atomic_fungus (atomic_fungus) wrote,

#7620: Less flatte than that.

I've woken up feeling halfway decent. Getting over being immunized. Woot.

The grass needs cutting thanks to the warmth and sunlight of yesterday. And it's supposed to rain every day this week except Wednesday, which means I'd better do it today, rather than tomorrow. Otherwise the code enforcement dick will be on me like a HOA Karen.

"Yes, I know you have a full-time job and it's rained every day this week, but your grass is half an inch taller than code. $50, please."


* * *

Saw an interesting thing--well, briefly interesting, anyway. Guy on YotzTubz was talking about "mechanical fuel injection" for small engines, mainly motorcycles: a self-contained unit you bolted to your bike which took all the fussing out of jetting and so forth. Lectron, he said, and their TCT line of carburetors. So, I looked into it. Eventually I want to get the TS-90 back together, and I was having a lot of trouble dialing in the mixture setting on the thing. Perhaps this would be a way to get around all that.

A) NOT mechanical fuel injection. It's a regular old carburetor with some nifty changes that make it largely self-adjusting. The main one is that the metering needle is chamfered, with a flat face that tapers larger the farther towards the bottom you go. This sets up a condition where the engine will only pull as much fuel from the float bowl as it needs, regardless of things like air pressure and the like, obviating the need for re-jetting the carb for different conditions.

B) $450.

Now, I am not entirely certain what new motorcycle carburetors cost, but $450 seems excessive, even for one that you don't need to dick with. What I do know is that, upon seeing that, I lost all curiosity about the product. Don't get me wrong: $450 would be an amazing price for fuel injection, but this isn't that, not even mechanical-style, and the largely self-adjusting nature of the carb does not make up for the fact that it's just a carb with a few minor alterations.

One rather interesting part of all this, however, is that the thing has inlets for both gasoline and propane, and the installation instructions stress the point that the larger fuel inlet is for propane and not gasoline. So if you ever wanted to run your ATV on propane....

* * *

Hmm--looking over my posts from 2017, there were several where solid-state batteries were "a couple of years out", which was what the articles I'd seen (and linked) were saying. Here it is 2021--four years later--and we're still using lithium ion batteries. I guess the solid state ones were just a little more complicated than they thought, eh?

Meanwhile, all the auto manufacturers are claiming they're all-electric 9 or 19 years from now. Volvo was supposed to have been all-electric already but I don't think they made it; the grown-ups must have stepped in and said, "You'll run us out of business if you do that."

Electric car adoption--just like renewable generation--is only happening where there are significant government subsidies for it. There are two reasons: electric cars are fucking expensive, and they're inferior to fueled cars.

Expensive: I don't think I need to support that. Tesla is what kicked off the electric car craze but they started well north of $50,000 and only now are they coming down anywhere near the already-stratospheric "average" price of $30,000.

Example: Chevy Bolt. Economy car size, but far above a family-car price: $36,500 for the base version, and GM is not eligible for subsidies because they are now selling too many electrics. I say "family-car" because you can get a Toyota Camry base model for under $25,000.

(Incidentally? V6 and AWD available, and it gets a 0-60 time of 5.7 seconds, which is damned fast for a "family car".)

Inferior: 300 or 400 mile range, sure--but when you run out of juice, what do you do? You can't pull into a gas station and refuel. You need to find a charger, and then you need to wait while electrons trickle into the battery. If there is no charger, you're stuck. Oh--and you can't walk down the road to the next station, buy a can of electrons, and dump them in.

Towing anything cuts your range, drastically.

Generally speaking, people don't want electric cars. It's not because they're stupid or hidebound; it's because electric cars are obviously inferior to fueled ones.

I once did some rough back-of-the-envelope calculations to get a rough idea of how much energy England used on personal transportation. Not even freight--just people and their gasoline cars--and it came out to something like a thousand megawatt-hours per year. Where does that electricity come from?

If you said "windmills and solar", or "renewables", kindly be quiet; adults are talking. You could cover every rooftop in the nation (England) with solar panels, at some ungodly cost, and it still would not be enough. And that's before we start talking about charge times. "Windmills"? Take a look at Texas earlier this year and say that again. Or don't, rather, because (as I said) adults are talking.

A square meter of solar panel generates, under the absolute best of conditions, 300 watt-hours for every hour it's in direct, strong sunlight. And I'm being really generous, there, because in practical terms solar panels are only about 25% efficient at best. When the sun is shining directly on them.

Cover the south-facing part of the bunker's roof with solar panels. It's about 70 square meters.

21 kilowatts. Again, under the most incredibly ideal conditions you can imagine: perfectly clean, brand new, and very expensive high-efficiency panels, direct sunlight, low humidity. To be even more generous, assume that the hours between 11 AM and 1 PM are peak insolation.

I generate 42 kilowatt-hours during that time period. How much does it take to charge a Tesla battery?

Well, Tesla boasts a capacity of 82 kilowatt-hours. That's for a full charge. (It's actually more, because of the Laws of Thermodynamics, but as I said I am being generous.) So the two peak hours of daylight get me enough electricity to give me "half a tank", so to speak.

Now if we take a step back from the extreme ideal?

1) You won't get anywhere near 300 watt-hours per square meter. 200 is more like it. And that's just between 11:30 and 12:30 on cloudless days. Clouds, humidity, the position of the sun in the sky, all of these things affect how much power your solar panels generate. It's generous but more reasonable to assume 75 watt-hours per square meter averaged across any given day's daylight hours. And remember, in winter, you have fewer daylight hours than in summer. 70 square meters of solar panels generate 5.3 kilowatts, so for an average winter day you make maybe 37 kw-h of electricity. The average house uses 30 kw-h per day. Leaving 7 kw-h to charge your car.

2) Charging is not 100% efficient, and even if it were, charging rate is effected by the chemical process in your batteries. You can't charge a battery faster than the chemicals can react, as otherwise you get a nice fire and maybe an explosion. This is true of lead-acid but triply true of lithium ion.

So even if you have more solar panels and one of those Tesla battery bricks? Double the numbers. 140 square meters of panels, 10.6 kw-h, 74 kw-h of electricity, and the 90% efficiency of charging knocks that down to about 67 kw-h. House still uses 30 kw-h. You now have 67 kw-h in your house battery. To charge your car, another 10% off the top when you transfer it to the car battery, and we're at about 60 kw-h. But--

3) The lowest price I saw for a 10 kw solar panel install? $17,000. They say about $3-$5 per watt. But that's the cheap way, the solar panel that feeds power to the grid rather than store it for local use. So to charge your car and power your home, you're looking at more money. There is some question in my mind as to how they get that "10 kw" figure, by the way, but I'm assuming a typical house with one face of the roof (the one that best faces the sun) being covered with solar panels. That's my 37 kw-h example, above, but twice that area yields 10 kw under direct sunlight and other ideal conditions. (Admittedly, my estimate of the available roof area was basically PDOOMA.)

4) Solar panels wear out and must be replaced when they do. They don't quit working so much as merely become less efficient as time goes on.

Now, multiply this across every house in the land.

* * *

Understand that a "kilowatt-hour" is one kilowatt of electricity for one hour. Like, your wife's blow drier running at its medium setting for one hour. Ten 100-watt incandescent bulbs, lit for one hour. The instantaneous measure is just watts; at any instant in time the blow-drier, or our ten bulbs, are dissipating a kilowatt of energy.

So a solar installation that is rated at 10 kw might make 10,000 watts of electricity at any given moment; if it does so for an hour it generates 10 kw-h.

Look at it this way: "watts" by themselves is how fast; "watt hours" is how much.

* * *

So, I'm thinking that I ought to get outside and cut the grass, because it's going to rain all week etc. It's not what I had intended to do with my Sunday, but WTF, it's not like I have very much else that I was planning to do.

The master bedroom is painted, but it's stalled there. We need to go buy curtains and wall plates, and haven't. I'm going to replace all the sockets and the switch, and we're going to get a new ceiling fan. All of which takes time and money we, so far, have not cared to expend. But the room is painted!

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