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Tesla Energy

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351–360 of 590 posts

Re: Tesla Energy

#351
post #46

The maximum temperature will be an issue here in Australia. In a typical place where it will be mounted, i.e. the garage, the temperatures will readily get over 40, close to 50 during summer. I could see this also being a problem in places like Nevada and Arizona in the USA.

If your garage is getting to 50°C you've got a major insulation problem! Where are you located? In both cases if min and max operating temperature are an issue it may be best to install in an FIP enclosure and use ducting to keep the enclosure and an optimal temperature.

My garage door faces the southwest meaning it gets hit by the sun for a good chunk of the day. It easily gets to 120F during a Houston summer in there.

Re: Tesla Energy

#352
post #15

Earlier quoted context omitted.

I'm intrigued at the backup possibilities, because we live in a forested area of the northeast where outages are common during storms. But at 3Kw a single unit isn't large enough to power our entire home, and I didn't see a figure for how long it can operate at peak load. If I need two then we're getting closer to the cost of a natural gas fired generator. This analysis, of course, is completely ignoring the environm…

can we just try living without electricity for 2 days? millions of humans did it for hundreds of years prior to us and they managed just fine

During hurricane Sandy our family was without power for 12 days. What's the longest you've gone?

Re: Tesla Energy

#353
I felt the 'area needed in the US' to be a bit disingenuous. I very much recommend David Mackay's Without the Hot Air, a great talk he did at Harvard on area required can be found here:

https://www.youtube.com/watch?v=GFosQtEqzSE

Beyond that, very glad to see this happen. It's one of the factors necessary to push a sustainable electrified future forward.

Re: Tesla Energy

#354
post #280

Earlier quoted context omitted.

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.

Just make sure you prepare your evening meal at noon in the Winter... Solar ovens are not a practical means of cooking unless you've dedicated your life to being off-grid and have few other obligations.

Re: Tesla Energy

#355

Funny that something called Tesla Energy brings back direct current to the home. I wonder how many people will catch that.

I wonder if technology becomes prevalent if we will see appliances change to run on DC.

I would take a wall plug standard for low current DC. If I have a giant battery pack in my garage full of DC, why do I need to convert it back to AC to run 15 feet into my house where it then gets turned back into DC to charge my phone & laptop?

I had a boat with both AC & DC sockets, but we had the normal socket for both and the label plates showed you which was which. I don't think that solution is acceptable for the wider marketplace, the plugs should probably be physically distinct. Maybe USB-C is the solution, though I don't know how long the cables can be.

Re: Tesla Energy

#357
post #124

Earlier quoted context omitted.

But they could now, and most deep cycle lead acid batteries are flooded, not sealed, which means they have to be ventilated to prevent hydrogen explosions hazards. Not so with Tesla's offering.

Fine. 4.8kW Li-Ion battery for USD$3,278 1.9kW for USD$1,678. My point is that Tesla isn't really doing anything really unique here. Sure, they're giving it more press than anyone really has before, but the products aren't especially cheap, innovative or special. http://ironedison.com/12-volt-lithium-battery-for-solar

Tesla is selling over double the capacity of your quoted 4.8kWh system for about the same price, and you say it's not especially cheap?

Re: Tesla Energy

#358

What I'd love to see is a ROI calculator that: * uses my zip code to figure out what my non-peak costs might be. * allows me to optionally calculate solar energy capture (so I can see what impact having solar would be, given the average sunny days in my area) * takes into account the wear and tear average cold weather would have on the lifetime of the batter and the payback period. For example, I live in Michigan, an…

I would guess for most people it would show an ROI number that is not conducive to sales. Also, what is the environmental impact of the manufacture of LI batteries at this scale? Lithium mining, processing, assembly, delivery... we can't just ignore that.

The environmental impact shouldn't be significantly more than any other hunk of metal of the same mass. And that has to be weighed against the fact that cost-efficient battery technology can make solar/wind viable and cost-effective relative to fossil fuel plants.

Re: Tesla Energy

#359

While I think this announcement is great news, there are at least two caveats to keep in mind that can mine the long term value proposition: - If there are many users, the peak/non-peak price differences (arbitrage) will disappear. This is because of supply/demand law. - If solar energy/battery storage takes off, it will be heavily taxed. There is an impending "Sun tax" being implemented in Spain, that aims to make m…

Your analysis of the arbitrage is faulty - if there's a cost associated with time-shifting energy, then the gap will only narrow to the extent that it's still economically justifiable for people to invest the money in time-shifting energy. What you're describing (no peak/non-peak difference plus people still buying batteries to time-shift energy) isn't a steady state - why would people continue to buy the batteries when they're going to lose money on the deal? You'd actually expect the gap to be the price difference per watt plus some additional amount for the capital and inconvenience.

Also, if there's significant arbitrage, it will also reduce peak prices - because of reduced demand, and also because of reduced costs of expensive additional capacity. I.e. it can reduce energy costs for people who don't use it.

Re: Tesla Energy

#360
post #92

Earlier quoted context omitted.

2 is not enough. 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 inverters seem to be around the $1000 mark… but they don't seem to increase linearly (10kW inverter $4000 for example). Of course you could go totally off-grid, but the cost isn't going to be just $7k… it's likely to be at least $15-20k by the time you get everythin…

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

Is it that crazy? The amount of energy you'll spend on an electric oven isn't that large, relative to your overall consumption, unless you run a bakery or have somebody in your house who does nothing but make cookies and bread all day.
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