Electricity Eaters
By Parkhurst Post Editor, Tim Truluck
The mantra that our hot water tanks (also called cylinders or geysers) make up 40-50% of our electricity bill has been passed down as a household law along with such myths that leaving the cut crust on one end of the loaf stops it getting stale. I always wondered why our electricity bill didn’t really get any less when we went away for a few weeks and turned it off. So with the fuss going on about cutting our electricity usage by at least 10%, I felt it was time to do some research of my own.
My starting point was the excellent table of the drawing power and cost of using various household electrical appliances that appeared in the Star on 21 January 2008. I added a few extra items that are applicable to my household and worked out exactly how much we are paying for our electricity in Parkhurst (R0.5191 cents a Kilowatt hour including VAT). And the results lead to some interesting findings which I have presented here (cost of using domestic electrical equipment).
This graph shows, in descending order, how much it costs in rand to use an item of electrical equipment that we often have in our homes.
Sure enough the hot water cylinder or geyser tops the list at R2.338per hour when it is heating water. Of the top 20 energy hungry appliances, only 4 items are not related to heating something up.
Right at the bottom of the list is one of those energy saving bulbs with which we are being urged to replace the old incandescent bulbs. It only uses 0.4 cents an hour, while the old style 60 watt bulb costs 3.1 cents an hour (or 12 times more electricity than the energy saving one).
This kind of information is useful, but it is limited as it doesn’t take into account the actual usage of the appliances. I therefore used my house as an example for actual energy usage. It is a normal 3-bed 2-person house with pool, security system, loft insulation & granny flat.
Annual Electricity Cost:
The pie chart above shows the breakdown of energy use categories (like heating, electronics & computing, lighting, cooking, etc) as well as some of the appliances that use enough electricity to be placed in their own category.
What I have done is estimate how much I use each appliance (and it is only an estimate). I was gobsmacked by the results. Contrary to popular belief, our hot water cylinder only accounts for R900 (or 9%) of my annual electricity bill (based on it heating water the little bit of water we use in showering and doing the washing up). It came in at # 7 in the list of most costly electricity catagories.
Top of the list was the pool pump which costs me R2000 a year to run (or 20.37% of my energy bill). My pool guy recommends that it should be on 12 hours/day for the 8 months of summer/spring and 8 hours/day in the 4 months of winter. It is by far and away the worst energy consuming single item in the household - about the same as all our cooking appliances together.
Other energy sapping culprits are
• 19.60%: Cooking (stove, oven, microwave, kettle, etc);
• 10.49%: Heating (we have four 7-fin oil heaters used for about 5 hours a day in winter);
• 9.93%: Electronic and computing equipment (2 computers, printers, answering machines, hi-fis, TV, etc - we both work from home);
• 9.67%: The 2 fridge-freezers cost R475 each per year to run);
• 9.57%: Lighting - we have a mix of energy savers where we can and normal bulbs in the chandeliers and spots. Note that despite bulbs being cheap to run it is number of them and the long time they stay on that racks up the bills (we have a total of 38 in our house);
I have included another item we leave on 24 hours a day - the electric fence (R00 or 1.02%). Despite putting out 12000 volts it uses very few amps (the bit of electricity that has the power to make things work) and so it hardly draws any current and costs less than R10/month to run.
This, then, is a much more useful analysis and really does give me pointers where I can make real savings based on real facts. So here is what I have done and will be doing to reduce my energy consumption both to save me money and to help Escom (and therefore you) to avoid those dreaded planned power cuts.
• Roof insulation - recycled paper treated with fire retardent and rodenticide that was installed in 07;
• Install timer switch on hot water geysers and pool pump to reduce the load on the electricity grid - about to do in early March o8;
• Replace electric hot plates with gas - about to do in March 08;
• Use an electric blanket in the bedroom instead of oil heater - bought one in 07;
• Reduce pool pump usage - I have a salt chlorinator and so need to run it to generate chlorine. I will add a chlorine floater to the pool and run it for 8 hrs in summer and 5 in winter;
• I will replace ALL my old incandescent bulbs with the energy saving ones;
• I will use those light sensitive energy saving bulbs for my outside lights;
• I will replace the two old brass chandeliers with more modern low energy light fittings;
• I will turn off my PC more often (even if only the screen when I am away from the desk and office);
• I will turn off the at the wall all the devices that have a standby function (like the TV, hifi, DVD player, toaster, cell charger, etc).
What are you going to do? I would suggest that you use the figures in the first graph and work out your own usage. Then have a look at what is really costing you money and wasting electricity. Then DO SOMETHING about it and make those changes.
Geysers - Beyond the Truth
OK - the above analysis exploded the geyser myth about it being the major electricity user in the home. But it is a major power user when it is on, especially at certain times of the day when EVERYBODY else’s geysers are on. This is what ESCOM are getting at when they want us to turn them off at certain times of the day.
From listening to “experts” on Talk Radio 702 and chatting to my plumber and electrician I have come up with the following information on geysers.
If you were to turn it off from time to time, would you (1) help save electricity and make you feel that you are doing something to help with the electricity shortage; and (2) save you any money? The answer is “it depends.”
The geyser uses electricity to heat up water in a large cylinder. When the water gets to a certain temperature, the geyser turns itself off. When the temperature of the water starts dropping, the geyser turns itself on to heat it up to the desired temperature again. This continues all the time often as much as 20 minutes per hour in an old geyser. So obviously the insulation of the hot water cylinder or geyser is important.
Old Geysers
If you have an old geyser, it is unlikely that it is not well insulated. This means that you will save money AND electricity by buying an insulated jacket and fitting it so that you decrease the heat loss. An uninsulated geyser loses heat quickly and so it has to work harder to keep the water hot.
If you turn off this type of geyser for several hours a day, you will save money. I asked a plumber about stressing the element (the thing that heats the water) in an old geyser by turning it off and on and he said that he hadn't come across this problem.
I have one of these in the granny flat I only turn it on when we have visitors. The element hasn't blown so far.
New Geysers
These tend to be the more like square boxes. The box often has insulation inside it to keep the water warm and the water loses about 1'C every 24 hours. Because the heat loss is less, the element doesn't have to work as hard to keep the water hot. Turning off this type of geyser will not really save you money as the money saved in turning it off will be added on when you have to reheat it again.
I have one of these in my house and I find out that the water stays warm enough to have 4 showers a day and sundry hand and dish washes for two days.
You can also turn down the thermostat on the geyser. I found that when I did this, I used more hot water as you don't use so much cold water to cool it down. I also found that the shower was weaker as it needed the cold water to boost its power. I will be investigating a low flow shower head which may solve this problem.
Ethics
As mentioned above, expense and just saving electricity is often not the main reason for turning off the geyser. The main problem we are facing is that at certain times in the day, the demand for electricity exceeds the ability of Escom to supply it. So if we can have our cylinders (and pool pumps, etc) turned off at these peak times (from 6-10 am and 4-9 pm), then we WILL be helping to solve the energy crisis.
Recommendations
I would recommend that you install a timer on your geysers (and also on your pool pump) that isn't affected by power cuts (it has a little battery built into it) that turns on your geyser at night and your pool off during off-peak periods. Ask your electrician about them they cost R1500 to supply a good quality one.
You can also fit an insulated cover onto the cylinder which will help a little bit for the new cylinders and a lot on old ones. Of course it will work better in winter when the temperature is colder. They cost from R200-300 each depending on your geyser size and are available from Parkhurst Paint and Hardware.
Power Cuts that Killed the DVD
We all know about power surges and outages causing damage to your computer equipment, but they can also have a disastrous effect on many of your electrical devices in the home.
Those most at risk are the ones that themselves powered by small micro-computers such as the more obvious MNET/Multichoice decoders, TVs and DVD players. However many other devices like fridges, microwaves and toasters also now have little computers or microprocessors built inside them.
They are also designed to operate on a constant and steady power supply to work well. They have been designed to be disconnected one or two times a month, but once or more a day is bad for them.
But the main problem is the on-off, on-off with the surges and dips in the current when the power is reconnected. An expert on Talk Radio 702 said that the best thing we can do during planned power cuts (and also in case of unplanned ones) is to shut down the device and turn it off at the wall. Only turn it back on when the electricity has been switched on again.
For the devices like fridges, you can fit one of the many external power supplies like a UPS or surge protector.
For more, click here
Source:
The Parkhurst Post
Back to main page
|
