Portasol Motorless Solar Tracker

Motorless Tracking System for Solar
Ecogeek reports on an Australian man’s invention for tracking the sun using a motorless tracking device. It uses a hydraulic system powered by the sun.

The device works by absorbing heat from a combination of increasing ambient air temperature and direct solar radiation to provide an expansion of a liquid at a controlled rate. Increasing hydraulic pressure drives the mechanism until sundown when the liquid cools and contracts allowing gravity and a small spring bias to return the array to the morning position.