A Common Sense Tax Proposal

My neighbors with plug-in electric vehicles are getting a free ride not paying the fuel taxes that pay for roads and highways. Perhaps it’s time to put a tax on electricity used to charge EVs and to require EVs only be charged from properly metered connections to the electrical grid. After all, it’s illegal for me to fuel my diesel VW from a pump for non-road (farm and construction) equipment.

Meanwhile, Back in the Real World …

I wound up spending most of the holiday weekend lashed to a computer but not on the Interwebz.

While taking Real World performance data on a bit of hardware last week, my colleagues and I discovered some odd behavior that was not completely unexpected but had not been predicted by the original modeling of the circuit. I’ve spent a large part of the past few days refining that model. I’ve improved it to the point where it will do the same kind of tricks as the Real World circuit, but not yet in exactly the same way.

It turns out that a couple of the components are more temperature sensitive than assumed in the original model. The warming isn’t global. It’s just a local phenomenon, and the unexpected performance has turned out to be a feature rather than a bug.

Cleaning House at Twitter

Elon Musk has announced Twitter 2.0 and is taking the company back into startup mode. At midnight PT, employees received an email telling them to expect long hours and high performance standards. They were given until close of business Thursday to either sign on to the new program or take three months’ severance pay.

A few dedicated hardcore engineers will generally deliver a better product than a large team of 9-to-5ers. Think of the Macintosh computer ecosystem versus Windows 95 or the reusable SpaceX Falcon 9 versus the finally flying SLS.

I’ve been on several the kind of engineering teams that Musk is trying to form at Twitter. I’ve even had the privilege of leading one. It can be exhilarating. It can be draining. And it’s for the young. I’ll be 75 on New Year’s Eve, and I’ve had to slow down a bit, but I still find myself working overtime to get things not just right but the best they can be.

Twitter is noticeably better since Musk bought it. I look forward to seeing what he can do with the deadwood out of the way.

UPDATE—Corrected the drop dead date for getting with new program.

Artemis I Launch Attempt Scrubbed

NASA’s statement:

The launch director waived off today’s Artemis I launch attempt at approximately 11:17 a.m. EDT. Teams encountered a liquid hydrogen leak while loading the propellant into the core stage of the Space Launch System rocket.  Multiple troubleshooting efforts to address the area of the leak by reseating a seal in the quick disconnect where liquid hydrogen is fed into the rocket did not fix the issue. Engineers are continuing to gather additional data.

The Actual Cost of Electric Cars

I’m an electrical engineer. My day job involves designing the electronics that will drive a set of motors in a robot arm to be used on a NASA satellite. While the motors are not as powerful as those used in cars, the technology is similar. The paperwork below goes a long way in explaining why one of my VWs burns gasoline and the other is a diesel.When I first saw this quote, I thought it was fake. However, a bit of research showed that a low end estimate for replacing a Volt battery is around 9,000 bucks. A Los Angeles Chevy dealer was cited online as estimating just short of 20,000 dollars for a Volt battery replacement, and costs as high as 32,000 are reported.

I ran the VIN shown on the estimate at the AC Delco parts website. The car is a 2012 Volt hybrid which means that the battery could now be out of warranty. Because the car is hybrid, there is still a 1.4 L gasoline engine to maintain in addition to the battery and electric motor.

It would probably be more expensive to replace the diesel engine in my New Beetle that that gasoline engine in my GTI, but it would still be less that the cost of a low end estimate for a Volt battery job. And I’d expect a diesel engine to go a lot further than 70,000 miles before needing to be rebuilt or replaced. My other diesel cars all went past 300,000 miles before requiring serious engine work.


UPDATE—The estimated cost of this battery replacement is almost the same as the original 2012 sticker price for a Volt.

Slow Blogging Day

I’ll be on the road most of today, in transit from Tennessee.

BTW, I’m traveling in my 2021 VW GTI. Driving down from Maryland on Saturday, I was rolling with the flow of traffic at a speed that my first car, a 1962 Beetle, could not reach, and the GTI gets better gas mileage than the old Bug. OTOH, I spent about $90 for the gas for the drive down which would have paid for almost 10,000 miles of driving the Beetle back in the late ’60s.

Also, during roughly 650 miles of driving on Saturday, I saw only one Tesla. Based on the county shown on its license plate, it was not far from home.

Learning to Code

As CNN+ bites the dust, …Of course, they can always learn to code. I learned Fortran when I was a teenager and several other programming languages since then. These days, most coding is done with a keyboard, but I’ve found another tool useful for some forms of communication.OK, at least one of the Gentle Readers is going point out that manual telegraphy is as slow, essentially obsolete form of communications. That’s true, but Morse code still can deliver truthful information faster than CNN+ ever has. That’s why it will still be in use next month.

Coal Fired Teslas

The electricity flowing from a charging station doesn’t magically appear. It must be generated and transmitted to the charger.

Let’s do a bit of analysis.

Looking around the interwebz, I found that the typical Tesla uses 34 kWh of energy to go 100 miles. I’m more used to dealing with energy calculations in joules. 34 kWh = 122 MJ. That’s megajoules.

The typical charging station has an efficiency of about 90 %. In order to deliver 122 MJ to the Tesla’s battery, it will draw about 136 MJ from the power line. The typical efficiency of the power grid from generating station to end user is about 89 %. Some power station needs to generate 153 MJ to get 122 MJ into the Tesla’s battery.

Let’s assume it’s a modern coal fired plant. The efficiency of the process of burning coal to heat water to make steam to turn a turbine to spin an electrical generator is typically around 32 %. That means we need 472 MJ of energy from the coal.

Burning a ton of coal delivers about 22 GJ (gigaojoules) of energy, so we’d need to burn about 43.4 pounds of coal to charge a Tesla to drive 100 miles. That gives a fuel economy rating of 2.3 miles per pound of coal, and that’s roughly equivalent to 15 mpg for a gasoline vehicle.


My Solar Powered Volkswagens

I have a couple of Volkswagens, a 2014 Beetle and a 2021 GTI. The 2014 has a diesel engine, and the 2021 has a gasoline engine, but both are actually solar powered.

Let me explain.

Both the cars have internal combustion engines which derive their energy from the combustion of hydrocarbons with oxygen. Those hydrocarbons are so-called fossil fuels derived from petroleum. The petroleum was created over time by the compression and heating of organic matter buried in the ground, and that organic matter came from the remains of living organisms, plants and animals, which lived a long time ago.

The brontosauri that filled my cars’ fuel tanks survived by eating vegetable matter that lived by synthesizing organic molecules from the environment, and that synthesis required energy. That energy came from sunlight.

So there you have it. The energy to operate my Volkswagens came to Earth as photons from the Sun. So did the energy from fossil fuel fired power plants used to charge my neighbor’s Tesla.

Chipping Away at the Supply Chain

Milton Friedman once remarked that if the government were put in charge of the Sahara Desert, we would quickly have a shortage of sand. The looming supply problem for the electronics industry isn’t a sand shortage but one of silicon metal used to make semiconductors. SMM News is reporting that government imposed power restriction in China are adversely affecting silicon production.

The insufficient power supply will inevitably lead to a decline in the output in Q4. The impact of the dual control of energy consumption is more significant on the supply of silicon. The major silicon metal producing regions including Yunnan, Xinjiang, Sichuan will have to cut the production, where the silicon plants cannot maintain the normal production from September to November. The power shortage also restricts the production.

BTW, silicon isn’t rare; it’s the most abundant metal in the Earth’s crust. Oh, and a vast array of products uses semiconductors. Even the toaster I bought last year uses an integrated circuit as the basis of its timer.

Magnesium and Wheels

I’m so old I remember when the only significant quantity of magnesium in an automobile might have been a set of aftermarket wheels. That’s not the case now. More and more parts on cars and trucks, including large body parts, are aluminum, and many aluminum alloys contain magnesium. There’s a lot of magnesium in a modern vehicle.

China produces over 80 % of the world’s magnesium. Recent power shortages have severely affected the region where most of China’s production is based, so a magnesium shortage is expected to hit vehicle manufacturers before the end of 2021.

Saving the Public Some Money

NASA has announced that the Europa Clipper mission to Jupiter and its moon Europa will be launched by SpaceX using a Falcon Heavy vehicle. The total contract award is for $178 million. The competing vehicle was NASA’s SLS. The estimated cost of the SLS launch would have been $2 billion.

The SLS has not flown yet, but the Falcon Heavy has several successful launches to its credit.


A billion here, a billion there, and pretty soon you’re talking about real money.

—Everett Dirksen