Solar... who's clued in?

Dales Cannon

The Olden Dazed
Staff member
Anyone gone the solar battery route at home?

Just got a "letter to the household" envelope from solar battery group (SBG) spruiking a $3,980 out of pocket solar battery installation deal (after SBG discount and state government rebate)...
How many W or AH?
 

downunderdallas

Likes Dirt
Small print says...

"Offer refers to the Alpha ESS Smile B3 plus 5.04kwh solar battery which is expandable up to 30.245kwh."
I got the same letter, apparently, there has been a version of this kicking around for a long time, with various different companies. This mob look new and pretty suspect to me.

$4K installed is cheap for 5kwh but it still would take over 10 years to pay back by my rough calcs if it was 90% efficient and I used 90% of the battery every day all year.
 

fjohn860

Crypto curious
I got the same letter, apparently, there has been a version of this kicking around for a long time, with various different companies. This mob look new and pretty suspect to me.

$4K installed is cheap for 5kwh but it still would take over 10 years to pay back by my rough calcs if it was 90% efficient and I used 90% of the battery every day all year.
Yeah they do look like a fairly new company.

$8.5k total price before the rebates.

I've been looking at the battery specifications which has 4.79kwh usable power.

Our daily usage is 3.72kwh. It would possibly make sense if our yearly daily usage is around 3-4.
 

Fred Nurk

Likes Dirt
There are fuckloads of dodgy installers around, flogging cheap systems. Have a look at Solarquotes to check if the installer is listed, as well as review their battery system viability assessments.

Last time I ran the numbers batteries weren't worth it, don't think anything has changed in that regard, and even less benefit if you don't get the battery backup option...
 

fjohn860

Crypto curious
Well "solar battery group" aren't listed on the VIC gov solar rebate approved installer list so either the list hasn't been updated recently, or just another dodgy company haha
 

SummitFever

Eats Squid
...Last time I ran the numbers batteries weren't worth it, don't think anything has changed in that regard, and even less benefit if you don't get the battery backup option...
I couldn't get the numbers to work either. To get close to recovering the initial outlay seemed to require pretty much full charge/discharge every day and 10 years. There is no battery system out there that would last at that rate.
 

dazz

Queen Karen of Ballarat
I couldn't get the numbers to work either. To get close to recovering the initial outlay seemed to require pretty much full charge/discharge every day and 10 years. There is no battery system out there that would last at that rate.
Lithium Titanate Oxide cells will do that and and then some! They deliver some pretty amazing results in testing that I've seen ...but... you'd better have deep pockets!
 

indica

Where did I come from?
Yeah, no good ATM.
Hopefully in 4 years when my powerstation has paid for itself it will be a better prospect.
 

rowdyflat

chez le médecin
5 Kwh isnt a huge battery .
Its not a days worth for most people .
In other words it will store about a 1 Kw system 4-6 panels worth x 5 hrs.
 

goobags

Likes Dirt
Batteries are definitely hard to justify on cost alone. However a smaller battery is generally what you want, if you pay for a larger battery and never use the capacity, then it’s a waste of money. The only time this is not the case is when you use it for a battery backup due to regular grid outages.

At $4k, one complete discharge of 4.79kWh per day for 10 years will end up effectively costing around 22.8c/kWh. This is overly simplistic as the battery won’t have its full capacity after that many cycles. Take into account the cost of charging the system via solar by not getting feed in rates, say 5c/kWh, you need to be paying more than 27.8c/kWh currently for electricity to justify on cost alone.

Further to that, you may still import power due to the 3kW inverter, put the kettle and microwave on at the same time and you will be importing power.

If I were to get a battery, I would be on time of use electricity plan and aim to discharge the battery each evening when electricity prices were over 50c/kWh. I would not get a huge battery as we have not lost mains in 2 years.


Sent from my iPhone using Tapatalk
 

Fred Nurk

Likes Dirt
If I were to get a battery, I would be on time of use electricity plan and aim to discharge the battery each evening when electricity prices were over 50c/kWh. I would not get a huge battery as we have not lost mains in 2 years.

Sent from my iPhone using Tapatalk
That's the closest option to making it cost effective, but still not economical without an excess of solar.
The thing that always bothered me with such an arrangement and a smaller battery is that none of the battery chemistries like sitting discharged but that's exactly what needs to happen with a solar system, the battery sits there flat until the solar is running the next day.
 

goobags

Likes Dirt
That's the closest option to making it cost effective, but still not economical without an excess of solar.
The thing that always bothered me with such an arrangement and a smaller battery is that none of the battery chemistries like sitting discharged but that's exactly what needs to happen with a solar system, the battery sits there flat until the solar is running the next day.
Assuming a 70% capacity at 10 years and linear degradation the cost goes up to 26.9c/kWh before charging costs making it harder to justify again.

Agree regarding low state of charge for extended periods are bad. Would be interesting what the various companies require for warranty if that were the cause of a failing battery pack


Sent from my iPhone using Tapatalk
 

beeb

Dr. Beebenson, PhD HA, ST, Offset (hons)
What makes the sums tricky, is the variability / unpredictability of future costs of pulling power from the grid. In ten years time, 27c/kWh might look laughably cheap and we'll all be looking back regretting not putting in batteries.
 

indica

Where did I come from?
I'll give it a go in a few years. From last month I have a massive excess of solar.

It produced 2,603.76 kWh and total consumption was 399.08 kWh, 288.11 kWh was self-consumption.
Be interesting to see how a year goes.
 

Fred Nurk

Likes Dirt
I'll give it a go in a few years. From last month I have a massive excess of solar.

It produced 2,603.76 kWh and total consumption was 399.08 kWh, 288.11 kWh was self-consumption.
Be interesting to see how a year goes.
No wonder you're getting a credit on your bill... my consumption was about 1300kWh for last month.
 

goobags

Likes Dirt
What makes the sums tricky, is the variability / unpredictability of future costs of pulling power from the grid. In ten years time, 27c/kWh might look laughably cheap and we'll all be looking back regretting not putting in batteries.
Meanwhile the demand for batteries would have increased and prices go up…


Sent from my iPhone using Tapatalk
 

downunderdallas

Likes Dirt
I'll give it a go in a few years. From last month I have a massive excess of solar.

It produced 2,603.76 kWh and total consumption was 399.08 kWh, 288.11 kWh was self-consumption.
Be interesting to see how a year goes.
Wow that's small consumption and huge production! I'm assuming this is a shoulder low consumption month and at least somewhere in the year you use a fair bit more than that? In my pre EV days our lowest consumption month we might get close to 400kWh. These days it is more like 750 in Oct/Nov. Producing about 1100kWh in those months. Since getting 2 EV's we are definitely using much more of what we produce but still exporting more than we use from Sept to April.
 
Top