.

Sunday, May 15, 2022

5 Years of Battery Degradation Compared (Nissan LEAF vs Tesla Model X)

In this post, we'll compare the battery degradation of a 2011 Nissan LEAF LE and a 2016 Tesla Model X 90D. Why these two vehicles? Not because they are comparable in any significant way, but simply because these were my last 2 EVs and I have collected years-worth of data on each of them.

Here's the chart:

First, I want to point out that the graph is not zero-based on the left side. The bottom of the graph is 75%. This is to zoom in and see the degradation in detail, not the make it look worse than it is. 

Looking at the Leaf (blue line), you can see that it had less than 80% of the original range at the 5-year mark. The Tesla (red line), on the other hand, has more than 90% capacity when hitting the 5-year mark. The Tesla has less degradation; additionally, the rate of degradation slowed significantly after year 3. Unlike the Tesla, the Leaf's degradation showed no sign of slowing. 

At 5-years old, the Tesla had about 42,000 miles. The Leaf had a similar 44,000 miles. Working from home the last couple of years has meant fewer miles driven for the Tesla; otherwise, the Tesla would likely have about 60k miles by now.

This result is not surprising. As the Leaf aged, I wrote several posts about my disappointment with the Leaf's degradation. I'm happy to see that our Tesla has aged much more gracefully.

Disclaimer: I am long TSLA