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Thursday, December 29, 2022

Oregon Joins West Coast Gas Car Ban

In 2035, if you want to buy a new car to drive from the Space Needle to Crater Lake to the Golden Gate Bridge and then to Rodeo Drive, that road trip will be in an electric car. 

In December of 2022, Oregon was the final of the west coast three to ban the sale of new gas-powered vehicles in the state in 2035. 

This unites the west coast in banning the sale of gas-powered cars in the middle of the next decade. California was first to announce their ban in August of 2022. Washington state followed suit two months later with their own ban. Keeping the beat, two more months later the Oregon was the last domino to fall on the west coast of the lower 48.

The Oregon Environmental Quality Commission voted to approve the Advanced Clean Cars II Rule at a special meeting December 19th. The rule is based on vehicle emissions standards initiated by California.

The ban will not affect cars already on the road or the purchase of used gas-powered cars but will require those interested in purchasing a new gas-powered vehicle to take their business outside of these states.
This is the next step in Oregon's journey. In 2020, Governor Brown signed Executive Order 20-04 which directed state agencies to drastically reduce emissions by 2035. This is part of Oregon's plan to cut climate-warming emissions 50% by 2035 and 90% by 2050.

This timeline allows for the continued build out of the electric vehicle charging infrastructure. The state already has a robust Tesla charging network. The other networks have had reliability issues. A 2035 timeline allows these to be ironed out by early adopters (hopefully sooner rather than later).

How Big Of A Car Market Is This? 

California is the top region for automotive sales in the US. As of 2021, car sales in California was $137 billion and accounts for ~12% of US car sales. Add Oregon's $13B and Washington's $21B and that brings you to $172B market or 15% market share. This is obviously far too big of a market for automakers to just walk away. They will need a robust EV line-up.

What About The Other CARB States?

Massachusetts and New York have also adopted similar rules. These five states together account for almost a quarter of the U.S. population. This is adding more fuel to the fire to stop burning fossil fuels (pardon the anachronism).

There are 17 states that have announced intentions to follow California's vehicle emissions standards to one level or another. These states are New York, Massachusetts, Vermont, Maine, Pennsylvania, Connecticut, Rhode Island, Washington, Oregon, New Jersey, Maryland, Delaware, Colorado, Minnesota, Nevada, Virginia, and New Mexico. Four of these have already vowed to follow the 2035 ban. How many more will soon follow? Colorado, I'm looking at you to join next.


Tuesday, December 27, 2022

Powerwalls and Power Outages

Look at the map above. This is the region where I live. More than 55 thousand people here are currently without power right now. We had an Arctic blast blow through with snow and ice last week and this week there's a wind storm taking out branches and trees. To pile on to all of that, there's domestic terrorist movement that somehow thinks that attacking electrical substations will manifest their extremist political agenda.

Tesla Powerwalls don't have a "grid under attack" setting (yet). 

There's no good time to lose power, but during a winter storm is the worst. Without power, you cannot run your furnace to stay warm. This is true even if you have a gas furnace because power is needed to run the fans and control systems. If you opt to evacuate to stay with friends or family or to check into a hotel, the road conditions can make travel difficult. These storms and outages can be deadly.

Powerwall to the rescue

So here we are with our Powerwall full and the lights flickering occasionally. We are getting a meager amount of solar production on this rainy winter's day. Even with a small amount of solar production, this can stretch the battery uptime significantly. 

Here's something that many people without solar on their roof don't know. If you have solar without batteries (the most common type of solar installation), when the grid goes down, your solar turns off. This seems like the time when you'd need it most, but there are a couple of reasons it works this way. It's unlikely that your solar will create exactly the amount of power that your home needs. If it doesn't make enough, you'll brownout your home and could damage your more sensitive equipment (computers, TVs...). If your solar makes more than your home currently needs, it has to go somewhere. This would usually be the grid, but if the grid is down, it can't go that way.

This is where Powerwall comes in handy. Even when the grid is down, it can fill in the passing cloud  gaps and prevent the brownout that might fry your flat screen and it can absorb the surplus for use after the sun goes down.

A distributed power grid is more resilient and a harder target for weather or violent extremists to attack.

Saturday, December 24, 2022

Solstice, Storms, & Solar - Tesla Powerwall: StormWatch vs VPP

The winter solstice is a milestone day in solar energy. It's the shortest day of the year, so nothing but longer days from here for the next 6 months.

Usually for the solstice, I note our solar production, sunrise, sunset... I'll cover that, but something unexpected happened on the solstice this year. 

Winter Storm Event
Red Flag Warning

Unstoppable Meets Immovable

Like much of North America, our area is currently being hit by snow and ice storms during this yuletide. In response to the storm, on the solstice, two things happened. One, at 4PM our Tesla Powerwall went into Storm Watch mode. This charges it up to 100% and keeps it there so the battery pack has the energy needed to keep our home running if the grid power goes out. An outage is a real possibility during ice storms, so the precaution is smart. The second event in response to the storm is that our local utility scheduled a virtual power plant (VPP) event. The VPP event was scheduled to run from 5PM till 8PM. 

Portland General VPP event

So what happens when Storm Watch mode is trying to hold the pack at 100% charge and a VPP event is trying to discharge the battery to support the grid? The good news is we could to opt-out of either one or both of the events if we had a preference as to which one we wanted to win out. However, I was far more curious to see what happened if we did nothing and watched the result. 

Without further ado, the VPP won out. Our Powerwalls discharged for 3 hours at 3kW. This removed 9kWh from our ~40kWh pack.

Powerwall Discharging 
While in Storm Watch Mode

Solstice Energy Use and Production

Below is the graph of our energy use on the solstice. The colors tell you the source: grey is the grid, green is the Powerwall, and amber is solar direct from our roof.  

The sun didn't spend long in the sky on December 21st. Sunrise was at 7:47AM and sunset was at 4:29PM. That's just 8 hours and 42 minutes without the cold inky black winter sky overhead. Combine this with the sun low in the sky and storm clouds and the result is a yield of 12.7kWh of solar production for the day. 10.5kWh of that solar went directly into running our home with the remaining 2.2kWh going into the Powerwalls. 

For comparison, on the summer solstice, we generated 72.9kWh (almost 6 times more), along with feeding ~50kWh of that into the grid. Here's looking forward to sunnier days.

Other Solar Posts: 

Other Powerwall Posts:

Sunday, December 11, 2022

Tesla Semi: Another "Impossible" Achievement

Tesla Semi Exploded View at Production Release Customer

Tesla has done things that were once considered impossible. They made the Roadster when EVs were regarded as slow golf carts or milk floats. The zippy roadster was fast and fun and could blow the doors off cars costing ten times as much. This was the first of Tesla's "impossible" achievements and they've had a string of them. 

Tesla's Semi is the latest of their impossible achievements. 

Why Electric Class-8 Semi-Trucks are 'Almost' Impossible

Making an electric long-haul semi is not easy. It takes a lot of energy to move thousands of pounds/kilos of load. For an EV, that energy is stored in batteries. Adding more batteries adds more energy storage, but it also adds more weight, requiring yet more energy. This negative feedback recursion has led some to say that it is not possible, even with "big breakthroughs." As you can see below, one of these nay-sayers was Bill Gates.

Even with big battery technology break throughs, electric vehicles will probably never be practical for things like 18-wheelers, cargo ships or passenger jets.

Bill should understand that the march of progress opens new doors. He seems to be stuck in 1990s battery technology thinking. Even before Tesla's semi came out, there were class 8 trucks from Volvo, Freightliner, Kenworth, Peterbilt, and others (see table below). These non-Tesla class 8 vehicles generally had less than 350 miles of range, but it was a start; a foundation to build upon. 

Gates is not the only one to have doubts, Daimler Trucks CEO Martin Daum has commented, "if the claims Tesla is making about its electric semi-truck are true, they are breaking the laws of physics." Gates and Daum seem to be confusing 'what has been done' for 'all that can ever be done.' 

Tesla improved the aerodynamics, they improved the drivetrain, they improved the battery technologies, and they achieved what Gates thought impossible.

As we discussed in this article, Musk and Co. focus on the Class ½ Impossibilities. These are the things that are physically possible but at the edge of our technical know-how. Class ½ Impossibilities have just been enabled by technological advances, either directly or by advances in tangential areas that can be applied with other optimizations. These are not easy to achieve, they require breakthroughs, optimizations, hard work, and some luck. When completed, these enable something that we've never seen before and therefore something which many people will say is impossible. 

An Elephant That Moves Like A Cheetah 

The Tesla Semi has three Tesla carbon-wrapped Plaid motors. Musk described the vehicle as a beast. He said it's a giant Semi, but unladen, it moves like a sports car. He went on to say, "It's like watching an elephant move like a cheetah."

Tesla's "Impossible" Achievements  

One Roadster: When Tesla started, the founders often heard things like, "This is a fool's errand. Nobody wants an EV. They are slow, there's nowhere to charge them."

The Roadster showed that EVs can be sexy and fast. In the quarter mile, this electric car would blow away gas cars costing 10 times as much. It changed the perception of EVs. But the nay-saying continued, "A few Silicon Valley millionaires and billionaires will buy them, but no one else is interested (or can afford) an EV." 

Two Model S: The Model S disproved the "only in Silicon Valley" narrative. Tesla had sales around the world. 

Three Supercharging: Tesla's Supercharger network is impressive. There are currently more than 40,000 Superchargers installed around the world. These have high availability and locations near major travel corridors. This is vital infrastructure for electrified transportation.

Four Energy Storage: Vehicles are just part of Tesla's business. Tesla's Megapacks have 3.9MWh of capacity. This is enough to run the average home for over 130 days. Gang these together and you can make an impressive installation like the 730MWh Elkhorn Battery Energy Storage System in California or the 600MWh Arroyo Solar Energy Storage in New Mexico. As I write this in late 2022, Tesla has 5GWh of Megapacks and Powerpacks installed or under construction. 

Before we had significant energy storage, the amount of renewable energy that could be placed on the grid was limited. The legacy fossil fuel generation of the grid could not handle the fluctuations that wind and solar caused. However, with renewable sources buffered behind a battery pack, all of those fluctuations are washed away. The grid, instead see a steady, adjustable rate from the batteries that can be dialed up or down in milliseconds to support the grid exactly as it needs, exactly when it needs. 

Tesla's semi is the most recent on this list, but it won't be the last.  

This is The Beginning - Commence Iteration 

As impressive as the Tesla Semi is, this is just the beginning. As we saw with the Model S, a decade from now the Tesla Semi will be much improved. It will go from just a day cab to a sleeper cab. The range will grow from 500 miles to over 750 miles. The recharge times will improve. And the software will improve. 

The in-cab entertainment options will improve (will the sleeper bunk have a video game / movie screen)? Software integration for load pick-up, delivery, and schedule will improve; reducing the number of running empty deadheading trips. 

Wrapping It Up

The Tesla Semi is an important milestone. The fuel cost savings will drive fleet managers to adopt electric semis. Tesla's semi has limitations today on range and load weight, but innovation is Tesla's life's blood. Currently, it is perfect for many day-use loads. As the vehicle improves, the number of drives it's suited for will increase, until the range and refueling times rival and surpass Diesel semis. 

Friday, December 2, 2022

How Big Is The Tesla Semi-Truck Battery Pack?

Tesla delivered the first of their semi-trucks to a customer last night. The Pepsi / FritoLay company was the lucky customer. We learned a lot about the vehicle's capabilities in the presentation, but one thing we didn't learn is the size (energy capacity) of the battery pack. 

In this entry, we'll use what we know about the battery to put upper and lower bounds on the capacity and infer a likely size. If you don't want to read to the end, our current estimate for the size of the battery pack in the Tesla Semi is 914kWh usable. Read on if you'd like to know how we came to this conclusion. 

We know the cells are produced at Giga Nevada and, given the hauling use case, they are likely the high-Nickel chemistry that was developed in partnership with Panasonic. 

Tesla has said that the semi (fully loaded) has an efficiency better than 2kWh per mile. Additionally, the semi recently completed a fully loaded 500-mile drive. 

Using these two numbers gives us a 1000kWh (1GWh) capacity estimate, but there's more to the story. 

Taking a close look at the drive above, you can see that it started with 97% charge and ended with a 4% charge; so if you were doing a true 100 to zero percent trip, you'd have another 7% of capacity to use. That would be a 537-mile range, at 2kWh per mile, the upper bound for the pack size is 1,075kWh. 

As Musk often does, he gave us more info on Twitter. Specifically, he said that the current efficiency of the semi is 1.7kWh per mile. Another digit of precision would be nice, but we'll go with this for now. 

Recalculating using this number and the 500-mile trip yields an 850 kWh battery. Using the inferred 537-mile trip would use a 914kWh capacity battery pack usable.

In battery-powered electric vehicles, there's usually some reserve capacity that's locked away from the driver's use. This helps extend the battery lifespan. If we assume a 6% reserve, this adds another 55 kWhs to the pack, bringing the total pack size to 969kWh.

A 1.7kWh/mile efficiency is the energy equivalent of about 20 miles per gallon (20 MPGe while hauling a full load). For a comparison, with a full load, Diesel class 8 semi-trucks average about 6 MPG. The most efficient Diesels semis out there (the Freightliner Cascadia Evolution) gets 10 MPG on a good day. So the Tesla Semi has a fuel efficiency that's triple the average (and double the best), compared to Diesel semi-trucks.

Today, semis are primarily Diesel-powered. Electrifying semi-trucks is very important. In the US, they are only about 1% of vehicles on the roads, but they have a very outsized pollution impact; they generate about 20% of vehicle emissions and about 36% of particulate emissions. This directly has an impact on health and air quality. Semi-trucks from Tesla, Freightliner, BMW, and others will help make a cleaner world.