About Solar Powered Electricity - Solar Panels and Energy from the Sun

SOLAR POWER ELECTRICITY

Solar Photovoltaic Panels

Solar panels produce DC electricity when exposed to the sun. They produce more electrical output on long sunny days and less output in cloudy weather or when shaded. The angle of the panel in relation to the sun is important as the panel will produce higher electrical output when faced directly to the sun.

Solar panels are made up of solar cells, which are mainly made up of silicon. When exposed to direct sunlight the electrons receive equal or greater energy than is required to bind them to the nucleus of the silicon atom, they are then ejected from their electron shells and become free electrons and are now able to make up and move as part of an electric current.

ARRAY STRUCTURES

Fixed Arrays

This is the means of securing solar panels to a roof or building, but they may also be ground mounted. Array structures can be custom built to suit the roof angle and fixing points. This type of array structure is commonly referred to as a fixed array. The array angle is often able to be adjusted allowing the panels to be manually moved to coincide with the sun's seasonal angle.

In the southern hemisphere the array faces north and only receives maximum solar irradiation for a few hours around midday. Due to sunrise and sunset being low on the east and west horizons, the morning and afternoon sun angle to the

north facing panels is much greater than midday. This greater angle limits the amount of solar irradiation the solar panels will receive.

Tracked Arrays

This type of structure still has seasonal sun angle adjustments that can be manual or automatic. The big difference is that the panels are moved by an electrical device allowing the array to follow the sun through out the day. The array will track from east to west so as to place the panels' face directly at the sun. This maximizes the amount of solar irradiation that the panels will receive during the day.

Array Summary

Consideration should be taken in to account when deciding between a fixed array and a tracked array. Trackers cost more initially but offset the amount of panels required due to higher output characteristics.

A fixed array will require more panels, costs less initially and requires very little maintenance.
Trackers and ground mounted arrays are generally only used on rural properties where there is lots of room. Ark Energy manufacture both tracked and fixed array structures.