Nord geared motors have been cho-sen to position and securely hold solar modules of photovoltaic plants in Northern Germany. Energy efficiency was a key success factor for Nord solution, as the solar panels permanently tracks and follow the sun over the course of the day.

Intelligent tracking technology from Solarpark Roden?s GmbH increases the efficiency of photovoltaic plants. It requires robust geared motors in order to position and securely hold solar modules against strong winds. Commonly available drive units use conventional brakes and require heaters to prevent them from freezing. These are cost and maintenance-intensive components, which also increase the energy consumption of the drive unit.

Nord solution described here better fulfils the requirements for weather-resistance, precision, energy efficiency and economy. Solarpark Roden?s GmbH specialises in fastening systems for solar panels. As solar cells are most efficient when the sunlight falls on to them vertically, precise tracking of the sun considerably increases their efficiency, at least if the tracking does not consume too much energy. In addition to systems with a fixed mounting, the company develops manually controlled as well as fully automatic systems for tracking the sun. They are driven by compact, powerful geared motors from Nord Drivesystems, for example at the Roden?s Solar Park, which with a nominal output of 2 MW is the largest outdoor system in Northern Germany.The tracking control is calculated on a daily basis from the data for sunrise and sunset. At sunrise, the solar panels turn to the east in order to track the sun over the course of the day. Every 15 minutes, Nord geared motors are activated by an impulse from the central control unit to track the sun for four degrees and then switch off again. Due to the tracking, the solar collectors achieve a 25 to 30% greater efficiency in comparison with fixed collectors. With a surface of 16 m? each, the panels offer a large area of resistance to the winds from the North Sea. The gear units from the modular Universal series, which combine two worm gear units, hold the panels in position without additional brakes.

They position the panels precisely and firmly against winds, which often exceed force 10 gales. Over 700 geared motors are doubly protected from the harsh North Sea climate by the corrosion resistant one-piece aluminium housing and a special paint. A high quality synthetic lubricant ensures reliability even at sub-zero temperatures and also minimises maintenance.

(Nord Drivesystems Pvt Ltd, Pune, India. Tel: 020-39801200. Fax: 91-20-39801216. Email: info@nord-in.com)