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I'm in NSW - curious on what you got, what subsidy/ies you were able to obtain. I'd previously looked into this and it sounded like a package was required - PV

by Jedd 1y ago

I'm in NSW - curious on what you got, what subsidy/ies you were able to obtain. I'd previously looked into this and it sounded like a package was required - PVC + battery - whereas I've already got 10kW inverter + 12kW panels, and basically just want something around that size (40kWh). Street pricing seemed to be around the $9k installed per 10kWh, so a) your subsidy options sounds spectacular - around 60% discount? - and b) payback for me would probably be around 8 years. But if I switch vendors (Amber I think is what one of my friends is on) I can engage in something analogous to wholesale market activity, 10m bidding / sales, rapidly decrease the projected lifetime of my battery, but potentially be $-positive even through the winter months. But all that feels like something the power companies here in AU are going to try to try to undercut / tax.

discordance 1y ago
5 x SigEnergy SigenStor Bat 8.0 (8kWh/battery) + 12kW inverter (Sigenstor EC) on single phase. The SRES battery rebate (https://cer.gov.au/batteries https://cer.gov.au/batteries) was ~30%. Total was a bit under $15k. I already have 16.6kW of panels on the roof from 5 years ago. There are two providers (Globird and Ovo) I have been researching that provide 2-3 free hours of electricity per day between 11-2pm. That + solar would easily fill the batteries, so that power bill might drop even more. You should get some quotes from battery/solar installers (no doubt you have heard of solarquotes.com.au). Prices have dropped a lot this year.
- Jedd 1y ago
  Excellent info - thank you. Yes, I've been through solarquotes.com.au a few times but haven't looked in earnest for some time. This is encouraging information. I know my usage can easily be 15-20kWh in a day, and I can get a week of overcast though it's not common. The 'free' electricity offers presumably are in return for a guarantee to feed-in to them outside sunlight peak, I suppose? I assume the power providers have come up with ToU and FiT tariffs based on a LOT of data, so we here with our spreadsheets and one or two datapoints aren't likely to come out far ahead, but it sounds like break-even within a few years is feasible.
  - discordance 1y ago
    They don't require that we feed in at any specific time, but they do price their peak rates quite high so you have to ensure you have enough storage to not consume at those times. No doubt their models and prices will be updated once more large homes BESS are installed.
slaw 1y ago
15Kwh Lifepo4 48V 300Ah is less than $2k USD. You are overpaying a lot for installation.
- XorNot 1y ago
  You need inverters to run them, and you can't just put more battery on one inverter. The price is about 1:1 now for battery and inverter costs when I looked into it last.
  - slaw 1y ago
    6.2kW 48V -> 230AC inverter is $300
    - XorNot 1y ago
      And if you run the numbers, the battery which can deliver 6.2kW is only about 1.5kwH in capacity. This matters because while discharging slowly is fine, to gain any economic benefit you need to be able to charge at essentially full power. If you have 100kwh of batteries and only 6kw of AC connection then it would take 3 days of typical solar charging to get them to full capacity. And any kwh sitting there that you don't charge/discharge is costing you money for grid batteries - the economics still depend on being grid interactive. The best demand signal in my local grid for example is exactly 1 hour wide. Which means s you get 4 15 minute intervals to basically try and dump power for the best price.
  - Filligree 1y ago
    You absolutely can put multiple batteries on one inverter. The limiting factor is the DC bus bar and breakers, not the inverter, which just needs to be sized to consumption.
    - XorNot 1y ago
      Yes there's nothing stopping you, but economically a given kW battery installation stores about 4 hours of power. There's 4 to 6 hours of peak renewable energy per day. If you add more batteries, you increase power and energy at the same time and ratio: so for any practical home battery system you're cycling the cells daily, which means you your power for charging must match. If you put more batteries on one inverter, then you're scaling a lot of other costs (BMS, bus bars and space) but you'll never actually be able to utilize that capacity - it'll sit idle most of the time because you can't get it in and out of the cells fast enough.
nl 1y ago
I have a relative with a 30kWh battery on Amber. They spent AU$10k for it after subsidies. They don't expect to ever pay for electricity again - instead their biggest problem with Amber is what to do when they are overproducing. They got charged $2.50 the other day when they didn't curtail production and had to dump power into the grid!

by Jedd 1y ago

discordance 1y ago

5 x SigEnergy SigenStor Bat 8.0 (8kWh/battery) + 12kW inverter (Sigenstor EC) on single phase. The SRES battery rebate (https://cer.gov.au/batteries https://cer.gov.au/batteries) was ~30%. Total was a bit under $15k. I already have 16.6kW of panels on the roof from 5 years ago. There are two providers (Globird and Ovo) I have been researching that provide 2-3 free hours of electricity per day between 11-2pm. That + solar would easily fill the batteries, so that power bill might drop even more. You should get some quotes from battery/solar installers (no doubt you have heard of solarquotes.com.au). Prices have dropped a lot this year.

Jedd 1y ago
Excellent info - thank you. Yes, I've been through solarquotes.com.au a few times but haven't looked in earnest for some time. This is encouraging information. I know my usage can easily be 15-20kWh in a day, and I can get a week of overcast though it's not common. The 'free' electricity offers presumably are in return for a guarantee to feed-in to them outside sunlight peak, I suppose? I assume the power providers have come up with ToU and FiT tariffs based on a LOT of data, so we here with our spreadsheets and one or two datapoints aren't likely to come out far ahead, but it sounds like break-even within a few years is feasible.
- discordance 1y ago
  They don't require that we feed in at any specific time, but they do price their peak rates quite high so you have to ensure you have enough storage to not consume at those times. No doubt their models and prices will be updated once more large homes BESS are installed.

slaw 1y ago

15Kwh Lifepo4 48V 300Ah is less than $2k USD. You are overpaying a lot for installation.

XorNot 1y ago
You need inverters to run them, and you can't just put more battery on one inverter. The price is about 1:1 now for battery and inverter costs when I looked into it last.
- slaw 1y ago
  6.2kW 48V -> 230AC inverter is $300
  - XorNot 1y ago
    And if you run the numbers, the battery which can deliver 6.2kW is only about 1.5kwH in capacity. This matters because while discharging slowly is fine, to gain any economic benefit you need to be able to charge at essentially full power. If you have 100kwh of batteries and only 6kw of AC connection then it would take 3 days of typical solar charging to get them to full capacity. And any kwh sitting there that you don't charge/discharge is costing you money for grid batteries - the economics still depend on being grid interactive. The best demand signal in my local grid for example is exactly 1 hour wide. Which means s you get 4 15 minute intervals to basically try and dump power for the best price.
- Filligree 1y ago
  You absolutely can put multiple batteries on one inverter. The limiting factor is the DC bus bar and breakers, not the inverter, which just needs to be sized to consumption.
  - XorNot 1y ago
    Yes there's nothing stopping you, but economically a given kW battery installation stores about 4 hours of power. There's 4 to 6 hours of peak renewable energy per day. If you add more batteries, you increase power and energy at the same time and ratio: so for any practical home battery system you're cycling the cells daily, which means you your power for charging must match. If you put more batteries on one inverter, then you're scaling a lot of other costs (BMS, bus bars and space) but you'll never actually be able to utilize that capacity - it'll sit idle most of the time because you can't get it in and out of the cells fast enough.

nl 1y ago

I have a relative with a 30kWh battery on Amber. They spent AU$10k for it after subsidies. They don't expect to ever pay for electricity again - instead their biggest problem with Amber is what to do when they are overproducing. They got charged $2.50 the other day when they didn't curtail production and had to dump power into the grid!