Thursday, June 8, 2017

Using Renewable Energy: MPPT Controller, Additional Panel

A lot has happened since the last update!  I have upgraded to an HQST MPPT charge controller, 40A.  I figured if 30A was good, a 40A was just better.  It works fantastically!  More on that in a moment. 

I also added a third panel when I added the MPPT charge controller.  I have the panels in series, thinking I should get about 36v out of them.  The thought is that the higher the voltage, the lower the voltage drop over a long run of wire.  To my surprise, the panels are putting out significantly more than 12v.  They are closer to 20v.  I've even observed 62v at one point!  While the voltage is high, the amps are still on the low side.  I don't think I've ever observed 3A.  These numbers are from the display on the MPPT controller. 

I also drilled a 3/4 hole to get the cable into my house.  This makes it super easy to prop the panels against my shed in the backyard, temporarily, until I can get a more permanent solution in place. 

The ExelTECH 600W inverter is performing flawlessly.  I installed a rocker switch so that I can turn it on and off.  It was set up with an internal transfer switch if the power was lost.  To turn it on, one of the jumpers needs to be grounded.  This made it pretty easy to put a rocker switch on it.  From the inverter I run an extension cord to a power strip.  this power strip has a bunch of chargers on it.  We have charged:  iPhones, iPads, Anker 10k and 21k portable battery banks, rechargable AA and AAA batteries - basically anything that can be charged we charge via that power strip.  That means that all of these devices have been on clean solar power for a few months now.  The only exception we have is when we are in the car when we use the car chargers. 

To date the MPPT controller says that it has output 6 Kilowatt hours.  Not bad for a small off grid system! 

Plans:
Wiring - I'd like to clean up the wiring a bit and make it a little nicer.  I bought some new wire to run from the panels to the charge controller. 

Panel Mounting - I would also like to put something a little more permanent in place rather than have the panels propped against my shed.  maybe something on the shed roof? 

BATTERIES - The more I research batteries, the more I realize why more people are not going off-grid.  It would be great if there was some kind of inexpensive energy storage solution, but there isn't.  Maybe the industry will eventually come up with something efficient and cost effective but it really doesn't exist right now.  The best bet is thousands of dollars in a battery bank.  And to maintain the life of the bank, only use 20% of it. 

I've learned a LOT so far.  I also have a decent idea in my mind of what it would take to go entirely off-grid, which is a pretty sizable price tag mostly because of the batteries.  This is why Net Metering is so popular.  With Net Metering, the household gets credit for every single watt of power that is produced by the panels.  No batteries are needed.  With an off grid system, if the batteries are charged, and the house is not using all of the electricity the panels are producing, it's essentially a waste. 

I'll post more once more progress is made!


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