Dr. Andrew Venter Blog
WATTs our future
February 1, 2012
One of my New Year’s resolutions is to actively “walk the talk” when it comes to reducing my environmental footprint. Now I’m no green “hippie”. I like my creature comforts, I eat meat, drive a car, have a laptop, cell phone, TV, etc.. I love my lifestyle and I want to continue enjoying it. I also want to reduce my impact on the environment and my contribution to global warming, and I think that in this regard, I’m no different to my fellow South Africans. So I thought that one of the themes for my column this year should be the lessons I learn as I try to reduce my impact whilst maintaining my lifestyle.
I thought I’d start this journey by figuring out how to take our house “off grid”, i.e. use solar and / or wind energy to provide the power we’re using. I started this process with an internet search for solar panels, wind turbines and DIY installation advice. I’m no electrician, and so I was rapidly befuddled by the many websites offering me panels, turbines, batteries, invertors, regulators and all the other bits and pieces available to the “green” enthusiast. I realised that I was out of my depth, or literally in the dark. One of the websites pointed me at local expert, who very kindly agreed to come out to my house and to walk my wife and I through the basics of alternative energy. He had a quick look around and then sat us down to break the news that it was going to costs us upwards of R 300 000 to take us off grid, if we continued to use energy the way we were. This made no sense as it would take us over 15 years to recover this investment through our ESKOM savings. Chatting to him it became apparent that we should focus on reducing our consumption before worrying about going off grid.
Now I’m one of many environmentalists who promote energy “reduction”, so it was rather embarrassing when he began to point out the many ways in which we could reduce our energy use! We thought we were doing quite well. We’d changed the majority of our lights to CFL’s bulbs, adjusted our geyser thermostat and switch off lights and appliances when we’re not using them. What we’d never done was actually try to understand our energy use.
This is where the WATT comes into its own. Energy use is measured in watt’s, more specifically, 1 watt is the use of 1 joule of energy per second. Every appliance is labelled with a watt use indicator. Now we’ve used the term for many years, e.g. we’d often talk about the light difference between a 60 watt and 100 watt light bulb. We just never understood what it actually meant. In practise, if we use a 60 watt light bulb for 4 hours each day, we’ll use 240 watt hours per day or around 7 200 watt hours per month (7.2 kilo watt hours (kwh’s). In Pietermaritzburg we pay around R 0.52 per kwh, so we’d pay 7.2 x R 0.52 to use this bulb, or around R 3.50 per month per bulb. A TV uses around 150 watts per hour, so 4 hours TV per day is the equivalent of 18 kwh’s or around R 9.00 per month. A kettle uses 2 000 watts per hour, so assuming we use a kettle for 30 minutes each day, then we’re talking about 30 kwh’s per month or around R 15 per month.
I apologise if you already know this, but understanding this was definitely a “light bulb” moment for us. In fact it helped us understand why we’d taken out all the old style (60W and 100W) light bulbs and replaced them with CFL (Compact Fluorescent Light) bulbs. We knew we were saving energy and simply did the “sheep” thing. CFL bulbs are commonly 15 watt bulbs. So we save around 5 400 watts and R 2.50 per month per CFL bulb that we use for 4 hrs per night. The latest innovation is LED lighting, which allows us to replace the 15 watt CFL bulb with a 4 watt bulb. This will save us a further 1 800 watts and R 0.68 per month.
So we’re now working on our lights, making sure that we minimise our lighting related energy use. Next step geysers and then appliances. At the moment we use around 3 000 kwh’s per month and hope to have reduced this by at least 60% by the end of our “reduction journey”. We’ll then go back to figuring out how to go off grid. I’ll keep you posted and would like you to share experiences, advice and guidance on my blog: andrewventer.wordpress.com.Go back