Inverting Solar

We've been teasing ourselves about solar since the 1970s, when Jimmy Carter installed solar panels on the White House roof.  With oil prices skyrocketing last year, and their creeping rise this year, there's much talk about solar power being the wave (or ray?) of the future.  Recently I've been to several solar conferences, and the promise of houses in the Southwest and beyond generating their own power, and even contributing to the local grid, are tantalizing prospects.

  One issue, however, is what's done with that converted power that solar panels collect.  The way solar panels work is very similar to the way in which those Christmas tree lights surrounding your tree or house worked--or didn't work.  If one light went out, the whole strand went out.  In IT geek speak, solar panels also work the way daisy-chained computers on a network operated:  if one computer petered out, the whole network went down.  Solar power is expensive to install--and I have a feeling that many salesmen are not quick to tell customers that well, if one panel goes out, they are out of luck till that inverter gets repaired.

  Once those solar panels collect the sun, there must be a way for the DC (direct current) electricity to convert to AC (alternating current) electricity.  For those who are not electricians (like me), it's AC current that powers your home and the appliances in it; you would then sell any "leftover" AC current back to the grid.  This is done through solar inverters, ideally through a process called MPPT, or maximum power point tracking.  Here's the problem with solar inverters that used in most solar installations:  if one inverter goes out, the entire set of solar panels shuts down, and well, it's back to your local grid to keep those refrigerators humming.  Many solar installations also suffer from the "weakest link"; the entire scheme only runs as well as the weakest panel.

One company providing a solution is Enphase Energy, based in Petaluma, CA.  Enphase manufactures microinverters which calculate the amount of sunlight currently hitting the panel to which it is attached, and then estimate how much power should be generated from that panel.  These "smart" inverters are able to increase power generation by approximately 25% from each panel regardless of the amount of sun or clouds in the sky.  Furthermore, the panels can compensate for each other if one stops working.  In geek speak, this is avoiding the "single point of failure" that is the bane of current solar panel installations.  When one of these microinverters fails, it can simply be swapped out or repaired, keeping the entire operation powering away without interruption.  As a collection of solar panels grows, more and more inverters can be added, the way in which you can expand your computer networking by adding another computer or server--i.e., it's scalable, a word that doesn't apply to a lot of the alternative or renewable energy solutions that purportedly are out there.

  It's difficult for many of us to wrap our head around products and technologies from companies like Enphase, but this is where current investment focus must occur.  We have the contraptions such as wind turbines and solar panels:  what are critical are better bells and whistles that will allow us to harvest forms of energy that are definitely out there, but are too costly for implementation on a wider scale.  The speaker representing Enphase at a recent conference I attended said that their sales reps are so busy that they sometimes run out of product; with all the snake oil solutions I see out there, let's hope they can meet a continued growing demand.