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

[Darryl Thayer]

Thanks for the discussion, I have found that for me there is no time advantage in micro inverters.  The wire management under the modules slows me down.  But for very small systems they seem to advantages.  The industry is rapidly changing, and with the code 2011 NEC and the arc fault protection clause, it will be a game changer with module optimizers and microinverters taking the lead.  
Darryl

--- On Sun, 9/5/10, Ryan J LeBlanc <ryan at naturalenergyworks.com> wrote:

> From: Ryan J LeBlanc <ryan at naturalenergyworks.com>
> Subject: [RE-wrenches] Micro-Inverter Challenge Winners Declared. Interesting details to follow.
> To: re-wrenches at lists.re-wrenches.org
> Date: Sunday, September 5, 2010, 8:33 AM
> 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
> 
> **********************
> 
> _______________________________________________
> List sponsored by Home Power magazine
> 
> List Address: RE-wrenches at lists.re-wrenches.org
> 
> Options & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
> 
> List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
> 
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
> 
> Check out participant bios:
> www.members.re-wrenches.org
> 
>