Solar Power for Ham Radio

It’s been about a year since I installed two 40w solar panels on the tower. 

Background
The system drives a Kenwood TM-D700 for aprs and messaging. It also fills in as a temporary igate from time to time. Occasionally I will also use the system to drive my Yaesu ft-817nd and a small Asus laptop for FLDIGI. A few LED lights on the desktop, and that about covers it.

In addition to the 2x 40 watt solar panels on the tower, there is a Sunsaver 10L managing charge and load functions. I did the modification on the SunSaver, minimizing its noise when I’m running HF. There are no inverters in the configuration nor will there ever be. The Shack is completely dc-powered.

Here’s the original video, and some observations which eventually need to be addressed.

 Why Implement a small DC system like this?
I suppose small DC systems can be excellent resources for emergency communications in a grid down scenario. The charge controller does a wonderful job of keeping the batteries topped up, making this the ideal system for occasional ecomms and backup lighting. 
This system is also a more than adequate power supply for an Elecraft KX2, KX3, Yaesu ft-817,  or any number of radios operating at 20w or less. 


Observations over the past year.

  • Summer
    During summer months at 65°N, the system collects enough sunlight to power my Kenwood TM-D700 24/7 dual band, Medium power, beacon every 15-20 minutes.
  • Winter
    In contrast, from the beginning of December to the end of January, there is no chance to power the system more than a few hours each day ato summer settings. The Kenwood is put in ultra minimal mode, backlight off, output power set to low, vhf only, and beacon set for every 30 minutes.
  • Panels
    The conclusion is: system needs 4x more panels. 2x 40w pointing east for morning sun. Right now I have no panels pointed towards the east. This means the system doesn’t get any direct sunlight until midday. 2x 40w pointing southwest to maximize collection from the afternoon too early evening. This would also allow additional energy collection during gray days.
    I’ve already removed trees on my property allowing for East and Southwest sunlight. Let’s see how we can finance that project later on.
  • Batteries
    It’s also way past time to think about the batteries. I’ve have absolutely no experience with Battery Systems for fixed installations. I would be grateful to hear from other people who have off-grid solar installations.

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