Questions: Solar, but want battery

[whydontwe]

I have a 7kw system on SCE but from NRG using SolarEdge inverters. Almost $0 dollar bills. Sometimes it's $6 up to $20. I have a MYLR.

I am interested in a Powerwall, maybe 1 or 2, unsure.

Will I be able to monitor real time usage on the Tesla app? Also, who's a good retailer in the So Cal area?

 

[arnolddeleon]

Yes, you will give some rough form of real time usage and production.

I'm assuming you are not really looking to save money since you don't have any real bill to offset unless you are planning to increase your usage dramatically.

 

[jjrandorin]

I have a 7kw system on SCE but from NRG using SolarEdge inverters. Almost $0 dollar bills. Sometimes it's $6 up to $20. I have a MYLR.

I am interested in a Powerwall, maybe 1 or 2, unsure.

Will I be able to monitor real time usage on the Tesla app? Also, who's a good retailer in the So Cal area?

What is the driver for wanting a powerwall? Its not time shifting since you already have zero bill you say. It shouldnt be "I want to charge my car with my powerwalls" since buying powerwalls to do that doesnt make much sense (its like using 2 AAAs to charge 3-4 D batteries. Possible? sure. Make long term sense? No, since the car has a 75ish kW batttery and 1 powerwall is 13.5kW (so 2 is 27kW).

If its for backup / power outage, or to hedge against higher rates that makes sense, but its going to be a while to never for it to financially pay for itself.

 

[arnolddeleon]

What is the driver for wanting a powerwall? Its not time shifting since you already have zero bill you say. It shouldnt be "I want to charge my car with my powerwalls" since buying powerwalls to do that doesnt make much sense (its like using 2 AAAs to charge 3-4 D batteries. Possible? sure. Make long term sense? No, since the car has a 75ish kW batttery and 1 powerwall is 13.5kW (so 2 is 27kW).

If its for backup / power outage, or to hedge against higher rates that makes sense, but its going to be a while to never for it to financially pay for itself.

I would add that this is ok. Not all purchasing decisions have to have easy to quantify economic returns. I used to compare my first solar purchase as akin to people buying boats. The economic return wasn't really there (it was larger than what made economic sense) but it gave me great pleasure. The fact that I got some economic benefit was a bonus.

 

[jjrandorin]

I would add that this is ok. Not all purchasing decisions have to have easy to quantify economic returns. I used to compare my first solar purchase as akin to people buying boats. The economic return wasn't really there (it was larger than what made economic sense) but it gave me great pleasure. The fact that I got some economic benefit was a bonus.

Yeah I agree. I have 2 powerwalls myself, and I am still on nem 1 with a tiered rate plan. My driver was more self reliance / less reliance on grid power so I could reasonably not worry about losing food again through another Power safety shutoff. I didnt really care if it penciled out or not. I have been exceedingly happy with my 2 powerwalls, but I didnt try to buy them for "ROI" or something.

Thus the question on "whats the driver?" A lot of people think they should have one to charge their car, etc.

 

[Matt-FL]

I think Powerwalls become a viable option for resiliency, and for anyone on a non-1:1 buy/sell ratio. For me, I wanted resiliency and I have a non 1:1 ratio, so it was a win/win. Ok, maybe a win/tie.

 

[jgleigh]

My ROI with batteries is probably 10-15 years compared to 5-7 years with just solar, but there are so many benefits to having the batteries that it was worth it for me. Most of the year, I'm able to run my house fully off solar/battery unless we're charging the cars. It's nice to be somewhat self-sufficient. I think people saying you'll never get your money back from batteries assume the batteries die on the day the warranty expires. Most likely they'll continue to function well after that, but maybe with reduced capacity.

 

[Matt-FL]

My ROI with batteries is just over 10 years. I'm coming up on 10 months installed, and my calculations have my savings at $4,141. Figuring around $4,500 by 1 year mark. However, like you, I saw far more benefits for batteries that I didn't calculate them into my system ROI. My thoughts were, in 10 years or so - when I may have to consider replacing the PWs, there would be newer, better (and hopefully cheaper) alternatives.

 

[RoBoRaT]

I have a 7kw system on SCE but from NRG using SolarEdge inverters. Almost $0 dollar bills. Sometimes it's $6 up to $20. I have a MYLR.

I am interested in a Powerwall, maybe 1 or 2, unsure.

Will I be able to monitor real time usage on the Tesla app? Also, who's a good retailer in the So Cal area?

Check out Baker Electric Home Energy.

They are based in Escondido but services SoCal since 1938. They installed my solar PV panels (non-Tesla with SolarEdge inverters) and 2 Powerwalls. Good install and warranty service.

Baker Solar, Battery Heating, and Air | Baker Home Energy

We are the best Solar Electric Company in San Diego County providing high-quality solar, home batteries, heating & air services.

bakerhomeenergy.com

 

[whydontwe]

Yes, you will give some rough form of real time usage and production.

I'm assuming you are not really looking to save money since you don't have any real bill to offset unless you are planning to increase your usage dramatically.

I am looking to save money...I recently installed a heat pump HVAC for cooling/heating, so I anticipate my bill going up a bit.

 

[Matt-FL]

Probably slightly off-topic, but using a soft start or purchasing a variable stage heat pump HVAC can help reduce the initial amperage spike of a system startup. My prior 5 ton AC would spike at 83 amps startup, the soft-start unit dropped that down to the low 50's. That could mean the different between two or three powerwalls for initial load spikes. My old AC kicked the bucket, and I paid a little extra for a variable stage heat pump and variable speed air handler. That reduced the starting amperage to mid 40's. Which, by the way, if anyone needs a Micro-Air Easy Start 5 ton (368-X72), I've got an extra now.

 

[tomuo]

I used Semper Solaris in Los Angeles. Solid company.

 

[Konicom04]

I would add that this is ok. Not all purchasing decisions have to have easy to quantify economic returns. I used to compare my first solar purchase as akin to people buying boats. The economic return wasn't really there (it was larger than what made economic sense) but it gave me great pleasure. The fact that I got some economic benefit was a bonus.

Thats brilliant point.
For me - the decision to go solar was simple once I understood what portion of my bill was actual energy, and what portion was taxes and fees.

 

[GregBallantyne]

My ROI with batteries is just over 10 years. I'm coming up on 10 months installed, and my calculations have my savings at $4,141. Figuring around $4,500 by 1 year mark. However, like you, I saw far more benefits for batteries that I didn't calculate them into my system ROI. My thoughts were, in 10 years or so - when I may have to consider replacing the PWs, there would be newer, better (and hopefully cheaper) alternatives.

Or, rather than replacing, I think about adding in the future. If my PW capacity drops enough to make that a consideration, perhaps a better PW will be available to add capacity. The remaining capacity in the older PWs will still have plenty of value, assuming they don't just crap out.... I'm with you on the ROI subject - if that was my aim, I'm probably on the wrong journey!

With regard to the OP, a heat pump most likely translates to 2 PW minimum depending on size. My variable speed system would start with 2 PW, but it's a 2 ton unit. I went with 3 due to run time availability without grid anyhow, along with whole house backup. But if ROI is your aim rather than power security, that changes the calculation. If low bill is your priority along with power security, you could also begin to see some generation shortfalls develop running the heat pump with a smaller solar array. The app does give you real time house demand monitoring, but just one number. No greater granularity that I'm aware of.