Cement Energy Environment

85 Figure 5: Solar PV System arrangement A rooftop PV system, is a photovoltaic system that has its electricity-generating solar panels mounted on the rooftop of a commercial building. The various components of such a system include photovoltaic modules, mounting systems, cables, solar inverters and other electrical accessories. Occupancy sensors for lighting control typically use infrared (IR), ultrasonic, tomographic motion detection, microwave sensors, or camera-based sensors (image processing). The field of view of the sensor must be carefully selected/adjusted so that it responds only to motion in the space served by the controlled lighting. For example, an occupancy sensor controlling lights in an office should not detect motion in the corridor outside the office. Sensors and their placement are never perfect, therefore Rooftop photovoltaic power station System design The urban environment provides a large amount of empty rooftop spaces and can inherently avoid the potential land use and environmental concerns. Estimating rooftop solar insolation is a multi-faceted process, as insolation values in rooftops are impacted by the following: • Time of the year • Latitude • Weather conditions • Roof slope • Roof aspect • Shading from adjacent buildings and vegetation. we incorporate a delay time before switching. This delay time is often user-selectable, but a typical default value is 15 minutes. This means that the sensor must detect no motion for the entire delay time before the lights are switched. If lights are off and an occupant re-enters a space, sensor systems switch lights back on when motion is detected. However, systems designed to switch lights off automatically with no occupancy, and to switch lights on when person re-enter.