Solar Energy

Energy can be derived from the sun by a number of means. The now familiar solar hot water service uses a black absorbing surface that heats water from the visible and infra-red (heat) portion of sunlight.

Electricity can also be produced from sunlight using what are known as Photo-Voltaic Cells. These cells are thin glass-like plates of silicon material that produce electricity between the front and back surface when sunlight falls on the front surface. The electricity is produced from the visible portion of sunlight, not the heat part. The more intense the light the more electricity it produces. Even under cloudy conditions electricity can be produced although in lesser quantities.

The electricity that the solar panel produces is placed into storage batteries for later use. These batteries are run at near 100% charge. During night and dense cloud cover electricity is drawn from these storage batteries. During cloudy conditions, the batteries will drop in the amount of charge stored. However, once bright sunlight reappears the batteries will go back to 100% charge.

When using solar panels it is important not to allow shadows to fall over the panel. A shadow covering as little as 5% of a panel can cause the output to drop up to 90%. The solar panel should be cleaned regularly to maximize the amount of power received from the sun.

Types of Panels

There are two main types of solar panel: polycrystalline and amorphous.

Polycrystalline

The polycrystalline solar panel is a quality product. It will last longer, is smaller, generates more power, and will give consistent performance with age.

You can recognize these quality solar panels simply by looking at them. Polycrystalline panels are constructed from a number of individual silicon cells that are connected together to form the complete panel. They look like many square or rectangular pieces making up the pattern of the cell. All Sureguard products use these superior quality polycrystalline type.

Amorphous

The Amorphous type of panel is cheap to produce. However, it does not produce power very efficiently. It is often double the size of a polycrystalline panel of the same power rating. They also deteriorate significantly with age. You can recognize amorphous panels by their uniform black colour. They look like a glass surface with a black under coat. This under coat is a very thin layer of silicon. Often you'll see irregular edges where moisture has eaten into this thin coating.

Performance in Cloud

Solar panels will produce electricity in cloudy conditions but not as much as full sunlight. To keep the device operating during cloudy conditions and at night, power is stored in batteries. This stored power can be used when necessary. Sureguard products store enough power to keep the device operating until full sunlight is received again. Overnight the device consumes only a small portion of the stored power.

Aligning the Solar Panel

Solar panels must be installed correctly or the device will eventually run out of power. Set up the solar panel as follows:

• The solar panel MUST face north in Australia. To check the North direction, stand behind the device on its mounting post at 12-noon. You will see a shadow at your feet. You are now facing North. (During daylight-saving-time use 1pm instead of 12-noon.)
• For locations in the Northern Hemisphere, face the solar panel south not north.
• The angle of the solar panel to the horizontal must be 30~45 degrees. Sureguard devices automatically set this angle.
• It is vital that NO shadows fall on the solar panel between 9am and 3pm. Any shadowing, however small, will cause the whole panel to cease operating and your battery will go flat.

How Many Hours of Sunlight?

Sureguard's devices will operate successfully over the whole of Australia provided the setup instructions have been followed correctly. For our International customers, we have provided this Animated Sunshine Map to determine whether your location receives sufficient sunlight.

Map areas coloured in shades of blue receive less than three hours of bright sunlight per day on average during that month while accounting for cloudiness. This is insufficient power for running our solar products 24 hours a day.

All coloured areas, other than blue, receive sufficient sunlight for proper operation even in cloudy conditions.

KEY: The top right hand side displays the month as SUN01 to SUN12 meaning January to December. The sunshine fraction (%) relates to the average number of hours of sunlight. For example, 31% to 40% represents 3 to 4 hours / day of bright sunlight.

The sunshine data in this 0.5 degree grid data set are basically those published by R. Leemans and W. Cramer in 1991 (The IIASA database for mean monthly values of temperature, precipitation and cloudiness on a global terrestrial grid. Research Report RR-91-18. International Institute of Applied Systems Analyses, Laxenburg, pp. 61.).