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What does a kilowatt hour look like?
51–60 of 147 posts
Re: What does a kilowatt hour look like?
#52Earlier quoted context omitted.
You would get very little out of it. Enough to run a dim LED for a couple hours at most. If you did it in addition to (as opposed to instead of) your exercise then the energy in the food you ate is massively greater than what you can get from the bicycle. If you eat more as a result then you wasted your money.
It wouldn't be quite that bad. You're probably putting out something like 100-200W. Even factoring in generating and storage losses, you're looking at running a reasonably bright LED bulb for several hours on the proceeds of a 30-minute session. Still not worth the effort of building the equipment, of course.
200w seems for pro cyclists. 100w for above average sports fan. Today lots of computing devices fall under 10w power usage. Hence my daydream. For light or electric appliances that's another story.
Re: What does a kilowatt hour look like?
#53Less acronyms please. (COP, PV, and even EV)
COP: Coefficient of Performance. PV: Photovoltaic. EV: Electric Vehicle. TMDA: Too Many Damn Acronyms (It's a joke I heard at a company that had acronyms for everything).
We name different projects after Greek Gods + acronyms. The names can be pretty fun.
Re: What does a kilowatt hour look like?
#54Not related, but I hate this unit. Can't we just talk about Joules?
Horsepower ftw
Re: What does a kilowatt hour look like?
#55Earlier quoted context omitted.
SI prefixes FTW. 1kWh = 3.6 MJ
That has the opposite problem a 3.6 TJ per hour powerplant = 1 GW. Aka 1billion joules per second * 1 hour / 1 hour. Might as well just say 1 billion joules per second aka 1 GW then tack on or remove an hour if needed.
I don't think they were proposing using J per time as a unit for power, just for power instead of using W * time.
Re: What does a kilowatt hour look like?
#56Earlier quoted context omitted.
COP: Coefficient of Performance. PV: Photovoltaic. EV: Electric Vehicle. TMDA: Too Many Damn Acronyms (It's a joke I heard at a company that had acronyms for everything).
We name different projects after Greek Gods + acronyms. The names can be pretty fun.
"Where's Dionysus' Project Manager?"
"In a bar, somewhere.."
Re: What does a kilowatt hour look like?
#57Given how popular (and damn near impossible to discern) unsafe and unprotected lithium-ion batteries are, the idea of making a homegrown power wall terrifies me in ways I can't even begin to contemplate. An 18650 battery, if combusted, can produce hydrofluoric acid with just water vapor in the air (or the water in your lungs) if they use lithium hexafluorophosphate as the electrolyte. Hydrofluoric acid can and will c…
You have to realize that 1kWh is a lot of energy. Imagine being hit (in a world without an atmosphere) by a 60 pound suitcase falling out of an airliner flying at 45,000 feet. Same amount of energy as that battery pack. (Alternatively: the most powerful air conditioner you can buy running full blast for 30 minutes. Incidentally, that battery pack has as much energy as 100mL of gasoline, which is why gasoline-powered cars are so popular.)
When you put a lot of energy in a small space and release at all at once, it's called a bomb. Li ion batteries are small bombs that can be used to power electrical devices.
Some chemistries are safer than others, like A123 cells. The market did not care about safety and they went bankrupt. Energy density is king.
Re: What does a kilowatt hour look like?
#58Earlier quoted context omitted.
1kWh as aluminium is about 66g (assuming 15kWh per kilo manufacturing input) or about 4 drink cans.
Wow so I could gather up a bunch of cans and heat my house.
The key to batteries is being able to use the stored energy. Bonus points if you can add energy and get it back later.
Re: What does a kilowatt hour look like?
#59Earlier quoted context omitted.
As a reference point, a Tesla 85D uses 290 watt-hours to go one EPA rated mile. So 1 kWh takes you 3.448 miles.
> one EPA rated mile Are EPA miles not the same as normal miles?
just guessing, it's a standardized way to declare the driven distence, given all the variables.. such as: up hill, down hill, low/high rolling resistance surface?
Re: What does a kilowatt hour look like?
#60"So, what a kilowatt hour of high-grade electric energy can do for you? Many useful things, i.e.: deliver 4-5 kWh of low-grade heat (or cold) into your home (depending on COP of a heat pump)" Huh? I assume he means 0.4 - 0.5 kWh?
It's an air conditioner in reverse. You run your AC at 2kWh (or so) and you've heated the outside environment by more than 2kWh; otherwise your house wouldn't be cold, energy and heat don't magically appear or disappear.