14 Comments
Nov 10, 2021Liked by John Birmingham

Nissan Leaf for the battery makes sense. Especially for someone working from home. I'm waiting for it to be approved in NSW, then it's just getting the wall-system that allows it to feed back in.

I think it's already available in Queensland.

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That's cool, hadn't see that yet here, although it looks like its only in a trial phase at the moment across a few states

https://www.racv.com.au/royalauto/transport/electric-vehicles/bidirectional-charging-explained.html

Makes the whole EV story a little bit more affordable

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Yeah, it's part of the big picture that we are keen on

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A friend of mine on Bribie Island decided to go all out to replace his old solar/lead acid battery setup. Spent ~$40k on a 15kW (20kW panels) system with a Tesla Powerwall 2 to cover the evenings.

Since May he has only used 160kWh from the grid. When Calide blew up he didn't even notice.

Payback for him will be about 8 years.

I only know this stuff because he's been nerding out and sending me updates constantly! He's a good test case though. We'll probably do something that suits us once the same feed in that John was on runs out in 2028 (Worth about $20k so I don't want to make any changes to our setup)

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It's all a matter of maths and locations JB. Let's say you want to have one of Elon's love babies in the form of a Tesla Powerwall 2 with gizmo's so Casa Birmingham is Zombieproof electricity wise (you can also have a gizmo installed that in a blackout shut you off of the grid and runs the place on battery power etc). https://www.canstarblue.com.au/electricity/brands/tesla-powerwall/

That will set you back A$14K for a 13.5 KWh setup. Then its a matter of cost: what does a nighttime Kilowatt hour cost you? For simplicity sake let's say that is A$1 and you drain the pack every night, it would take around 1000 cycles or just shy of 3 years to recoup the cost.

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The problem is that power costs here are around 20c - 25c /KWh which on you're model pushes the payback time to 12 - 15 years, added to that, the chances of draining the pack overnight is pretty slim - I mean everyone's power usage profile differs but using that much every night might not be realistic and you also have to add to the equation that you're not selling that 13.5KW's back to the grid which is another 7c - 18c / KW you have to take off. I still can't see how batteries are a viable option in the burbs where we have pretty reliable power.

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Our rural place is entirely dependent on batteries. Even off-grid like us, it's eminently doable, you just need enough storage for your usage. Where you are grid connected, it will smooth out the bills even more if you set it up smart. All night AC for the summer months gets much cheaper.

Yeh, it's still nascent in the market for on-grid load balancing with batteries and micro-grids but it's all heading in the right direction. Battery tech is moving forward as fast as any nerd tech and there will always be a better return just around the corner.

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I'd be checking out your pay off period vs warranty period before going down the battery road, my understanding if that unless you have intermittent power or are off grid the battery story isn't worth it yet.

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author

Yeah, I’ve got another 12 months on the panels to pay off. I figured the way battery tech is advancing it’d worth waiting to see what happens. Especially if there’s a change in gubbermint.

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Nov 10, 2021Liked by John Birmingham

when when when, not if if if

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God I hope so, but I don't think that a change in government will make the battery option more attractive, unless they put some pretty big subsidies on them, and I doubt that they'd be targeting home installations (especially for metro peeps) I imagine they'd be looking at street / suburb style battery installs

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I see micro grids as the way to go. Hasn’t some work been done to work out who contributed and who used how much electricity in that situation?

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I read something about that on the weekend, yes. They already exist here and there.

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Wrote the paper on this a while ago. Micro grids are technically feasible but the contractual arrangements present a lot of problems. I would also hold off on the battery. The financials don't stack up currently and the market is still relatively young. Currently they are like a brick phone, you get them if you have to, if you love the tech or just to show off, but you may also regret them pretty quickly.

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