Living Sustainably
in the shadow of climate change

March 2015
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Adding 2 more solar panels
Filed under: General, Solar Power
Posted by: Guy @ 10:40 pm

Since we purchased the Chevy Volt last year, it has been clear that I will need to add more solar panels to make up for the extra energy required to charge it (around 13 kWh per day).

Last year I added three panels to the west facing array which now totals 5.1 kW.  This leaves no more space on that roof.  The only remaining surface on the building that is exposed to the sun is the south wall above the collectors, so I intend to put two more panels on each side of the window angled out at about 25°.  Here is a Google SketchUp model showing the proposed location for these two new panels:

In keeping with my desire to install only American-made hardware, I have purchased two Solar World 245W panels, and two Enphase M215 inverters from altE.  Rather than pay the very expensive truck freight to have this hardware delivered, I will be driving down to Marlborough, MA (a 2.5 hour Drive) to pick them up from the altE warehouse.  After measuring very carefully I have determined that the 2 solar panels should barely fit inside the Chevy Volt which is fitting since the panels will be providing power to charge it.

I hope to mount them as soon as the snow clears off the roof, and the weather is amenable for outdoor work on ladders.

5 Responses to “Adding 2 more solar panels”

  1. RJ Says:
    Will the three plus two new panels cover the Chevy Volt or will more be needed? Have you considered an array on the ground? One builder in the Central Texas area has setup his panels on metal racks on the ground. Easier cleaning and access to the micro-inverters was cited.
  2. Guy Says:
    RJ, I have not done the math to calculate exactly how much of the Volt charging power these panels will offset. The Volt requires around 13 kWh for a full charge. One way to look at it is that we were exporting a small amount of power for three months last summer and I would like to get that up to 6-9 months with the goal of breaking even electrically on an annual basis. I have too many trees to consider a ground mounted array, but I did give it serious thought for a while. I am eyeing the East facing roof of my house for another array down the road.
  3. Guy Says:
    According to my math I need 3kW of solar panels to charge the Volt in the summer. These 2 panels add about .42kW in July (and way less in the winter), so they won’t make a huge dent in the total needed to charge the Volt.
  4. Jamie Says:
    are these the ones you just purchased? down to 93 cents per Watt! wow…how low can they go! Now if I could only find a good price on the micro inverters. Thank you again for all the information over the years!
  5. Guy Says:
    Yes, those are the panels. If you scour the web you can find to occasional really good buy on the Enphase microinverters. I have paid as little as $160 for M190 inverters in the past. Also some warehouse dealers are negotiable if you show them competing prices.