7.7kW LG/Enphase System in San Diego

[sensij]

These are all intangible reasons. There are many other "intangible" reasons we justify purchases throughout our lifetime.

Maybe I've made the point too sharply. I am not saying "Don't buy M250's." I am saying, "Don't expect the excess energy produced by the M250's over M215's to be worth as much as the price difference between them, when paired with panels per Enphase's design guidelines."

Solar is a big purchase for most people, maybe the biggest they'll make after a house and a car. I think there is value in identifying the most financially cost-effective package, and once it is known, the relative cost and benefit of the options can be evaluated. $400 for peace of mind could be a bargain.

There is a *lot* of misinformation about cost-effectiveness out there. Some of it can be reduced to a math problem with a solution, but some parts of the decision making will require assumptions and guesses about a future that no one knows. I try to help with the math problem portion of it, the rest is for each of us to decide individually.

[J.P.M.]

Maybe I've made the point too sharply. I am not saying "Don't buy M250's." I am saying, "Don't expect the excess energy produced by the M250's over M215's to be worth as much as the price difference between them, when paired with panels per Enphase's design guidelines."

Solar is a big purchase for most people, maybe the biggest they'll make after a house and a car. I think there is value in identifying the most financially cost-effective package, and once it is known, the relative cost and benefit of the options can be evaluated. $400 for peace of mind could be a bargain.

There is a *lot* of misinformation about cost-effectiveness out there. Some of it can be reduced to a math problem with a solution, but some parts of the decision making will require assumptions and guesses about a future that no one knows. I try to help with the math problem portion of it, the rest is for each of us to decide individually.

+1.

A few of us (I'm in that cabal) rant about cost effectiveness. I'd strongly agree that there is a lot of misinformation in that area, some of it self generated by potential users who do not educate themselves in the rudiments of the time value of money, etc.

More misinformation comes from those with money to make by taking advantage of that misinformation, and also potential users general solar ignorance.

Those two seem to come together here. The M250's may well result in more generation than the M215's. There seems to at least be the potential for more power production.

The question of how much more electricity can potentially be generated is technical. The question of how much that potential added generation is worth as a $$ figure is the stuff of financial analysis.

There is, in my mind anyway, no question that the third rail in this decision making - the emotional part - governs. That's probably as it should be.

The sad part, again to me only, is that the logical portions, which can serve to moderate the emotional part, are usually not given serious consideration. IMO, any decision can be reached. Getting informed and then crunching some #'s does not limit choice, it adds information. I'm not sure there is such a thing as too much information - at least for this discussion.

At least the decisions would be more informed. I can't see the harm in that.

[Alisobob]

There is a *lot* of misinformation about cost-effectiveness out there. Some of it can be reduced to a math problem with a solution, but some parts of the decision making will require assumptions and guesses about a future that no one knows. I try to help with the math problem portion of it, the rest is for each of us to decide individually.

+2

[logdin]

I won't question most of your logic: hey, if it makes you feel good why not. But the suggestion that the M250 is in some way "newer technology" is incorrect. Enphase updated the M215 last year to same 4th generation platform as the M250. I suspect the most significant internal difference between the units is the size of the capacitors. And for what's it's worth, the capacitors are the biggest reliability issue and my guess would be the failure rate is higher on the larger ones.

Well I'll have crow for dinner tonight. I did not know about the update. Made me look. http://blog.gogreensolar.com/2014/01...ot-better.html

Looks like M215's got an update in Spring 2014. Thats why we come to this site. To learn. If those had been available at time of my purchase, it might have made a difference, especially if there were a $30 or $40 premium for the M250s. Thanks for sharing.

[Alisobob]

solar115.JPG

So, a few weeks ago when my system was clipping, I called my installer. I told him about the clipping issue, and he assured me I would never recoup the lost production value of the clipping with the bigger, M-250's.

He also said to call him back a two weeks, when the clipping stops.

I said "Stop? Its only going to get sunnier?"

He said, "Yea, its also going to get hotter, and the clipping will stop."

Well, he was right ...again

Funny how good installers know their products, inside and out...

[thejq]

[ATTACH]7094[/ATTACH]
So, a few weeks ago when my system was clipping, I called my installer. I told him about the clipping issue, and he assured me I would never recoup the lost production value of the clipping with the bigger, M-250's.

I'm not sure what else he can tell you.

Clipping or not, it's very much dependent on your location and orientation. I actually had one of the better days at peaking today, even with the June gloom.
Capture4.JPG

[rwb1921]

I'm not sure what else he can tell you.

Clipping or not, it's very much dependent on your location and orientation. I actually had one of the better days at peaking today, even with the June gloom.
[ATTACH]7095[/ATTACH]

Temp here was near 95 today. This is the highest my 285 Solar World panels could get today (mid 220's). Total output was 35.5. My m250's will never clip in the summer. My highest so far has been 253 when first installed. Also a cloudy/sunny day.

[J.P.M.]

FWIW: Today, 06/19/2015 was quite clear at my house and I suspect some others in the area.

The clearness index from 7:00 - 17:00 solar time was .740 which means the atmos. passed 74% of the solar energy hitting the top of the atmosphere to the ground at my location. A good to very good day might be ~ .70 -.72 or so.

The Global Horizontal Irradiance at my location peaked today at 984 W/m^2 several times between 12:26 P.D.T. and 13:09 P.D.T. Solar noon was at 12:45:45 P.D.T. or so. That's a pretty clear sky and the max. I've measured under clear skies.

The P.O.A. global irradiance on my array peaked at 996 W/m^2 at 13:09 P.D.T. Also a high under clear skies. Basically, For those keeping track, it don't get better than that around here in terms of clearness. However, the heat and generally low wind velocities hurt production a bit, so some arrays might not clip as much, if at all.

[bcroe]

We got 4" of rain the past week. Now at the longest day, more clouds; I may never live to see what record
energy might be taken on a mid June really sunny day. Bruce Roe

[71SoCal]

So I got my PV permit today from the city. My roof is now open and I'm getting ready to install the Q-Base footings for the racks.

Here's a hypothetical question: Once I get everything installed, I might still be down a week or more waiting for the final inspection, POCO/AHJ coordination, etc. If an unknown good Samaritan comes along and flips my PV breaker on early, will the power company know? I currently have a smart meter, but not a net meter yet. Of course I would hope that person would come by and flip the breaker off before any inspections occur.

[logdin]

So I got my PV permit today from the city. My roof is now open and I'm getting ready to install the Q-Base footings for the racks.

Here's a hypothetical question: Once I get everything installed, I might still be down a week or more waiting for the final inspection, POCO/AHJ coordination, etc. If an unknown good Samaritan comes along and flips my PV breaker on early, will the power company know? I currently have a smart meter, but not a net meter yet. Of course I would hope that person would come by and flip the breaker off before any inspections occur.

Thats an easy one. You will in all likelihood get a robo call advising you that your system is not approved to operate. Please ensure your system is not operating until approved. They will tolerate a few hours of initial testing, but beyond that, you'll be on report. I'd guess that lack of compliance will result in at a minimum, a "schedule re-arrangement" for your inspection and PTO.

I say in all liklihood because I know of at least one person that operated for two weeks without a call. But I also know of several that got the robo call after 24 hours of non-permitted operation. Let me caveat this.... I am only referring to SDGE. I have no experience with other POCO's.

Probably not worth it for much more than an hour or two. I'd recomend letting the dogs chase off the good samaritan. He could cost you a 1 week delay or more.

[bcroe]

So I got my PV permit today from the city. My roof is now open and I'm getting ready to install the Q-Base footings for the racks.

Here's a hypothetical question: Once I get everything installed, I might still be down a week or more waiting for the final inspection, POCO/AHJ coordination, etc. If an unknown good Samaritan comes along and flips my PV breaker on early, will the power company know? I currently have a smart meter, but not a net meter yet. Of course I would hope that person would come by and flip the breaker off before any inspections occur.

If you don't have a net meter, they may end up charging you for your own energy. That was the situation here, waited
6 (supper sunny) weeks for the meter. Best I could do was turn on a string or 2 to help run the A/C; exceeding that would
cost me. Bruce Roe

[71SoCal]

Just wanted to post an update on my progress. I opened up the roof yesterday, and started papering it in and adding Q-Bases today. Re-roofing about 9 squares with double 40lb felt. Hope to get it all tiled in by Friday.
SML Solar1.jpgSML Solar2.jpg

[SunEagle]

Just wanted to post an update on my progress. I opened up the roof yesterday, and started papering it in and adding Q-Bases today. Re-roofing about 9 squares with double 40lb felt. Hope to get it all tiled in by Friday.

Nice. What are you going to use to cut the tiles to fit over the Q-bases?

[71SoCal]

Nice. What are you going to use to cut the tiles to fit over the Q-bases?

Just using a standard circular saw with a diamond blade. It's going to be a lot of cuts! I've got 40 new Q-Base mounts along with a fireplace and four other flashings. My electrical will drop down into the attic and pop out above the service panel. My wife has been running the A/C like crazy lately, so I'm really motivated to get this thing done!