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Batteries: How cheap can they get?

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Re: Batteries: How cheap can they get?

#221

Post by moffkalast »

iamthemonster wrote: post #135
oezi wrote: post #119

Earlier quoted context omitted.

Unlikely that you need more than 10kwh. You just want to cover morning and evening electricity consumption. During the day you recharge and consume directly.

Absolutely agree - I think people fall into a major fallacy with sizing their battery systems. Their power consumption probability* distribution is skewed, and they think their battery needs to be sized for 99% or 100% of their daily consumptions. This gives a drastically oversized battery. Instead, a simple approach is to download the daily power consumption for a year and size the battery for about your 80th-90th p…

It depends on how many cloudy/winter days you want to be proof for right? There needs to be some backup capacity for when you won't be able to fully recharge for weeks on end.

Although I suppose it is cheaper to oversize solar and not the battery, but that's usually already maxed out and limited by roof space. Maybe a small wind turbine to compensate for stormy days...

Re: Batteries: How cheap can they get?

#222

Post by nicois »

iamthemonster wrote: post #137
denkmoon wrote: post #120

Earlier quoted context omitted.

Some people cold knocked on my dad's door and 3 weeks later he's got a wall of batteries in the garage. Rural Australia. So yeah, there are businesses that'll do it.

Australia has become SO competitive for solar and battery installation you can actually be fairly safe nowadays just picking any old supplier that has >4.7* on google and there'll almost definitely be Going with a door knocking sales rep for home batteries would be madness in most countries but chances are pretty good that in Australia you would get a perfectly decent product.

Despite what you get in Australia being pretty reliable, it's too expensive to justify quite yet. My 8kW solar is connected to a Fronius inverter, but until I find a less expensive option I can justify adding a battery.

A 13kWh system is over $AUD10k, and the ROI is on par with the expected lifespan of the battery.

If sodium cells can bring the price down to $AUD100 it would indeed be a massive game changer.

Re: Batteries: How cheap can they get?

#223

Post by SergeAx »

> stormy electricity grid

For me (living in Europe), stable 220V 50Gz from any wall socket is one of the traits of civilization, like potable water tap and flush toilets. "Stormy grid" is something from a rural village lifestyle, with a water well and a cold basement to keep winter food supply. Is it really that huge problem in parts of US?

Re: Batteries: How cheap can they get?

#224

Post by roygbiv2 »

unwind wrote: post #210
selcuka wrote: post #147

Earlier quoted context omitted.

> P.S. I've never heard of sparky being used as slang for an electrician, sounds very aussie. When I moved into a new house in Australia I asked the real estate agent if I could extend the fence, and he said I'd need a cheapie to do that. I said ok but scratched my head as to why it needs to be cheap, only to find out later what he actually said was chippy, slang for a carpenter.

Why, though? Is there some kind of requirement that only fully trained carpenters can build fences?

Just about everything in Australia needs a license to do. Even down to network cabling.

Re: Batteries: How cheap can they get?

#225

Post by Dylan16807 »

kolinko wrote: post #85
dgacmu wrote: post #57

Earlier quoted context omitted.

Over provision the panels by a good margin and have them at a more southerly angle (for northern hemisphere). You can play around on nrel pvwatts to see what configuration produces the most even expected monthly output: https://pvwatts.nrel.gov/pvwatts.php Most solar charge controllers allow a certain amount of PV overprovisioning.

In central/northern Europe in january solar goves 10% of the output of summer, and you need 3-4x power to heat compared to cooling down in summer.

Where in central Europe is it 10%? And you get extra in summer, the actual overprovisioning is when you compare to the equinoxes.

Re: Batteries: How cheap can they get?

#226

Post by Dylan16807 »

moffkalast wrote: post #110
oezi wrote: post #78

Earlier quoted context omitted.

Current European/German prices for home storage of 2-10kwh are at 400-500 EUR per kwh. https://geizhals.de/?cat=bmseswresp&sort=t&hloc=at&hloc=de&v...

So... about 30k for 60kwh to cover 30kwh daily use with solar charging, and probably another 10k for installation. Hmm yes super cheap, might impulse buy later.

> Hmm yes super cheap, might impulse buy later.

It's part of a house. Of course it's not an impulse buy. That's not a useful basis for comparison.

Re: Batteries: How cheap can they get?

#227

Post by defrost »

lazide wrote: post #215
defrost wrote: post #207

Earlier quoted context omitted.

Sure, you're saying some people shouldn't DIY. Where I live many people DIY as a great many people have mad skills (lots of FiFo workers making a good living from O&G installions and big mining projects). They build their own houses, their own planes, off grid power systems, water proof EV's to drive across harbour floors, etc. If you've got a big (shipping container sized) battery pack you need a big thermal blanket…

No, you’re talking about building structures. I’m talking about assembling a bomb. A 5kwh battery contains about 18MJ of energy, equivalent to 4.3KG of TNT. Short that out or puncture on of its component pouches, and it’s going to be very dramatic. One of them requires a different degree of care than the other.

You're still making the same irresponsible and frankly silly generalisation about "average" people.

Most people, full stop, don't build houses, metal work shops, treat their own sewerage, build their own power systems, etc.

So "average" people just don't start fires or set off bombs because they're not doing anything that dangerous.

Of the people that do, say, build their own glass furnaces, annealing ovens, laying out gas lines and installing small truck sized propane tanks with more energy than a 5kwh battery .. easily less than half, well below the "average" number of people that do such things, have accidents.

Sure, some people do watch Forged in Fire and have a go at knife making in a home built furnace, and then set fire to their barn | house | shed.

Most people don't try, and of those that do have a go most of them don't screw it up.

The point being, this:

> Also prone to average people setting themselves or their houses on fire, eh?

is just silly.

Average people don't attempt this, and of the people that do attempt such things most don't cock it up.

Perhaps your personal experience differs.

Maybe you can't dig your own septic system and fit it out without shit running back into your house.

Re: Batteries: How cheap can they get?

#228

Post by Dylan16807 »

moffkalast wrote: post #221
iamthemonster wrote: post #135

Earlier quoted context omitted.

Absolutely agree - I think people fall into a major fallacy with sizing their battery systems. Their power consumption probability* distribution is skewed, and they think their battery needs to be sized for 99% or 100% of their daily consumptions. This gives a drastically oversized battery. Instead, a simple approach is to download the daily power consumption for a year and size the battery for about your 80th-90th p…

It depends on how many cloudy/winter days you want to be proof for right? There needs to be some backup capacity for when you won't be able to fully recharge for weeks on end. Although I suppose it is cheaper to oversize solar and not the battery, but that's usually already maxed out and limited by roof space. Maybe a small wind turbine to compensate for stormy days...

> There needs to be some backup capacity

I think they're talking about the situation where you're still connected to the grid, in which case you don't need to handle the backup capacity.

Re: Batteries: How cheap can they get?

#229

Post by Gibbon1 »

taneliv wrote: post #199
gpm wrote: post #109

Earlier quoted context omitted.

Solar panels are mildly more efficient when colder, the same latitude in an area with similar cloud cover in north America is probably generally slightly better for solar than Europe because it is colder, not sure if it would ever be more than a rounding error though.

The difference between surface solar radiation levels in the US and Europe are wild[1], fully agree on the rounding error view. Anchorage seems to receive the same level of watts per area as Germany and Poland. [1] https://1.bp.blogspot.com/-I5kzJIeV4Ds/VFSHUX3374I/AAAAAAAAA...

Amusing southern California is getting more watts per m2 then A lot of North Africa.

This is a good source, population by latitude.

http://www.statsmapsnpix.com/2021/11/world-population-by-lat...

Re: Batteries: How cheap can they get?

#230

Post by Dylan16807 »

SoftTalker wrote: post #46
jonathanlydall wrote: post #30

Earlier quoted context omitted.

Aside from it benefiting energy companies, is there any justification for such a law? In South Africa we’ve had load shedding on and off since 2008. It’s becoming pretty standard for middle class homes to have inverters with batteries and optionally solar. It does create an issue though that when a load shedding window ends, a whole lot of batteries start charging all at once (especially during non-daylight hours). A…

Utilities get a local monopoly and guaranteed tariffs in exchange for the considerable investment in building out the supply grid and generating capacity, and the obligation to maintain it. If individuals are allowed to opt-out, that changes the financial promises made to the utilities. Of course this was mostly done at a time before it was economically feasible for anyone to go off-grid with solar and batteries. I q…

They said it's illegal to install a grid-charged battery backup.

How is that opting out of the grid?

Are you sure you're answering the question that was asked?

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