New battery storage system

[begreen]

Introduced in the UK, Nissan and Eaton have developed a home battery storage system using repurposed EV batteries. Looks like a 4.2kW system would be about $4500.
http://www.newsroom.nissan-europe.com/uk/en-gb/Media/Media.aspx?mediaid=145249

 

[maple1]

What is the capacity of Elons setup? I wasn't really paying much attention to it.

We use between 15 & 20 kwh per day, so 4.2kwh put in that perspective doesn't sound quite big enough. But I think this kind of stuff is part of our future. Solar doesn't generate at night, after all. And the wind doesn't blow all the time. This kind of approach would seem more practical & efficient than a mega-scale storage project - as would micro-generation.

 

[begreen]

4.2kW is the smallest pack offered by Nissan/Eaton. Larger packs are optional at additional cost. Same thing with the Tesla Powerwall packs. Each of those packs are 6.4kW.

 

[Highbeam]

You keep saying kW. Do you mean kwh? As in battery capacity? Or is 4.2 just the available current for some unspecified timeframe?

We too use 10-20 per day when our luxury hot tub is off which could be reduced by switching some appliances to propane. I wouldn't need 10-20 kwh per day from the batteries since there would be some time during the day when the solar would be directly providing power to the loads while charging the battery.

It's just around the corner. A 30kwh battery pack. Imagine that. The battery would be charged by a solar system or by variable voltage from an insufficient power grid. The batteries would run an inverter to provide good AC to the home while being charged by whatever source is cheapest and/or available at the time. Enough solar, no grid tie is needed.

 

[begreen]

Should be kWh. These packs only seem to make sense to me if one has a large capacity solar bank that can charge by day or a very large difference between daytime and nighttime electric rates.

 

[maple1]

I think they make a lot of sense when talking balancing overall supply with demand - if there gets to be enough of them out there. I'm not sure what our off-peak rates are, but if you could shift all your consumption to off-peak with a large enough battery, that should be some serious savings while also taking load off the grid at peak use time. I see potential for wins all around.

 

[begreen]

At current pricing, the economics don't make sense to me where off-peak pricing is not available. And even then the difference between rates would need to be high for it to make good financial sense.

This article explores the payback. Like the Tesla car, this author sees the powerwall as another toy for the wealthy.
http://www.forbes.com/sites/christo...other-toy-for-rich-green-people/#4bef5f84879b

 

[kennyp2339]

Those packs are measure in out put KW (demand) to know what size battery you would need for your house you would have to take a 24hr recording amp reading then take your highest reading and convert that to KW, a typical house with (2) 3 ton ac units (usually the highest amperage equip) will have a 6.0 kw demand, and don't confuse the demand with a energy spike / pulse, the demand is measured in increments of 10min at a time.
Ohms law I*e / 1000

 

[peakbagger]

Green Mountain Power offers their customers a Tesla battery for around $35 a month. VT is pretty notorious for a shaky grid as the utilities have underinvested for years and the locals like narrow tree lined roads which makes for frequent outages. The real money in distributed storage is to be able to dispatch it when there is short term grid imbalances. If a big power line or generator fails its takes 5 to 15 minutes to get replacement generation on line, during that period anyone who has spare power can sell it for a premium. A company like Tesla will retain rights for short term dispatch of units in private homes (that's why they want to lease them rather than sell them). They can make money on the short term high prices and also get paid just for having it available (capacity payments) if needed. I worked on 35 MW generator recently that has sat idle for much of its 25 year life, the municipality makes more money letting it sit there getting paid to have it ready to run than actually running it. I helped them upgrade it so that it can even put out more power so they can get paid more not to run it.

I do like the concept that the car companies are going for to take batteries that are no longer suitable for use in a car and reuse them for power backup. Anytime there is primary and secondary market for product it reduced overall environmental impact.

 

[jebatty]

Arguing presumptively against something because it is a toy for the wealthy doesn't quite cut it for me. Most things we now have started out as toys for the wealthy, who could afford a new technology. Then as the technology improved, scale of production increased, and prices fell, what was only for the wealthy became a product for the masses. Advances in electronics/computing might be the most current and dramatic example, from the transistor back in 1947 to the sky's the limit now for just pennies when inflation is factored into the equation.

Early adopters pay a premium but also drive the market to acceptance and low prices. My 2-year old LED bulbs were $10/each, now are down to $1-2 each, for example, nearly the same price as remaining available incandescent bulbs.

 

[begreen]

Good point. Volumes need to increase to lower prices.

 

[Seasoned Oak]

Would be great for off grid power storage. Living off grid is a challenge. I may be doing that at some point in the future.

 

[jharkin]

$4500 for a measly little 4.2KWh battery pack???

Why the heck would anyone pay that kind of money when you can put that capacity together with old fashioned lead acid batteries for under a grand. off grid people have been doing this for decades.

One of these would do @ $1100
http://www.solar-electric.com/batte...batteries/suprdecyba/12voba/su12357ampho.html

Better yet, 2 of these in series gets the same capacity for $600
http://www.solar-electric.com/batte.../suprdecyba/6voltbatteries1/suba6vo350am.html

If you want to go cheaper, 3 golf cart size batteries in series will do it for $500
http://www.solar-electric.com/batte...tteries/trdecyba/trdecysoba/trt16vo225ah.html

Which the golf cart cells we can build Highbeams mythical 30kWh battery for about $4000.

 

[begreen]

120v (or 240v) vs 12v? Not sure but that price may include the inverter + grid interface too.

 

[jharkin]

120v (or 240v) vs 12v? Not sure but that price may include the inverter + grid interface too.

If the price includes inverters and hookeup then its not so bad. $1000 a kWh just for a battery is highway robbery.