So Watt? What do watts really mean in Rands and Cents?

With all the figures around electricity, watts, kilowatt-hours, amps, volts… it’s very easy for people to lose sight of what’s important. MONEY! 🙂

We all see things saying save power by filling up your kettle less, turning lights off and loads of other things; but what really matter isn’t the WATTS it’s the RANDS! To make your life just a little bit easier we’ve put together a little cheat sheet for you. You can download it here. Cost Cheat Sheet

It’s quite simple to use. Look up the POWER in Watts in the first column, then read across for how much that device will cost you every minute, hour, 4-hours, all day etc. There’s two separate sheets, one for if you pay around R1.00 per kWh, and one if you pay closer to R1.50 per unit. 

As an example, I found in the last article (Free Energy Monitor) that my kettle uses 2400W – that’s pretty close to 2500. So read down the cheat sheet until you get to 2500W. Then if I read across, I can see that the kettle being on for 1 MINUTE costs me R0.04. Make sense? So if you’re kettle is on for 2 minutes, it probably costs you R0.08 to boil the water.

On another end of the scale and trying the second sheet (for people who pay R1.50 per kwh) – old style light bulbs can be 100W. Leaving one of these on for a whole month will cost R109.20. Whereas if I replace that with a CFL or LED light that only uses 10W, it will only cost R10.92. So if I leave that light on for 24-hours every day, replacing an old 100W bulb with a 10W bulb will save me almost R100 every month.

That is a little unrealistic, I know, so let’s say I only have it on for 4 hours every day, I can also use this sheet — just look up 4 hours rather than 1 month. Here we can see that a 100W bulb costs R0.60 every day, whereas a 10W bulb only costs R0.06. So you’d save R0.54 every day. Over a month that would be R16, or over a year almost R200. You can see why everyone is so keen to replace your light-bulbs now!


PS – we just knocked this up quickly, so if our math is wrong, please tell us and we’ll fix it! There is the original spreadsheet here: Cheat Sheet and the print out again here: Cost Cheat Sheet


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