Solar Panel Discussion

[Tee2]

Thanks for for the info. I'm not sure if I want to lease or own the PV system yet. Do you find the system specs meet your needs to offset your charging costs?

 

[Dsinned]

Yes. I own (and qualified for 30% Federal tax credit) a relatively small size 4.25kW PV system and it more than meets all my power needs. Even while charging TWO EVs exclusively at home, and running central AC a lot during this time of year. We are empty nesters though. :mrgreen:

 

[Tee2]

That's great to hear. Making pulling the trigger on the PV system even easier.

Thanks!

 

[TonyWilliams]

That's great to hear. Making pulling the trigger on the PV system even easier.

Thanks!

Congrats on joining the soon to be 2600 member Rav4 EV Club, which will prove to be VERY exclusive in the years to come (just like the first 1484 leased/sold as a Rav4 EV, 1997-2003).

I have 8kW of SunPower panels (California, USA) and Enphase inverters (California, USA).

I don't have a singular "big clunky" inverter that has a high failure rate, and if any of my 35 individual inverters should ever fail (25 year warranty), then I lose 1/35 of my total solar production until it gets repaired.

There are no high voltage DC cables running through my walls... they are all 120 volt AC, just like the rest of the house.

 

[Tee2]

8k is a fairly large system, no? I was thinking that a 4kish system would hit my needs since my power bill seems to hover around 180+- per month. It used to be a lot higher until I swapped out all my lighting for Philops Hue bulbs for interior lights and regular flood style LEDs for all exterior lighting. I also have been a home automation enthusiast for years and everything is controlled by software running on my wife's Mac. Getting the EV just seemed like the next logical step, plus the added fun and performance is a bonus.

What I'm wondering if is I should size up a little since my wife is getting a little interested in going electric for her next car. She might even take the Rav when the lease is up. I want to make sure I have enough juice to offset the added power consumption I expect to add to the system over the years with possibly more EVs coming online at home.

It's funny, it was a childhood dream of mine that I would as an adult drive an electric car powered by solar panels, having witnessed as a pre adolescent the gas lines of the mid 70s and thinking that I wanted no part of that. It's taken 30 years longer than I thought it would but the reality of that idea really is now here.

I'm thinking with regards to charging solitons maybe I should return the 40 amp Leviton wall unit and get the portable JESLA unit instead. They're basically the same thing, right?

 

[fromport]

I have 8kW of SunPower panels (California, USA) and Enphase inverters (California, USA).
I don't have a singular "big clunky" inverter that has a high failure rate, and if any of my 35 individual inverters should ever fail (25 year warranty), then I lose 1/35 of my total solar production until it gets repaired.
There are no high voltage DC cables running through my walls... they are all 120 volt AC, just like the rest of the house.

I already had 2x M175 inverters under warranty replaced by Enphase for M190's
Great service.

 

[DevinL]

Thanks for for the info. I'm not sure if I want to lease or own the PV system yet. Do you find the system specs meet your needs to offset your charging costs?

Our solar system covers 100% of our household usage and 50-75% of our EV charging for both cars, meaning a very small electric bill since the EVs charge at a discounted rate from LADWP. We run our central AC heavily during the summer (it's the valley so non-optional) and our house is about 1750 sq ft. If your house is 2500 sq ft or less then you shouldn't need more than a 6kW system unless you're colliding hadrons in your basement or something.

 

[rayray]

That's great to hear. Making pulling the trigger on the PV system even easier.

Thanks!

Congrats on joining the soon to be 2600 member Rav4 EV Club, which will prove to be VERY exclusive in the years to come (just like the first 1484 leased/sold as a Rav4 EV, 1997-2003).

I have 8kW of SunPower panels (California, USA) and Enphase inverters (California, USA).

I don't have a singular "big clunky" inverter that has a high failure rate, and if any of my 35 individual inverters should ever fail (25 year warranty), then I lose 1/35 of my total solar production until it gets repaired.

There are no high voltage DC cables running through my walls... they are all 120 volt AC, just like the rest of the house.

I thought this was a RAV4 EV forum, but since we are talking solar, let's clarify some facts, so others don't make the wrong decision if they decide to go solar, and get ripped off by solar leasing companies .
With your 35 Panels, you are most likely using the M215's . These inverter are split phase, which means they are 240 volts at about 1 amp each (not 120 volts). You can only have 17 per string, which means, they sold you 3 strings worth of cable, when it should have only been 2, with a little larger panels that woudl have had a better ROI in the longe run .. But I guess you can always add more if needed .. So, maybe that was a desire ...
All of these strings end up in a junction box in your attic that is then fed to your panel at 240 volts and with 35 total amps of power ..... So, I'm not sure what the hype is vs DC ? DC may burn you, and melt itself away, but 240 volts @ 35 amp will kill you. (they both have their arguments) ...

On your warranty ... Enphase has not been around for a long time, and I believe this is the first quarter they actually reported a profit, while it was bogged down by their warranty costs... They have also changed their warranty to only include parts..... Labor is no longer covered .. So, that's 35 times that either you or someone has to go up on your roof ... VS. a single inverter from SMA that has been around for more that 25 years .. And if they are not failing - then why such a high warranty expense ?

A straight string inverter will also be 15% to 20% cheaper, than micro-inverters or power optimizers ....

So, unless you have a shading issues, or a challenging roof, the only reason to go with an enphase, or a solaredge system is to get individual panel monitoring, which for some may be worth the additional cost, and complexity ....

 

[miimura]

The point about 120VAC is from a hazard and code standpoint. Enphase inverters always operate at 120V from ground. Yes, they are out of phase so they produce 240VAC, but they still only present a 120V hazard. My solar system is two circuits of 9 panels and Enphase inverters on each circuit. Simple Romex cable goes through the attic and walls to individual double pole 20A breakers. I have no exposed conduits on the outside of my house because it was pre-wired during construction. This is a much simpler and cleaner install than high voltage DC in metal conduit all the way down to string inverters.

Winter shading was the primary reason I chose the Enphase inverters though.

Also, most solar products do not include labor reimbursement for warranty replacement. That labor warranty coverage should be provided by your solar installer. SMA also does not cover labor, and their warranty is only 10 years. Enphase warranty is 25 years on newer products.

 

[Dsinned]

I have an Enphase microinverter PV system as well with 17 M215s on one 240V circuit. That's the limit I could add to my existing 100A service panel without violating the code. One M215 was not producing power as well as the others during the first year, so I had it replaced by my Installer at no cost to me. Enphase is on its 4th generation of microinverters, having introduced the M250 last Summer. From what I have heard, microinverter reliability seem to have become much better starting with their 3rd generation (M215). M190s not so good! The BEST thing about microinverters is their individual panel level monitoring capability. This is how I was able to determine one of mine was "weaker" than the others. With string inverters (e.g. SMA), I think their projected life expectancy is about 12 years and hence they have shorter warranties. Enphase warrants microinverters for 25 years, and the panels may be warrantied just as long as well if made by well established OEMs, while Installers will generally cover the first 10 years for any labor costs due to replacements and/or repairs.

"Owning" is the only way to go if you want to get the 30% tax credit (not a rebate) from Uncle Sam. The leasing company generally gets that if you opt to lease instead.

 

[fromport]

Enphase is on its 4th generation of microinverters, having introduced the M250 last Summer.
From what I have heard, microinverter reliability seem to have become much better starting with their 3rd generation (M215). M190s not so good!

Afaik the M215 == M250. No difference in electronics
The maximum an M215 could output in AC is 250 watt, so they renamed it.
The M190 should be named M199
I have 3 systems:
6 panels with M190 enpase inverters
3KW inverter (powerone) with 3500 Watt panels, grid tie only
6 panels (about 1000 watt) connected to 5000watt inverter , connected to 48 Volt lead acid battery system plus grid tie.
I think I put them in sequence of efficieny
My freezer&fridge will keep running for a few days when there is no power on batteries alone.

I am trying to find info how to run a home in emercency of a chademo power system ;-)
We live in interesting times !

 

[swogee]

We have owned our RAV4 EV since June 22, and we are looking for ways to reduce our power bill as well. Since everyone is bringing up the topic of solar panels in this thread I thought I would mention that I have gotten a bid for a 4.4 KW system with 16 panels and 16 Enphase M215 micro-inverters. I was trying to decide if the micro-inverters or the string inverter would be better in the long run. As the meter and main panel are located on an exterior wall near the master bedroom a large string inverter would be less desirable due the noise. It also seems that the micro-inverters would make for a cleaner install with no metal conduit and only Romex wiring running thought the attic/wall space to the main panel. The only unknowns/disadvantages are the long term reliability of the micro inverter units and the higher cost. The individual panel monitoring ability of micro-inverters is also nice.

So how do the persons (Dsinned, miimura, TonyWilliams) that have the solar systems with Enphase micro-inverters like them? Have there been any issues or problems? Any things to look out for or things that you would do differently next time? (I'm also trying to decide if the PG&E E6 or EV-A rate plans are better but that is for another thread.) Any thoughts or ideas are welcome.

 

[pchilds]

I was trying to decide if the micro-inverters or the string inverter would be better in the long run. As the meter and main panel are located on an exterior wall near the master bedroom a large string inverter would be less desirable due the noise.

Not all string inverters make noise and the ones that do make much less than an AC system. When standing next to the inverter my neighbors AC unit, 75' away, is louder than the inverter. This 12 year old inverter is the first grid tied inverter on the market, I have had no problems with it and will probably will replace it with another string inverter when it fails.

 

[Dsinned]

I DO LIKE the Enphase microinverter design, and especially their "built-in" monitoring capability. The M215s are actually each rated to 225W maximum, (not 250W as stated by some else here). The M250 is the latest design and have an output power rating a bit higher, plus no longer require external case copper wire grounding. The M250 has essentially replaced the M215. As I mentioned, 1 out of 17 total of my M215s proved to be initially defective, which I would have never realized without the Enlighten Monitoring System. Unfortunately, Enphase no longer supports Enlighten subscribers for free opting for individual panel/inverter monitoring, but is still worth having just the same. Also, to have monitoring, you have to buy an (way overpriced) Internet Gateway specifically designed for the Enphase system. This connects to your home network and this can be done wirelessly as well. Tech Support from Enphase can be kind of a mixed bag and they are slow to make improvements in their Enlighten software. I have proposed a few enhancements and have received ZILCH for my efforts. Oh an btw, there are several 3rd party cell phone apps that support Enphase sytems as well; a couple actually quite good, but also not free.

The company that did all the hardware procurement, permitting and installation work for me was PetersenDean. They are headquartered in the East Bay Area near SF, but serve customers in several other locations and even some other States. PD advertises heavily on local TV infomercials. They did a good job for me at a very reasonable price, so I do recommend them.

http://www.petersendean.com

 

[TonyWilliams]

There are no high voltage DC cables running through my walls... they are all 120 volt AC, just like the rest of the house.

I thought this was a RAV4 EV forum, but since we are talking solar, let's clarify some facts, so others don't make the wrong decision if they decide to go solar, and get ripped off by solar leasing companies .
With your 35 Panels, you are most likely using the M215's . These inverter are split phase, which means they are 240 volts at about 1 amp each (not 120 volts).

You're not reading what was said in an effort to play down Enphase. I didn't state the inverters were 120 volt... I correctly stated that 120 volts was running through my walls. That's precisely what makes 240 volt "split phase".

You're also jumping on the assumption bandwagon... I have M190's, not M215's.

I also didn't argue that Enphase was cheaper... yes, I'm confident that string and big clunky inverters are cheaper. If that's you're criteria, please, buy the cheaper inverter(s).

The warranty scare that you dredged up (no more labor for Enphase) sounds very scary, like they will be replacing all 35 of my inverters any day now, and I will "get the bill" for labor. The fact is that none have failed, and if one ever does, they are "plug-n-play". Yes, they may have to lift a couple panels to get to the affected one (each panel has four small screws holding them), but I'm confident the labor won't be bad, should that happen to me.

Heck, I can actually do it myself. It doesn't weigh 150 pounds, like the "big clunky hot ones". But, you claim that those don't fail, and I'm here to tell you that they do. Actually, you can virtually count on replacing those big clunky ones at least once over the 20-30 years of your solar system.

 

[Dsinned]

Tony, just out of curiosity, how has the reliability of your M190s been so far? I have heard many "horror stories" about M190s. Some people think it may just be a bad batch that got into the production process in the past, but even warranty replacements have been known to fail. The presumed field failure rate appears to be quite high; perhaps as much as 5 to 10%! You have a lot of these units, so how have they been holding up?

*** Oops, sorry, your last post wasn't there when I typed in this one. ***

As I mentioned I had one M215 replaced and that took ~2 months going back and forth with Enphase before they would accept a warranty RMA claim from my Installer. Even though I could demo a clear cut case of measurably less power production on a daily basis from this one M215 (compared to all the others), via Enlighten Manager, Enphase insisted on forcing my Installer to make no less than "3" truck rolls to "troubleshoot" up on the roof. A bit of NIVH mentality I think, or case of "a typical Enphase customer is too dumb to know what he is talking about". Using their own monitoring capability there was an obvious problem, consistent over time, but they still wanted to play the old swap neighboring modules troubleshooting game. With Enlighten Manager, it is fairly easy to determine the "internal" DC to AC power conversion efficiency of each microinverter in a system. The one replaced was running at about 85% and dropping a bit lower from week to week, while all the others were holding at closer to 95%. CEC Weighted (nominal) Efficiency spec for the M215 is 96%. Initially, this information was almost ignored by Enphase Tech Support. I had to talk with a "supervisor" to escalate the problem, but even then it took about 10 more days of continuous monitoring of the reduced efficiency trend in this inverter to convince them.

 

[smkettner]

Thanks for for the info. I'm not sure if I want to lease or own the PV system yet. Do you find the system specs meet your needs to offset your charging costs?

We bought our 3kW system. It provides about half our usage. Although with TOU it often covers 100% of cost.
This month is projected to net use 550 kWh with a small credit of $2.
Last month net usage 442kWh and recieved $38 credit.

Aiming to zero out your bill is overrated. With TOU aim closer to produce 50% to 70% of usage.

I did the purchase and got my tax credit direct. I don't want any issues when selling or lease buy out settlements.
With current TOU credits it looks like 5 year payback.

 

[DevinL]

"Owning" is the only way to go if you want to get the 30% tax credit (not a rebate) from Uncle Sam. The leasing company generally gets that if you opt to lease instead.

True, but being a tax credit you must also have adequate tax liability to realize it. Just like leasing our cars, the solar leasing company should factor the tax credits and rebates into your lease price and it should be reduced accordingly. My lowest quote to purchase a system was $17,000 with LADWP rebates. My 20 year lease was $4,080, which factored in credits and rebates with the bonus that I didn't have to jump through any further hoops. The life expectancy of most panels is about 25 years, so these costs are comparable.

I did the purchase and got my tax credit direct. I don't want any issues when selling or lease buy out settlements.
With current TOU credits it looks like 5 year payback.

My lease contract with SolarCity is pretty clear about that stuff. I'm selling my house next year (didn't expect to do that at the time) and the remainder of the lease will transfer to the new owner. Since I pre-paid the whole lease up front this means I can advertise the house as having solar panels just like a house where they were bought since the new owner won't have to pay anything. I would even argue it's a better deal for the new owner since they will also benefit from the remaining 17 years of service SolarCity is obligated to provide.

I pre-paid my entire lease up front, so it is as much like a purchase as possible. I wouldn't consider leasing panels with a monthly payment because then you do run into issues when you sell your house etc.

Here are some relevant pieces copied and pasted from my SolarCity contract...

(a) If you sell your Home you can:
(i) Transfer this Lease.
The person buying your Home can sign a
transfer agreement assuming all of your
rights and obligations under this Lease
where permitted by the local utility.
(ii) Move the System to your new Home.
If you are moving to a new Home in the
same utility district, then where permitted
by the local utility, the System can be
moved to your new home only pursuant to
the Limited Warranty. You will need to
pay all costs associated with relocating the
System, execute and deliver to SolarCity
an easement for the replacement premises
and provide any third party consents or
releases required by SolarCity in
connection with the substitute premises.

(a) Unless you are grossly negligent or you
intentionally damage the System, SolarCity will
bear all of the risk of loss, damage, theft,
destruction or similar occurrence to any or all of
the System.

(b) Warranty Length
(i) The warranties in Sections 2(a)(i) and (a)(iii) above will start when we begin installing the System at your Home
and continue through the entire Lease Term but never less than ten (10) years. Thus, for as long as you lease the
System from SolarCity, you will have a System Warranty and our Repair Promise.
(ii) The Roof Warranty Period may be shorter than the System Warranty, as described in Section 2(a)(ii) above.
(iii) If you have assumed an existing Lease, then this Limited Warranty will cover you for the remaining balance of the
existing Lease Term.

A. If at the end of each successive twelve (12) month anniversary of your first monthly payment the cumulative
Actual Annual kWh (defined below) generated by the System is less than the Guaranteed Annual kWh, then we
will send you a refund check equal to the difference between the cumulative Actual Annual kWh and the
Guaranteed Annual kWh multiplied by the Guaranteed Energy Price per kWh (defined below). We will make that
payment within thirty (30) days of the end of the calendar year. Your cumulative Actual Annual kWh is
dependent on a shading percentage of 7 % on your Home. If this shading percentage increases, your Guaranteed
Actual kWh will be reduced proportionately.

 

[mikeEmike]

Heck, I can actually do it myself. It doesn't weigh 150 pounds, like the "big clunky hot ones". But, you claim that those don't fail, and I'm here to tell you that they do. Actually, you can virtually count on replacing those big clunky ones at least once over the 20-30 years of your solar system.

I have two SMA string inverters and I did have to replace one after about two years of service. I was able to do it myself in about fifteen minutes after I received parts from SMA. I can vouch that SMA's support was top notch. The inverter I replaced weighed just over 50 pounds, including the DC disconnect (which I did not have to replace fortunately) so I probably only have to lift about 40 pounds. I'm not opposed to micro-inverters, but in my situation, string inverters made more sense at the time I installed my system. If I installed a new system now, I'm not sure which one I'd choose. They both have their merits.

 

[Tee2]

Anyone have info regarding the use of a TOU meter on a PV system? Is it even needed? I'm trying to figure what the best solution will be with the least amount of dealing with DWP as possible.

thanks again