Removing old solar thermal collectors

5 new 375W solar PV panels

A few weeks ago I completed the DIY installation of a mini split heat pump system in my workshop.  The system essentially replaces the solar heating system I built that used to use four large 4' x 8' solar collectors on the south facing shed roof of my workshop.  

I had installed the solar heating system 20 years ago and it had offset the use of propane over the years.  But that system could not begin to compare with the efficiency of electric heat pumps, and it is my goal to get off of fossil fuel as much as possible. The system used a few hundred gallons of propane last year.  Over the years I had learned to optimize the use of that system which originally used over 800 gallons a year, in the last two years it has been below 300 gallons.  You can see historical records of my propane consumption on this page of my blog.  The problem with fossil fuels is that their prices are unregulated and the cost of a gallon of propane has nearly doubled over the last 20 years.  

The propane tanks will remain in place to feed my automatic standby generator which is a necessity here in rural Maine.  Eventually I hope to replace that with a battery system since I can run that generator up to 7 days cumulatively in any given year due to extended power outages from storms etc.

The new REC brand solar panels are rated at 375 W each with a total theoretical maximum capacity of around 1800 W.  So far, I am seeing a maximum output of a little over 1400 W at noon at this time of year.  I don't have enough energy data for the new heat pumps to know whether this will completely offset the energy required to operate them.  But I am hoping it will.

 

mounting rails installed

inverter installed

I purchased a complete kit from the altE store in Massachusetts.  I simply called up my account manager, Ben and asked him to spec out a system that could produce close to 2000 W and cost less than $2500.  He specified everything that I would need including every single nut and bolt and it came in at around $2000.  I drove down to Massachusetts (a three hour trip) with my friends pickup truck to get all the equipment.  This includes five brand-new IQ7A micro-inverters made by Enphase.  These are state-of-the-art seventh generation devices that convert the solar panel power to 240 V that feeds right into my building.  (My original system used the M190 model inverter which was their first product over 10 years ago and 8 of those 30 units have failed over the years but were replaced under warranty).

I am so familiar with installing systems like this that I didn't glance at any documentation because it is so simple and plug-and-play for someone with my experience. 
The sequence involves:

• installing mounting rails
• mounting the micro inverters to the rails and connecting them to the umbilical
  
• running wire from the breaker box to the roof
• Mounting and connecting the solar panels

What could be simpler!

last year my solar power system provided all the power for my property from June through October. you can see historical statistics of my solar power system here.  I'm hoping these added panels will get me close to net zero.  Time will tell!

Here's a video I made about this whole project: