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Expanding Tesla Solar Panels with vs without Powerwall+ (& Backup Switch?) questions

Mardak

Active Member
Oct 13, 2018
1,901
4,249
USA
We're thinking of more than doubling our existing Tesla Solar Panels, so using up all available roof space (all South-facing is used already) probably resulting in many years of rollover energy credits. We've been using the utility as a better-than-battery energy multiplier as we sell credits at peak summer hours to buy back many times more kWh at EV charging rates, so combined with Tesla's low prices, this has allowed for much sooner breakeven in cost. I think this extra nighttime energy usage from charging 2 Tesla vehicles will allow us to oversize our solar expansion if calculated based on kWh delivered from the grid.

If we go without batteries, what inverter might we get nowadays? We basically went the whole summer season without solar waiting for SolarEdge inverter replacement for hardware failure.

Is it worthwhile to try to get Tesla to combine the existing solar installation with the expansion to not be dependent on SolarEdge inverters even if it costs (much?) more?

If we do get batteries, does that basically ensure a Powerwall+ with Tesla inverter?

We don't really have grid outages and aren't usually home during peak production (overlaps peak grid) hours, so backup protection and load shifting (we'll have excess energy credits anyway) isn't as useful for us, so is the main benefit then monitoring? If so, then a single Powerwall+ would provide that benefit?

I believe with the Clean Energy Credit changes with Inflation Reduction Act, starting in 2023, the 30% credit for battery storage will allow it to be charged from the grid instead of previously requiring exclusive solar charging (if claiming the tax credit). Is that grid-charging ability useful enough to wait until next year?

Our utility / public utilities commision currently doesn't provide incentives for dynamic battery response, so might it still be beneficial to install batteries ahead of time for some potential future virtual power plant paying out per kWh or kW? Although the utility does provide a $3k upfront incentive that caps out basically with 1 Powerwall's kWh probably as a broad way to get at the benefits of a virtual power plant without actually needing to measure the dynamic energy or power response? Maybe we can double-dip with the upfront credit and potential future incentives? 🤷‍♂️

It sounds like our utility is evaluating Tesla's Backup Switch and might have a decision soon. Should we wait for that as it seems like Tesla offers $500 discount for the simpler installation with whole home backup?

On the note of waiting, we're not in a particular rush for any of this, so we're okay with delays but probably more importantly, anything that we should hold off on? Tesla only does Solar Roofs through certified installers here, but maybe we can wait for Tesla installers to maximize solar production of our roof? Significant upcoming improvements to batteries in the next year?

I guess overall, we're okay with building out excess solar even if it's not the best return on investment as hopefully it does indirectly benefit the neighborhood. We're less sure about the actual benefits of batteries in our case, so maybe 1 is good but more might just be wasteful (not just money but actual resources too)?
 
We're thinking of more than doubling our existing Tesla Solar Panels, so using up all available roof space (all South-facing is used already) probably resulting in many years of rollover energy credits. We've been using the utility as a better-than-battery energy multiplier as we sell credits at peak summer hours to buy back many times more kWh at EV charging rates, so combined with Tesla's low prices, this has allowed for much sooner breakeven in cost. I think this extra nighttime energy usage from charging 2 Tesla vehicles will allow us to oversize our solar expansion if calculated based on kWh delivered from the grid.

If we go without batteries, what inverter might we get nowadays? We basically went the whole summer season without solar waiting for SolarEdge inverter replacement for hardware failure.

Is it worthwhile to try to get Tesla to combine the existing solar installation with the expansion to not be dependent on SolarEdge inverters even if it costs (much?) more?

If we do get batteries, does that basically ensure a Powerwall+ with Tesla inverter?

We don't really have grid outages and aren't usually home during peak production (overlaps peak grid) hours, so backup protection and load shifting (we'll have excess energy credits anyway) isn't as useful for us, so is the main benefit then monitoring? If so, then a single Powerwall+ would provide that benefit?

I believe with the Clean Energy Credit changes with Inflation Reduction Act, starting in 2023, the 30% credit for battery storage will allow it to be charged from the grid instead of previously requiring exclusive solar charging (if claiming the tax credit). Is that grid-charging ability useful enough to wait until next year?

Our utility / public utilities commision currently doesn't provide incentives for dynamic battery response, so might it still be beneficial to install batteries ahead of time for some potential future virtual power plant paying out per kWh or kW? Although the utility does provide a $3k upfront incentive that caps out basically with 1 Powerwall's kWh probably as a broad way to get at the benefits of a virtual power plant without actually needing to measure the dynamic energy or power response? Maybe we can double-dip with the upfront credit and potential future incentives? 🤷‍♂️

It sounds like our utility is evaluating Tesla's Backup Switch and might have a decision soon. Should we wait for that as it seems like Tesla offers $500 discount for the simpler installation with whole home backup?

On the note of waiting, we're not in a particular rush for any of this, so we're okay with delays but probably more importantly, anything that we should hold off on? Tesla only does Solar Roofs through certified installers here, but maybe we can wait for Tesla installers to maximize solar production of our roof? Significant upcoming improvements to batteries in the next year?

I guess overall, we're okay with building out excess solar even if it's not the best return on investment as hopefully it does indirectly benefit the neighborhood. We're less sure about the actual benefits of batteries in our case, so maybe 1 is good but more might just be wasteful (not just money but actual resources too)?
Tesla is strange. An acquaintance of mine bought a house that had Solar CIty panels on it. He went to Tesla to buy a powerwall. They refused. A year or so later he got a design order for more panels from Tesla Energy. They were ready to go until Tesla cancelled and said since the Solar CIty panels weren't paid off they would NOT do it. So your questions begs the response. FInd somebody else to do the panels and there are other batteries besides powerwall. If you can afford it get a battery so when the grid goes out (Don't know where you live) for days you'll have the only house in the neighborhood with lights like that community in Florida that had power after hurricane Ian
 

Mardak

Active Member
Oct 13, 2018
1,901
4,249
USA
They were ready to go until Tesla cancelled and said since the Solar CIty panels weren't paid off they would NOT do it
That's good to know. The Tesla technician who replaced the SolarEdge inverter also seemed initially concerned about trying to modify the existing setup but was more okay after realizing the existing panels were paid off. I think he also pointed out the difference in optimizers if trying to change inverters.

Find somebody else to do the panels and there are other batteries besides powerwall
I suppose is there much "future potential" with other installers? E.g., Tesla putting together a virtual power plant from existing installs? Or is that more of what the local utility / PUC allows? I've heard of people around here where the installers went out of business leading to even worse maintenance issues, but that's something I can do more research on who's available here.
 
That's good to know. The Tesla technician who replaced the SolarEdge inverter also seemed initially concerned about trying to modify the existing setup but was more okay after realizing the existing panels were paid off. I think he also pointed out the difference in optimizers if trying to change inverters.


I suppose is there much "future potential" with other installers? E.g., Tesla putting together a virtual power plant from existing installs? Or is that more of what the local utility / PUC allows? I've heard of people around here where the installers went out of business leading to even worse maintenance issues, but that's something I can do more research on who's available here.
I don't know where you are but Sunrun I believe is national
 
Seems like they can leave a state with no service support. Rooftop-solar company Sunrun says it is also exiting Nevada

Did you have a bad experience with Tesla Energy service and/or Powerwall?
It is true that about 7 years ago, NV changed the rules for a short time and most all solar companies stopped installing during that time.

This had nothing to do with Sunrun specifically but the political climate in Nevada. My understanding is that Sunrun didn't leave existing customers high and dry but I am sure that year's service waits weren't pretty.
 

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