I guess by this time everyone has seen requests to switch off your lights on Saturday evening in support of Earth hour. From the Earth Hour website:
Earth Hour 2009 has one major aim: to unite the citizens of the world in the fight against climate change in order to convince governments and world leaders that our planet cannot wait any longer. There simply isn’t enough time, and therefore 2009 is a colossally important, if not the most critical year, to take action on climate change. 2009 is the year we decide the future of our planet.
So I take it we are now quite sure that climate change is caused by some factor that is within human control, as per the Al Gore movie?
It must surely be that Megawatts are a measure of power whereas Megawatt hours would more accurately depict energy consumption. I.e. 400 Megawatt hours were saved.
At a time when Eskom is finding it difficult funding new projects (PBMR) and paying salary bonuses, they may find the Earth Hour hit of R158 000 a bit inconvenient Eskom shouldn’t find the R44 000 lost to the event an inconvenience at all. But with annual consumption in the ballpark of 241 million megawatt hours (2007), a very rough estimate for that day’s saving when compared to average daily consumption in 2007 (not corrected for weekend industrial downtime, mostly because I don’t have the detailed figures) was about 0,60581%. For any average hour of consumption in 2007, the comparative saving was 1,4181%.
I know, it’s about the message. I did take part, although I was at a well-lit wedding reception at the time, the mains switch at home was off that night. ;D
Yes indeed, well spotted. “Megawatts” is a time-rate of energy consumption whereas “Megawatt-hours” is a quantity of energy. Earth Hour reduced the time-rate of energy consumption and thereby saved a quantity of energy. The journalist’s claim – and one should bear in mind that it may well have been taken verbatim from an Eskom PR minion (Oh, the shame!) – is akin to saying, “I took a shortcut and saved myself 4 kilometres per hour” rather than, “I took a shortcut and saved myself 4 kilometres.”
The issue is not so much the (very much debatable) benefit of an initiative like Earth Hour. The issue, to us, is the media’s general ignorance of, disdain and casual apathy for scientific matters – almost as much as it is that they continue to get away with such abuses.
We objected. Strenuously.
And we think you should too because these are the gaps that sceptics can fill.
'Luthon64, you’re right of course, and shame on me for not spotting it right away. But let’s for argument sake accept the breathless idiot made a mistake, let’s accept she really meant 400x10exp6 kWh. Now our monthly consumption last month was 285kWh. But we’re not average (just two old farts), so say 500kJ (or kWh) average per real household per month in SA. After dividing and multiplying as necessary (if everything was drawing power as per avarage) the energy usage per hour is about 0,7 kJ per household. So, how many households took part in Earth Hour? Say a million, or 1x10exp6. Therefore saving should be 0,7x10exp6, or (about) 700 000kWh (or kJ). Which is a little less than 400x10exp6 as breathlessly reported. Why the hype?
Armando.