Tesla to sell battery packs for home use

[electrodacus]

I do live offgrid and I do use Lithium for energy storage.
I'm also the developer of the Solar BMS a solar charge controller for Lithium (any type but I recommend LiFePO4)
That Tesla battery seems to be large enough is 10x the capacity of my main battery (but I'm more in to high energy efficiency than most people)
Form what I see in the photo they use the same or similar battery used in Nissan Leaf there are 4 cells in each of those metal box connected 2s2p 30Ah each cell for a total of 8.4V (fully charged) 60Ah that is around 0.5kWh and I see about 50pcs in that also see a 24 something on the other side so most probably 24kWh capacity.
My OffGrid battery is 10x less at just 2.5kWh and together with 3x 240W PV panels allow me 60 to 90kWh/month power consumption (good enough for me) but most people use up to 10x that so the Testla battery seems adequate capacity.

Here is a photo with my OffGrid Setup and a 7 day energy production / consumption graph.


   

[dannyf]

You guys are so not green.

Here are my energy storage devices: I chop two or three of them down each year and no need for all of your fancy stuff.

It is renewable, clean and most of all, greenest of the green energy your green dollars can possibly buy.

[electrodacus]

You guys are so not green.

Here are my energy storage devices: I chop two or three of them down each year and no need for all of your fancy stuff.

It is renewable, clean and most of all, greenest of the green energy your green dollars can possibly buy.

Can you prove that ? Also how did you post this message based on that energy source ?

[johansen]

Can you prove that ? Also how did you post this message based on that energy source ?

its amazing, even harvard scientists don't know that trees are not carbon sinks.

[miguelvp]

Energy from trees are considered zero emission because it's not trapped carbon.

And Harvard scientists know that.

[RJFreeman]

The graph below (hopefully) shows NSW power consumption 1st to 9th February 2011 (data from AEMO - http://www.aemo.com.au/ )

these dates are interesting because we had a cool change on the 6th and it clearly shows the difference in power consumption between hot days and much cooler days.
The interesting thing is that power demand (on hotter days) peaks around 3:00pm whereas I understand Solar power generation peaks a couple of hours earlier (this does seem to be supported by the graph from Electrodacus) so a couple of hours storage would help smooth that out.

now while as consumers we pay a fixed price for power AEMO determine pricing throughout the day and this price (per MWh) can vary between around $20 (at night when demand is lowest) and $2000 (when demand is around 14GW) so even if you just added a battery in theory you could buy power at 2C/kWh then store it to sell back at peak times on hot days at $2 per KWH and if you are a data geek you can find current and projected pricing at:

http://www.aemo.com.au/Electricity/Data/Price-and-Demand/Price-and-Demand-Graphs/Current-Trading-Interval-Price-and-Demand-Graph-NSW

[electrodacus]

now while as consumers we pay a fixed price for power AEMO determine pricing throughout the day and this price (per MWh) can vary between around $20 (at night when demand is lowest) and $2000 (when demand is around 14GW) so even if you just added a battery in theory you could buy power at 2C/kWh then store it to sell back at peak times on hot days at $2 per KWH and if you are a data geek you can find current and projected pricing at:

Not sure I get where you fount that $20/MWh to $2000/MWh ?
I can only see there a 3:1 fluctuation on price not 100:1.
 

[RJFreeman]

Not sure I get where you fount that $20/MWh to $2000/MWh ?
I can only see there a 3:1 fluctuation on price not 100:1.

the price starts climbing significantly once power consumption goes over 11-12GW, and over 13.5 GW it climbs even more steeply, while recent power consumption has been a leisurely 9GW or so peak (it has been humid, but not really hot in NSW).
So you do need to look further back to see where it peaks for example if you pull the CSV for NSW from Feb 2011 from say:
http://www.aemo.com.au/Electricity/Data/Price-and-Demand/Aggregated-Price-and-Demand-Data-Files/Aggregated-Price-and-Demand-2011-to-2015#2011
you can see where power prices really hit their peak on 1/02/2011 the price hits $5039.89 at 13:30, and by the time power consumption hits 14.525GW at 16:00 the price is at $12,136.
so you need a good hot summer to earn the serious money (and of course by then keeping your batteries cool may be an issue)

[electrodacus]

the price starts climbing significantly once power consumption goes over 11-12GW, and over 13.5 GW it climbs even more steeply, while recent power consumption has been a leisurely 9GW or so peak (it has been humid, but not really hot in NSW).
So you do need to look further back to see where it peaks for example if you pull the CSV for NSW from Feb 2011 from say:
http://www.aemo.com.au/Electricity/Data/Price-and-Demand/Aggregated-Price-and-Demand-Data-Files/Aggregated-Price-and-Demand-2011-to-2015#2011
you can see where power prices really hit their peak on 1/02/2011 the price hits $5039.89 at 13:30, and by the time power consumption hits 14.525GW at 16:00 the price is at $12,136.
so you need a good hot summer to earn the serious money (and of course by then keeping your batteries cool may be an issue)

I see what you mean but it seems extreme not sure what was the problem there. You can actually produce energy with about 3 cent/kWh from PV panels and the LiFePO4 storage cost around 20cent/kWh all this do not include cables controller inverters support is just the cost of amortisation for 1$/Watt PV over 25 years considering you can actually use all that energy and LiFePO4 battery storage varies from manufacturer to manufacturer it can be as low as 8cent/kWh stored over the life of the battery up to 25cent/kWh so it depends on how optimist is the manufacturer with the spec. I think 20cent/kWh is reasonable in my experience and knowledge about LiFePO4.
Here in Saskatchewan Canada electricity to consumer is sold at a fix rate It was about 11 cent/kWh about two years ago before moving offgrid but total bill is higher with some fixed costs so if you divided the monthly bill to kWh was about 20cent/kWh Canadian dollar but at the moment about the same value as Australian.
There are provinces with even lower cost of electricity in fact significantly lower.
I will expect price for electricity to drop and not rise in the future. Price of grid power was not my reason for moving OffGrid.
For me the amortisation cost will probably be the same as I paid when I had grid power but is not as convenient since you need to manage power consumption in a more active way.   

Here is a link with electricity cost in Canada is quite small especially in some locations https://www.hydro.mb.ca/regulatory_affairs/energy_rates/electricity/utility_rate_comp.shtml

[RJFreeman]

In NSW as a consumer we buy at a fixed rate, but not as cheap as that. either around 26c per KWH (without time of day metering) or if we move to time of day metering there are 3 different rates:
Peak - (2pm to 8pm, Monday to Friday) =  51.8C /KWH
Shoulder - (7am to 2pm and 8pm to 10pm Monday to Friday, 7am & 10pm Saturday/Sunday and Public Holidays) = 20.4c/KWH
off peak - ( 10pm to 7am, Monday to Sunday) = 11.2c/KWH
(https://secure.energyaustralia.com.au/EnergyPriceFactSheets/Docs/EPFS/E_R_N_RSOT-E_EA_01-01-2015.pdf)

Solar power we currently get paid 9c per KWH for excess power fed back into the grid (so if you use it you can save 20.4 to 51.8C but if you aren't at home during the day and feed pretty well all that power back into the grid you only get 9c)

The other prices are what the power generating companies get paid by the distributors and I am  being overly generous in presuming that a small scale generator would be able to get those sort of rates.....

The power grid in NSW is mostly coal fired power stations, with about 4GWof Hydro available from the snowy mountains scheme, but I am not sure what transmission losses from there are (I would be guessing fairly high) - some of the dams in the snowy mountains scheme are used for energy storage in that they pump water back up hill during the night. The snowy mountains scheme is also shared with (and closer to) Victoria so I am also not sure how much of that 4GW we would be getting on hot days anyway.
Power is also shared to some extent with other states and I am guessing that hotter days they just start firing up the brown coal stations and bugger the expense but as my earlier graph showed, on cooler days power demand plateaus around 9-10GW while peak on hotter days exceeds 14GW and it seems that last extra GW or so, is the really really expensive bit  ....

[electrodacus]

In NSW as a consumer we buy at a fixed rate, but not as cheap as that. either around 26c per KWH (without time of day metering) or if we move to time of day metering there are 3 different rates:
Peak - (2pm to 8pm, Monday to Friday) =  51.8C /KWH
Shoulder - (7am to 2pm and 8pm to 10pm Monday to Friday, 7am & 10pm Saturday/Sunday and Public Holidays) = 20.4c/KWH
off peak - ( 10pm to 7am, Monday to Sunday) = 11.2c/KWH
(https://secure.energyaustralia.com.au/EnergyPriceFactSheets/Docs/EPFS/E_R_N_RSOT-E_EA_01-01-2015.pdf)

Solar power we currently get paid 9c per KWH for excess power fed back into the grid (so if you use it you can save 20.4 to 51.8C but if you aren't at home during the day and feed pretty well all that power back into the grid you only get 9c)

The other prices are what the power generating companies get paid by the distributors and I am  being overly generous in presuming that a small scale generator would be able to get those sort of rates.....

The power grid in NSW is mostly coal fired power stations, with about 4GWof Hydro available from the snowy mountains scheme, but I am not sure what transmission losses from there are (I would be guessing fairly high) - some of the dams in the snowy mountains scheme are used for energy storage in that they pump water back up hill during the night. The snowy mountains scheme is also shared with (and closer to) Victoria so I am also not sure how much of that 4GW we would be getting on hot days anyway.
Power is also shared to some extent with other states and I am guessing that hotter days they just start firing up the brown coals stations and bugger the expense but as my earlier graph showed, on cooler days power demand plateaus around 9-10GW while peak on hotter days exceeds 14GW and it seems that last extra GW or so, is the really really expensive bit  ....

Thanks for the overview. As expected those peaks are so occasional that is worth paying much more for them. Not sure there is any advantage to the 3 rates for most people over the fix rate but is an advantage for the energy suppliers since it encourages the use of less energy in the peak periods.
I think people should integrate more thermal mass in buildings and use solar PV directly to cool the house.   But I'm relay getting off topic here.
That Tesla battery has the right capacity for heavy users ( 800 to 1000kWh/month) but not sure if that battery is economical based on cost. If is the same battery in Leaf then that will degrade fast in high temperatures.
Maybe they will only charge each cell to only 4V so that it will last much longer at reduced capacity since energy density is not important in stationary applications and thus having a better amortisation cost.
But since people are not educated they will prefer a battery rated at 20% higher capacity and wont know to care about the fact that it last 4x less.

[RJFreeman]

Not sure there is any advantage to the 3 rates for most people over the fix rate but is an advantage for the energy suppliers since it encourages the use of less energy in the peak periods.
I think people should integrate more thermal mass in buildings and use solar PV directly to cool the house.

oddly the fixed rate seems to have come down relative to peak time of day pricing, 4 years ago (2010) it was:
18.8 cents per KWH for the first 2,500 KWH (per quarter) then 26.62 cents per KWH.
while the time of day pricing was:
Shoulder  18.48 cents per KWH
Peak    31.68 cents per KWH
off peak    9.46 cents per KWH

so it was between 60 and 84% of peak pricing, but is now about 50% of peak time of day pricing?

probably the biggest power consumer in NSW is cooling in summer, heating in winter is mostly only a concern at night (below 20C is a cold day here    ), when other power consumption is dropping off anyway. and cooling is mostly required when solar energy is available.....

[electrodacus]

probably the biggest power consumer in NSW is cooling in summer, heating in winter is mostly only a concern at night (below 20C is a cold day here    ), when other power consumption is dropping off anyway. and cooling is mostly required when solar energy is available.....

It was -33C last night in here luckily is easier to heat than to cool. I will to the heating with PV electric in the near future.

[miguelvp]

Hasn't been to bad here in Chicago this year, I think the lowest has been is -8F  (-22C) in a 100 year old house, but nothing like last year that we had Highs below 0F (-18C)
natural gas heat our water radiators just fine

Right now it's a toasty 4F (-16C) and it seems we are going to break the 32F (0C) by next week, time to wear t-shirts again

[eneuro]

Future energy storage might look different and winner might be not Tesla

You probably won't want to be around that during an earthquake...

Do you mean a few kWh flywheel in the garden a few meters under ground or Tesla flamable Lithium inside your bed room wall inside the house ?   

[tom66]

You guys are so not green.

Here are my energy storage devices: I chop two or three of them down each year and no need for all of your fancy stuff.

It is renewable, clean and most of all, greenest of the green energy your green dollars can possibly buy.

Chopping down trees to burn is carbon neutral. Is it sustainable? Maybe, if carefully managed. Still produces pollution but not so much of a problem if kept away from large population areas. In the UK we have a few tree-/bio- fired power stations converted from old coal plants (it's less than 500MW total though)

Deforestation has led to increases in net carbon (as well as human emissions), as there are less trees to absorb the carbon. Also don't forget about %CUTE_ANIMAL% that lives in the same area otherwise greenpeace will be after you.

[eneuro]

The tracking is entirely passive in most cases; rather than use a motor they just use liquid filled balloons that react to heat and keep the panels pointed towards the sun.

For PV it might work, but for CSP thermal system more accurate positioning is needed.

Anyway decent scientific work prooves this what I've got from Bird Sky Model simulation with my sun tracking software and conclusion from this paper
researchgate.net: Performance comparison of a double-axis sun tracking versus fixed PV system
is:
It is calculated that 30.79% more PV electricity is obtained in the double axis sun-tracking system when compared to the latitude tilt fixed system.

Some CSP thermal systems could be useless without sun tracking and while I'm talking abput 3m dish and area of 7m2, so if we get from the sun 500W/m2, we have 3.5kW thermal energy, so 30% less energy means 1kW of lost power.
Maybe for very small and unefficient PVs (in comparision to thermal solar systems efficiency), this 30% loss and additional costs for sun tracking mechanical system  means that our ROI will not be significant and we can forget about sun tracking unless we haven't got compact mechanical design of solar system 

[electrodacus]

The tracking is entirely passive in most cases; rather than use a motor they just use liquid filled balloons that react to heat and keep the panels pointed towards the sun.

For PV it might work, but for CSP thermal system more accurate positioning is needed.

Anyway decent scientific work prooves this what I've got from Bird Sky Model simulation with my sun tracking software and conclusion from this paper
researchgate.net: Performance comparison of a double-axis sun tracking versus fixed PV system
is:
It is calculated that 30.79% more PV electricity is obtained in the double axis sun-tracking system when compared to the latitude tilt fixed system.

Some CSP thermal systems could be useless without sun tracking and while I'm talking abput 3m dish and area of 7m2, so if we get from the sun 500W/m2, we have 3.5kW thermal energy, so 30% less energy means 1kW of lost power.
Maybe for very small and unefficient PVs (in comparision to thermal solar systems efficiency), this 30% loss and additional costs for sun tracking mechanical system  means that our ROI will not be significant and we can forget about sun tracking unless we haven't got compact mechanical design of solar system 

Not sure you read my answer to this there are many other problems fist is the cost effectiveness of the tracking in any form vs just adding 30% more PV,  second for OffGrid you have wasted energy since battery size is limited you do not have the grid to push any excess and third those 30% are an annual average most of that is done in the summer when there is even more excess as you seen from my date 4 to 10% is only done in winter when I will actually need the most and that percentage is just a few $ of additional panels 72$ I think for my 3x 240W PV array.
I will be happy to see any method of tracking that cost 72$ for 3x 240W panels and last for 25 years since that is what additional 72$ of PV will do for winter and about 200$ for the entire year but like I mentioned in Offgrid you have excess so producing more with tracking, PV or any other method is normally useless especially in summer.       

[eas]

That Tesla battery seems to be large enough is 10x the capacity of my main battery (but I'm more in to high energy efficiency than most people)
Form what I see in the photo they use the same or similar battery used in Nissan Leaf there are 4 cells in each of those metal box connected 2s2p 30Ah each cell for a total of 8.4V (fully charged) 60Ah that is around 0.5kWh and I see about 50pcs in that also see a 24 something on the other side so most probably 24kWh capacity.

Thanks for your perspective and the details of your system.

FYI, the reason it appears to use the same or similar battery as the Nissan Leaf is that some blog used a photo of a Nissan Leaf battery pack (and many others copied them). The photo puzzled me at first, because I assumed that Tesla would be leveraging their 18650 pack technology, and probably be repurposing modules from retired Tesla automotive packs. Once I did some digging, I found that it was a picture of a Leaf pack. Only then did I notice the nissan logo on the left of the photo, and the fact that the filename for the image is something like "nissan leaf battery pack."

Tesla has actually been deploying packs to some SolarCity customers for a while now. I don't know what they look like on the inside, but my understanding is that they are ~10kWh, so, smaller than that Leaf pack, but still 4x the size of yours.

On the subject of LifePO4, my understanding (from a lecture by Dr Jeff Dahn on Why Lithium Batteries Fail) is that aging accelerates rapidly with temp (at least for commercial varieties available a coupel years ago), with obvious differences even at 40C. Do you have temperature control for your packs?

[eas]

That Tesla battery seems to be large enough is 10x the capacity of my main battery (but I'm more in to high energy efficiency than most people)
Form what I see in the photo they use the same or similar battery used in Nissan Leaf there are 4 cells in each of those metal box connected 2s2p 30Ah each cell for a total of 8.4V (fully charged) 60Ah that is around 0.5kWh and I see about 50pcs in that also see a 24 something on the other side so most probably 24kWh capacity.

Thanks for your perspective and the details of your system.

FYI, the reason it appears to use the same or similar battery as the Nissan Leaf is that some blog used a photo of a Nissan Leaf battery pack (and many others copied them). The photo puzzled me at first, because I assumed that Tesla would be leveraging their 18650 pack technology, and probably be repurposing modules from retired Tesla automotive packs. Once I did some digging, I found that it was a picture of a Leaf pack. Only then did I notice the nissan logo on the left of the photo, and the fact that the filename for the image is something like "nissan leaf battery pack."

Tesla has actually been deploying packs to some SolarCity customers for a while now. I don't know what they look like on the inside, but my understanding is that they are ~10kWh, so, smaller than that Leaf pack, but still 4x the size of yours.

On the subject of LifePO4, my understanding (from a lecture by Dr Jeff Dahn on Why Lithium Batteries Fail) is that aging accelerates rapidly with temp (at least for commercial varieties available a couple years ago), with obvious differences even at 40C. Do you have temperature control for your packs?

[eas]

You guys are so not green.

Here are my energy storage devices: I chop two or three of them down each year and no need for all of your fancy stuff.

It is renewable, clean and most of all, greenest of the green energy your green dollars can possibly buy.

Chopping down trees to burn is carbon neutral. Is it sustainable? Maybe, if carefully managed. Still produces pollution but not so much of a problem if kept away from large population areas. In the UK we have a few tree-/bio- fired power stations converted from old coal plants (it's less than 500MW total though)

Deforestation has led to increases in net carbon (as well as human emissions), as there are less trees to absorb the carbon. Also don't forget about %CUTE_ANIMAL% that lives in the same area otherwise greenpeace will be after you.

Burning biomass is interesting, because depending on how you manage the combustion, you can end up with a significant amount of the original carbon content trapped as charcoal. If you then grind that charcoal up and put it in the ground, rather than burning it for fuel, it will take a very long time before it is returned to the atmosphere, and it provides an excellent soil amendment.

There is a big push to provide better cooking stoves for the 1B or so people who still cook over wood or charcoal. The potential benefits are huge, because the existing approach creates a lot of indoor and outdoor air pollution, causes extensive deforestation, and requires families spend more and more time finding fuel. More efficient cleaner burning stoves can bring health improvements, reduce deforestation, and allow kids time to go to school. I'm particularly impressed with the approach Nate Mulchay of Worldstove is taking. His stove designs have a pleasing elegance, and that elegance is matched by the elegance of the manufacturing supply chains and economic networks he's creating to produce stoves and fuel.

[electrodacus]

Thanks for your perspective and the details of your system.

FYI, the reason it appears to use the same or similar battery as the Nissan Leaf is that some blog used a photo of a Nissan Leaf battery pack (and many others copied them). The photo puzzled me at first, because I assumed that Tesla would be leveraging their 18650 pack technology, and probably be repurposing modules from retired Tesla automotive packs. Once I did some digging, I found that it was a picture of a Leaf pack. Only then did I notice the nissan logo on the left of the photo, and the fact that the filename for the image is something like "nissan leaf battery pack."

Tesla has actually been deploying packs to some SolarCity customers for a while now. I don't know what they look like on the inside, but my understanding is that they are ~10kWh, so, smaller than that Leaf pack, but still 4x the size of yours.

On the subject of LifePO4, my understanding (from a lecture by Dr Jeff Dahn on Why Lithium Batteries Fail) is that aging accelerates rapidly with temp (at least for commercial varieties available a coupel years ago), with obvious differences even at 40C. Do you have temperature control for your packs?

Thanks. I did not realised it was a Leaf pack it make sense since is the size (capacity) of an EV pack.  I knew Tesla used smaller 18650 cells so I was surprised to see those cells but did no future investigation.
I seen that video and normal operation without any significant degradation for LiFePO4 is 0C to 45C for charging and for discharging lower temperatures are no problem.
Based on Sony LiFePO4 there is more degradation even in storage at 45C vs 23C for 20 years it was 3% at 23C and about 10% at 45C
LiFePO4 is quite different from LiCoO2 variants but Solar BMS supports  both even if I recommend LiFePO4 for stationary energy storage.
Yes the Solar BMS has an external temperature sensor but I do not use it in my pack. It makes no sense since my Battery is inside the house with ambient range of 15C to 27C and at the charge discharge rates it is used in this sort of applications usually under 0.5C the battery temp raise above ambient is less than 2 or 3C so is well within the normal operating range.       

[electrodacus]

Burning biomass is interesting, because depending on how you manage the combustion, you can end up with a significant amount of the original carbon content trapped as charcoal. If you then grind that charcoal up and put it in the ground, rather than burning it for fuel, it will take a very long time before it is returned to the atmosphere, and it provides an excellent soil amendment.

There is a big push to provide better cooking stoves for the 1B or so people who still cook over wood or charcoal. The potential benefits are huge, because the existing approach creates a lot of indoor and outdoor air pollution, causes extensive deforestation, and requires families spend more and more time finding fuel. More efficient cleaner burning stoves can bring health improvements, reduce deforestation, and allow kids time to go to school. I'm particularly impressed with the approach Nate Mulchay of Worldstove is taking. His stove designs have a pleasing elegance, and that elegance is matched by the elegance of the manufacturing supply chains and economic networks he's creating to produce stoves and fuel.

I was thinking at biomass for my house heating but that was when I designed the house  few years ago now the least expensive option is to use solar PV panels for heating so that is what I will be using. Already most of the energy I use is for electric cooking.
I do not think biomass is a good idea and can not be used at large scale that will be a disaster with 7B people.