This section will help you decide on the type of lights to use in your garden lighting project and the power sources needed to run them. Garden lighting and solar garden lighting can be used for decorative or functional purposes. Decorative lighting can be used to highlight trees, walls, rockeries and ponds whereas functional lighting is for lighting up garden pathways, entrance porch lights or floodlighting large areas. To view garden lighting products click on lighting.
Power sources for garden lighting can come from AC, DC or even Solar power arrays and rechargeable batteries. In the main, brightness of the light sources dictates the power source requirements. Each of the sources are discussed here outlining the merits of each and the appropriate uses. The use of Solar power warrants deeper discussion and is detailed at the end of the section on lighting.
AC power comes from the consumer box at 240V, 50Hz and can be routed to the outside for garden use. AC for outdoor use such as garden ponds and lighting needs to come directly from the consumer unit with its own fuse backed up by an RCD (Residual Current Device). Once routed outside, the power supply cable should go to a all weather proof box in which you can mount the power sockets. The weatherproof box should be located in a position in the garden where it is easily accessible for routing cables either for pond equipment applications or for lighting purposes. Most weatherproof boxes that you can obtain from DIY stores are large enough to house the low voltage power supplies used for garden lighting and water pumps.
DC power is converted from AC using a transformer and output is in volts DC. A lot of the garden equipment such as pond filters, pond pumps and low voltage lighting use DC output but are powered by AC. These equipment have their own power supply transformer with a 13A plug fitted to them. You can also get DC using solar powered rechargeable batteries.
Using Solar Powered outdoor lights is an attractive alternative to the above sources and if you don't want high power cables buried through a garden. Solar power is low-maintenance and very reliable, and installation is often as easy as pushing a stake on which the fixture is mounted into the ground.
The simplest system consists of a solar array module, a 12v battery and electronics to regulate the charging of the battery during the day. The battery stores the energy from the solar array during the day and then uses it at night. The stored energy in the battery (depending on the battery capacity) can be used to power low voltage lights at any time, day or night.With modern PIR sensors automatic dusk to dawn operation eliminates any human intervention. This type of system is ideal for use in garden sheds, garden lighting, greenhouses, pond pumps or lighting.
Solar powered lights can also be purchased as complete packages. These lights are generally sold as a pack of two or four. These lights are very convenient to install as all you have to do is drive a stake into the ground where you want the light and the installation is complete. However the cheaper versions of these lights have their drawbacks. To begin with avoid buying solar powered lights that have the plastic shafts as these break easily. Secondly, position lights where there is plenty of sunlight for the solar cells to charge.
The lights incorporate an LED lamp, solar cell array on the top and one or two rechargeable batteries inside. These lights operate by solar energy charging the rechargeable batteries during the days and discharging the battery power to LED lights at nights.
LIFETIME OF RECHARGEABLE BATTERIES.
The rechargeable batteries used in the solar garden lights vary in quality. To begin with some lights have just a single battery and some have two. I would get the lights with two battery cells in them. This is for two reasons firstly the battery cell capacity and secondly the old english weather. On not so sunny days the solar cells do not pump out sufficient current to charge the cells to last all night and as a consequence the garden lights get dimmer as the days go by. The shorter days in winter also reduce charging of the cells.
I have found that some solar lights have rechargeable cells with a capacity of 550mAh. The mAh stands for milliamp-hour, the milliamp being a unit of electric current. I found that by replacing these batteries with higher capacity 1300mAh cells produced brighter light and longer duration as well. Typical garden lights use LED's which take a current of about 20 to 50 mA should give about 16hrs of operation but they rarely do. This could be due to insufficient charging of the cells by the solar cells or reduced cell efficiency.