[RE-wrenches] Micro-Inverter Challenge Winners Declared.Interesting details to follow.

[Joel Davidson]

Hello Ryan,

I wonder if SMA still thinks their 569 Sunny Boy system at the Mont-Cenis 
Academy is a good design? See 
http://www.google.com/imgres?imgurl=http://www.sma.de/uploads/tx_templavoila/SB04_04.jpg&imgrefurl=http://www.sma.de/en/products/references/solar-inverters.html&usg=__z_925mXuLKvJFrs9XG6_snB1bHE=&h=156&w=222&sz=58&hl=en&start=3&zoom=1&itbs=1&tbnid=dZezHYAqkkXV5M:&tbnh=75&tbnw=107&prev=/images%3Fq%3Dphotovoltaic%2BAcademy%2BMont-Cenis%26hl%3Den%26gbv%3D2%26tbs%3Disch:1

Joel Davidson


----- Original Message ----- 
From: "Ryan J LeBlanc" <ryan at naturalenergyworks.com>
To: <re-wrenches at lists.re-wrenches.org>
Sent: Sunday, September 05, 2010 6:33 AM
Subject: [RE-wrenches] Micro-Inverter Challenge Winners Declared.Interesting 
details to follow.


> Hello all,
>
> Jay Ruzicka of Occidental Power (CA) was the first to submit a design that 
> I
> could not find a reasonable solution that would work as smartly with
> available string inverters as they would with a micro-inverter design.
> Allan Sindelar of Positive Energy (NM), gets a runner up win, for a value
> equaling a case of good stout.  Having been in the large commercial space
> for a while, it was nice of these guys to submit designs and have the
> discussions.
>
> My guess would've been that folks were going to be submitting a typical 
> 3kW
> residential system design with multiple planes, or shading issues, and
> arguments of MPPT, or reliability, or that putting a bunch of inverters
> behind the modules would be fine because "they" said it was ok, but what I
> found was definite lack of efficient, cec listed, small power inverters 
> for
> these sub 2kw, and sub 1kw systems, and designers just have a lack of
> options in this smaller territory.
>
> Good lesson to String Inverter Manufacturers to continue to develop higher
> efficiency single string inverters to compete, meanwhile some seem to be
> bailing from this space, regarding smaller listed inverters and lower 
> input
> voltages.  There are literally no sub-1000's or 1100's listed with
> competitive efficiencies.  Kaco has the 1500 at 95.5% the same as 
> Enphase's
> best number.  After that, there's a few other 1500's and 2000's that post
> 95%, 94.5% and worse.
>
> For projects in this system size territory, that is sub-2kw, where one 
> could
> reason that only a few inverters behind the modules may be ok, there is a
> lack of alternatives.  So, some of the things that would be good for 
> string
> inverter manufacturers to work on to combat the micro-inverter craze, 
> seems
> to be continuing in the race to bring up the efficiency of smaller units,
> perhaps working on multiple MPPT units, perhaps with power stages like the
> larger fronius units but at lower or wider voltage ranges and smaller 
> power
> ratings, perhaps offering units with lower input voltage windows to
> accommodate shorter strings, integrating better/cheaper monitoring, or
> letting more people know about their existing monitoring solutions, 
> keeping
> cost down, and getting them listed and approved soon.
>
> In a podcast recently @
> http://www.renewableenergyworld.com/rea/news/podcast/2010/02/micro-inverters
> -vs-central-inverters-is-there-a-clear-winner, Raghu said that a couple
> hundred thousand units have been sold since 08, for the sake of discussion
> let's say they're 200W each and $1/Watt.  That's 200,000 (x) 200 (x) $1 =
> $40 Million in sales...  Guess I should listen to the podcast again to 
> make
> sure he said that many, but if so, that's quite a chunk of change these
> other guys should be working for.  If micro-inverter efficiency were to 
> hold
> up, and installation speed could be dramatically increased, a string
> inverter that would compete will have to be able to accommodate shorter
> strings, at better efficiencies.
>
> Obviously, not ground breaking work, we've all already known that sub 2kw
> systems were viable candidates for micro-, but I was very disappointed to
> see such a lack of competition on the CEC list for those of us looking to
> keep our inverters out from underneath the array.
>
> Ryan
>
> **********************
>
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