Energy efficient behaviour pays

Summary

Investing in energy efficient buildings is a powerful way to save energy, but ultimately the occupants' behaviour is what determines power use. Without spending any additional money, you can reduce your consumption right now by changing your behaviour.

Background

I work as an energy efficiency consultant. Generally, this involves finding investments that can be made (eg. LED lighting, better insulation, variable-speed-drives) that will result in decreased energy consumption. This works well, and there are generally good opportunities for people and organisations to make targeted investments in energy efficiency with good economic returns. However, it is easy to be blind to the most significant effect on energy consumption: human behaviour. Let me illustrate this by way of an example.

My family and I lived in Brisbane for almost three years, arriving in late 2010. We owned our home, and made some energy efficiency investments in it (solar PV, solar hot water, better lighting, blinds). Once these measures were completed, we were using about 5 - 6 kWh/day. When it came time for us to leave Brisbane, the real-estate market was poor, so we decided to rent out the house rather then sell it. We did this for a year and, because of the way the feed-in tariff (FiT) operates in Queensland, we kept control of the electricity supply and were reimbursed by our tenants (had we transferred the supply to them, they would have lost the solar PV FiT). Thus, we were able to see their consumption on a quarterly basis. What was immediately apparent was that their consumption was much higher than ours -- generally it was 2 - 3 times higher. Where we were using 5 - 6 kWh/day, they were using 14 to 18 kWh/day -- in the same house. Clearly, their appliances were different, which could account for part of this, but the majority of this difference I attribute to behavioural differences [1].

What this shows is that simple behavioural change can be hugely significant. Simple behaviours like these have a huge affect on household power consumption:

• whether the oven is used in batches to cook a lot at once, or if it often turned on for only one small dish
• whether appliances are turned off at the wall when not in use
• whether there are many energy-hungry appliances (eg. large TVs)
• when and how air-conditioning is used
• whether lights are turned off
• whether hot food is routinely put in the fridge without pre-cooling
• how hot water is used
• whether computers are left running when not used

Conclusion

This shows that energy efficient measures are important, but that the energy use of a building is determined in the end by its occupants. A positive way of seeing this is that you can save energy, without spending any money, merely by changing your behaviour.

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[1] We were regularly washing nappies, and we also cook a lot. At that time, we had a relatively inefficient fridge -- thus we could have used a lot less also. Also, note that this house has one small through-window reverse cycle air conditioner, but is mostly not air-conditioned. Thus air-conditioning cannot account for this difference either.

This article was written by Angus Wallace, and first appeared at guesstimatedapproximations.blogspot.com.au

Focus your energy, reap the rewards

There are only so many hours in the day

A common saying. I think it means that we need to focus our energies on the activities that further our goals. We need to recognise that we can't achieve everything and that if we try, we will merely dissipate our energy and achieve little.

This is also true when it comes to energy use. If you want to save power and money (we all have better things to do with our money than waste it) then you need to focus your consumption to achieve the outcomes you want, and avoid using it where it gives little or no benefit.

This article goes part-way to explaining how I have reduced my power consumption to $1/day ($90 consumption per bill).

Heating and cooling

Heating and cooling are probably the biggest users of energy in Australia (even though the climate is fairly benign here). What is the outcome are we trying to achieve with heating and cooling?: Personal comfort. This is fine, but is it really necessary to heat/cool an entire house to achieve this?

Heat/cool just the room

Instead of trying to heat/cool your entire house, why not close some doors, and just focus on the room you occupy. This will save you a large amount of money.

Heat/cool your personal space

This will save you even more, since it is only your immediate environment that you're affecting. For example:

• Use a pedestal fan to gently move air over you in summer -- the room feels much cooler when there's air movement
• Put on a jumper in winter
• We use an electric rug (eg. these) when sitting on the couch or at the computer. They use as much energy as a light bulb, but feel very warm (a typical reverse-cycle air-conditioner might use 3 - 5 kW that's between 60 - 100 times more power than a heated throw)
• Have a warm or cool drink (depending on the season)
• If your room is unbearably hot, try evaporative cooling (in hot-dry climates) instead of reverse-cycle -- your wallet will love you. An typical portable evaporative cooler uses 50 - 300 W, less than 1/10th what a reverse-cycle system uses.

Cooking

Cooking can add a lot of heat to your house. This might be welcome in winter (though it's probably not the best way), but in summer it's a clear negative. Try to cook in ways that release less heat into your house:

• avoid the oven where possible 
• use insulated cooking to keep the heat in the food 
• put lids on pots/pans (and turn the heat down)
• use the microwave, rice cooker, electric frypan, slow cooker -- insulated where possible, to focus the heat in the food (they're more efficient than a pot on the stove and much more efficient than an oven). Use a haybox cooker to achieve even more
• Then off the heat early, and cover the food with a couple of tea-towels (beware of fire risk -- take off the stove first) the food can finish cooking with the heat it already contains, and stop heating your house
• cook outside -- particularly in summer. You might consider a solar cooker and save energy at the same time
• cook for shorter periods -- a pressure cooker is good here
• substitute cook methods. For example, I've found that a pasta bake cooks well in the microwave, and then can be quickly browned under the grill. This avoids using the oven: it saves energy and keeps the house cooler.

A lot more information on the relative efficiency of different cooking methods can be found here.

Money savings

The money you save from using less energy can be used to further your other goals. Energy efficiency makes you richer! Right now, many Australians feel under pressure from their power bills. It does not have to be that way. If you are unhappily paying more than $300/quarter -- you are doing it wrong and have huge opportunities to save money.