PITA
Model 3 Performance
That moment... when 'Winter' has died... the Grid has flat-lined and Summer is coming...
100% Self-Powered
100% Solar
100% Self-Powered
100% Solar
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Solar Panels UK - is it worth it?
- Thread starter jdwuk
- Start date
RedMod3
Member
That’s good, but with only one Powerwall, this is the best I can do. My second Powerwall could come in a month.
The blips were me charging the M3P and the immersion.
My Uncle is being offered Pylontech US 2000 batteries with a 5.25kW 14 panel solar install (QCell 375watt panels and Solis inverter)
The choice is 4.3, 6.5 or 8.6KWh.
Does anyone know their max charge/discharge rate?
I can’t find it anywhere
The choice is 4.3, 6.5 or 8.6KWh.
Does anyone know their max charge/discharge rate?
I can’t find it anywhere
PITA
Model 3 Performance
Here's an interesting combination.
Our house is running Self-Powered at the moment on two Powerwalls.
Tonight they're about 44% full, which is good. Ready to take on more Solar tomorrow.
But... our M3P car needs a 15% top up tonight. If I use the 7kW charger, will it charge from the Powerwalls tonight at 00:30 ? ... or will it charge from the Grid?
Reason I ask, is that the Powerwalls are in Self-Powered mode, and the cheapest power would be from them, not the Grid. In Self-Powered mode the Powerwalls won't be charging at 00:30 so they would be available to discharge.
But... I don't want to disturb the Powerwalls charge level at the moment.
Any guesses
Our house is running Self-Powered at the moment on two Powerwalls.
Tonight they're about 44% full, which is good. Ready to take on more Solar tomorrow.
But... our M3P car needs a 15% top up tonight. If I use the 7kW charger, will it charge from the Powerwalls tonight at 00:30 ? ... or will it charge from the Grid?
Reason I ask, is that the Powerwalls are in Self-Powered mode, and the cheapest power would be from them, not the Grid. In Self-Powered mode the Powerwalls won't be charging at 00:30 so they would be available to discharge.
But... I don't want to disturb the Powerwalls charge level at the moment.
Any guesses
RedMod3
Member
I reckon the charge will be taken from the PW as when I'm using my solar diverter, it drains power from the PW when there isn't enough free solar.Here's an interesting combination.
Our house is running Self-Powered at the moment on two Powerwalls.
Tonight they're about 44% full, which is good. Ready to take on more Solar tomorrow.
But... our M3P car needs a 15% top up tonight. If I use the 7kW charger, will it charge from the Powerwalls tonight at 00:30 ? ... or will it charge from the Grid?
Reason I ask, is that the Powerwalls are in Self-Powered mode, and the cheapest power would be from them, not the Grid. In Self-Powered mode the Powerwalls won't be charging at 00:30 so they would be available to discharge.
But... I don't want to disturb the Powerwalls charge level at the moment.
Any guesses
Today, for the 4th day running, I've used no peak grid power, but I've had to use some 5p GO power to charge my single PW as one PW is now enough.
Just had my Octopus bill for the last month, it was £79.99, a good reduction, but it will reduce further with my second PW.
PITA
Model 3 Performance
Yes I agree, I think it would. The only way to stop it would be to put the Powerwalls Backup percentage to 44%... and stop it from drawing any power past this point. Downside is it's Manually Set... so the house would start drawing from the Grid until the backup percentage was manually reset at a lower limit... as it'd be the middle of the night, you'd have to remember for the morning.
Hmmm...
Well, I found a way around it anyways. I've plugged the 3 Phase charger in instead, which bypasses the Powerwalls completely, and goes straight to the Grid on scheduled charge at 00:30
This means the Powerwalls can remain at peace, doing their thing without any Ev interruption.
I mentioned this scenario, because having a second car charger wired up for Grid only, can have some benefits, if you don't want to disturb the home's Powerwall levels.
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RedMod3
Member
Agreed, my Granny Charger is on my 5th terminal and outside the PW control, and I use it for that purpose too.
PITA
Model 3 Performance
WannabeOwner
Well-Known Member
Curious why not use the 44% in the powerwalls?
Assuming sunny tomorrow, then I want my Powerwall down close to 0% by the time that the PV starts charging Powerwall.
I have too much background usage / not enough Powerwall to get through the night, they are down to the 10% reserve by 5AM. I'm on E7 - 00:00 - 07:00 - shortly before 07:00 I drop the reserve from 10% to 5% - accepting possible risk of powercut (mine are typically just a second or two), and then the powerwalls start charging by 7:30 or 8:00.
I'd be happy to put any overnight excess from PowerWall into Car, and then remainder for Car, or House, from grid during off peak, and then back on PowerWall from when Off Peak ends until PV can charge the PowerWall again.
I'm looking for optimum setup for my system (recently added PV so now in position of too much daytime PV), hence curious as to how others mange their systems
PITA
Model 3 Performance
Yeah good question.
I'm at home all day, so can 'spot' charge the car at a moments notice 100% from Solar... if Solar is in excess during the day.
For our Solar Array the most we'll get is 30kWh at this time of year... and I can easily use 25kWh of that with Heat Pump and other stuff during the full day.
Which means I'd rather have 44% left in the Powerwalls overnight for backup purposes, knowing I'll have plenty of excess storage tomorrow anyways... and the 11kW I topped up the car with has only cost me 82p
Just balancing risk, capacity, and solar expectations... 'messing about' basically
scdoubleu
Member
With the PWs in Self-Powered mode, they will supply the power to the car regardless of the time of day. A 15% top-up will probably draw about 10-12 kWh. Add on the house load, with 44% in the PWs you'll probably drain them before sunrise!
PITA
Model 3 Performance
Yep... agreed.
When using the 3 Phase charger, it's wired separately 'upstream' to the Powerwalls... so the Gateway doesn't see it.
This means I can just jump on that anytime and it doesn't affect the Powerwall charge status, or Solar Power Diversion.
Also, being upstream, it doesn't ruin my 100% off-grid Home Stats in the Tesla App
RedMod3
Member
I'm curious, why are you using the heat pump? We turned ours off two weeks ago as the weather got warmer?
Otherwise, when I get my 2nd PW, I think we will have near identical generation and use stats as well as IT infrastructure, but each of our set-ups tailored to our specific needs.
WannabeOwner
Well-Known Member
Me tooI'm thinking that what I would like is some API stuff to do things like that "unattended".
e.g. when PowerWalls get to 95% start charging the car / dump to any other sources. If PowerAll gets to 96% then increase the AMPs on those ... and as it falls reduce the AMPs.
And when we get to, say, 4PM then stop doing that so PowerWall can get to 100% before the sun goes down ...
... and have best-I-can indication of Weather Input, and adjust for if expected to be "wall to wall sun" or "cloudy"
Maybe I should just let the Zappi charge the car when it detects some Export ... although I do wonder how much exports before it reacts - over the last few really sunny days I've had to charge the car at 32AMP to get to the point where PowerWalls actually have to contribute ... maybe Zappi will do that and save me messing around with "prediction", don't have enough data / experience yet to decide on that (and awaiting some improvements to my CONFIG before the logged data will actually be valuable)
I think the zappi will track export and once it gets to the minimum charge rate (6a?) it will start at that, then track against output, varying as required up to your chargers max. I think.
I'm thinking that what I would like is some API stuff to do things like that "unattended".
e.g. when PowerWalls get to 95% start charging the car / dump to any other sources. If PowerAll gets to 96% then increase the AMPs on those ... and as it falls reduce the AMPs.
And when we get to, say, 4PM then stop doing that so PowerWall can get to 100% before the sun goes down ...
... and have best-I-can indication of Weather Input, and adjust for if expected to be "wall to wall sun" or "cloudy"
Maybe I should just let the Zappi charge the car when it detects some Export ... although I do wonder how much exports before it reacts - over the last few really sunny days I've had to charge the car at 32AMP to get to the point where PowerWalls actually have to contribute ... maybe Zappi will do that and save me messing around with "prediction", don't have enough data / experience yet to decide on that (and awaiting some improvements to my CONFIG before the logged data will actually be valuable)
PITA
Model 3 Performance
I'm curious, why are you using the heat pump? We turned ours off two weeks ago as the weather got warmer?
Otherwise, when I get my 2nd PW, I think we will have near identical generation and use stats as well as IT infrastructure, but each of our set-ups tailored to our specific needs.
Air Conditioning...
Our Sons bedroom is South facing, so he likes the Air Conditioning feature.
Well... I'm blaming him, but as Summer comes around we'll all have the Air Conditioning on in the bedrooms throughout the night. Get a much better night's sleep.
These Toshiba Haori wall units are whisper silent... as the Heat Pump compressor is outside a long way away...
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RedMod3
Member
I get it, only ours are turned off, and I agree, the Toshiba wall units are whisper quiet. Our units are off at the moment, but come summer one room warms up by IT and needs cooling.
Attachments
@PITA/@RedMod3 - do you mind me asking what external compressors you have paired with those and how noisy/big they are? Thanks.
I looked at a relative’s large external Samsung unit recently (air-to-water) - and once I got more than three or four metres away - I was thinking the local road/aircraft noise was louder. The air-to-water setup needed a lot of ‘plant’ in the loft. But I’m suspecting air-to-air plant requirements might be near nought.
(PITA - I remember you mentioning new installs would also need to consider the condensate pump need/siting)
I looked at a relative’s large external Samsung unit recently (air-to-water) - and once I got more than three or four metres away - I was thinking the local road/aircraft noise was louder. The air-to-water setup needed a lot of ‘plant’ in the loft. But I’m suspecting air-to-air plant requirements might be near nought.
(PITA - I remember you mentioning new installs would also need to consider the condensate pump need/siting)
PITA
Model 3 Performance
Lot of answers here...
Each wall unit can have it's own dedicated compressor. This gives you the advantage of being able to set preferences independently per room. Each room can choose hot or cold as an example.
Our system is different, it's called a Split System where all 4 internal wall units are connected to one outside compressor (which handles all 4 units). The downside is, all units have to be on cool mode, or heat mode at the same time. So there's no ability to have heating on one, cooling on the other, at the same time.
Each wall unit has to get rid of condensate. If the wall unit is on an external wall, then you can simply use a gravity feed pipe routed through the wall to outside, which is silent.
Upstairs in our bedrooms, the units are not always best sited on external walls. So we route all the condensate pipes upwards into the loft space. Here we have peristaltic pumps which suck the water out and down the outside wall, inside conduit ducting.
The peristaltic pumps are about 8 feet away up in the loft on acoustic damping boards, so you cannot hear them.
If you install level pumps alongside the wall units... they trigger when the water level reaches a point... and then turns on to suck the water away. These are noisy and no good for bedrooms, as they're too close to the wall units.
Doesn't matter how quiet the wall units are, if the attached pump is 40 dB... and turn on and off randomly... it'll disturb your sleep.
Our setup is 'quality hotel' quiet... you can only hear slight airflow.
Outside, the compressor units are very very quiet. Ours is about 5 metres from our neighbour and she didn't even know it was there.
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