Most cost effective GTIs for solar?

Discussion in 'Solar Power' started by Prairiewind, Jul 4, 2012.

  1. Have any of you done some number-crunching on the most cost-effective GTI for solar right now? I'm looking to expand on my modest solar system of 2 x 235w panels paired with Enphase M215 microinverters. 'Good setup, but...
    1. M215s aren't cheap
    2. I don't need/use the Enphase/Enlighten software (for one thing it updates way too slowly and has been buggy for me...TED 5000 is working well for now)
    3. there are some great solar panel prices out there right now, but usually for panels sized well below the 260w max Enphase recommends to optimize performance from their M215s.
    4. UL listing isn't an issue (at least right now)
    This gets me wondering whether other GTIs exist that would make a good alternative, say the popular SunGs, etc. On paper you look at the price of a SunG 500w compared to 2 Enphase M215s or a 1000W compared to 4 M215s and it seems like you could save some real money with the SunGs.

    On the other hand, a guy posted a video on YouTube showing some dramatic differences in output/efficiency between the two (I think Fearlessthinker crunched some numbers showing a 37% lower output from the SunGs given the same solar input)...if that's typical then it would seem hard to justify not sticking with the Enphases... And the Enphases have been reliable and idiot-proof in the 6 months I've been using them (although I've read that other customers haven't been so lucky with their Enphases not even lasting a year)...

    Maybe there are some other cost-effective GTIs out there to consider?

    'Any thoughts/ideas appreciated :)
  2. leamywind1

    leamywind1 WindyNation Engineer

    Enphase has a 15 year warranty. Ask for Jeremy at and tell him i sent you. He may be able to give you better pricing then your avg. web site price.:)

    FYI Enphase is not making M-190's any more there may be close out pricing on them.
  3. I think Enphase is probably the best way to go. On the surface it seems that using the Chinese inverters like SunG would be more economical, but from what I've read/seen from folks who have experimented on these a fair amount, there are all sorts of potential issues with them when stacking them, you can't come anywhere close to getting the full nominal output out of them, etc. I think once you take this into consideration, something more reliable like Enphase makes more sense. Right now the best price I could find was $146 for M215s from free shipping for orders over $400...I couldn't find anything cheaper than that.

    The biggest hassle with Enphase is matching panels to them to maximize their output. Sure Enphase will work with most 60-cell panels, but if your panel is too small you've wasted money on the M215, and if its too large you've wasted money on your panel. Panels within the "ideal range" for the M215 (230-260?) aren't the ones that I've been finding on sale lately. So that's where you get into some below-the-surface extra expense when you're setting up a system.

    I'll also say that I had real problems with the Enphase Envoy conflicting with my TED 5000 energy monitoring system (since they both communicate over the power line), as have others. Some apparently have no problems. The recommended solution is to have a dedicated circuit for your TED 5000 which is then "islanded" from the rest of your grid by using filters. This may work for some, but I had 4 TED MTU/CTs spread out over several buildings so that was not going to work. And there really wasn't a similar alternative to TED (Current Cost/Envi has too limited of a communication range and it was uncertain Brultech would work over a 300' distance too). So what I ended up having to do was create a filtered circuit for the Enphase. 'Tough part was that my panels/M215s are mounted on a building most distant from my house. So basically I used inline filters to isolate the branch circuit the panels/M215s were on in that remote building, and then I ran a 300' powerline *from within that filtered branch circuit* back to my house/computer. I plugged the Envoy into that powerline (I won't use it for anything else) and so far everything is conflict between TED and Enphase. 'Kind of a PITA, however, but a solution...
    leamywind1 likes this.
  4. leamywind1

    leamywind1 WindyNation Engineer

    Thanks Collin great info to your solution.
    You have come a cross very good pricing for the M 215's. I know Enphase is particular to the type of panel that a person might use but it may be one reason to weed out using a cheaper brand so the two last longer. Just my thoughts on that. I use Schott, and Canadian solar, both work with Enphase and both have a great company and product repour. I can see how you would have conflicts with the TED and the EMU unit due to they both are sending remote line signals. I have always just used my Ted cutting the cost down but the EMU is a very cool thing to have for an internete based system with the Enlighted web system. Thanks for posting a resolution to a potential problem. I agree that an using Enphase is more of a better long term choice then a China GTI when it comes to solar. Solar is more productive then wind so the ROI will be better. You do not see any "fix video's" for Enphase. lol

    I have a 10kW system in the feild for 3 years now using the M-190's and not one failuar so far on the inverters. This system is also tied to my web site to watch in real time if you would like to see what the web base system looks like. (solar/wind tab)

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