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Comment: Re:Backup Generator replacement? Not so much (Score 1) 250

by Luckyo (#49612167) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

Because snow happens for extended amounts of time every year in relevant regions which are huge, whereas huge earthquakes happen only at faultline regions and only once a century or so.

Also, "severing pipelines" on regional level doesn't really matter in case of earthquake for single household in case we're discussing. If you get severed connections from disaster, chances are that you either leave the region if roads are still operable and logistics work until basic damage control has been done by emergency services, or they are too damaged to allow you to leave and you're stuck and limited to what you have directly on site.

In which case, you likely have far more energy in a single tank of your ICE generator than in a battery bank.

Comment: Re:wow. 2 stories about Tesla/Musk (Score 1) 250

by Luckyo (#49611553) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

Considering the existence of residential flooded cells and VRLA batteries for decades and the fact that they absolutely destroy these li-ion batteries in all relevant factors except weight, I'd say you're barking up the wrong tree.

It's more about "ignorant people that didn't know battery backup for residential and small business existed for decades and is far more efficient than these batteries" vs "people who know battery backup for residential and small business existed for decades and is far more efficient than these batteries".

Considering the fact that instead of actual hard numbers, initial release mostly focused on how pretty said batteries look, it's pretty obvious who they are going to be marketed towards however.

Comment: Re:So your house has no A/C? (Score 1) 250

by Luckyo (#49611523) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

Sun's thermal radiation heats roof, thermal energy goes into attic though the roof, there is no active cooling in the attic other than the fan that kicks in at 43C.

That is how thermal energy works. Just because temperature in well ventilated shady area is 23C doesn't mean that it's going to be the same in well lit enclosed space.

Which incidentally is likely to be the site of battery installation.

Comment: Re:Lead Acid (Score 1) 250

by Luckyo (#49611485) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

Factually incorrect on all accounts. VRLAs are sealed and do not discharge significant amount of H2 outside of the individual sealed cell. Lead wear and tear is also minimal in residential use as batteries can have far greater capacity (than say li-ion for the same cost).

Finally realistic discharge rate for lithium batteries is about the same as lead. The only way to hit the numbers you suggest is to have minimal discharge on li-ion, in which case acid-lead will likely be able to match them.

Which is why warranty for typical VRLA is the same one as Tesla is willing to give it's li-ion batteries - 10 years. With exchange costs being massively in favour of lead-acid.

Comment: Re:Uh, no. (Score 2) 250

by Luckyo (#49611423) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

There are plenty of companies on the market that sell the entire systems with either VRLA and flooded cells, including the hook up and the inverter. Which is profitable not only because lead-acid absolutely destroys everything else in the market when you care about cost, capacity and safety but not weight, but also because control electronics for lead-acid are much cheaper than those needed for li-ion.

Comment: Re:Well in some cases you can't have one (Score 1) 250

by Luckyo (#49611361) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

If you want one, just get residential VRLA battery system. Minimum fuss with maintenance and control electronics, costs significantly less than li-ion for the same capacity, is more efficient than li-ion and there are plenty of companies that have well proven residential VRLA backup batteries in their inventories.

Or if you don't mind the fuss, just get the wet cells. Even cheaper and more efficient but require some regular maintenance.

Comment: Re:Backup Generator replacement? Not so much (Score 1) 250

by Luckyo (#49611329) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

Inefficient in comparison to what? Batteries that waste significant amounts of energy on being charged and then even more on discharge?

I can understand the comparison to things like large plants with burners rated in multi-megawatt range, but that's not what we're talking about, is it?

Comment: Re:Last Sentence... the point of this exercise. (Score 1) 250

by Luckyo (#49611251) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

We're not even close. Lead-acid is way ahead in everything except energy density. You don't need to deep discharge if battery you get for the same cost has far more capacity than li-ion could ever hope to be, with far cheaper control electronics, is far more efficient and so on. As long as you don't care that it weighs far more than li-ion (which you don't in most homes), there is no reason to pick li-ion over VRLA battery.

Comment: Re:Last Sentence... the point of this exercise. (Score 1) 250

by Luckyo (#49611207) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

We already have different chemistry batteries for use in those things. You have special kinds of lead-acid (typically valve-regulated lead acid for safety reasons) for home use and we're testing sodium-acid for utility use. And then you have flooded lead acid for cheapskates that don't care about maintenance intensity.

All of them utterly destroy li-ion in all relevant factors except one very important in mobile applications - weight per energy stored. That is why it doesn't make sense to use li-ion in applications where mobility and low weight are not key considerations.

Comment: Re:Last Sentence... the point of this exercise. (Score 1) 250

by Luckyo (#49611151) Attached to: Tesla's Household Battery: Costs, Prices, and Tradeoffs

Actually it seems more about the fact that "gigafactory" which was supposed to produce massive amounts of li-ion automotive batteries is being ready at the time when we have oil price that is less than half of one it was planned for.

As a result, EV sales are down, and factory needs alternative markets for production.

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