Watt: This unit measures the power that is needed for a certain application – for instance you need 100 watts to run a 100 watt light bulb. Technically, this is defined as the amount of Joules per second.

Volts: A unit of measure that expresses how many electrons flow through a given circuit. For example, if you compare this concept to the water in pipes, it is equal to the water pressure, or more specifically, how fast or slow the water is flowing. Generally speaking, the US standard for homes is 110 Volts but in Europe and in South Africa it is 220 volts.

Lumens: These units are used to measure the power of light that is perceived by the human eye. These measurements are intended to gauge the varying sensitivity of the human eye to different wavelengths of light,

Kelvin: This unit is used to measure temperature. In relation to lighting it is the most important number to look at to determine the color of fluorescents and LEDs. The lower the Kelvin temperature the warmer the color of the light, and the higher the temperature the more blue and cool the light is.

Top Energy-Saving Tips

1. Monitor Your Energy Use
You can reduce your monthly electric expenses — typically by as much as 15 percent, according to a recent IBM study — by knowing how much power you’re actually using and where you can most effectively cut back. Add a plug load monitor to any outlet where you plug in an appliance or device; the monitor will display how much energy the device is consuming and when, helping you decide which ones should be turned off and at what time. Some models are programmable, to cut power automatically.

2. Install Dimmer Switches
Not yet ready to say buh-bye to incandescent bulbs? Then consider that simply dimming a light by 10 percent more than doubles the bulb’s life — and switches only cost about R200 depending on the type required.

3. Add a Motion Sensor
Add motion sensor to your outdoor lighting fixtures. One of these little helpers (around R180 each) turns off the light when nobody’s present. The gizmos are great for the seldom-used areas of your home, like the basement and guest room.

4. Install an Energy Star-Rated Ceiling Fan
Prices start at just R800. In cooler months, run the fan in a clockwise direction to push warm air down from the ceiling, reducing HVAC load by as much as 10 percent. And in the summer, reverse the motion to circulate cool air — and make the temperature feel up to eight degrees cooler!