Comment by discordance
6 months ago
Here in Australia, the government is providing subsidies to households for buying batteries (backed by solar).
After paying $15k (after subsidies) for a 40kWh battery, our battery is filled by roof solar and grid provided renewable energy, when needed, at very cheap rates (6c/kWh). I pay $1 a day for grid connectivity. Our total annual energy bill will be approximately $500 for the foreseeable future.
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.
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) 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.
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.
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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!
15Kwh Lifepo4 48V 300Ah is less than $2k USD. You are overpaying a lot for installation.
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.
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This is actually very regressive policy because it only rewards people who 1) own their own home and 2) can afford a significant capital investment. And under current retail rate structures it shifts the burden of maintaining the grid onto those who can't afford to make these investments and who will end up seeing there rates rise unless the cost of grid connectivity is increased.
It's also economically questionable because it's simply much cheaper to build and manage a smaller number of large batteries then thousands of home batteries.
I understand why these schemes are politically attractive; people like to own their own stuff. But there is a very real chance this increases the cost of energy here.
I'm curious how you see this potentially increasing the cost of energy? Why can't we do both large systems and small distributed systems?
I see the following benefits:
1. Stabilises the grid
2. Smooths peak demands. Check the Price and Demand graph here: https://www.aemo.com.au/energy-systems/electricity/national-...
3. Increases supply -> energy prices decrease?
4. Accelerated move away from coal generation and towards renewables.
5. Job creation (solar and storage installation)
Drawbacks:
1. Renters, lower income houses and apartment dwellers don't have access the subsidies
2. Exposure to dodgy installers and systems just like we saw with the Australia solar scheme.
That would be cool if I could afford to own a house.
A great example of what's possible when policy actually aligns with long-term sustainability goals
How does the cheap rates work? You get subsidised grid rates because of the batteries?
In Australia it's common to have Time of Usage (ToU) billing.
Figures depend on provider and plan, but sometimes cheap (as per parent's 6c / kWh), but during the midday to 6pm range it may be up to 60c.
So, grid rates aren't subsidised, but having a storage medium means you can arbitrage power quite easily.
The AEMO (Australian Energy Market Operator) website has some good data can see price of electricity in realish time. This is for the NEM (which is east coast states + South Australia), the west coast is on a separately managed grid with no interconnection.
https://www.aemo.com.au/energy-systems/electricity/national-...
You can also view the breakdown of where the grid is sourcing energy from (i.e. what portion of the grid is supplied from solar pv etc at any given time).
I know that some big industrial users (large factories etc) can optimize/spin up production lines etc based on the spot price. Although I'm not sure if they use the same public AEMO data there might be a dedicated api or similar involved.