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Tesla Energy

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Re: Tesla Energy

#271

Post by roel_v »

brc wrote: post #252
roel_v wrote: post #197

Earlier quoted context omitted.

" 4kW seems to be the maximum potential drain from the battery. That wouldn't power an oven… let alone anything else at the same time." 4kW is enough to power an entire home continuously, without thinking about energy use, even a large one with a home office with several people working in it + washing machine + oven + electrical stove at the same time . I have the data to prove it, too - 10 second interval power cons…

My air conditioner is 12 kW. No chance.

If your air conditioner actually draws 52 amps at 230 volts (or 110 @ 110 if you're in the US), you must be air conditioning a gym hall with a black, tin roof somewhere in a desert.

But you're probably not, and that was my whole point - my stove top is rated at 10kW, too, yet even when using alongside all other appliances in my house I have never gone above 4kW actual use. Actual need != summing all the nominal maximum rated loads of all appliances. In other words, it's not because your AC is rated 12kW, that you'd need 3 of these battery packs just for the AC. You might need 2, or maybe 3, I'm not saying that 2 (or 4) kW is enough always, everywhere for everybody - but there is no 'normal' (middle to upper middle class) home anywhere that would need 5 or 10 of these units, as is suggested at various places in this thread.

Re: Tesla Energy

#272

Post by meric »

IkmoIkmo wrote: post #251
meric wrote: post #196

Earlier quoted context omitted.

They can afford scooters, which cost one quarter that much. On $50 a day, it could be saved for in less than a year even if it costs $5000. Relative to their income, Indians have a lot of savings, due to their high savings rate (30%+). India's accumulated household wealth per adult is $5500. If you have two pairs of parents and one pair of grand-parents in one house, that is 6 * $5500 = $33000. Could be worth it, IMO…

You'll find about 50 million people in middle class in India, who'll earn about $1k a month. Once you buy it, ship it, install it etc, I think $5k is a pretty typical cost figure. That's quite steep. It's nearly 50% of your income. Also consider that as a rule, generally, the less affluent you are, the smaller percentage of income will be 'disposable' income. i.e. if you make $100k, you might have $60k in essential e…

True, and also it would have to compete with a typical generator using petrol.

Re: Tesla Energy

#273

Post by kragen »

brc wrote: post #252
roel_v wrote: post #197

Earlier quoted context omitted.

" 4kW seems to be the maximum potential drain from the battery. That wouldn't power an oven… let alone anything else at the same time." 4kW is enough to power an entire home continuously, without thinking about energy use, even a large one with a home office with several people working in it + washing machine + oven + electrical stove at the same time . I have the data to prove it, too - 10 second interval power cons…

My air conditioner is 12 kW. No chance.

Is that the output or the input? If it's the output (i.e. the amount of heat coming out of the condenser outside your house), the input might be only 5kW or even less.

(Probably some jackass is going to downvote me because they think this violates conservation of energy, but no — those 12kW coming out of the heat exchanger include the 5kW of electrical energy that went in, plus another 7kW of heat that’s being extracted from the air being conditioned; and if you were to try to run a heat engine off that 7kW of heat difference, you wouldn't be able to recover the original 5kW. All perfectly thermodynamically copacetic.)

Re: Tesla Energy

#274

Post by kragen »

brc wrote: post #252
roel_v wrote: post #197

Earlier quoted context omitted.

" 4kW seems to be the maximum potential drain from the battery. That wouldn't power an oven… let alone anything else at the same time." 4kW is enough to power an entire home continuously, without thinking about energy use, even a large one with a home office with several people working in it + washing machine + oven + electrical stove at the same time . I have the data to prove it, too - 10 second interval power cons…

My air conditioner is 12 kW. No chance.

Is that the output or the input? If it's the output (i.e. the amount of heat coming out of the condenser outside your house), the input might be only 5kW or even less.

(Probably some jackass is going to downvote me because they think this violates conservation of energy, but no — those 12kW coming out of the heat exchanger include the 5kW of electrical energy that went in, plus another 7kW of heat that’s being extracted from the air being conditioned; and if you were to try to run a heat engine off that 7kW of heat difference, you wouldn't be able to recover the original 5kW. All perfectly thermodynamically copacetic.)

Either way: have you thought about insulating your house or tinting the windows instead of using 120 energy slaves to desperately battle against the sun on your behalf?

Re: Tesla Energy

#275

Post by CHY872 »

IanCal wrote: post #204
hackerboos wrote: post #176

Earlier quoted context omitted.

Economy 7 power is significantly cheaper in the UK than peak power. Charging overnight in the E7 period could save money long term depending on the lifetime of the battery.

I did a quick bit of calculation on this. Assuming you use 10KWh per day and a perfect battery: Economy 7 KWh cost : 8.4p (Best deal I saw was 9.4 for me, but this was a figure on MSE) Standard tariff KWh cost : 14.5p (Best deal I saw was ~12 for me, but this was a figure on MSE) That'd be a £306/year cost on economy 7 and £530 on a standard, taking some more extreme figures. A $3500 (~£2300) battery would then have…

If you get 90% charge/discharge efficiency, you're multiplying the economy 7 tariff by 1/0.81 = 1.23456790 (so close) so it's more like 12.5 years, and a bit less compelling.

Re: Tesla Energy

#276

Post by watty »

ZoFreX wrote: post #261

This is a three-pronged stroke of genius: 1) Immediate benefits to just about anyone. If you have your own solar panels, you need this (or something like it). Even if you don't, you can benefit by drawing more power during cheaper off-peak times. 2) If lots of people get in on this, we'll have the storage capacity we need on the grid to be more dependent on renewable energy. Lack of storage capacity is one of the big…

I don't see how it's immediately beneficial for just about everyone. I currently have a flat rate for kWh and no solar panel... and moving soon. It's not worth the $. In 6 months I'll be renting for a year, still not beneficial. Perhaps in a couple years I can purchase solar, a battery, and an energy system that can automate some demand shedding but we're talking about 1%ers here.

In fact, I'd say it's only immediately beneficial to a minority.

Re: Tesla Energy

#277

Post by zachalexander »

SCAQTony wrote: post #80
TaylorAlexander wrote: post #64

Earlier quoted context omitted.

Some people (like me) are simply unwilling to keep using carbon-based sources of energy. At some point it just feels awful to be contributing to such a terrible problem. I'm counting the days till I can sell my worn out petrol car and get an electric car. If I had a home and dollars, I'd want one of these batteries.

Batteries are not clean; lithium mines are one ugly slight and recycling is difficult: http://whenonearth.net/awe-inspiring-aerial-images-worlds-me... In my clueless opinion these batteries should be used strategically in places where solar, wind, and hydro power are unavailable.

> Batteries are not clean; lithium mines are one ugly slight and recycling is difficult:

You are conflating two senses of "clean" that are radically different in meaning and importance.

-- Fossil fuels are !clean in that they may destroy all life on earth via catastrophic climate change.

-- Lithium mines are !clean in that they present waste disposal challenges and some people find them "ugly".

It's like saying "your non–blood diamond is still a blood diamond because the jeweler got a papercut while handling the documentation".

Re: Tesla Energy

#278

Post by timmaah »

dzhiurgis wrote: post #253
wtallis wrote: post #86

Earlier quoted context omitted.

Likewise for boats. It's high time we stop using lead batteries in vehicles where weight matters, and the pricing on this looks great .

I thought about boats as well. Do you know the weight and dimensions of this? It looks like it is equivalent to 835 Ah @ 12V. That is 10 lead batteries. You probably can buy more than 3 lead batteries for 300 dollars, but the weight and 10 year warranty does look attractive.

Those would be crap lead acid batteries at $100.

I have 500 Ah in 4 AGM batteries that cost me $1200. If all that 835 is usable I'd have to spend $3600 to come close with the same AGM's I'm using now.

Re: Tesla Energy

#279

Post by nkohari »

watty wrote: post #276
ZoFreX wrote: post #261

This is a three-pronged stroke of genius: 1) Immediate benefits to just about anyone. If you have your own solar panels, you need this (or something like it). Even if you don't, you can benefit by drawing more power during cheaper off-peak times. 2) If lots of people get in on this, we'll have the storage capacity we need on the grid to be more dependent on renewable energy. Lack of storage capacity is one of the big…

I don't see how it's immediately beneficial for just about everyone. I currently have a flat rate for kWh and no solar panel... and moving soon. It's not worth the $. In 6 months I'll be renting for a year, still not beneficial. Perhaps in a couple years I can purchase solar, a battery, and an energy system that can automate some demand shedding but we're talking about 1%ers here. In fact, I'd say it's only immediate…

A better way of looking at it is that it's immediately beneficial to anyone who owns real estate.

Re: Tesla Energy

#280

Post by kragen »

Dylan16807 wrote: post #180
Johnythree wrote: post #163

Earlier quoted context omitted.

The key to successful Solar Living is an understanding of energy efficiency. Suggesting running an electric oven on solar is crazy talk.

So if your main priority is carbon what do you do, use a wood oven?

Maybe a solar oven? Unlike Li-ion batteries and solar cells, you can make a solar oven without mass production and using materials fabrication technologies available 2000 years ago. (You can make it cheaper if you use modern mirrors instead of polished bronze.) Typical solar cells are 16% efficient; your pre-medieval-materials solar oven will be about 50% efficient.
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