Tesla Solar and Powerwall Install Complete - SoCal Oct 2021

[yblaser]

1 month is reasonable. My project is still stuck at LA county permit office since before Thanksgiving,

Sorry to hear you are still waiting on permits. I think it took a little less than two months to get my permits issued from the city.

 

[yblaser]

It's been 1 year since PTO for my system and just received my SCE Settlement Bill. I ended up being a net producer by 240 kWh. SCE credited me for the net production at $0.07276/kWh which was a bit higher than I expected. I ended the year with a net energy credit of about $300 so certainly room to use more power this year .

Ignoring NEM for the moment, my gross consumption from the grid was reduced by 73% from roughly 1100 kWh/month to 290 kWh/month. It's good to know that even if NEM disappeared I could still save a decent amount of money unless they add fixed charges for solar customers. I operate in self powered mode during late winter, spring, and summer with a 30-40% reserve so that probably went a long way in reducing my gross consumption from the grid.

Over the year I ended up paying SCE about $275 with $90 of it being NBCs, $160 from daily basic charges ($0.46/day) on TOU-D-PRIME, and the remaining taxes. I could probably save about $100/year by switching to TOU-D-4-9PM that has a lower daily basic charge ($0.03/day) but does have a MDC ($0.35/day). I also found it interesting that the city utility tax is charged on the monthly net energy charges each month so I get taxed on those charges even though I do not end up paying them in the end due to carry over energy credits.

 

[hkninja]

Our current electrical bill is $200-$300 per month so I am expecting to save about $200/month on average. I haven't done the detailed calculation on the ROI, but if you simply look at the breakeven point (i.e at what point have a saved on my electric bills to equal the cost of the system ignoring the cost of the upfront money and lost interest) if I had just gotten solar it is ~5 years. Powerwalls themselves don't actually save you much money given the current NEM. They do help you not buy power at peak times, but when I did that calculation the breakeven point for the powerwalls alone was over 20 years beyond the expected life of the powerwalls. Instead I look at it as the savings from the solar are subsidizing the powerwalls and the breakeven point of the whole system is on the order of 10 years.

I know some people say that looking at the breakeven point is not the way to look at it, but it's easy math I can do in my head.

I've ordered Tesla's 14kWh system with two Powerwalls. If you were to do this again, would you still purchase the Powerwalls?

 

[yblaser]

I've ordered Tesla's 14kWh system with two Powerwalls. If you were to do this again, would you still purchase the Powerwalls?

I would but I think the decision is really based on one's personal value they put on Powerwalls. Looking at Powerwalls purely by themselves they are never going to financially pay for themselves in terms of money saved.

Our electricity service is pretty reliable here and the only outage longer than a minute I've had since installing was a 10 hour scheduled outage. It was sure nice to have them on that day but probably doesn't make up for the cost.

Personally the value I put in them is that I can use more of my own generated solar power, I can be less dependant on the grid, and I can put a miniscule dent in the duck curve. It also insulates me from future TOU price structures that will likely further reduce the value of energy during solar producing hours.

Looking at the system as a whole adding the Powerwalls increased the "break even" point from roughly 5 years for solar only to 10 years with Powerwalls. I view it as I'm using the money I would have saved with a solar only system to pay for the Powerwalls.

 

[h2ofun]

I would but I think the decision is really based on one's personal value they put on Powerwalls. Looking at Powerwalls purely by themselves they are never going to financially pay for themselves in terms of money saved.

Our electricity service is pretty reliable here and the only outage longer than a minute I've had since installing was a 10 hour scheduled outage. It was sure nice to have them on that day but probably doesn't make up for the cost.

Personally the value I put in them is that I can use more of my own generated solar power, I can be less dependant on the grid, and I can put a miniscule dent in the duck curve. It also insulates me from future TOU price structures that will likely further reduce the value of energy during solar producing hours.

Looking at the system as a whole adding the Powerwalls increased the "break even" point from roughly 5 years for solar only to 10 years with Powerwalls. I view it as I'm using the money I would have saved with a solar only system to pay for the Powerwalls.

I have a number of folks working on getting solar. I tell them all ignore powerwalls, not worth the money. Instead, put as much
solar on as they can fit!! I have 7 Pw's, and have yet to have a power outage. They are just another thing to break and deal with.
I am trying to get my solar/batteries rewired so they work the way I wanted, but so far, installer does not want to learn the little stuff
that would have to be done to do this. Frustrating.

 

[charlesj]

... but so far, installer does not want to learn the little stuff
that would have to be done to do this. Frustrating.

Another installer perhaps is more willing?