[ale] OT Just bought my 1st & 2nd "lighting-class" LED bulbs

Alex Carver agcarver+ale at acarver.net
Tue Jul 23 22:23:06 EDT 2013


On 7/23/2013 19:07, Ron Frazier (ALE) wrote:

> Hi Alex,
>
> Now that you mention it, it's been several years since I ran the
> pricing, so my number may be off.  You have to account for all the
> "balance of system" stuff.  Grid tie inverters and net metering
> weren't as readily available, so my original estimate probably
> included a 3 day battery bank, which would be BIG.  The number I
> posted in this message was more of a rule of thumb number than a
> precise estimate.  But, I distinctly remember that the rule of thumb
> used to be $ 10 / watt all said and done.

Yeah, not quite that anymore as your later figures showed (12kW for $44k 
installed).

Also, there's a thing that many people overlook when using grid-tie and 
complaining about no power if there's no grid.  The solution is to make 
your own grid.  Grid-tie inverters expect to see a sinewave on their 
terminals so that they can sync and supply power to the grid.  If you 
have an all-out failure you can get around this problem by having a 
transfer switch installed on the main and then adding a small generator. 
  The generator doesn't need to supply much power, it basically acts 
like the grid and will allow the inverters to fire up and sync to 
something.  So for the price of a few kW generator you can have your 
whole 12kW solar power during the day.  At night you run in low power 
mode (essentials only).  It's not quite as nice as full batteries 
because the batteries could supply lots of power at night with no noise 
but a generator doesn't require a lot of continuous maintenance or space 
and the replacement is cheaper than a new battery bank.


Payback on the system isn't immediate as you can tell.  It's getting 
there, though.  Breaking the $1/Watt barrier is when the tables will turn.


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