Skytopia > Articles > Tips on how to Save Energy    (article created 23/12/06)

Tips on how to Save Energy
(or how Heat swamps Light swamps Sound)

  • Heat swamps Light swamps Sound
  • Energy consumption of appliances
  • Stand by mode and switching 'off'
  • "Space-age" aerogel as a miracle cure for heating!
  • Ways to save on heating the house
  • Future of energy; nuclear power, solar power and cold fusion
  • One can but dream

  • Heat swamps Light swamps Sound

    For most of the world, you can bet your life that the largest chunk of your electricity bill will be thanks to heating your house ($2000 per year per household in the US in 2005). In fact any kind of heating, whether it's the iron, washing machine, convector, kettle, or cooker, all eat up exorbitant amounts of energy which put other electricity bills to shame. Yes, it's no coincidence that searching for "battery powered radiator" in google returns zero results.

    Sound you get practically for free.

    KiloWatt hour (kWh): one KiloWatt (1000 watts) supplied for one hour; this is the normal unit of electricity supply for domestic purposes. (The cost of electricity is measured in pence per KiloWatt hour (p/kWh)). 11,630 kWh is equivalent to 1 Tonne of Oil Equivalent (TOE), i.e. the energy produced from one tonne of oil.
    Lighting is somewhere in the middle. On average, you can light up 20 bulbs to match your power hungry electric radiator. Trying to diligently save on lighting bills by keeping them off while you're out is like trying to hopelessly blow into a falling hot air balloon whilst ignoring the heavy rocks next to you in the basket. In fact, leaving one of those energy saving bulbs (20 watt = 100 watt equivalent) day and night solidly will only cost $18 per year (assuming 11 cents per kwH, the average over the US according to the 2006 EIA report).


    Did I mention how cheap sound is? A year of sound pumping out your speakers at moderate volume will eat up only FIVE DOLLARS. Even your top of the range 40 watt speakers will usually eat up around only 2-20 watts because the power varies according to the volume. The '40' only represents the maximum power that the speakers allow. Incidentally, switching from no bass to full bass on my speakers eats up around 50% more power consumption at the same volume.

    Note that the below energy consumption of appliances does not take into account how long you use them for. So the kettle, although high power will eat up less energy per year than the fridge, which is low power, but on all the time.

    Energy consumption of appliances

    Appliance off Appliance standby
    (or doing nothing)
    Appliance on
    Kettle - 0 2200
    Convector heater 0 - 2000 (high), 1000 (low), 15 (fan only)
    Portable radiator - 0 1900
    Iron 0 - 1350
    750 watt microwave - 0 1150
    Washing machine - 1 1000 average (2000 max)
    24" CRT Television (2000) 0 6 80 (about)
    17" CRT monitor (2000) 1 2 60 (45 black screen)
    14" CRT monitor (1990) 0 5 60
    Lamp with 60w bulb 0 - 55
    Desktop PC (2000) 2 - 55 (90 in heavy use)
    Desktop PC (1990) 1.5 - 33 (45 in heavy use)
    14" CRT Television (2000) 0 4 30 (about)
    8.5" cooling fan 0 - 20 (low), 30 (high)
    11w flourescent lamp 0 - 12
    VHS video player 3 8 12 (playing), 17 (FF)
    N64 games system 0 - 9
    PC loudspeakers 3 5 5 (low vol), 10 (high vol), 15 (very high vol)
    Fridge - - 55 (while cooling), ()
    Phone charge - - 4
    Portable tape player - 1 2
    Portable radio - - 1

    Yes it's true. Leaving your convector heater on uses up more than double the energy of all the other 17 appliances (from the 24" CRT Television downwards) COMBINED. As should be clear by now, all the heating appliances are near the top, while the lighting ones are in the middle, and the sound type appliances are at the bottom.

    For perspective, heating your home will use 55% of your electricity bill, heating your water will eat up a further 20%, and you can bet a large proportion of the remaining bills are heating (or cooling) orientated (reference). At this point, I'd just like to rant at this point and say how irritating it is that companies such as Powergen don't state on their website how much we pay for each kilowatt hour of electricity. It wouldn't just be easier for calculating bill costs, but it would also encourage market prices to drop due to competition of offering the 'cheapest deal' for power.

    For testing I used the cool Power meter from Maplins (about 25 quid).

    Stand by mode and switching 'off'

    Due to various manufacturers' stupidity, 'standby mode' will not always eat up near zero energy. A good example is my video recorder, which when not in use will eat up 8 watts of power! That's about $10 a year which to be honest, isn't all that much, but from an investigation (testing power consumption in ten California homes): That's why there's call for the enforcement of manufacturers to limit appliance standby to 1 watt maximum. See the "One watt plan" for more information. It's a good thing, as the consumer should not be forced to turn their appliance off when it's so easy for the manufacturer to fix the problem instead.

    Perhaps even worse is the number of watts used even when certain appliances are switched off. As this guy found much to his surprise, his computer+monitor leeched 30 watts. Of course, to avoid this, he would need to switch off at the wall, instead of just the power buttons on his PC/monitor.

    * Insulating your home with window panes of pure aerogel

    MarkeTech International is about the only place on the net where you can buy vast quantities of aerogel, so we can estimate the cost of insulating your home. Assume an average size room is 12' by 12' by 8', and assume you want to insulate 4 rooms, and for each room, insulate 3 room sides (floor, and two walls). We can also see from MarkeTech that it costs $1170.00 for 4x8x0.5 inches of aerogel. That means a one square foot of quarter inch thick aerogel costs $2632.50.

    Wall 1 + Wall 2 + Floor = total area needing covering for one room
    (8x12 + 8x12 + 12x12 = 336 square feet)
    Four rooms = 336 x 4 = 1344 square feet
    Total cost = $2632.50 x 1344 foot2 = $3,538,080 !!!

    I estimate 75% of all house heat is lost through the walls, floor and windows combined, and since heating applies for 55% of the bill, that's 41% potential saving. Since aerogel insulates 10 times better than glass, we can say 41%-4% = 37% total energy saving with aerogel insulation. The average US household bill in 2005 was $2000, so we can save $740 each year.

    Therefore, it would take $3,538,080 / $740 = 4781 years to recoup costs from aerogel insulation!
    Using "space-age" aerogel as a miracle cure for heating!

    Aerogel is a really cool substance. I mean it. One thousand times less dense than glass (0.003-0.35 g/cm3) makes it the lightest substance going (down to 1 mg/cc), and yet it can withstand temperatures up to 1200 C (cast iron standard!), and supports over 2000 times its own weight. It even looks really weird and cool thanks to its super low index of refraction (around 1.03 - another record (water & ice are over 1.3)).

    Of course what use is any of this for your heating bills if it doesn't insulate well? Well no worries there, as it's also the best sound, electric and thermal insulator of any material (1 cm of aerogel = 10 cms of glass!!! (reference)).

    So don't delay, swap your glass windows for aerogel windows, fill your wall cavities with the stuff, and put it under your carpets. At a cost of $3.5 million* to insulate your house, you'll get your money back after only 5000 years!** After that, the rest is gravy!

    Ways to save on heating the house

    Despite the jokey nature of the above section, aerogel is beginning to worm its way into various products in small quantities (see Wikipedia article). Until the technology matures though, you may want slightly cheaper ways of cost cutting :)

    Interestingly, 35% of heat is lost through the walls (reference), so there are a few types of wall insulation you might want to explore. If your house is newer than 1930, then Cavity Wall insulation is possibly the simplest approach (fills inside of walls without causing disruption to house), and could apparently save $250 a year (outlay cost is around $500). Here are some good approaches, taking account of laziness/effort and cost effectiveness:

    In order:
  • Cavity wall insulation (if house is new enough) ($500 outlay, $250 saving a year)
  • Hot water tank jacket ($15 outlay, $40 saving a year)
  • Floor insulation ($200 outlay, $100 saving a year)
  • Loft insulation ($400 outlay, $200 saving a year)
  • Internal wall insulation ($600 outlay, $? saving a year)
  • Filling gaps between floor and skirting board ($40 outlay, $30 saving a year)

    (It should be noted these prices are only a rough estimate of how much it will actually cost)


    Overall, we're consuming up more energy than ever, but appliance efficiency is gradually improving. Take light bulbs for instance. An old style 100 watt light bulb can now be replaced with a 20 watt equivalent, giving the same amount of light. Thanks to efficient LCD and OLED panels, we can start to see television power usage come down. CPU technology in computers is also being streamlined to make for quieter, faster, and lower power PCs. New refrigerators however have apparently gotten twice as bad on average since 1960 (reference), or have they???? (reference).

    Ultimately, none of that really matters much though, since the real energy killer - heat - will always require vast amounts of delicious energy. Of course, there's always ways to reduce heat loss by using incredible materials such as aerogel, but they are a fair way off from mass production. Some are reheralding nuclear power as the saviour of our energy needs, as it's actually not dangerous at all (one or two accidents in nuclear history account for only about 0.00001% of total deaths). Of course, 'green' solar power should become more and more useful as the cost of mass producing the panels at reasonable efficiencies comes down. In the end, some kind of cold or hot fusion will be a dream come true, but don't hold your breath for that.

    One can but dream...

    But imagine if we truly had a limitless supply of clean, disposable free energy. Free heating, free lighting, free electricity, free everything! No longer would we have to rely on a precarious supply of oil and fossil fuels (or the pollution to go with it). "Free energy" (or nearly free) would banish hunger and poverty and give everyone a better quality of life, mainly due to cheap heating/cooling of airspace, transport, less chance of war, and the revolution that would take place in the farming industry:
    "Free" energy would lead the way to complete automation of so many products and services and get us into space more easily. Other more exotic uses of unlimited energy include rebuilding many of the rainforests we destroyed, and launching rubbish into space as an efficient means of waste disposal. Materials such as oil could be even produced instead of mined:


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  • Soaring energy costs make solar power a bright idea
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