AllEarth Renewables. The AllSun Tracker combines PV collectors, inverters, and controls with a ground-mounted, dual-axis tracker that uses GPS to follow the sun across the sky, producing up to 45% more energy than a standard fixed system, the firm says. Two models, a 4.2-kW unit or a 5.5-kW unit, deliver approximately 5,900 kWh and 7,700 kWh per year, respectively. www.allearthrenewables.com.