What solar panel brands can I trust most?

[BayGirl]

I'm extremely interested in getting solar panels for my home and wanted other people's recommendations of the brands they prefer. Thanks.

[Cal_State78]

I would stick to the more commonly used brands such as Kyocera, Sharp, Sanyo, SunPower etc. If you are going for the thin film solar panels, Uni-solar is a great place to go. Personally I got my solar panels from SunPower. I would also like to hear what other people are using.

[solar_geoff]

I have found that all of the major manufacturers' modules to be of very good quality. There are simply some modules that are more suited for certain applications i.e.: higher voltage modules such a sanyo lend themselves better to lots of small sub arrays, while lower voltage such as Evergreen ES-A series are better for one large array.

My personal favorite inverter type is SMA's sunny boy due to the highest efficiency, however other inverters have different voltage windows which again lend themselves better to different array/string sizes. It really again depends on the specific site conditions, etc.

Contact a qualified PV contractor!

[solar_geoff]

To add one more thing: If this were my system what I would look at most is $/Watt. I wouldn't be overly concerned with which brand to use.

Hope this helps!

[BayGirl]

wow, that was a detailed answer. thanks. so higher voltage are better with literally smaller panels or panels that give out less watts? I'm definitely looking mainly at the cost, but this is also great info to know.

[solar_geoff]

wow, that was a detailed answer. thanks. so higher voltage are better with literally smaller panels or panels that give out less watts? I'm definitely looking mainly at the cost, but this is also great info to know.

Not exactly... And I appologize if my answer was a little too technical in nature. It's just that certain manufacturer's modules have different characteristics than others (not sure exactly the reason). Usually ones which operate at a higher voltage will have a lower current, which translates into more strings of fewer modules. And vice versa, modules (panels) with a lower operating voltage usually have a higher current which means less strings but more modules per string.

The result is that with more small strings you can have a lot of small arrays scattered around your roof, which may or may not be advantageous. Typically this is an advantage if you have a lot of small roof spaces facing different directions (this is because best practice dictates that all modules on a string be at the same pitch and orientation).

Most modules will be about the same size (usually in the realm of 3'x5') with a wattage in the range of 160-225 Watts regardless of the voltage and current they operate at. Because Power=Current x voltage, your name plate wattage will be approximately your Max power voltage (Vmp) x Max power current (Imp). It comes out about the same when you have high current, low voltage as high voltage x low current

Again, I hope I am not going overboard, but this is a very good topic.

[BayGirl]

Thanks again Geoff. It's starting to become more clear.

Please forgive my ignorance, but when you say "strings," what are you referring to exactly? Would you happen to have a visual of what they are?

[solar_geoff]

Here is a typical wiring diagram I put together to hopefully clarify things. The number of modules per string depends on the voltage the modules put out and the operating voltage range of the inverter. The higher the voltage the fewer modules per string (series) because voltage adds in series. You can then add strings of the same size in parallel (connected either at a disconnect or combiner or at the inverter - it doesn't matter) up to or beyond the maximum usable current of the inverter (current adds in parallel.) Best practice dictates that all modules on a string will be oriented at the same pitch and compas azimuth. If you have a lot of small roof areas that are at different orientations (for example) a higher voltage module would be an advantage, as you could put a string (of say 4 or 5 modules) on each small roof. One example of this type of module is Sanyo, which is also one of the highest efficiency ones too. Higher voltage is of no advantage, however, if you had a large roof or ground area where differential orientations or shading conditions do not existed, as lower voltage modules allow for fewer stings of more modules, which means less wiring, combiners, etc. which is an advantage. So in an ideal world, what should dictate the choice of equipment is the site conditions, but $/watt is what I would look at, as long as you can find a configuration that works for your application. Most of the time you can make things work with some creativity.

[D_Robbins]

that seems like lots of wiring. I just watched a little video on the enphase inverter website and the design looks much more easier then what you have drawn up. does REC not use them?

[solar_geoff]

that seems like lots of wiring. I just watched a little video on the enphase inverter website and the design looks much more easier then what you have drawn up. does REC not use them?

No this is not a lot of wiring. This is only 1 DC postive and, 1 DC negative and a ground on the DC side and your 2 hots, 1 neutral and GEC on the AC side. This is as simplistic as it gets, especially as this diagram is solely for clarification. Whether you use a traditional inverter like what I have shown or micro-inverters, you will never have much less than this. The only difference is that your micro-inverters wire together and then go into some kind of combiner and from that it goes to a circuit breaker.

REC Solar does not deal in any micro inverter technology... There is really not a huge incentive to roll out another entire product line. The ONLY true advantage to micro inverters is shade performance: it would not be detrimental to entire system performance to have partial shading, only the shaded modules are affected. Some say there is less wiring but, I don't see that being true.

[D_Robbins]

Gotcha, thanks for the clarification. So is enphase the only company to come up with these types of micro-inverters? Is the combiner box somehow connected inside of the micro-inverter, or is it hidden under the solar panels?

[GoodDaySolar]

Enphase Advantages, Detailed

Gotcha, thanks for the clarification. So is enphase the only company to come up with these types of micro-inverters? Is the combiner box somehow connected inside of the micro-inverter, or is it hidden under the solar panels?

D_Robbins,

Yes, there are other companies besides Enphase coming to market with microinverters. The next one on the horizon is Solarbridge, launching early 2010. Also, Accurate Solar, Array Converter, Azuray, Enecsys, GreenRay, Petra, and Sympagis are other companies known to be developing microinverter-like technology.

Geoff from REC didn't mention some other advantages for microinverter installations. With all respect to Geoff for his talent and advocacy, I believe companies like his are slow to adapt new disruptive technologies

[solarf.helen]

hi,

For modules, I would like to recommend Solon, Suntech, Yingli.

For inverter, I would like to recommend SMA, Fronius.

[Off Grid Solar]

BayGril, Where do you live? The best solar panels are a opion. The best thing to do is find the best solar company. Do you want to deal direct with the producers of the entire system? Dealers? Installers? Distributors? You see it is important that service and support and cost must be part of your choice also.

[Off Grid Solar]

All solar panels are good. I could only recommend American made solar panels. The cost of importing and too many hands in the profit of solar panel sales off shore may just hurt our economy like imported oil. Off shore solar panels are just as good as our solar panels that are made here. It is just a good practice to buy American solar panels first.