Are the LG 305w worth an extra $0.30/watt than Solar world 280w?

[thejq]

But beside the extra space, are they better panels as far as brand/reliability etc...?

LG is definitely a premium brand compared to solar world or Canadian solar. On paper it has slightly better performance numbers and supposedly has better quality. To compare real life performance, it might be best to look at your neighbors' performance on pvoutput.org. For example in San Diego, http://pvoutput.org/listteam.jsp?tid=859. If you go back to May to August numbers (best production months), you will see LG based systems consistently ranked at the top of the efficiency charts, although the benefit can be subjective, as the difference is often less than the 7-8% premium in cost increase. So the choice is very much personal. It all depends what's important to you. Based on pvoutput.org, locally I see way more LG systems than any other brand. If you think people who can manage and care enough to link their system to pvoutput.org is at least technically savvy statistically, their collective vote of confidence (with their money) must mean something.

[sensij]

LG is definitely a premium brand compared to solar world or Canadian solar. On paper it has slightly better performance numbers and supposedly has better quality. To compare real life performance, it might be best to look at your neighbors' performance on pvoutput.org. For example in San Diego, http://pvoutput.org/listteam.jsp?tid=859. If you go back to May to August numbers (best production months), you will see LG based systems consistently ranked at the top of the efficiency charts, although the benefit can be subjective, as the difference is often less than the 7-8% premium in cost increase. So the choice is very much personal. It all depends what's important to you. Based on pvoutput.org, locally I see way more LG systems than any other brand. If you think people who can manage and care enough to link their system to pvoutput.org is at least technically savvy statistically, their collective vote of confidence (with their money) must mean something.

This is BS. There is no evidence of anything special about the performance of LG panels, except that they do offer higher area efficiency for those who want to minimize the number of panels installed. The top performing systems in PVOutput's Team San Diego in May though August were those systems with optimal panel orientation, installed in locations with good weather, and had very little shade... there isn't any more to it than that. Some LG systems met those criteria, but so did systems from other vendors.

[thejq]

This is BS. There is no evidence of anything special about the performance of LG panels, except that they do offer higher area efficiency for those who want to minimize the number of panels installed. The top performing systems in PVOutput's Team San Diego in May though August were those systems with optimal panel orientation, installed in locations with good weather... there isn't any more to it than that. Some LG systems met those criteria, but so did systems from other vendors.

Ok, before calling someone else BS, maybe you can offer some counter evidence first. At least I presented some real evidence and statistics to backup my logic. How about you take ANY period including now and on clear days (so orientation and location can't be a factor), I can bet that you will find more LGs in the top 10 than any other brand (maybe combined). BTW, I do think CS and solar world are a decent brands for the price, but you do get what you pay for.

[J.P.M.]

This is BS. There is no evidence of anything special about the performance of LG panels, except that they do offer higher area efficiency for those who want to minimize the number of panels installed. The top performing systems in PVOutput's Team San Diego in May though August were those systems with optimal panel orientation, installed in locations with good weather... there isn't any more to it than that. Some LG systems met those criteria, but so did systems from other vendors.

Beyond the mongrel market, I'd add that there doesn't seem to be much of anything special about the performance of just about any panel - LG, Canadian Solar, Sunpower or any other quality product. Sort of like most solar panel products produce the same annual output/STC Watt for about equally as long under identical (side by side) conditions.

Example: Sensij's system slightly out produces mine by about 2%, +/- a bit, on a daily kWh/STC Watt basis, in a fairly consistent way even though we're about 20 or so miles apart. He's using Canadian Solar, I've got Sunpower. I probably have slightly higher daily irradiance by some fraction of a % (note to Sensij: Hurry up on the Davis), but I've got a slight loss due to late afternoon shading of ~ 1-3% depending on season. Our orientations are similar. The diff. due to those factors, while seeming consistent, is probably too small to a ascribe to any one factor. Note S.P. vs. C.S.

If performance for most quality products in terms of annual output under similar conditions is nominally the same, that would seem to cease being a figure of merit. Other factors then move up on the importance scale when determining cost effectiveness.

In a bigger sense, this all comes back to most bang for the buck.

Since, at his time anyway, panels don't seem to be failing much, a product warranty isn't much use as a criterion, and performance warranties are, even with almost impossibly detailed monitoring, about useless because they are essentially unverifiable and therefore meaningless. That leaves things like appearance and IMO, the most important - the vendor/installer quality and reputation as one of the big arbiter of price. The extra few bucks paid to a quality vendor will be quickly forgotten. The poor quality risk from "Larry with a ladder" type vendors is greater than from established quality vendors. Such poor quality will be as visible as a boil on a nose and will never heal or leave.

Since most of the cost of residential solar is a first (installed) cost, the goal is to figure out/decide how to translate first cost into most long term bang for the buck.

Low initial cost and lowest long term cost (or max. long term savings) using life cycle costing, LOCE or other methods of costing/process economics are not the same.

Do the homework - know what's available and possible. Learn how you're charged for electricity and how that may change. Determine your loads and goals. Determine suitable equipment for your needs. Choose you vendor wisely. Negotiate tough but fair without squeezing the vendor so hard they feel forced to skimp on quality in ways you'll never know. Get your roof inspected/serviced.

Take what you want of the above. Scrap the rest.

[ButchDeal]

Ok, before calling someone else BS, maybe you can offer some counter evidence first. At least I presented some real evidence and statistics to backup my logic. How about you take ANY period including now and on clear days (so orientation and location can't be a factor), I can bet that you will find more LGs in the top 10 than any other brand (maybe combined). BTW, I do think CS and solar world are a decent brands for the price, but you do get what you pay for.

The higher ranking in kWh/kW has far more to do with local install details like tilt, azimuth, shadowing. All of that being nearly equal you will find solarEdge, micros, string inverter in that order far more than modules. They don't have a kWh/ module ranking wich is pretty meaningless but lg might come out in top ten with that measure.

[tehan]

One thing I don't see discussed here is the impact of more efficient panels on balance of system (BOS) costs. It seems reasonable as a first approximation to assume BOS costs are proportional to number of panels installed. If this is true, then a 10% increase in panel efficiency will reduce BOS costs per watt by 10%. So in many situations I can believe a 30c/watt premium for more efficient panels is more or less returned in BOS savings.

[ButchDeal]

One thing I don't see discussed here is the impact of more efficient panels on balance of system (BOS) costs. It seems reasonable as a first approximation to assume BOS costs are proportional to number of panels installed. If this is true, then a 10% increase in panel efficiency will reduce BOS costs per watt by 10%. So in many situations I can believe a 30c/watt premium for more efficient panels is more or less returned in BOS savings.

Not necessarily. For example using larger panels dose not decrease costs since they are larger they still use about the same rail, optimizers are more expensive for larger systems, wire lengths are similar etc. Higher efficiency modules would slightly reduce the BOS COUNT but often comes with more expensive BOS materials : black rails, black flashing, higher end optimizers or micros.

Also a $0.30/w increase in module costs is more than 30% increase in module costs. Modules are the most expensive part of the materials so a 30% increase in modules comes to more money than a 30% decrease in BOS.

[tehan]

Also a $0.30/w increase in module costs is more than 30% increase in module costs. Modules are the most expensive part of the materials so a 30% increase in modules comes to more money than a 30% decrease in BOS.

That really depends on if you are including labor costs in BOS. With labor included, BOS costs are going to be higher than modules costs in many situations.

[ButchDeal]

That really depends on if you are including labor costs in BOS. With labor included, BOS costs are going to be higher than modules costs in many situations.

well most don't consider labor as part of the Balance of System costs.:

https://en.wikipedia.org/wiki/Balance_of_system

But even the labor is not going to go down that much. One module or even two modules less is very slight less labor.
We pay contractors on a $/w basis like most other large installers using local contractors.

[dannieboiz]

hey guys, i was able to negotiate the price down to 3.60/w on the LG panels. So now there's only a 20 cents difference. HOWEVER, something I never thought about before was the use of Solar Edge vs Enphase.

Solar edge performance is slightly better from what I saw which would potentially allow me to maximize the 300w panels but the 10 year warranty is making me shy away. I do have the option to use Enphase... what to do... what to do....

[tehan]

We pay contractors on a $/w basis like most other large installers using local contractors.

That's interesting. So you would pay 20% more to a contractor to install a standard size 300 W panel vs a standard size 250 W panel, even though the work involved is identical? Did I understand that right?

[solar_newbie]

hey guys, i was able to negotiate the price down to 3.60/w on the LG panels. So now there's only a 20 cents difference. HOWEVER, something I never thought about before was the use of Solar Edge vs Enphase.

Solar edge performance is slightly better from what I saw which would potentially allow me to maximize the 300w panels but the 10 year warranty is making me shy away. I do have the option to use Enphase... what to do... what to do....

It is good ... Go for it The key for life is to make you happy ... If you happy to have LG panel, you should not be shy. I like is to have American Made panels as I am American ... So I choose SolarWorld. I will choose SunPower if I could get better deal at that time. I do not want to use Chinese stuffs.

I choose enphase over solaredge. It is for the 25 years warranty and I like to buy from someone who learn their failure and fix their mistake vs someone is new and never taste a failure. It is the way I learn. Solaredge has some claims for the advance on their optimizer. However, there is not much time for them to prove.... 10 years later you can see the different, but not now. Everything now is just talk ...

If you like Solar Edge, buy additional warranty up to 25 year, you will get what you need.

10 years later, we will compare note

[ButchDeal]

hey guys, i was able to negotiate the price down to 3.60/w on the LG panels. So now there's only a 20 cents difference. HOWEVER, something I never thought about before was the use of Solar Edge vs Enphase.

Solar edge performance is slightly better from what I saw which would potentially allow me to maximize the 300w panels but the 10 year warranty is making me shy away. I do have the option to use Enphase... what to do... what to do....

what 10 year warranty? SolarEdge inverters come with a 12 year warranty that is extendable to 20 or 25 years at slight added cost.

http://www.solaredge.com/files/pdfs/solaredge-warranty-january-2015.pdf

http://www.solaredge.us/groups/us/service/warranty

[ButchDeal]

That's interesting. So you would pay 20% more to a contractor to install a standard size 300 W panel vs a standard size 250 W panel, even though the work involved is identical? Did I understand that right?

well we don't pay by the module just like everyone else we pay by the watt. so we would pay the same for installer to install a 10kw system regardless of the number of modules. Most of the work is NOT in putting the modules on the roof. One less module makes very little difference. There are thousands of other things that will change the amount of work regardless of the size or number of modules.

[dannieboiz]

what 10 year warranty? SolarEdge inverters come with a 12 year warranty that is extendable to 20 or 25 years at slight added cost.

http://www.solaredge.com/files/pdfs/solaredge-warranty-january-2015.pdf

http://www.solaredge.us/groups/us/service/warranty

thanks I didn't know that. for my size system it's about $750 to extend the warranty. It's probably worth it but in today's market not matching comparable warranty tells u something about the company. The only thing that's keeping me back from Enphase is the 250w vs the higher wattage of Solaredge