Tesla Battery

[eggbert]

Anyone here have solar with a power wall installed?
If so, what settings do you use for the backup reserve?

 

[Gargravarr]

I'd be interested to learn from others' experience too, even though my off-grid solar is presently based around a lead-acid battery bank. I plan to change to Li in the not too distant future, though I would prefer not to give my $$$$ to Elon Musk...

Incidentally, @eggbert, I believe the default is 10% of your battery capacity. Even if your solar setup will get going with less, it's never a good idea to drain any battery down to zero. Li batteries generally prefer to be kept charged in the 45-80% range for longer lifetime. The same goes for our phones.

If you have a really intelligent charge controller, it will instantly switch to solar input where possible when under load, so you may not need to drain your battery.

 

[Gargravarr]

Incidentally, my on-grid neighbours "down the hill" were complaining about yet another power outage this morning. I had to restrain myself from being too smug...

 

[eggbert]

Incidentally, my on-grid neighbours "down the hill" were complaining about yet another power outage this morning. I had to restrain myself from being too smug...

That's the main reason I bit the bullet and went for it, otherwise all you are doing is pre-paying your electricity for the next xx years. With the electrical storms we get up here, power loss is a not infrequent occurrence during the wet season.
We are using roughly 1/2 the power we generate on a good day, and that includes charging the battery so we should at least break even over a billing season, so long as my wife can break a few bad habits of putting the washing and dishwashing machines on after the sun has gone down.

 

[Nanook]

I've had my 6kW system for 5 years now and I'm also looking at installing a battery. I wanted to when the panels were installed but was told by the installers to wait a few years. I make so much electricity throughout the day and except for what my pool pump uses and 2 fridges, the rest of it just goes back into the grid. Now that the buy back price is getting smaller and smaller, I think it's the right time to it.

My inverter is a Sungrow so I'll probably stick with them. I can't stand Elon Musk, so unless it's cheaper than the rest. I won't be using a Tesla.

 

[eggbert]

I've had my 6kW system for 5 years now and I'm also looking at installing a battery. I wanted to when the panels were installed but was told by the installers to wait a few years. I make so much electricity throughout the day and except for what my pool pump uses and 2 fridges, the rest of it just goes back into the grid. Now that the buy back price is getting smaller and smaller, I think it's the right time to it.

My inverter is a Sungrow so I'll probably stick with them. I can't stand Elon Musk, so unless it's cheaper than the rest. I won't be using a Tesla.

The energy provider up here changed our rates from $0.27/kWh buy/sell to $0.27/kWh sell, $0.08/kWh buy in their favour which caused is to have to start paying for power again.
That meant from being in credit each quarter we are now having to pay several hundred dollars. Unfortunately they decided there was no grandfathering in of pre-existing contracts with them.

 

[Nanook]

The energy provider up here changed our rates from $0.27/kWh buy/sell to $0.27/kWh sell, $0.08/kWh buy in their favour which caused is to have to start paying for power again.
That meant from being in credit each quarter we are now having to pay several hundred dollars. Unfortunately they decided there was no grandfathering in of pre-existing contracts with them.

I had two big gum trees that shaded my panels in the afternoon which meant I never got to zero. My lowest bill was $80, with all the price hikes it's now around $300. Even though, I had the 2 gum trees removed.

 

[Mark1966]

The energy provider up here changed our rates from $0.27/kWh buy/sell to $0.27/kWh sell, $0.08/kWh buy in their favour which caused is to have to start paying for power again.
That meant from being in credit each quarter we are now having to pay several hundred dollars. Unfortunately they decided there was no grandfathering in of pre-existing contracts with them.

OUCH! I presume you looked very carefully at the existing contracts?

The ACT Government had a ridiculous Feed-In Tariff scheme in the mid to late 2000s. I just snuck in when we built and am getting 50.05c/kWh up to 10 kW capacity (which closed 30 June 2010) as a gross FiT. With consumption rates in the low $0.20s kWh this was really looking SWEET until ...

... we were required to install 'Smart Meters'. Suddenly I was getting bills, small bills but still bills. This is not an isolated experience it seems either ...

 

[Gargravarr]

Grid connect was never an option for us here, as installing poles and wires up our mountain would have been prohibitively expensive. And then we would have to suck up the outrageous power bills that Aurora charge. Given that the power costs virtually nothing to produce (it's all hydro), it's pretty rude, especially when the reliability is (unaccountably) so poor. And now they're telling us that this new cable they're dropping across the Bass Strait to flog power to the North Island is going to somehow magically reduce people's bills here.

Yeah, right.

I have a bridge I'd like to sell them...

 

[Nanook]

I just got a quote to add a 10kW/h battery to my system. I wasn't expecting it to be $14k though. Even so, I was nearly about to go ahead with it but decided not to.

I have a solar hot water system that's on it's last legs so the money will be spent on replacing that instead. I'll revisit the battery in 12 months time.

 

[Monsta_AU]

Batteries for home will not be coming down any time soon due to demand from EV's. We have already seen a cell price increase in the last 6 months where battery pack prices were going down, now it is rising again. If prices for power keep increasing and the batteries remain the same, then we can expect it to be worthwhile to get a battery. Paybacks were around the 10yr mark but if it falls to 8yrs or even 7yrs then there is enough savings there to make it worthwhile.

I just looked at some basic prices and saw a few there that are interesting. Not that I would ever recommend Huawei, but they have a 15kW battery for $11k (pre-installation) which is well under the $1000/kW mark. There's some others similar including the BYD Battery Box well under that price point too.

I am waiting for our energy plan renewal which is May I think. I was able to lock in just prior to all the price rises last year. That will probably be the trigger to get panels on the roof.

 

[Nanook]

The company that were going to install mine said the same thing. Lithium keeps going up in 0rice due to demand so solar batteries aren't going to get any cheaper.

As much as I want a battery because I'm putting more back into the grid than I'm using throughout the day, the hot water heater comes first.

 

[Gargravarr]

As much as I want a battery because I'm putting more back into the grid than I'm using throughout the day, the hot water heater comes first.

Fair enough. But when the war with China gets started in earnest (only a matter of time), it's going to be mighty hard to get batteries or solar panels.

 

[Nanook]

Fair enough. But when the war with China gets started in earnest (only a matter of time), it's going to be mighty hard to get batteries or solar panels.

China can't afford a war, sanctions will absolutely devastate their economy and they know it.

Like North Korea, they will huff and puff, but won't do anything else.

 

[Gargravarr]

China can't afford a war, sanctions will absolutely devastate their economy and they know it.

Like North Korea, they will huff and puff, but won't do anything else.

Let's hope you're right, but if they go on pulling everyone's rag, they might end up with a war, regardless of whether or not it's good for business.

 

[Nanook]

Let's hope you're right, but if they go on pulling everyone's rag, they might end up with a war, regardless of whether or not it's good for business.

I've had some experience with China's navy and army during my service and they aren't that good.

Yes, they are modernising and have more ship's than the US but they don't know how to use them as they gave no idea on tactics.

The only advantage they have is there are more of them but that will only take them so far.

 

[glenos]

Back on topic. I've been getting quotes for 6.6kW and 7.8kW PV system. Prices are quite high down here compared to interstate.
6.6kW $7500 - $10000+ depending on panels and inverter.
7.8kW adds about $1500.

Thinking of going with Trina S panels and Sungrow inverter and probably 7.8kW panels, 6kW inverter. N (60%) and W (40%) faces.

 

[glenos]

no idea on tactics.

My observation as a tourist is there is such a strong culture of "me first" and trying to get things done as fast and cheap as possible with a decent facade but a lack of ensuring durability.

 

[Nanook]

Back on topic. I've been getting quotes for 6.6kW and 7.8kW PV system. Prices are quite high down here compared to interstate.
6.6kW $7500 - $10000+ depending on panels and inverter.
7.8kW adds about $1500.

Thinking of going with Trina S panels and Sungrow inverter and probably 7.8kW panels, 6kW inverter. N (60%) and W (40%) faces.

My inverter is a Sungrow, I've had it for 5 years now with no issues whatsoever. I definitely recommend them.

My panels are Canadian Solar made and are designed for low light. Even after the sun sets, they're still making power.

 

[Monsta_AU]

Back on topic. I've been getting quotes for 6.6kW and 7.8kW PV system. Prices are quite high down here compared to interstate.
6.6kW $7500 - $10000+ depending on panels and inverter.
7.8kW adds about $1500.

Thinking of going with Trina S panels and Sungrow inverter and probably 7.8kW panels, 6kW inverter. N (60%) and W (40%) faces.

Sungrow is good. Look at the batteries and what is compatible with what. Depending on your roof and aspect you might actually be better with Microinverters and face panels dfiffernt directions. Extracting max efficiency for longest is the name of the game down south.

Down there, you are probably better off to overspec the panels and inverter to get as much production as you can, especially in winter. If you can get a battery then you will want to get as much juice into it as you can during winter especially. Most of them will cap the grid export to 5kW which seems to be standard.