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dpack

local/domestic energy storage

this seems a good development,they are a bit expensive but if they are serious about producing a couple of billion of them i suspect the costs will drop.

there are other developments in battery tech but this crew do have the ability to go for mass production quite quickly.
henchard

um......... now I could store my generated solar during the day and put it back through the generation meter at night.

There's probably a flaw in that plan somewhere!
Hairyloon

These looked promising.
dpack

the velkess ones are quite big and heavy compared to the paypal chaps offering.

from the few bits i have heard about battery tech developments it might be that before they make 2 billion of them they could be using a better design and they will store ten times as much for the same size and cost

i suspect batteries are subject to a version of moore's law of pooters
Hairyloon

Velkess are flywheels, not batteries.
Tavascarow

Another link for an article on Tesla battery. $3,000 for a 7kw battery with a ten year guarantee (plus installation). That's only $300 a year. Shocked How much do you want to bet it will be more than double that when it's released in the UK?
Even then it's a good investment IMHO. I know people who spend 300 a quarter on leccy.
Hairyloon

Excuse my lack of faith in battery reliability: it needs to last at least 10 years doing a full cycle or less every day.
dpack

Velkess are flywheels, not batteries.


yep big and heavy
Hairyloon

But not plagued by chemical breakdown, or whatever it is that kills batteries.
RichardW

Another link for an article on Tesla battery. $3,000 for a 7kw battery with a ten year guarantee (plus installation). That's only $300 a year. Shocked How much do you want to bet it will be more than double that when it's released in the UK?
Even then it's a good investment IMHO. I know people who spend 300 a quarter on leccy.


See my reply to your other post.

300 per quarter is 3.28 per day or 23kWh per day at 14p per unit. A 7kWh unit is not going to replace that 300 a quarter bill. You need 3 of them, still think its a good investment? Oh & with a 92% efficiency (which I doubt) the saving from the 14p per unit is not 3p as expected but 1.12p.

So with 3 units at 3k each you will have to use 803571 Kwh to break even. At 23 units per day thats 34937 days or 95 YEARS.
dpack

my "bit expensive"seems an understatement when i see your maths .

how long til battery tech will do the job at a reasonable price ?
Hairyloon

Oh & with a 92% efficiency (which I doubt) the saving from the 14p per unit is not 3p as expected but 1.12p.
From where are you deriving those figures for savings?
Tavascarow

Another link for an article on Tesla battery. $3,000 for a 7kw battery with a ten year guarantee (plus installation). That's only $300 a year. Shocked How much do you want to bet it will be more than double that when it's released in the UK?
Even then it's a good investment IMHO. I know people who spend 300 a quarter on leccy.

See my reply to your other post.

300 per quarter is 3.28 per day or 23kWh per day at 14p per unit. A 7kWh unit is not going to replace that 300 a quarter bill. You need 3 of them, still think its a good investment? Oh & with a 92% efficiency (which I doubt) the saving from the 14p per unit is not 3p as expected
but 1.12p.

So with 3 units at 3k each you will have to use 803571 Kwh to break even. At 23 units per day thats 34937 days or 95 YEARS. But if you are being paid to generate through FITs & can store the majority of your solar arrays production for use in the dark wee hours when we most need, it makes sense. Even if that only replaces a quarter or third of what some people use. & they aren't 3k they are $3k or $3.5k for a 10 Kw.
Exchange rates as they are that's not a lot of money. How much would a similar lead acid deep cycle system cost, how much maintenance, & how long a lifespan in comparison?
This is a major advance IMHO.
vegplot

There is no realistic local energy storage system that has acceptable efficiency with perhaps the exception of pumped water. The best option is to use at the point of use unless your investment in renewables is so low as to make it viable. We are still years away from this utopia but it's a goal worth achieving. Hairyloon

There should be incentives like FIT for energy storage systems.
It does occur to me that you could be naughty and store the energy then feed it back through your generation meter, but of course that would be fraud...

On cost effectiveness though, my electric is about 15p/kWh, if I switched to an economy seven tariff I could get it for less than half that, so potential savings of about 7p/kWh...
Would still take a -ing long time to pay for itself though.
RichardW

There is no realistic local energy storage system that has acceptable efficiency with perhaps the exception of pumped water. The best option is to use at the point of use unless your investment in renewables is so low as to make it viable. We are still years away from this utopia but it's a goal worth achieving.


This says it all.

If you are on grid then any current storage system will not be cost effective.

Even pumped water only works as they buy the cheapest elec possible in the middle of the night for far less than you & I can pay (around 1p) & then sell it as a load balancer at the highest levels again for more than you & I buy it for.

Just because you have made the elec does not mean its viable to store it. Take FLA (thats standard lead acid batteries) systems. They cost 8p per kWh used in battery replacement alone.
Mistress Rose

Developments in electricity storage are interesting and it is the next step in the renewables story. Without storage, intermittant production is the main problem. As you have already said, these batteries will be superceded within a few years, but the main interest is that money is being put into battery development, so there could be a major improvement in them in a fairly short time. RichardW

If you want to use all your locally made elec on site then get an Emma or similar & turn it into hot water. dpack

storing electrical energy as heat is a fairly good option if you need heat.

there have been attempts to use air compression as an energy store but this is not very efficient
Tavascarow

There should be incentives like FIT for energy storage systems.
It does occur to me that you could be naughty and store the energy then feed it back through your generation meter, but of course that would be fraud...

On cost effectiveness though, my electric is about 15p/kWh, if I switched to an economy seven tariff I could get it for less than half that, so potential savings of about 7p/kWh...
Would still take a -ing long time to pay for itself though. & if you charged a battery on low tariff to use on high would that be fraud? I doubt it.
I thought you where paid feed in tariff on the amount you generate (estimated in most cases) not what you exported. I know a lot of newer systems are fitting smart tech to divert excess to water heating when not needed elsewhere, they still get the same amount of FIT, or am I missing something here?
Hairyloon

There should be incentives like FIT for energy storage systems.
It does occur to me that you could be naughty and store the energy then feed it back through your generation meter, but of course that would be fraud...

On cost effectiveness though, my electric is about 15p/kWh, if I switched to an economy seven tariff I could get it for less than half that, so potential savings of about 7p/kWh...
Would still take a -ing long time to pay for itself though. & if you charged a battery on low tariff to use on high would that be fraud? I doubt it.
Sorry, did I blur two thoughts into one there? Perhaps I should've done two posts.

Quote:
I thought you where paid feed in tariff on the amount you generate (estimated in most cases) not what you exported.

Yes, but if you generate it and pass it through the meter into the store, then you get paid, and if you pass it through the meter again when you take it out of the store, then you would get paid again (until you got caught).

It is just a hypothetical idea, I wouldn't dream of actually doing it. angel5
RichardW



Yes, but if you generate it and pass it through the meter into the store, then you get paid, and if you pass it through the meter again when you take it out of the store, then you would get paid again (until you got caught).

It is just a hypothetical idea, I wouldn't dream of actually doing it. angel5


You would soon get caught if you were making more than your system should be.
Tavascarow

Report in Forbes re Tesla battery.
dpack

interesting article ,the comments are rather mixed .

if the equation and maths is correct the 20 cent(us)price per kw stored is getting close to grid prices but not there yet.
for places with no grid it seems a bargain.

the price is based on start up prices and there is a fair chance that the cost per kwh stored will drop considerably
vegplot

Tesla is about advancing the technology. It's innovative and in the right direction a little like successful landing of SpaceX's first stage. It's yet to happened but I applaud the effort being made to make it so. john of wessex

The real issue is how many cycles the battery can cope with.

If you pay -say 1000 for a battery with a 1000 cycle life then it costs you 1 per cycle.

In the UK of course what about winter when a Solar PV isn't producing much if anything? The obvious use woud be to allow the batteries to be charged in the off peak & used to supplement supply at peak periods.

There is an interesting article at

http://www.lowtechmagazine.com/2015/05/sustainability-off-grid-solar-power.html
Tavascarow

The real issue is how many cycles the battery can cope with.

If you pay -say 1000 for a battery with a 1000 cycle life then it costs you 1 per cycle.

In the UK of course what about winter when a Solar PV isn't producing much if anything? The obvious use woud be to allow the batteries to be charged in the off peak & used to supplement supply at peak periods.

There is an interesting article at

http://www.lowtechmagazine.com/2015/05/sustainability-off-grid-solar-power.html The Tesla battery comes with a ten year warranty & options on an extended warranty. I haven't seen any estimates on how long it will last but if they are prepared to offer warranties that long they must be confident to its longevity. dpack

pv and wind are a bit patchy in many locations but there are local scale constant feed options such as moving water that could even up the curves .

perhaps the grid is a good place to start from

local grids that include battery racks might be a workable goal.

i still recon battery tech will develop rapidly
RichardW

The Tesla battery comes with a ten year warranty & options on an extended warranty. I haven't seen any estimates on how long it will last but if they are prepared to offer warranties that long they must be confident to its longevity.

Warranties do not cover you for abuse. Most batteries are murdered by user abuse not die from manufacturing defects or natural wastage. Oddly they claim that a Lithium Ion batty has a float life of 14-16 years. So that is its max life time even if not cycled at all. I would be very interested to see just what is written in the warranty. I'm betting most of the warranty is to cover the electronics & that bats are considered a consumable which is the normal case.
Hairyloon

I would hope that a system like that is designed to be idiot proof and incapable of self-abuse. RichardW

Never underestimate the ingenuity of an idiot. vegplot

The cost of electric car battery production is falling much like solar PV has done...
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