Saving Power
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The geyser is the prime consumer of electricity!Yes, the geyser is the guilty party in the majority of households, but there are a few other suspects discussed a little further on. How do you save power used by the geyser? Actually it's not as easy as some would have you believe, nor can you make really huge impacts on the consumption. The fact of the matter is that you use x litres of hot water per day and it will require y of energy (electricity) to raise the temperature of the cold water to 65 Degrees Celsius. If you really want to save electricity then cut your hot water consumption by 50% :-). The trick is to target the inefficiencies in the system. Here is where you do make savings but not huge savings if the system has been correctly installed. Here are some specifics: - Lag or insulate the pipes. Better still use new plastic pipe systems like "Marley, Pro-fit". These pipes don't need lagging, don't freeze and retain heat very well. - Turn the geyser down to 60 - 65 Degrees. It does take slightly more power to maintain the higher setting and your heat loss is a bit more. A "kitchen only" geyser can be turned down to 50? - Educate the family to use the mixers set on the COLD position if they don't need hot water. The saving here can be significant. Every time someone opens a mixer in the centre position they let a quantity of cold water into the geyser. This will cause the element to switch on sooner. Do this all day long and you will keep the thing on all the time - even though you may not need hot water. This is compounded by unlagged steel or copper pipes that ensure that the small amounts of hot water never make it to the tap. A solar pre-heater also helps with this type of usage. Replace your geyser with a new better insulated one. Geyser blankets do work but they must be substantial and fitted correctly. Modern geysers have an effective insulation layer of up to 50-75mm thick, but they can benifit from a good blanket. Switch it off when you are not at home. You may want to be patriotic and switch it off during Eskom's peak demand period. It helps us all and will not cost you any more or less in total energy consumed. At least not anything that you should worry about. Remember the energy required stays pretty constant no matter the timing of how you apply it. This assumes that you have the heat "losses" under control! You may want to look at a device called "Geyserwise". I have fitted a few and the owners are very happy. I do not have any firm figures to prove it's worth, but I suspect that you may mitigate the fact that people keep draining small quantities of hot water all day long and causing the geyser to cycle on and off a lot if you use this device. You can use "geyserwise" or just fit simple timers to follow the "on the farm approach" described next...... "Brute force saving" or "Living on the farm" I have tried this (briefly) and it can realise cost savings of between 20-50% - BUT your family will not love you as much as before. It's a very simple concept. You switch the geyser on for exactly 1.5 hours per day (avg. heating time to 65 degrees). You do this at the same time every day and you make sure that everyone understands that they need to take 4x showers of reasonable and equal duration. You must switch the geyser off as the first person starts showering. This approach achieves the following: 1. You heat a specific quantity of water - 150 litres and you use it immediately. Like a kettle. 2. You pay nothing to maintain the heat. There is very little heat left to maintain. 3. You are able to wash the dishes with the remaining warm water the next morning. This if you don't allow the showers to use all the hot water. In other words you leave a bit that stays warm overnight for the dishes. 4. You are able to quantify your usage exactly - 3kW x 1.5 hours = 4.5 kW hours x 30 days = 135 kW hours per month. 5. You may need to do this twice per day if your family rebels - in that case you are looking at 270 kW/hours per month. For example on between 05:00 to 06:30 and then again at 16:00 to 17:30. 6. Forget about baths - if you use this system then it's got to be showers for everyone. Baths simply use too much hot water! 7. Get basic (in the DB) electrical timers to do this for you - you will never remember to switch on and your family will eventually leave you :-) Consolidate the number of geysers in your house You may not need 2 geysers if there are only 4 people living in the house. If you have a seperate geyser that only services the kitchen turn it down to 45-50 degrees (warm). If you have three geysers then you may want to consider re-piping the system so that you can switch the third one off - permanently. This is especially true if you have a small bathroom serviced by it's own geyser, or both you and your wife both always use the shower. If you run out of water then stagger the usage a bit. The time I use to heat a geyser from cold is 1.5 hours. Invest in a Solar system - a clear winner! The Other Suspects. Underfloor heating - often the same (3000W) or more wattage than a geyser. Electric Lawnmower - now here is one that I did not think of at first - I use a petrol mower. These things - the electric jobs are around 2000 Watts and better. If you have a big lawn and you mow often then you are using a good few KW/hours to keep the grass short. This teamed up with the mower's china - the "weedeater" who adds a couple of hundred Watts to the cost. The pool filter - remember to reduce his hours during winter! A filter motor is typically 750-1000 Watts. It is an idea to check your pool pump motor power requirement. A customer of mine discovered that his was in fact just shy of 2K Watts. This after a R16000 electricity bill. My personal experience here is to reduce the size of the pump but increase the size of the filter housing. I went from 800 Watts to 650 Watts and my filter from a two bag to a three. I now run it 5 hours per day in summer with no problem - this from a high of 8 hours. Borehole pump - I have a few customers who think that their borehole water is "free". Well it's not totally free if you consider what a borehole pump consumes - 2000-4000 Watts, sometimes even 3 phase because it uses so much power. Tumble dryer - up to 2000 Watts and it gets used all day when its raining! Modern ones have brought this number down a lot... Electric heaters - try the new halogen ones? 2000-3000 Watts used by the conventional heaters. Pressure booster pump - turn the pressure down a tad below the average municipal pressure. Airconditioner - what can I say? Most of them use over 2500 Watts. Washing machines & dishwashers with heater built in - a mini geyser. Try to use cold water for washing! Also try and buy a DIRECT DRIVE washing machine with no belts. Belts reduce the efficiency by a significant amount. Incandescent light bulbs. They make more heat than they do light - change to "energy saver" bulbs. The Oven and stove - use a microwave! Ovens use more power than geysers. Put lids on pots and don't leave them on the stove! TV's, PC's, radios, Hi Fi's etc don't use much power individually, but you can easily add another 1000 Watts if you add it all up. Switch off when not used! Here is an example - a 450 Watt Pc running 24 hours per day works out at 11 kW/hours per day. This is 324 kW/hours per month or about R300 - just to run your PC!!! Fridges and water coolers - turn them up a bit and keep an eye on water coolers - water coolers often forget about their thermostats and stay on all the time. At around 250 Watts this can end up costing you money. 250 Watts x 24 = 180 k/Watt hours per month, or about R150/month!!! Ceiling fans - same as lights but they can also use about 250 Watts each. Four of them going all the time can cost you 720 Kilowatt hours per month.! Kettles - only boil the quantity of water that you need. If you are making 2 cups of tea then only fill the kettle with two cups of water. Hot water Urns - avoid using urns in a domestic situation. Most of them are not insulated and they are just acting as space heaters!
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