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.
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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.
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Hairyloon
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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.
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RichardW
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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
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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.
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RichardW
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If you want to use all your locally made elec on site then get an Emma or similar & turn it into hot water.
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dpack
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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
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Tavascarow
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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
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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.
RichardW
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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. |
You would soon get caught if you were making more than your system should be.
Tavascarow
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Report in Forbes re Tesla battery.
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dpack
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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
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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.
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john of wessex
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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
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Tavascarow
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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
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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
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RichardW
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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
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I would hope that a system like that is designed to be idiot proof and incapable of self-abuse.
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RichardW
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Never underestimate the ingenuity of an idiot.
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The cost of electric car battery production is falling much like solar PV has done...
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