National Energy Directory: Dr Deane's Blogs

Dr Deane says Plant A Tree

Thu, 03 Jun 2010 00:49:15 GMT

When did you last plant a tree or shrub? There are several very good reasons why you should plant a tree this week. What are those reasons? I'm glad you asked!

Green plants are amazing things! They take the poisonous stuff that we produce (carbon dioxide) and turn it into something we need to survive - oxygen. We produce carbon dioxide when we breathe out and also, we make lots of it when we burn fossil fuels such as coal, oil and gas. And, of course, humans are not the only animals contributing to the increase of carbon dioxide in the atmosphere. All animals do it. In particular, cows and sheep produce huge amounts of carbon dioxide (and methane) when they burp! And carbon dioxide is one of those nasty greenhouse gases which contribute to global warming.

But here's the problem. The number of green plants on Planet Earth is diminishing. We are losing more than 2,000 trees every minute as rainforests around the world are being torn down. We need to do something to redress the balance. By planting a tree or shrub this week, you can help.

Every tree planted this week will provide oxygen for two people for the rest of their lives. For the sake of Planet Earth, do it!

Dr Deane Hutton on Energy Efficient Lighting

Tue, 25 May 2010 08:16:41 GMT

LIGHTING

We need lighting in our homes, offices, businesses and schools. What sort of lighting should we use? I'm glad you asked! The experts have been telling us for several years that incandescent or tungsten lamps are inefficient and should be replaced. Should we replace them with compact fluorescent lamps (CFLs), halogen downlights, or LED lights? There are advantages and disadvantages of each.

COMPACT FLUORESCENT LAMPS

CFLs use the same light sockets that were used by incandescent lamps, so can be changed over readily. They are much more efficient. For example, an 8 watt CFL gives out the same amount of light as a 40 watt incandescent lamp. Also, CFL stay cool and last longer. However, CFLs contain mercury and must be disposed of very carefully after their useful life is over.

HALOGEN DOWNLIGHTS

Halogen downlights use a lower voltage than incandescent lamps (typically, 12 volts instead of 240 volts). They are much more energy efficient. However, they are costly to install in a house or other building that is already established. But for a new building they are well worth considering.

LED LAMPS

LED stands for Light Emitting Diode. An LED is very cool and extremely energy efficient but gives out a relatively small amount of light. However, LEDs can be grouped together in clusters or strips to make a very effective light source. Also, LEDs come in a wide variety of colours. LEDs are expensive at present, but prices will drop as they become more widely used.

Dr Deane Hutton on Greenhouse Effect

Tue, 25 May 2010 08:13:47 GMT

Everybody is talking about Climate Change, Global Warming, and the Greenhouse Effect. But what is the Greenhouse Effect? Well, I'm glad you asked!

Imagine that you are at a market garden, standing outside a tomato glasshouse or greenhouse on an autumn day with a thermometer in your hand. The temperature might be 17 degrees Celsius. Go inside the greenhouse and you could well find that the temperature is nearly 30 degrees Celsius. Light energy from the Sun passes through the clear glass or plastic walls and roof of the greenhouse and warms the air, soil and plants inside. Infrared heat energy radiated from the soil and plants cannot escape through the transparent walls and roof, so the temperature inside rises. And generally, plants grow better when they are warmer. This is the Greenhouse Effect and it's great for growing plants.

On a large scale, the Earth's atmosphere acts like a giant greenhouse - trapping heat near the Earth's surface. In a way, this is a good thing. Without the Greenhouse Effect, the Earth would be freezing cold all year round.

However, in recent times, we've been using up fossil fuels (coal, oil, and gas) at an alarming rate - putting extra carbon dioxide into the atmosphere and increasing the Greenhouse Effect. The climate is changing! The globe is warming! If we can decrease our dependency on fossil fuels, and increase our capacity to use renewable energy sources (such as solar, wind, waves, and geothermal energy) then we may be able to reduce the Greenhouse Effect and slow down Global Warning. That will be good news for Planet Earth.

Dr Deane Hutton on Water Heaters

Sun, 16 May 2010 22:16:13 GMT

WATER HEATERS

Hot water is needed in homes and commercial buildings. What is the best way to heat water - electricity, gas, solar or heat pump? I'm glad you asked! Traditionally, hot water systems have used electricity or gas to heat the water. Solar water heaters and heat pumps are newer systems which have claims of greater energy efficiency.

ELECTRIC HOT WATER SYSTEM

Electric hot water systems are like giant kettles. They have an electric heating element which heats the water to a high temperature and stores the hot water in a tank. These systems are not very energy efficient, .since they heat water to a temperature which is higher than needed to shower, bathe, or wash hands. For these activities, we add cold water to lower the temperature. Some of the newer electric hot water systems have a thermostatic control which heats water to the desired temperature on demand. They do not waste energy by storing a large volume of very hot water in a tank. Consequently, on-demand systems are more energy efficient.

GAS HOT WATER SYSTEM

Many gas hot water systems use a gas flame to heat water to a high temperature and then store it in a tank. Not very energy efficient! Newer gas hot water systems are on-demand devices with a thermostat to select the desired temperature. Much more energy efficient!

SOLAR HOT WATER SYSTEM

Solar hot water systems use energy from the sun to heat water flowing through tubes in special panels on the roof. In the summer, solar systems produce more hot water than needed by the average household. And the running cost for the solar hot water system is zero. However, in the winter there are two problems - less sunshine and more energy required to raise the temperature of the very cold tap water. So, solar hot water systems are usually supplemented by an electrical or gas booster system which kicks in when needed. But even in winter, running costs are lower than that of an all-electric or all-gas system. Solar hot water systems are very energy efficient. The limitations of solar hot water systems are high installation costs and the necessity of having a suitable room at the correct angle for solar heating panels.

HEAT PUMP

To understand how a heat pump hot water system works, we need to understand the workings of a refrigerator. A refrigerator has a closed system of tubes through which a refrigerant circulates. When the liquid refrigerant is pumped through a fine nozzle it expands into a gas or vapour and becomes very cold. The cold vapour passes through coils in the freezer section of the refrigerator, absorbing heat from the air and food inside the fridge. At the back of the fridge, the vapour passes through a compressor which changes the refrigerant vapour back into a liquid. The compressor increases the temperature of the refrigerant, which then flows through coils at the back of the fridge. Air surrounding those coils at the back of the fridge becomes warm. So the refrigerator has a cold region inside the cabinet and a hot region outside the cabinet at the back. Heat energy is transferred from inside the refrigerator to outside. It is a heat pump! Reverse-cycle refrigerated air conditioning is like a giant fridge - it is a heat pump with cold coils and hot coils. Reverse-cycle air conditioning can cool a home when air is forced into the house around the cold coils. And it can be used to heat the home when air is forced into the house around the hot coils. A dedicated heat pump hot water system forces water around the hot coils. This hot water can then be used for all the normal functions in a home or business. .

Heat pump hot water systems are useful in large-scale commercial applications and in buildings which do not have a suitable roof for solar heating panels. Heat pumps achieve approximately 80% of the cost savings of a comparable solar system - but they are cheaper to install. So heat pumps are very energy efficient.

Dr Deane Hutton on Home Fires

Fri, 14 May 2010 03:24:51 GMT

So you want a fireplace in your lounge room. What should you install - wood, gas or electric? Well, I'm glad you asked! There are pros and cons for each type. Since I've lived with all three types of fireplace, let me share my experiences with you.

WOODBURNING FIRE PLACE

I've always liked the idea of a crackling wood fire with flickering flames on a cold winter night. Perhaps the thought reminds me of my childhood. Some years ago, we installed a slow combustion wood fire. Much safer than an open fire. No chance of burning embers falling out on the carpet. And the safety glass door showed those flickering flames beautifully. But I had to visit the local wood merchant regularly to buy kindling, mallee roots and red gum logs. And I had to store the wood in a dry place in the back yard. With a bit of practice, I could get home from work and within ten minutes have the wood fire set and lit. During the evening my wood fire would need to be poked or added to only two or three times. Those flickering flames looked wonderful. Was it effective? Yes - the lounge and adjacent dining room and kitchen were warmed quickly. Was it energy efficient? Not really. Much of the heat energy from the burning wood went straight up the chimney. Cleaning out the ashes was time-consuming. And the price of wood seemed to escalate steadily every year. Also, it polluted the atmosphere, but we thoroughly enjoyed our slow combustion wood fire.

GAS FIREPLACE

In one house in which we lived, we had a gas fireplace for more than 20 years. It was very easy to start. Just push a button and switch on the fan. What did the fire look like? A row of small uniform bluish gas flames Boring! But the gas heater was very effective - heating the lounge and adjacent rooms quickly. It was cheap to run, but the fan developed an annoying rattle after 15 years. We couldn't complain; it had served us well.

ELECTRIC FIREPLACE

One of the first houses we lived in had a very cold lounge room with an electric fireplace set into the wall under the mantelpiece. It had two electric bar radiator heaters at the top and a row of fake plastic 'glowing coals' with a flickering light behind them. It was quite warm and comfortable for people sitting in line with the electric fireplace and reasonably close to it. But it did not seem to warm the air in the room very much. Electric fireplaces are easy to install, but expensive to run and notoriously inefficient.

What do we use now? None of the above! We now have ducted reverse cycle air conditioning. So it is a heat pump which now warms us in the winter. Heat pumps are as cheap to run as gas fires.

Footnote:

The cheapest way to stay warm in the winter is to put on a thick jumper and an extra pair of socks!

Challenge:

Send us an email telling us about your own experiences with home fires.

Dr Deane Hutton on TV Sets

Fri, 14 May 2010 03:22:36 GMT

TELEVISION SETS

Everyone wants a new wide-screen television set. Should you buy a plasma, LCD, or LED? I'm glad you asked! Actually, it is "horses for courses". It all depends on how you plan to use your TV, where you intend to place it, and how much money you plan to spend.

PLASMA TV

Plasma television is an older technology, but very reliable. Many claim that a plasma display is better for fast-moving objects. Also, colours are very life-like, and black areas are extremely black. A plasma TV is cheaper than an LCD or LED set of the same size, but plasmas are also heavier and use up more energy.

LCD TV

LCD stands for Liquid Crystal Display. An LCD screen has millions of microscopic liquid crystal shutters which open and close to allow light through. A picture on an LCD screen is extremely bright, even in a well-lit room. Also, LCD sets are lighter and more energy-efficient than a plasma set of the same size.

LED TV

LED stands for Light Emitting Diode, and an LED TV screen has thousands of these tiny electronic devices within it. A current LED television set works in a similar manner to an LCD set, but with an even brighter picture. And the screen is thinner. Future LED television displays may be flexible screens which can be rolled up and tucked under your arm.

SO WHICH ONE?

Plasma, LCD, and LED television displays are all very effective and extremely reliable. You can be reasonably certain that one you buy today will still be working well in ten years time. If you are setting up a theatrette in your home and watch many sports programs, plasma may be the way to go. However, if you are setting up a television set in a family room or lounge room with large windows and strong ambient lighting, LCD or LED may be your best option.

Dr Deane Hutton - Solar Energy

Mon, 10 May 2010 02:49:17 GMT

SOLAR ENERGY

The Sun is a huge ball of fire. Its temperature is around 6,000 degrees Celsius at the surface and more than 14 million degrees in the centre. The Sun is a fairly young star - only 4,600 million years old! And it will be around for a long time - at least another 5,000 million years.

More energy reaches Planet Earth, from the Sun EACH DAY, than we need for a whole year. But we're not very good at catching and using Solar Energy from the Sun. However, we are getting better every year.

Solar Energy can be captured and used in two quite different ways - solar thermal panels or solar photovoltaic panels.

SOLAR THERMAL PANELS

With solar thermal panels, metallic pipes are covered with a black heat-collecting surface. Water passes through the pipes and absorbs heat energy from the sun. The hot water can be used to heat homes or swimming pools. In newer solar thermal systems, lenses and reflectors are used to concentrate the sun's energy and increase the heating effect. In large scale solar thermal systems, the water boils to produce steam which can then be used to drive turbines and produce electricity. Power produced in this way is a zero-emission electricity source. Large scale solar thermal power stations have been established in India, Spain and Morocco. In Australia, the federal government will fund the development of several large scale solar thermal power stations in the near future.

SOLAR PHOTO VOLTAIC PANELS

Solar photovoltaic (PV) panels work on a different principle. Photo means light and voltaic means electricity. PV panels convert light energy directly to electrical energy. The PV panels are made of silicon. When hit by light, silicon atoms release electrons which are collected and sent through an external circuit - providing electrical power.

In Australia, more than 40,000 homes have solar PV panels on the roof - providing electricity for the house. In 30% of these homes, surplus electricity can be sold back to the grid. The Australian government has implemented incentive schemes to encourage more homes and businesses to install PV panels.

New developments in PV panels in the next few years will result in amazing new options. These will include: flexible PV panels which can be attached to any surface; transparent PV panels which can be installed on glass windows; and sliver cells which are much smaller and cheaper - and use less silicon.

THE FUTURE

Since Australia is one of the sunniest continents on Planet Earth, there is a huge potential for both solar thermal panels and solar PV panels. The federal government is committed to ensuring that 20% of our electricity supply will come from renewable sources by the year 2020.

Dr Deane Hutton - The Cost of Water

Fri, 30 Apr 2010 02:06:48 GMT

COST OF WATER

If you ever get the chance to travel to space, you will discover, when you look back at Earth, that our planet looks blue. 70% of the Earth's surface is covered with water, giving the "blue planet" its characteristic colour. However, most of that water is salty - the oceans. Only 2.5% of Planet Earth's water is fresh and most of that is tied up as solid water in ice and snow. A tiny fraction is all that is available for all the living plants and animals which need fresh water to survive. It is a rare and precious resource. But how much does a glass of water cost? I'm glad you asked!

The answer to that question depends on where you are on Planet Earth. Imagine that you have a large square box with a one metre by one metre base and one metre high. It's a cubic metre. Now imagine that the box is filled with water. That cubic metre of water, or a thousand litres, would weigh exactly one tonne. What could you do with that much water? Well, if you keep your showers reasonably short and your baths reasonably shallow you are using about 50 litres of water for each shower or bath. So you could shower or bathe 20 times. Alternatively, you could use your cubic metre of water to flush the toilet 200 times or to provide 4,000 glasses of drinking water. But how much would your cubic metre of water cost?

In Australia, we are charged approximately $2.50 for a cubic metre of water. This charge includes collecting it, purifying it, delivering it to our taps, and taking away what we waste or flush down the drain. That's very cheap! In Denmark, they pay much more - $7 per cubic metre. In Mexico, they pay much less - 55 cents per cubic metre. In Ireland, tap water is free! The cost of a glass of water in Australia works out at less than one-tenth of one cent per glass. (Compare that with the cost of a bottle of water from the supermarket or delicatessen!)

So we could say that tap water for drinking is almost free. But really, the the low cost of water is a distortion. Taxes and other subsidies, in most countries, make water delivery charges cheaper than the real cost. Perhaps we should be willing to pay more for our water. If we did, we might value water more and waste it less. We can make a start by making sure we don't leave taps running unnecessarily in the bathroom, kitchen or garden and by fixing all leaking taps. Not only will we be saving water, but also we will be reducing the water delivery and removal costs. That will save energy. And that's good news for Planet Earth.