Home/Residential Solar

[Drayday55]

FWIW, my 11kW system in FL (all South facing) made an average of 43kWh per day in 2021.

That was good enough for 100% offset of electric usage for my all-electric house (AC, Heater, water heater, stove, dryer, etc) and 2 EVs, but it wouldn’t even cover the usage of the Lightning driving 100 miles/day of that’s the goal.

I just finished my first full day of driving my lightning. Just added a 9kw system at my house on top of my original 5kw system that was existing. My original system produces an average of 24kw on good days. 33 on best days. My new system does about 40k on good days so far since installed October 17th.

We consume 50ish kw per day in summer ( 1400sf house in San diego) and about 30kw rest of the year.

I'm starting to realize I won't be able to power the Lightning purely off solar like I had hoped.

I have to drive less than 65 miles a day to come close. Most days I drive 80 to 100.

One problem with my formula is I'm going off straight kwh without considering actual energy cost. I'm hoping charging midnight to 6am at .10 cents a kwh will be less than or equal to the energy we produce in surplus during the day.
We use a lot of energy during peak hours 4 to 9pm. I'm gonna avoid charging during this time.

I know my energy costs but I'm not exactly sure what I get paid for my excess production. Im sure it's in the utility company's favor.

My original system is a early enphase m215 solar city 300 watt panel system.

New system is solar edge. From what I understand. Enpahse and solar edge are pretty close in terms of quality now. We shall see

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[Joneii]

i guess i have an alternate question. Being active duty military and moving every 3 years. This is the home we will retire at. It seems the price of panels are going down but labor and inflation are going up. Is it worth it to install panels now or later down the road?

How far from retirement are you? My wife and I were in the same boat, but are currently retired in our forever home with 20 kW solar system. However, when we were 15 years away from retirement we thought our forever home would be in the mountains of New Mexico. Then we had kids, our parents got older and needed help, life happened and we bought our forever home about 4 years before retirement in PA. We love it and it worked out nice for us, but the point is that a lot can change depending how much time you have.
That being said, we installed a 10 kW system during renovation about 3 years before we retired and moved to the house. It generated electricity and since no one was using power at the house and PA has net metering rules that require the power company to pay us what they charge us for power, we put a good dent into the payback of that system. After we lived there a couple of years and began to consider that our future would include an EV, we installed another 10 kW on the barn. If you can afford to install more, I would (especially if the net metering rules are favorable). Also consider designing a system for battery storage. When we did our system batteries were so expensive that we couldn’t make them make financial sense. Now that we have a giant rolling battery backup (ie, the Lightning) I wish we had gone with an inverter that could make better use of our system in a grid down scenario. We have SMA inverters with the Secure Power Sockets, but being able use our whole system instead of just a small portion in a grid down scenario would be better (SMA’s Sunny Island could do this and I’m sure other manufacturers make similar products). Try to future proof as much as you can afford. Once you retire and are on a fixed income you lose some financial flexibility (unless, of course, you get another…job…shhh, sorry-I try not to use such terrible language).

 

[Capertrj]

Just making sure I follow the question. So any solar you install now, will most likely no longer be used in 3 years until you retire at the house. Is that correct?

Very generally, I look back at my first system (10kW) and the only regret I had was not installing more which is why I have my 2nd system (36kW). The price per kW was about the same. Cost of materials went down, cost of labor went up. At the same time my 2nd systems installation was far better - as well as service, but the equipment has been less reliable.

I think an answer to your question depends on the 1st part. Will it only be used for 3 years and then not again for how long?

would use system for couple of years. Residence would then be rental, system would be used just not by me (which could factor into rent). Ideally would return in about 6 years but it’s unpredictable. Either way will end back here.

 

[Capertrj]

How far from retirement are you? My wife and I were in the same boat, but are currently retired in our forever home with 20 kW solar system. However, when we were 15 years away from retirement we thought our forever home would be in the mountains of New Mexico. Then we had kids, our parents got older and needed help, life happened and we bought our forever home about 4 years before retirement in PA. We love it and it worked out nice for us, but the point is that a lot can change depending how much time you have.
That being said, we installed a 10 kW system during renovation about 3 years before we retired and moved to the house. It generated electricity and since no one was using power at the house and PA has net metering rules that require the power company to pay us what they charge us for power, we put a good dent into the payback of that system. After we lived there a couple of years and began to consider that our future would include an EV, we installed another 10 kW on the barn. If you can afford to install more, I would (especially if the net metering rules are favorable). Also consider designing a system for battery storage. When we did our system batteries were so expensive that we couldn’t make them make financial sense. Now that we have a giant rolling battery backup (ie, the Lightning) I wish we had gone with an inverter that could make better use of our system in a grid down scenario. We have SMA inverters with the Secure Power Sockets, but being able use our whole system instead of just a small portion in a grid down scenario would be better (SMA’s Sunny Island could do this and I’m sure other manufacturers make similar products). Try to future proof as much as you can afford. Once you retire and are on a fixed income you lose some financial flexibility (unless, of course, you get another…job…shhh, sorry-I try not to use such terrible language).

About 8 to get to 20. Play it by ear at that point. Have family up here already so that takes a variable out of the picture. Puttin in a lot of work now to update (electrical, heat, AC). This is kinda the last thing on my radar that can be done. With the house now electrified and Maine having pretty high electricity rates, figured it makes sense.

roof is about 5-6 years old which is also nice.

 

[Yellow Buddy]

How far from retirement are you? My wife and I were in the same boat, but are currently retired in our forever home with 20 kW solar system. However, when we were 15 years away from retirement we thought our forever home would be in the mountains of New Mexico. Then we had kids, our parents got older and needed help, life happened and we bought our forever home about 4 years before retirement in PA. We love it and it worked out nice for us, but the point is that a lot can change depending how much time you have.
That being said, we installed a 10 kW system during renovation about 3 years before we retired and moved to the house. It generated electricity and since no one was using power at the house and PA has net metering rules that require the power company to pay us what they charge us for power, we put a good dent into the payback of that system. After we lived there a couple of years and began to consider that our future would include an EV, we installed another 10 kW on the barn. If you can afford to install more, I would (especially if the net metering rules are favorable). Also consider designing a system for battery storage. When we did our system batteries were so expensive that we couldn’t make them make financial sense. Now that we have a giant rolling battery backup (ie, the Lightning) I wish we had gone with an inverter that could make better use of our system in a grid down scenario. We have SMA inverters with the Secure Power Sockets, but being able use our whole system instead of just a small portion in a grid down scenario would be better (SMA’s Sunny Island could do this and I’m sure other manufacturers make similar products). Try to future proof as much as you can afford. Once you retire and are on a fixed income you lose some financial flexibility (unless, of course, you get another…job…shhh, sorry-I try not to use such terrible language).

I concur. I’ve got my hands on a bunch of Sunny Islands when a solar company went out of business. It gives me 24kW of backup on a dedicated critical loads panel, but the way it balances with solar generation is even more. The best part is the flexibility to use multiple types of batteries and sources. I started on AGM, but moved to LifePo4 and I can still use the F-150L as a generator when needed.

My 2nd system is a solar edge and I’d recommend SMA over solaredge for quality and longevity.

 

[Sealevel]

I'll jump in with what I've installed in Memphis.
I have 20 panels, LG 365s with Enphase Inverters and 10 KWh battery storage. I don't have Net Metering in Tennessee, so I purchase grid power @ 10 to 12 cents and sell generated power at 5 to 6 cents - essentially I purchase at retail and sell at wholesale. Went active in late December 2021. For 2022 YTD, I've produced 7.9 MWh, selling 2.0 MWh - so I've avoided 5.9 MWh of purchases.

I have a Mustang Mach E with the 91 KWh battery that I charge about every 5 to 6 days - 31 mile commute round trip, and a bit of fun driving - averaging about 1K miles / month. I usually charge about 60% of the battery (55 KWh) each session.

The mismatch is that the rate of charge (40 Amp GrizzlE Manual L2) draws down the battery and outpaces the array. I'm not complaining - assuming I'm purchasing 45 KWh above the solar production, I'm paying about $ 5.50 / week for the power. I pay about $ 25 / week for my wife's ICE Buick Encore (32 mpg).

I could use more of the solar on the MMe if I limit my charging sessions to only charge at a rate that the array can match - but I'm not that into it yet. BTW, I am a chemical engineer.

 

[gapsd]

The charge station Pro? Or the Pro Power on board? You can trick your powerwall into thinking your pro power is a generator, but it won’t communicate with the charge station pro to utilize your Lightning without the inverter.

I have the Pro Wall charger. It has DC outputs. I was hoping to either feed the Tesla Inverter or the Powerwall from that.

 

[Yellow Buddy]

I have the Pro Wall charger. It has DC outputs. I was hoping to either feed the Tesla Inverter or the Powerwall from that.

It’s been a while but that’s part of the problem. The powerwall is AC because it has a built in inverter that stands up the micro grid. I ended up selling my free one because it wouldn’t play nicely with my SMA DC battery bank nor synchronize with the existing micro grid.

You can try to make it work DC to DC with your solar inverter directly as a separate string, but that also means your Tesla (solaredge?) would need the ability to call for power, and be able to manage the draw, and be of appropriate size to handle the power. I don’t know the specs of the inverter to comment further on utilizing the existing inverter.

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