DIY Solar panel setup on a budget

As a renter, generating anything is a bit of a pipe dream - thats why I was intrigued by this portable solution that feeds excess back in via a power point! Yes it makes almost no financial sense considering the cost of the battery (not to mention getting the calculations right) still, an interesting approach.

https://www.theverge.com/24150901/ecoflow-powerstream-review-diy-balcony-solar-microinverter

 

As an electrician this worries me lol

 

batteries are a great idea BUT the prices are around $1000 per KWH
the average home is anywhere from 15-30kw depending on size and time of year so its likely your battery will only move the power around instead of give the average battery investor total independence from the grid.
most batteries are 5kw-10kw systems so it will cover those peak times if you have a big solar install to move it past that 8-10pm mark.

the biggest opportunity is to do a 10kw battery and use Amber's energy trading with the predictive model.
that means instead of you using the power it gets traded during high's and lows which gives the investor the ability to possibly get into the positives on their bills.

 

The numbers for batteries just don't add up. It's essentially impossible to break even in under 10 years & that's not including the interest you'd save if you had the initial cost still sitting in your mortgage.
We bought a 2KW system 10 or more years ago & that broke even after around 5 or 6 years from memory. Now it essentially pays for our pool pump during the day & we feed almost nothing back into the grid.

 

yes and no, there are ways to install BIG batteries cheaply but they arent brand name.
https://www.deyeinverter.com/ one of these inverters coupled with a bunch of rack mount batteries or your own and you are sitting at or below that $1000 per KW.
you could possibly get away with a 15kw system for between 8-10 thousand.
couple that up with joining amber and building out your own trading algorithm on amber and its highly likely you would be positive credit on your power bill.
https://www.fpv-power.com.au/products/48v-solar-storage-lifepo4-340ah-174kwh


$2000 for the inverter, $4000 for the battery
another $2-4k for sparky and parts
you have a 17.4kw battery

thats $517.24 per kw which is HALF the price (or more) of almost anything on the market.
BUT there are more risks around quality of the inverter and batteries.

for context, on a medium to high usage day im a 35kw house of which 12.5 kw of that is consumed during solar production hours.
that leaves 22.5kw which is pulled currently from the grid.
its winter at the moment so hard to predict my summer solar production but i have a 10kw system
i estimate 30kw around summer time (here in melbourne) so i could charge my battery AND self consume without pulling from the grid then with 17.5kw it would only be towards the early hours of the morning that my battery would run out and pull a little from the grid.

IF i was energy trading instead i would be charging to full during the day and then dumping as much power as i could between 5-8pm and at the highest feed in price and then the crtedit i made there would take me through the night and then some.
rinse/repeat

 

Sorry just to be clear, I'm talking an off the shelf retail system, not a DIY system or recycled parts system.
I've done the numbers twice in the last 5 or so years on off the shelf systems & it's not even close to adding up.

 

I'm completely self-sufficient during spring and autumn; the battery stays full enough to run the house 100% with no grid input. Summer if we run the aircon then we'll end up using some overnight. Winter is shite for solar so we reconfigure it to charge during the middle of the day and at the middle of the night so during peak TOU we're battery powered and paying the lowest consumption rates possible.

Still, not pretending this will offset the cost of the setup any time soon, but it makes me feel nice

 

The numbers are getting closer and closer especially if coupled with a solar setup and energy trading.
That and the possibility of v2g (vehicle to grid) I think we will see people move across in the next 2 years.
If this BS by NSW distributors sticks where you get charged to put energy into the grid I think you will find it adds up very quick.

I've run the numbers on 15 minute AEMO intervals for a 10kw system and if you don't include that outlay then a battery DOES make sense.
Especially if a sub $1k per kw install

 

Personally I cannot wait for vehicle-to-grid to become commonplace. That is when we'll REALLY see battery electric vehicles take off; being able to use a 60kWh+ battery pack on wheels (instead of the measly 5-15kWh units that you strap to the wall)will be a game changer.

 

FWIW Bluetti has a special on right now for their ep760 with 10kw of batteries for about $9k… without installation though…

 

Still not worth it, Add a couple of $K for install and the math on the pay back period would be a decade or more.

 

while true, as power prices continue to rise, and as power becomes more unstable as no states are replacing aging out base load, and you're also covered for storm and other power outages.

as time goes on, that pay back time is going to shrink and shrink and shrink.

 

If you are buying it for power reliability then that's a totally different story, not an issue in my area, I have many a hour or 2 every couple of years. I hear in South African they are all the rage (scheduled rolling black outs due to inadequate grid capacity).

Look I love the idea of batteries but power prices would have to nearly double before they really become a big cost saving.

 

the math on fixed or dual rate power sure but the math on market rate is very different.
energy trading is where things are going for batteries for early adopters much like solar early adopters with those BIG feed in rates.

 

The prices of batteries are dropping quickly. I just put a 5kWh LiFE battery in the camper with my 1.5kW of solar, so far so good. I'm just going through the motions of getting certified to do battery install and then off grid install and I'll probably go off grid after that, the cost to get certified hurts though but off grid is likely going to be the next big thing the way power prices are going

 

I doubt off grid will be more than a niche market. people will still want power when it's overcast/rainy/no wind for a week, and who's installing a week+ worth of battery capacity.

 

With the rate battery prices are dropping, combined with newer cheaper tech like Sodium ion, large batteries may become very affordable in the future. I do a fair bit of remote work so either way getting certified for off grid is something I need to do, but if power prices continue the way they are, then it might actually become a viable alternative

 

Doesn't matter how much storage you have if you can't charge it up for days. I think we'll be stuck with grid connections for a while yet, unless everyone also gets a backup petrol/diesel generator which kinda defeats the purpose.

 

What do you guys think of 2nd hand tesla power walls ? seen a couple online, but not sure i trust them in regards to bursting into flames :/