IMPROVEMENTS

If I rebuild this system for fun or commercialization, it will need to be packaged in a weatherproof enclosure to allow for outdoor operation. Additionally, since not everyone has a spare PV panel lying around the house, it would be important to increase the system’s efficiency to allow for a reduced panel size because this is the most expensive component. This can be done in many ways.

The first way would be to have a maximum power point tracking charge controller rather than the simple on-off switch used in this project. This would keep the voltage of the solar cells at the maximum power point on the I-V curve. It would effectively extract about 30% more power from the panel than allowing the battery to determine the panel’s operating voltage. The second way to improve efficiency would be to reduce the power consumption of the system. Because I had plenty of power from my PV panel and sufficient battery capacity, there was no need for this system to do more than turn the LCD screen off when idle. However, it would be possible to reduce power needs further by reducing the chip’s clock speed, letting the chip go idle between readings or at night, and eliminating the LEDs on the STK500 board or using another board entirely.

The sun was shining in my eyes as I started working on this article last summer. I think I’ll soon have to join the fold and get a PV system of my own to go with the logger.