BuildingEnergy SystemsWaste Systems & RecyclingWaste Water

Design with Energy in Mind

Permaculture designer, Robyn Francis (see also) looks at a variety of design strategies for using energy responsibly and sustainably.

The practical ‘down-to-earth’ farmer, gardener and layperson will often find the theories surrounding ecology and energy very heavy going, if not downright confusing. What I would like to do is offer some practical perspectives on how we can use resources responsibly.

Energy, in a holistic sense, involves much more than electricity and the use of fossil fuels, although these are certainly central to the energy issue. In permaculture design, energy and resource management are virtually synonymous and it is often difficult, if not impossible, to separate the two.

The statistics quoted in this article are for Australia, as they are the facts that are available to me, but the trends and general concepts can be applied to any industrialised society and need to be carefully considered by developing countries in the rapid process of ‘modernisation’.

Domestic Energy Use

The most tangible form of energy, in terms of understanding and immediate action, that most of the people living in homes in Australia use, is electricity. This accounts for 20% of the country’s total energy in electricity and fossil fuels, with 8.3 million private motor vehicles consuming almost another 20%. So in the household, with electricity and motor vehicle use, there is immense scope to have an impact on 40% of the national ‘energy’ picture. These two factors also account for nearly 40% of Australia’s total carbon dioxide emissions.

Another aspect close to the heart of every household is the issue of waste. This can be seen as energy lost, a loss that also incurs a lot of energy in both its generation and disposal. Domestic waste makes up 71% of Australia’s garbage, over 6 million tonnes a year.

Recycling is important but not enough – we need to look very carefully at everything we bring home and how much of it will leave. Then add to that the waste of domestic sewage and the valuable nutrients it contains along with grey water from our bathrooms and laundries: this too needs to be counted as energy lost.

It is more important to remember that although industry is guilty of consuming even more energy and generating more waste than domestic activities, it is largely our support as consumers using their products, and our consumption of imported goods (resulting in the need to over-produce for export), that helps perpetuate the industrial process.

At this point one could easily diverge into political aspects of the picture, so I think it appropriate to get back to the point of what we can do in a realistic and practical way.

As individuals we can approach energy and resource conservation on three different levels: behaviour, design and technology.

Design Strategies – Skylight versus Electric Light

House design: Appropriate house design creating a comfortable indoor climate can substantially reduce the heating bill in winter and cooling bill in summer. The average Melbourne house uses around 50% of its energy on heating. The use of thermal mass, insulation of well placed pergolas, verandahs and glass houses, and the design of surrounding landscape can support and enhance the house microclimate. Windows and skylights can be designed to make better use of daylight – it amazes me just how many buildings need the lights on in the middle of the day to read. There are many excellent books available on passive solar and energy conserving house design to explore, not only for building a new house but also for renovating or retrofitting an existing house.

Beyond the Home: There are numerous ways we can approach energy conservation in design beyond the home; in the garden, in our neighbourhood and on the farm. Often we need to import energy in the form of resources to get a system going – things like seeds, plants, mulch and manures to establish our gardens and orchards, bulldozers to construct swales and dams to collect water. When we design our strategies in time and consider these initial inputs as capital investment, we need to ensure that they will yield many times that investment over their lifespan.

A fruit tree will yield many times its initial investment cost if it’s well managed, but not if we drive many kilometres every year to collect manure and straw to mulch it. We need to design the system surrounding the fruit tree so that its needs are met on site. We can plant comfrey and lucerne as a living mulch under the tree to provide some of its nutrient needs and give a chicken a good life providing it with manure and managing its pests.

Don’t just plant a windbreak; plant a sun trap, bird habitat, bee forage and fuel source, some wild foods and a fire break – these are all things a windbreak can do with good design and plant selection, and consider the energy saved by stacking all those functions into that one element. These are basic permaculture design principles that address energy conservation in a very practical way.

The principles of zonation are similar, looking carefully at the inputs a particular species or system requires for maintenance and harvest, and placing it according to convenience within the landscape. For example, the chickens need to be visited twice a day for feeding, collecting eggs, letting into the orchard to forage and to be locked up safe from the fox at night. What else needs to be done on a daily basis that can be linked along the pathway to the chookhouse? It can be the vegetable garden, compost heap, wood heap, nursery – to name a few. So zonation conserves the time and energy we would have wasted if we had spread things all over the place.

Human Settlements: In the design of human settlements, communities and villages, much energy in the form of providing services can be saved through cluster placement of housing. Design can reduce motor vehicle use by ensuring that social and commercial centres and facilities are within easy walking and cycling distance of residential areas and preferably the two should be integrated as in traditional village cultures.

Technological Strategies – Solar, Pedal Power and Gravity

Here we need to consider the appliances and technologies that consume energy and the technologies that generate energy. In south-east Queensland (sub-tropics), 50% of domestic energy is used for water heating – imagine what could be saved if building codes made solar water heaters compulsory!

The major electricity consumers in the home are water heating (30%), space heating (22%), refrigerators (14%), cooking (9%), lighting (6%), freezers (4%), TV and VCR (4%), clothes washers (3%), clothes dryers (3%), dishwashers (3%), air conditioning (2%) – these percentages are the national average.

Good solar house design, solar hot water systems and energy efficient appliances can make a big dent in domestic energy consumption. Also, gas is cheaper than electricity, less polluting and generally more efficient.

Wood stoves can be used for cooking and space heating but do check their energy efficiency rating and remember that fire wood costs. Energy is used in cutting and transporting fire wood, and collecting and cutting it yourself also costs time, effort and often fuel for chainsaws and transport. In dense urban situations wood and coal stoves and heaters are a major source of air pollution during winter.

Most of the non-grid appliances (gas and DC) are more expensive than regular AC appliances, and all appliances represent energy in the extraction and processing of their raw materials, manufacture, distribution and ultimate disposal. This all needs to be assessed.

Water conserving devices such as control flow shower roses not only save water but also energy to heat water. Nearly 40% of domestic water consumption can be eliminated by installing water conserving devices like dual flush toilets, aerating taps in hand basins and sinks and front loading washing machines. Rainwater collection tanks should be standard practice along with grey water recycling for garden irrigation. Use gravity where possible to eliminate the need for pumping.

In remote situations where stand-alone water and energy systems are necessary, good design and choice of appliances are critical.

Where homes are connected to a central water supply and grid power, good design and conservation are equally critical if we are concerned about our long term security.

 

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