QUICKTIP

Are your patio and pool lights costing you a fortune?

I have three 120 W outdoor floodlights. This a total of 360 W. If these are left on for even two hours a day they will cost about $20 per year each. If I had all three on for 6 hours per night, it would cost $180 per year. Options to reduce this cost and the associated greenhouse gas production, include:

• replace the conventional PAR 38 globes with compact fluorescent globes. You are more likely to find these at a good hardware store, light shop or on-line rather than at your supermarket.
• install movement sensor control. (This is relatively inexpensive when they are installed, but may be expensive for existing lights)
• Replace them with self contained solar powered lights

The best solution will depend on your particular needs, but if you are currently leaving any on for extended periods, I urge you to find a solution. (I will convert mine to sensor lights with CFL bulbs which, in my case, will have a three year payback.)

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EDITORIAL

What do we need to do to create an export industry using geothermal energy?

I was recently reading an interesting article about Iceland and the fact that 100% of its electricity and building heat is from renewable sources. (80% of the electricity from hydro and 20% from geothermal.)

They are trying to turn this greenhouse gas friendly energy generation into profitable industries. One traditional one being aluminium smelting (aluminium has been described as solidified energy due to the high energy requirements for production). A less traditional one is data storage facilities, as they are high energy users. Iceland has data centres serving both Europe and North America.

This raises the question, can we do something like this? We can't expand our hydro power significantly, but we do have extensive potential geothermal resources. With carbon credits, I believe geothermal will be economical.

Unfortunately our largest geothermal resources are in the middle of Australia, so we need to think of things that can be done economically in the middle of the desert. In the long term it may be economical to connect into the national grid to power our cities, but initially the transmission costs are likely to be excessive. One option is to use the geothermal energy to power mines, but we need to think of other, longer term opportunities.

If you have any suggestions please contact us and I will publish them.

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PRACTICAL ENERGY SAVING

Tips to keep cool in extreme temperatures

The recent extreme temperatures across much of Australia, raise the question of how we should keep cool in these circumstances. The following suggestions are for extreme days (high thirties and forties), and are not necessarily intended to be adopted in more normal weather.

• If you are outdoors
• • If the temperature is above body temperature (approx 38 C), the air is actually adding heat to your body. Because your body is always generating heat, the only way your body can avoid overheating is by the evaporation of your perspiration. Thus you will need to drink copious amounts of liquid to avoid dehydration.
  • Stay out of the sun. The sun can add 15-20 degrees to the effective temperature. If you are in the sun wear light coloured clothing to reflect as much as possible.
  • Avoid heavy physical exercise in the afternoon. If you must do heavy work, do it as early in the morning as possible, or in the evening. Again drink lots to avoid dehydration.
• If you are inside
• • Keep the windows shaded
  • keep curtains and windows closed while it is hotter outside than inside
  • If it is too dark with the curtains closed and you have compact fluorescent (or LED) lights, you will be better off with the curtains closed and the lights. (Make sure the lights in empty rooms are off.) If you still have incandescents or halogen downlights, you will be better off leaving the lights off and leaving the curtain just open enough to give you enough light.
  • Assuming it cools down overnight below the house temperature, open the windows at night for ventilation.
  • Minimise the use of heat generating appliances. Unused electrical appliances should be switched off. Don't use your plasma TV as a source of background noise. Switch it off unless you are actually watching it. If you have a small TV, the small TV will probably use less energy than a larger TV. A radio will generally use even less electricity. Similarly, unused computers, home entertainment systems and the like should be switched off.
• If you are inside and the room is air conditioned
• • follow the instructions above, but unless the temperature drops right down at night, you are probably better off leaving the air conditioner running and keeping the windows closed, particularly if you have a brick house.
  • If you are out of the house during the afternoon, and the air conditioner is powerful enough to cool the house down when you get home, leave the air conditioner off while you are out. If the air conditioner struggles to cool the house down or trips out in extreme weather, you may need to leave it running all day. if you have a ducted or wall mounted evaporative cooler, leave it running all day as the energy used is much less than a ducted refrigerative air conditioner, and once the house gets too hot, the cooler probably won't be able to bring the temperature back under control until the weather cools.
  • If the air conditioner trips out on overload
  • • switch the air conditioner off and wait 15-20 minutes before turning it back on. While waiting, do the following.
    • clear as much space in front of the outdoor unit as possible - preferably 1-1.5 metres directly in front of the fan and 300 -400 mm (30 cm to 40 cm) at the sides.
    • If the air conditioner is in a side walkway, allow as much air to flow down the walkway as possible by clearing obstructions, opening gates, etc.
    • Minimise the area cooled. ie in a ducted zoned system minimise the number of zones. In any system, close doors to unused rooms, this includes laundries, bathrooms, guest rooms etc.
    • If the above still won't keep the air conditioner on-line, try setting up a means of wetting the outdoor unit coil. BE VERY CAREFUL NOT TO ALLOW ANY WATER INTO THE ELECTRICS. Depending on your setup, it may be possible to set up a temporary spray or slow drip on the outdoor coil, or spray it every now and then with the garden hose. Avoid flooding the area with water.
    • if the outdoor unit faces West or North, a small improvement may be gained by shading the unit. however the improvement is much less than most people assume. Ensure that the shading doesn't prevent air getting in and out of the air conditioner or you will be worse off.

Remember, many of these suggestions are just for an extreme day, although some are applicable more generally. At times, electricity supply authorities have recommended people turn off their air conditioners for short periods of times to reduce the risk of electricity blackouts. I disagree with shutting an air conditioner off, except as outlined above. If you do, it may trip out on restart and you will definitely lose control of the temperature. My suggestions above, particularly about minimising the area cooled, and turning off unneeded appliances, will have more effect on minimising energy demand than switching off the air conditioner for a short period of time. (Using a radio instead of a plasma TV during the hottest part of the day, will save more electricity than switching off the largest air conditioner for half an hour.)

I suggest you print this out and stick it on the fridge, so that everyone in your house can refer to it.

More ideas can be found in House Taming: How to reduce greenhouse gases in comfort which is available on line from my website, shipping in 2 working days maximum.

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