Wimminz – celebrating skank ho's everywhere

Effishunsey

wimminz

I have had this argument time and time and time again, with people who do not get it, do not want to get it, and do not want to deal with the consequences of getting it.

Usually it’s with things like lasers, in a plotter machine mirrors can move but cannot rotate, so a mirror on a carriage on the X axis to deflect the beam 90 degrees downwards, a mirror on the end of the X axis to deflect the beam 90 degrees along the X axis, and a mirror at the end of the Y axis to deflect the beam 90 degrees along the Y axis.

Let’s say you are starting with a nice round number like 100 watts of beam power coming out of the tube, lets say all three mirrors are equally dirty and made of a material that is equally reflective, or not.

Scenario 1 each mirror is 95% efficient.

Scenario 2 each mirror is 85% efficient.

Just for shits and giggles, lets add 3 more mirrors to scenario 2

The first problem is nobody understands that compound percentages are an exponential function, and exponential functions get very steep very fast as soon as you move more than a tiny distance from unity.

3 mirrors at 95% efficiency lose less power than one mirror at 85% efficiency…. One is “only” 5% from unity, the other is “only” three times as great…. but at 85% efficiency after six mirrors we are down to 37% of power, just over one third remaining.

I could delete laser and beam and power and replace it with electricity and battery and charge efficiency.

There are actually more than six steps between incoming mains voltage and tesla power wall and tesla car and travelling down the road, every voltage change is a step, as is every process within the system, putting power into a battery is a step, taking power out of a battery is a step.

Each step has a conversion efficiency.

With lasers I’d tell people it doesn’t matter what the optics cost, it’s one of the best possible places to spend money on a bang for buck basis, and you still see them trying to buy cheap optics or in some cases make their own from polished copper, and invariably these were the same fucking cunts that would refuse to do the math at the top of this page properly, I say refuse because any fucking retard with a pocket calculator or a pen and paper can do iterative “multiply by zero point eight seven” or whatever and get the right answers.

Long before Tesla became a thing I talk the same talk to people doing “off grid” living via some form of power harvesting or generation, inverters and lead acid batteries.

The smart ones who listened went out and bought new 2 VDC lead acid traction cells, most people “saved money” by using vast arrays of mis-matched old car and truck batteries strewn across a concrete floor.

Anyone with any electrical / electronics knowledge will know it isn’t just the charge and discharge efficiency you’ll have to take into consideration, plus “C” rates, but also total internal resistances, and this is all fucking lousy for a bunch of mismatched old car and truck batteries.

You can compound it further with home made alternators and home made water wheels or wind blades and so on, nothing operating at any sort of efficiency, old scrap conductors used.

ONE guy about 12 years ago asked me to spec a system and install it, for various reasons he wanted 12 VDC and not 24 so I got 2 sets of 6 traction cells, each one was something like 750 Ah and we put them in a proper box off the ground away from frost, one each side of the shed, for independent twin banks with isolators, at that point plans went wrong / changed and he went for a 24 volt inverter so we seriesed the two banks up, no big deal but these things happen…. and he started out with an inverter / charger / etc designed for twin banks and designed that you could module them together and they’d sync mains clock and also charging and so on, each one was rated at 7,000 VA continuous, it was all fairly expensive… outside the shed was a 1.2 kilowatt wind turbine (50 amperes) that worked when the wind blew and about 60 feet away was a very small stream that he dammed and made a fish pond and a small overshot wheel that would put out a steady 180 watts (7.5 amps) and the house was 60 feet the other way and fed 240 vac pure sine inverted… there was also a single phase 20 amp (4,400 watts) supply to the property that went to the shed and to the fancy inverter / charger / etc

Like I said it was all fairly expensive, we are talking small new car expensive.

So he had 4.4 kW available from the mains, it was just slightly unreliable and when it went out it was usually branches / trees / wind related and usually took a couple of days to fix, and usually a portion of the fix bill was handed to him, I do not know the details.

He had a steady 180 watts from the overshot hydro that pretty much ran 24/365

He had an intermittent up to 1,200 watts from the wind turbine, usually you’d see about 200 watts… average was around 250…

back then solar was ludicrous money.

7000 watts draw from 24 volt (with no losses and 100% efficiency) is 291 amperes, the reality is we expected peak surge currents up to around 400 amperes but that’s nothing exceptional to a traction cell.

24 volts at a 1500 Ah rate (150 amps for 10 hours) meant he had 36 kWh stashed away, and the 150 amps at 24 volts meant 3,600 watts at a 10 hour rate, as in 10 hour rate is no fucking big deal for the cells.

180 watt hours x 24 hours = 4.3 kWh per day from the mini hydro, day in day out.

250 watt hours x 24 hours = 6.0 kWh per day from the wind, day in day out.

WE fudged all the numbers to include efficiencies and losses by calling everything half to two thirds, so 36 kWh storage became 18, the 4.3 kWh per day from the mini hydro became 2.2 kWh etc.

The guy was a photographer, early into the whole digital thing, from memory large format more than regular DSLR stuff, so he absolutely had to have 24/7 perfect power for his bank of macintoshes and big storage arrays, and he was more than happy to sneakernet his files in and out (from memory his phone lines were alu and buried in the ground so even dsl 512k was a only when it’s dry proposition) to customers, and it meant he could carry on living where he was… he had a small honda genny for when the power went out for the house and they didn’t care about that much.

I can remember commenting about how much money we were spending doing this (he was throughout a do it right, don’t cut corners, ok, 50 x 25 mm copper bus bars..lol) because as I said it was new small / medium car money, and he said something along the lines of fuck it, I could spend this on a lens…

A couple of years ago I met someone who told me that guy is still there, he has retired, his wife died of something, and he lives a bit like a hermit, but a techo hermit, doesn’t want to meet anyone, the woman I met cleans the pond of leaves which now and again clog the hydro wheel a bit, cleans the house a bit, does shopping, the house is now all LED lighting, apparently a few years ago about when his wife died a winter storm took down the mains supply, and he never had it put back, but all that shit we put in around 2003-2004 is still in and working, I have no idea what %ge of the capacity of the traction cells has gone, I’d suspect fuck all, maybe 5%, but in any event the house is now all LED lighting so loads are way down, I remember even back when we put it in despite it being put in for his mac lab and digital camera work we discovered that the heaviest load every day was the oil fired boiler and circulation pump for the central heating, though to be fair his main concern was 24/7 clean and reliable power.

It was my marine experience that got me hired to do that, marine where there is no shore power, so it is not an option, and city/urban grade / reliability shore power wasn’t an option where he was either, and he wasn’t about to move.

So we cared about efficiency, you bought your power source whether it be solar or wind or hydro, and efficiency at each stage would make or break you, so a small / medium car for 12 years trouble free service and power even when you focus entirely on efficiency first still does not equal free power.

It just has to be still more expensive than good clean mains power, maybe not a lot, but it has to be more, but the thing is even then I can remember mumbling about a lister start-o-matic and a couple of small UPS’s for the mac stuff.

The “green” option would have been DC-DC PSU’s for the macs and a big bank of lead acid to power them, 750 Ah of 2 VDC traction cells up to 12 volts is 18 kWh, that would have run a few macs for days and if the power went out charge that from a genny.

In todays money I guess we spent 20k, maybe 25k doing that, but efficiency was the only driver, who gives a fuck if it is ugly and you have to build a 10 x 6 shed on a new slab to put it in.

I never *really* saw it running as I left when the job was done so basically 2 or 3 days making everything nice after it is all running, during that time the hydro and wind seemed to pretty much produce enough to run the house over 24 hours with the battery bank acting as a reservoir, maybe the mains supply was topping up a bit, but not much.

I could have done the job for 2k using scrap old parts, but efficiency would have been horrible, and total REAL output and capacity negligible…. nowhere near the 60% overall for the harvest > charge > discharge cycle we were working on, or 50% for our rule of thumb down the line.

And this was a guy with money, and this was only a dozen years or so ago, not 50, and we really couldn’t do much better.

I can’t remember what the traction cells weighed, muscle memory says I couldn’t lift one and it took two of us and an engine hoist to get them from the hiab dropped pallet into the cages in the shed, I can remember the conversation about we should have built the shed around the batteries where the wagon dumped them.

A tesla powerwall and car is like that, but using the battery power to pump water up to a big tank and then running another big hydro system off that, one that could generate 25 kW peak, not the few hundred watts we had, because that is all batteries are really, just holding tanks for energy.

My old lister is great because it is a static / stationary engine, put it in a vehicle and it would suck donkey balls, that old off grid install only worked as well as it did, even with 20-25k spent on efficiency, because everything was static.

A 1,200 lbs 75 kWh tesla li-on battery offers no advantages over what we did back then, like the 295 megawatt tesla battery install in Oz for the wind farm, it doesn’t make fucking sense.

The Oz wind farm is the same as matey’s wind turbine, it’s not base load and average real output was maybe 25% of rated power, so you need a reservoir or battery, and a reservoir adds extra efficiency losses, so you can get constant flows even when it aint being recharged or you can get peak flows greater than the charge rate, but you are not gaining on total energy, you are LOSING on total energy.

I can remember the mains electricity guy telling him to leave the fucking termination and meters where they were, and run his own mains cables 60 feet to the shed, and make sure they are 6 mm cables, and thank your luck starts your meter isn’t on the pole pig down the road, because the cables from the pole pig to your house are losing nearly 1.2% of the power, they have to be light enough to go on the poles… and to break and not take a pole down when a tree falls..

The Oz tesla battery may be next to the wind farm, but it is miles away from anything else.

The analogy is a bunch of wind powered pumps pumping water to a reservoir, not to drink, but to run a hydro system….

This guy actually had a small stream that ran 24/365 with about a fall of about 3 feet on his land, and he had a 1000 yard clear fetch up to the house from 300 degrees of the compass to his wind turbine, and he had the money to buy both and buy quality and efficiency, and he still never bothered with a grid tie / feeding energy back into the grid and getting paid for it, because he never generated a surplus, and this is a fairly well off guy with 2 or 3 acres of land, talk about low density.. him and his mrs were 1 person per acre, when she died it was 0.5 people per acre, and even with LED lighting I’ll lay money he still has heating oil trucked in once or twice a year.

He could probably get 3/4g up there now, that didn’t exist back then either.

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Go back to that beginning bit, 6 mirrors at 85% efficiency get you 37% overall, that means that in FUEL terms a tesla is no more efficient than an internal combustion engine, even with the economies of scale of central power generation, plus THE EXTRA FUCKING INFRASTRUCTURE AND EXTRA FUCKING POINTS OF FAILURE, my god….

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It is one thing, from an engineering perspective, so talk about putting a tesla power wall / local storage in every house, and how this could smooth out loads on the grid, it’s a valid argument, it could be done, but the cost is incredible…. I’ll come back to that.

It is quite another thing, from an engineering perspective, to talk about putting in a local storage in each house so that it can fill up at rate X, so when you come home and plug your EV in you can fill that at rate 20X from the local storage. These two things have nothing in common.

getting back to the local storage, it MUST be isolated from the mains (else you will kill the electrician out in the street working up the pole) but it also MUST synchronize with the mains perfectly, so what you end up with as the cheapest practical option is Mains > local storage > house with no connection at all between the mains and the house, so by definition the local storage must have a peak rating = or greater than peak demand for the house.

I have a 40 amp mains breaker here and at 240 VAC that means a shade under 10 kW, essentially in electronics terms you are talking about a 10 kilowatt high voltage mono hifi amplifier that plays one tone perfectly with lots of feedback and correction stuff, and it has to be able to do it 24/7 with zero faults, and if it does fault it has to fault safely to open circuit at the component level, no dead shorts…

You’re doing what a rich photographer did 12 years ago, and it cost him the price of a new car to do if efficiently, but it lasted 12 years that we know of… and he had plenty of land, eg his power shed took the space of another car.

I don’t know for a fact, but I doubt he got his money back in real terms.

I don’t know for a fact, but I suspect those big exides still have >90% of the capacity they had when new, there isn’t a li-on on the planet you can say that about.

Unless you drop a spanner across the terminals and refuse to vent them lead acid are safe, they won’t spontaneously combust like lithium.

Ford / Toyota / Honda / Renault etc etc etc are masters at saving money, if it saved them 5 cents per car every car would come with a li-on main battery, but they all come with lead acid.

Similarly if they could fit a 30 amp alternator instead of a 60 they would do it in a heartbeat, so they do not just care about loads, they care about charge cycles and power quality too, as well as charge retention and cold cranking amperages for at least three years from point of sale.

This is especially true for all modern cars with start stop engines.

This (economy) is why we are still on 12 VDC for autos and 24 VDC for wagons and many boats, 32 VDC for some yank boats, the old 110 VDC stuff has gone the way of the dinosaur.

I know of any number of people who have bought hugely expensive allegedly extreme quality li-on batteries for harleys (you wanna crank a high comp 1700 cc v twin from cold?) and I do not know of any except one who has stuck with them, they all failed…. maybe the vibes, maybe the parked leaning, maybe the usage cycles, who knows, everyone with a clue buys a Yuasa lead acid..

And this is when the “reservoir” is only an ancillary thing, not a prime power source.

Efficiency, I recently read a story, about a hunter and predator, and it made the point that by far the most deadly prey was the one that contained 100,000 kcal when you eat it, but which you expended 101,000 kcal to catch and kill.

The fat bastard creature you could feed on for a week was no problem.

Efficiency is a cumulative thing, so you always always always need to look at both individual processes and the over all picture, making 5 sub processes 86% efficient instead of 85% efficient is a dead loss if you have to introduce another process to make it happen, fewer less efficient steps are better overall.

The single combustion inefficiency of the IC engine can win overall.

The simple transmission losses of a grid and huge nuke plant can win overall

An electric tram running ob overhead cables will beat any and every “battery / local reservoir” EV, because everything else that you can do to the EV, you can do to the tram.

Diesel and petrol buses beat electric trams and buses economically, for one reason only, the cost of the power grid.

NO EV SUMS I have ever seen figure in the cost of the power grid.

I could say the same for wind and solar, neither one is base load so neither one counts, adding a reservoir to wind and solar doesn’t make them better, it makes them worse.

“Worse” works if you are at sea in a 200 foot hull and have no other options, in every other instance it will kill you stone dead, same as the lion trying to stay alive catching mice….