161–170 of 187 posts
Earlier quoted context omitted.
Utilities are actually planning on using parked electric cars for storage. https://en.wikipedia.org/wiki/Vehicle-to-grid
Wouldn't this wear out the battery life?
Earlier quoted context omitted.
Utilities are actually planning on using parked electric cars for storage. https://en.wikipedia.org/wiki/Vehicle-to-grid
Hell no! As soon as someone departs for a long trip and the battery isn't charged, there will be a huge class action lawsuit. The lemon law attorneys will also have a field day! This is a really dumb idea.
As you plug in your car, you set the time you need it charged, then you charge for a discount for your cooperation.
If you change your mind and use the car earlier than expected, you know what you signed up to. No need for a lawsuit.
Earlier quoted context omitted.
Wow - that's a crazy amount of energy. As a Brit who's never been the south of the US, is that figure really true? 100kWh is about 300 miles in a Tesla, or boiling a kettle constantly for about 30 hours. If that's really accurate, then I'm staggered at how much energy folks must be using to keep cool, and makes my efforts at saving energy seem paltry in comparison.
I can't find where the site now, but there was a fairly compelling argument that it was overall still more energy efficient for people to live in Arizona and AC dropping the temp from 90F to 70F than to live in a northern state where for 6 months out of the year you have to heat the house from 20-40F up to 70F.
A/C efficiency ("power factor") is measured using the ratio of heat (energy) moved outside to the amount of energy put into the air conditioner , which is usually >> 1 unless there is a huge temperature difference between inside and outside.
An ideal furnace has a 1:1 ratio of heat energy injected into the house to energy used to run the furnace. Heat pumps can get over 1:1 ratios, but come with caveats and are more expensive than A/C units.
Also, you can make it feel cooler with a dehumidifier, which often is more efficient than cooling. For furnaces, you need a sweater, but your article assumed a 70F indoor target.
Earlier quoted context omitted.
didn't they change it to three shifts to reduce injuries because of human error from being tired
God I hope so. Ford figured this shit out over 100 years ago... 3 shifts maximized factory output. Also having 5 day vs 6 day work weeks didn't significantly reduce factory output, but helped significantly reduce turnover. I swear, it's Musk's biggest weakness, not realizing the costs of mistakes people make when they're tired. I couldn't get through his recent biography because I kept seeing mistake after mistake be…
William Bratton, who headed the NYPD (twice) and the LAPD, was big on this. When he first started running the NYC transit police, he'd get on the subway late at night and ride around, talking to the cops on duty. Once the rank and file got used to seeing the commissioner on the subway, things started to improve.
A useful test for your local police department in a city of any size - find out who's the highest ranking cop on duty at 1 AM on a Saturday morning, peak time for most city PDs. If it's a lot lower rank than who's on during the day, the department is not well managed. Such police departments are derisively called "9 to 5 departments" in the business.
Earlier quoted context omitted.
In the last three decades battery technology was mostly about powering small, lightweight gadgets. Now that there's massive amounts of money to be made with car batteries and grid-level storage, I certainly expect some great battery technologies that focus on that in the next decade or two. That's also why I don't care about all these fears about us not having enough lithium: nobody is going to power the world on lit…
> That's also why I don't care about all these fears about us not having enough lithium Who is afraid of that? Take a look at this: https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth... Lithium is #33, estimated at 20 ppm of the crust. We presently mine 64000 tons per year. It is more common than lead, which is #37 and only 14 ppm. Yet we mine 4.8 million tons of lead per year. Now examine boron. #41, 10 pp…
I suggest that something is wrong with your assessment.
Earlier quoted context omitted.
100 kWh/day is just incredible. The average consumption per person in the nordics is about 1500 kWh per YEAR.
That doesn't quite seem right: http://shrinkthatfootprint.com/average-household-electricity... (Interestingly Canada's per capita consumption is comparable to the US despite being much further north)
Earlier quoted context omitted.
> That's also why I don't care about all these fears about us not having enough lithium Who is afraid of that? Take a look at this: https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth... Lithium is #33, estimated at 20 ppm of the crust. We presently mine 64000 tons per year. It is more common than lead, which is #37 and only 14 ppm. Yet we mine 4.8 million tons of lead per year. Now examine boron. #41, 10 pp…
Lithium has gone up in price about six fold in the last 15 years and is currently about 4 times as expensive as lead per metric tonne. I suggest that something is wrong with your assessment.
I wonder how much of this is simply the Gigafactory coming online at full production + others trying to keep their factories running. If you look at Tesla's plan to be making 10,000 model 3's a week, with a nominal 90 kWh battery in each that is 900 MWh a week of capacity or 46 GWh capacity a year. But it is all tied up in cars of course[1]. The power companies have been screwing around with rate plans to keep grid-t…
In a way, electric car batteries have demonstrated to outlive their cars by 2x-3x (there are already several Teslas who were driven beyond median lifetime of a car and they lost just a few percent of capacity). So when i car is trashed, a battery is essentially still new. They can be bought out for say half the price and used for electricity storage. If there is a billion electric cars in the world instead of the current billion gas powered ones, and they are on average 55kWh of which 10% is lost while they are in a car, and another 20% is lost while they are used for grid storage, on average they will have 45kWh of capacity. Grid storage takes 6 hour capacity (pumped hydro plants usually have 6 hour storage, enough to compensate any daily cycles), so 7.5kW power per battery or 7.5TW overall... the world has 6.3TW of installed generation capacity.
Probably grid storage will be a side business of car makers because all storage plant will need to use same type of battery. Maybe they'll even offer like 10% discount on a new car on a condition that the battery is theirs and to be returned when a car is scrapped.
Earlier quoted context omitted.
If you have a look through some of the Google datacenter tours you'll see they actually implement this idea on a massive scale, though I believe they use lead-acid batteries... Every motherboard in the datacenter has a small battery capable of powering it for a long enough period of time for the backup generators to kick on and take over. It's definitely a clever idea! Makes maintenance much less risky as it's distri…
I guess the hardware does exist, but I was thinking of a different use-case for it: not for fault-tolerance per se (i.e. waiting for the power to come back on or the generator to kick in), but rather for giving the disk cache up to 30 minutes (after the rest of the machine is well-and-truly cut from power) to flush to the disk itself before finally shutting off, rather than a few seconds to empty its pending writes a…
Now, they use super-capacitors and a flash memory device to flush the volatile RAM buffers to flash memory, then on next power up the firmware can flush the flash buffers to disk. This all happens within the RAID controller so the host OS just thinks it already got write confirmation back when the PCIe transactions finished and the data blocks landed in the controller's RAM.
Earlier quoted context omitted.
> That wouldn't work for much of the South where summer usage for a house can easily hit 100 kWh/day for air conditioning. It should be noted that peak energy expenditure for air conditioning happens more or less at exactly the moment when the influx of energy from the Sun is also at its peak. That's, like, a gigantic hint that mother nature is dropping on you, hoping you'll notice it. The disease, and its cure, are…
From the grandparent's post: > "The hottest part of the day usually starts at about the end of the prime solar hours."
https://en.wikipedia.org/wiki/Diurnal_temperature_variation#...