Battery storage system electrified by BMW i

Why would this succeed when the Powerwall seems to have failed to take off. It seems like the same concept.

I think power wall was an independent purchase/product. This is to re-purpose the old battery pack for an i3 owner. So you have a 2014 i3 and in 2019 decide that you want to upgrade to the new battery pack of the time. You could repurpose your 70% or so usable battery to provide back up and time of use savings at home.

Schnort said:

Why would this succeed when the Powerwall seems to have failed to take off. It seems like the same concept.

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Plus the Powerwall has only just made it to production, hasn't had time to fail.

I think nearly every cost analysis of the Powerwall has shown it to not pay off for a long time, or never pay off, in the case of the daily cycling to use solar power at night.

The backup use case is another story, but that's an expensive rarely used (for most people) insurance policy. I've only lost the contents of my fridge from a power outage one time in 25 years of being on my own.

If you have off-peak rates, and, needed to replace your i3's battery out of warranty (a long time in the future for most!), it might allow you to rely entirely on off-peak power, saving, in some places a very substantial portion of your energy costs. Use the battery pack during the day, and the utility direct during the night and for recharging. Some places are either talking or doing free energy during off-peak, so your costs would quickly be recovered, I'd think.

Anyone taken advantage of the 'upgrade' to the larger batteries (probably not, probably not available quite yet)? Does it require turning in the old battery, or is it something they'd give you for the same price? I'd expect their upgrade/replacement price is with a core return of the old battery, and would be much more if you kept the old battery pack. That could shift the overall costs considerably.

BMW had previously shown a design for the utility systems to act as a buffer to help prevent brownouts, if I remember correctly. IN that scenario, they'd have multiple units tied together and spread across the network.

What's the spread on pricing between peak and night? =

How many KWH would this thing be able to store and use overnight?

How many nights would that have to happen before you made your money back?

For the powerwall, I think they are $3k a piece and 6.4KWh. To get your money back in 7 years, the spread would have to be almost 20c per KWH. I don't think anybody has spreads like that.

This is very interesting, although a suitable PV inverter is also necessary. I am assuming all this kit would all have to be sourced from Beck.

Charging the battery storage overnight dirty off-peak electricity should, at least in the UK, not be encouraged. It is known that off-peak electricity is 'dirtier' than daytime, as more coal and gas-fired plants are brought online quickly to cover the peaks and troughs in nighttime demand.

I've been waiting for BMW to announce this, I'd love to get it when it's time to replace my battery which would probably be in another 2 to 3 years. I have a blog post on this for anyone interested:

http://bmwi3.blogspot.com/2016/06/bmw-i-home-energy-storage-system.html

psquare said:

Charging the battery storage overnight dirty off-peak electricity should, at least in the UK, not be encouraged. It is known that off-peak electricity is 'dirtier' than daytime, as more coal and gas-fired plants are brought online quickly to cover the peaks and troughs in nighttime demand.

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Not even slightly true. Have a look at http://www.gridwatch.templar.co.uk/ and you'll see that there is almost no coal generation at night, and gas is used less. Peaks and troughs can be handled by hydro, and bio, nuclear and interconnect provice a decent base load.

PhilH said:

Not even slightly true. Have a look at http://www.gridwatch.templar.co.uk/ and you'll see that there is almost no coal generation at night, and gas is used less. Peaks and troughs can be handled by hydro, and bio, nuclear and interconnect provice a decent base load.

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Coal and gas (both regarded as dirty ways to generate) are preferably used at night as these can be brought online relatively quickly to avoid outages. Nuclear takes longer to bring online, costs more and is only for bigger supply bandwidth, thus inefficient.

Hydro, Bio etc is only 5% of the current UK mix, which is insufficient. As much as I want a greener future - it is important to keep it real.

Current state can also be seen here: http://www.ecotricity.co.uk/our-green-energy/energy-independence/uk-grid-live

Update ! - I actually admit that you do have a point, since emission levels at night times are lower and hence usage can be beneficial. However, it is not clear whether higher demands or peaks can always be met by renewables during off-peak (which is what I have read before). This was my point.

I leave my original post in, for clarity and to admit that you do have a point.

Thanks for the update. You're still misunderstanding the true position. Coal is the dirtiest source of power, but also takes a while to bring online. It's not used to even out peaks and troughs. The fastest source of immediate power remains htdro - either pumped or flow - and that is the first resource for sudden demand - were it ever to happen at night. Nuclear runs flat out full time and provides base load, since when running, it's essentially free. Ditto biomass - currently providing 4.5% of demand. Gas has a considerably lower carbon dioxide output than coal, and is the main way of matching supply to demand. Because demand is lower at night, the percentage of electricity sourced from gas at night is lower than during the day. If you want to be green, run your house from solar during the day, and charge your car from the grid overnight.

PhilH said:

psquare said:

Charging the battery storage overnight dirty off-peak electricity should, at least in the UK, not be encouraged. It is known that off-peak electricity is 'dirtier' than daytime, as more coal and gas-fired plants are brought online quickly to cover the peaks and troughs in nighttime demand.

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Not even slightly true. Have a look at http://www.gridwatch.templar.co.uk/ and you'll see that there is almost no coal generation at night, and gas is used less. Peaks and troughs can be handled by hydro, and bio, nuclear and interconnect provice a decent base load.

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Exactly they actually pay them not to generate power using renewables during the off peak period as there's no demand. Using power storage devices such as these would be one way to make use of that power.