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

How much do we use?

One of the things that is hard to communicate to people, in the context of reducing energy or water use, is just how much we use, and just how little we really need to use. Using less has many benefits -- mainly that we save money, and cause less destruction to the natural systems that support us.

I want to convince you that when people talk about reducing consumption, they're not talking about hardship or being a neo-Luddite. They're talking about being a little bit less wasteful and profligate.

Energy

A typical Australian household uses more than 25 kWh/day. This is an extraordinary amount of power, and is an average consumption of more than 1 kW continuous. To put it in perspective, it is equivalent to one-and-a-half draught horses working for you -- all the time, day and night, without rest. If people had to do this work, it would take five to eight energy slaves [1], working contstantly, to provide it.

The other thing to appreciate is that, for every 1 kWh of electricity you use in your home, 3 - 10 kWh of energy have been used in mining, processing, transporting, generating, distributing and transmitting that electricity to you. This is another reason to avoid electricity use where possible [2] and use lower grade sources of energy.

Cars

This is brought into sharper focus when we consider cars. 1 L of petrol contains about 10 kWh of energy. If you drive 8 - 12 km, you will probably use about 1 L of fuel, which is the equivalent of a draft horse working for about 12 hours. When a moderately fit adult can comfortably cycle that same distance in about 40 minutes, it becomes clear what a waste of energy cars are!

Water

The average Australian household uses more than 300 L of water per day. When you consider that a four-person household would drink about 20 L per day, that is a lot of water! Also reflect that Australia is the driest continent in the world. I think that this kind of water use will not be sustained, because the cost to provide the water will become too great.

Conclusion

When people talk about reducing consumption, they're not talking about hardship or being a neo-Luddite. They're talking about being a little bit less wasteful and profligate.


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Links:

[1] https://en.wikipedia.org/wiki/Energy_Slave
[2] http://guesstimatedapproximations.blogspot.com/2014/10/principle-use-lowest-form-of-energy.html

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

Imagine 100% renewables -- what happens when there's no sun or wind?

Imagine an Australia running on 100% renewable energy:

1. Each house has 2 - 5 kW of solar PV
2. Each house has 1 - 2 days' energy stored (eg. in batteries, or similar)
3. Ditto for commercial and industrial buildings
4. There are also scattered wind farms and singleton wind turbines where feasible
5. There is scattered storage that is owned by the utility

What is the issue? Intermittency.

Intermittency

This is the problem that is always raised when renewable power is promoted: renewable power is intermittent:

• solar PV only produces electricity when the sun is shining
• wind turbines only produce electricity when the wind is blowing

Neither of these conditions are met all the time, so does that imply rolling blackouts?

Problem

Imagine an interval between sunny, windy periods in NSW during which the local renewable generation produces very little, if any power. Imagine that there is somewhere else in Australia that at that time is producing plenty of power. Let's say it is in SA. From where will people in NSW get electricity?

Solution

Luckily, our scenario includes some distributed electricity storage. There is not very much (a typical off-grid house would have 5 days' electricity storage or more), so it is much cheaper. It does mean, however, that after a few days of cloud and no wind people's batteries would be running down.

The solution is to use the existing grid. While Australia's current grid cannot send enough power around in real-time (ie. if it's sunny in SA and cloudy in NSW, SA can't in real-time supply Sydney's power demands), what is rarely considered is that this is unnecessary. Remember that the existing grid is vastly underutilised -- it is built with peak demand in mind (which occurs a couple of times per year). Most of the time, the grid is running well below capacity.

In this scenario, power can be sent from SA to NSW overnight, when demand is low, to keep batteries in NSW topped up. It does not need to power customers in real-time -- all it needs to do is stop the batteries going flat.

To restate it another way -- the transfer of power from SA to NSW would not need to match the maximum instantaneous rate of consumption in NSW -- it would only need to match the average rate over the period covered by the batteries. In fact, even this is not required since the batteries can be assumed to begin this period relatively full and end it relatively empty.

By doing this, we would obtain maximum benefit from the existing grid infrastructure, and also be able to install a much smaller storage system, while retaining the benefits of distributed generation.

In other words, I question whether the oft-repeated statement that high renewable penetration requires a much more extensive grid is true. We can use electricity storage to greatly mitigate this (though by exactly how much, I am not sure. Some time, I will try to get the data together and run the numbers).

The post "Imagine 100% renewables -- what happens when there's no sun or wind?" was written by Angus Wallace and first appeared at guesstimatedapproximations.blogspot.com.au

Reducing electricity consumption to affect political change

Many people are concerned about the negative effects that humans are having on the Earth's ecosystems, and with good reason: those systems support us, and without them we would not survive. It is estimated that for every dollar of GDP produced, the natural world contributes .75c -- these are services that nature provides for free and, without which, our quality of life would drop by 75%.

A big cause of human destruction of natural systems is in the provision and delivery of energy. The main culprits are fossil fuels which are starting to alter the world's climate -- a change that, if unchecked, will wreak great destruction on both the natural and human systems that support us. There are now technologies (solar PV and wind turbines) that can produce energy with much  less damage to the environment, and it is imperative that we transition to these as soon as possible. Unfortunately, there are entrenched interests that are heavily committed to fossil fuels and use their influence to slow the adoption of newer, less harmful, methods of energy production.
What is clear is that majority political support for serious action on climate change is currently lacking.

There are huge forces at work here. In the absence of a government with the ability and disposition for serious action, what can an individual do to help this process?

Number one: Use Less

When it comes to reducing one's impact on the systems that support us, there is simply no substitute for using less. Even "green" energy sources have impacts (albeit much more minor). Using less frees money and resources that can be better deployed by helping other, less fortunate, people adapt.

Number two: Avoid electricity or fuel where possible

Electricity is hard to produce, and there are always wastes and damage to the environment -- even when using solar PV or wind turbines. This is because the manufacture, installation and maintenance of these generally result in carbon emissions and other forms of pollution.
Therefore, if a task can be performed without using electricity at all, it is preferable to do so. A great example of this is hot water, which can be heated directly from the sun without need for electricity at all. By doing this, your electricity consumption will be much lower.
Similarly, a solar cooker can cook food without fuel or electricity, using only heat directly from the sun. These are simple and cheap to build.

Number three: buy carbon-emission-free ("green") power, and/or install solar panels

Here is where your large reductions in consumption will help -- because you're now using a lot less power, you will not need many solar panels to offset your electricity consumption (cheaper!).
At my house, we have reduced our power consumption to about 3 kWh/day for a family of four without significant lifestyle sacrifices. I think it can go lower still. We have a 2 kW solar PV system, which produces an average of about 6 - 8 kWh/day (averaged over the year) -- more power than we consume. We do draw power from the grid though, as we do use power at night (when the PV panels aren't producing), which is why we also buy carbon-emission-free power. By doing this, we ensure that we're not directly supporting the use of coal for electricity generation and because our power consumption is so low, the additional cost is very small. This also supports the businesses that are producing renewable carbon-free energy in Australia.

Dirty companies only have as much money as we give them

Using less means less revenue for the large energy generation, distribution and retail companies that, generally, are slowing the adoption of renewable energy technologies, and affecting public policy in negative ways. Make no mistake -- the combined actions of individuals is very powerful. The uptake of domestic solar PV has already had a huge effect on the energy generators and retailers in Australia.
This is because solar PV is usually producing power at precisely the times that energy is most expensive (energy retailers pay a fluctuating ("spot-") price for electricity,  and the times when the spot price is highest are the most profitable for the generators. Domestic solar PV is taking the edge from this demand, which is having a significant affect on the profitability of some of the big dirty producers. These kinds of commercial disincentives work to the advantage of renewable energy technologies.

If Australians continue to reduce their consumption and simultaneously install distributed generation (like solar panels, solar hot water, etc) and buy carbon-emission-free power, this will help to encourage the necessary changes. This will have a concrete effect on Australia's carbon emissions and reduce the likelihood of catastrophic climate change.

Remember, a carbon tax only has benefits because it causes people to use less -- we as concerned citizens can use less all by ourselves.

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