Local Isolation

Using the Sun’s Energy Inspired by Stuart Ball’s recent piece in Circuit Cellar on solar energy basics, I decided to build a low-voltage solar energy system. I talk about the battery and detail how I used the Modbus protocol with RS-485 serial communication for remote monitoring, with the ESP32-based HUZZAH32 Feather microcontroller (MCU). Topics Discussed How can I build a low voltage solar energy system? How can I use the Modbus protocol with RS485 serial communication for remote monitoring? What's a fun project with the HUZZAH32 Feather? Tech Used HUZZAH32 Feather SN75176 This is my fourth start on this month’s column. I’m not sure what’s going on, but I just can’t pull the trigger, so to speak. So I’ll try something different. I just read Stuart Ball’s article on solar energy (“Solar Energy—Getting Started,” Circuit Cellar issue #395, June 2023) [1]. I’ve used solar power in many projects over the years, and determining the minimum panel/battery size is always a major headache. Recently, my Scout Troop 96 built a two-story shed (the “Eagle’s Nest”) on our host’s property, to house our camping equipment. The shed has an attached carport where we can park a trailer and can load and unload it under cover. We camp year-round, and sometimes the weather is quite nasty. There are no utilities on this property, so the building’s interior has no lighting, except for what comes in the small windows. We can move around clumsily during the day, but once it gets dark, you’d better have a flashlight! I thought that installing some solar equipment might be a great educational experience for the scouts. We’re not talking tons of roof panels and AC lighting, but rather, a low-voltage system that could handle some LED lighting. The simplest system would consist of a solar panel, a charge controller, and a 12V storage battery. But first, let’s step back and look at the building’s layout and wha