The Greening of Gavin

Archives for February 2008

The Solar Revolution – Hot Water

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Just after we finished planting in the vegetable garden (May 2007), Kim and I decided to install a Solar Hot water system to lower our natural gas usage. This was because we had learned that heating water made up 16% of the Greenhouse Gas Emissions of the average Australian home. We knew that because of our weekly monitoring that our daily average gas usage was 55 MegaJoules (Mj). This was the non-winter average (we have gas heating), and it still seamed quite high to me. My existing hot water system (HWS) was a 6 star rated AquaMax 340 litre natural gas system, which I purchased about 18 months before hand. At the time it was more efficient than the previous HWS which used double the amount of gas. Not efficient enough, as far as I was concerned!

I was browsing through the Origin Energy website and found out that Origin advertised that they could “solarize” your existing HWS for approximately A$2100, and be fully installed by a licensed plumber. Not a bad price as I had seen other systems for over $4000.

After discussion with Kim about the pro’s and con’s, we decided to sell some shares that I had saved up and buy the system from Origin Energy. I would get a far better return on investment from a solar HWS than I would the shares. The proposed system had one large collector, a 300 litre pre-heat tank, a low wattage pump and a temperature sensor (located in the collector).

On the installation day, two plumbers arrived at 0830 in a Land Cruiser with a huge box on the roof and another in the back of the truck. After a quick inspection, they recommended that the collector be placed on a west facing roof. This was because the copper pipe run was about 8 metres shorter than where I wanted it, which was a north facing roof. The reasoning behind this was that during Winter the heat loss from the pipes would be greater than the heating value of the collector. Therefore there would be no heating effect. Also in summer the water would get so hot (99 degrees) that the safety valve on the tank would activate and then dump half the water until enough cold water entered and cooled it down. So being a wise man, I took his expert advice and let him install the collector on the west facing roof.

The plumber was three quarters complete when the electrician arrived to install the general purpose outlet. It was a simple job as there was already a 15 amp cable run that was the remains of a previous electric HWS. The cable run terminated in our fuse box and therefore only took them 20 minutes to complete. The electrician left as soon as his job was finished. Then something crazy happened. About 15 minutes later another electrician arrived to install a GPO! He was so surprised when I showed him the newly completed GPO from the previous electrician. He had just driven 80 Km from Frankston. Now that is what I call service!

Soon after the second electrician departed, the plumber announced that he was finished the job. He now showed me how it worked. The mains cold water entered the pre-heat tank. When the sensor on the collector determined that the collector was hot enough, it started the pump. The water was drawn from the bottom of the tank to the collector and returned to the middle of the tank. The pre-heated water was then fed on-demand whenever the existing gas HWS required a top up. Fairly simple really!. As the water is already heated when it enters the gas HWS it does not required to be reheated by that system.

My experience so far has been that the solar HWS is reliable. For five months of the year I have turned the thermostat of the gas HWS to zero, effectively only leaving the pilot light on. I did this so that if we had more than four cloudy days in a row, I could turn up the temperature of the water quickly to one and a half on the dial which equals about 40 degrees C.

Since the installation in July 2007, we now average 17 Mj of gas per day in the non-winter months, which is all taken up by our cooking needs. During the 3 or 4 colder months of the year we now average about 26 Mj, which is still greater than a 50% reduction in natural gas use. This we considered a great result, and the cost avoidance of gas purchase will pay for the solar HWS in approx three years. After that we technically have free hot water for 75% of the year.

You have just got to love the Sun!

I was a Weather Maker!

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On May 23rd 2007, I had the opportunity to attend a seminar held at Crown Towers by a company called Renewtek. This company had recently achieved accreditation from the Australian Greenhouse office and they wanted to show off their green credentials of which they should be rightfully proud. They invited Dr Tim Flannery to speak to us about the threat of climate change. Dr Flannery was given the award of Australian of the Year 2007, and the author of “The Weather Makers: The History and Future Impact of Climate Change”.

I was so excited to be going along, as was my green friend Jennifer! So excited in fact that I arrived an hour early at the venue and had a nice light breakfast and waited for everyone else to arrive. Three cups of herbal tea and a visit to the toilet later, most people started to arrive. So did Dr Flannery, and I had the good fortune to talk to him before his presentation. I told him of my journey so far and what I planned to achieve in the next six months. I could see that he was impressed, and we also talked a little about how he lived off of the grid and was self sufficient in water resources. He even gave me a suggestion on how to solve the energy problems I was having with my pool pump. He suggested to convert to a DC pump and use a solar panel with battery backup. A pretty good effort, as this guy walked the walk as well. How cool was that!

His talk was informative and he had some interesting concepts. For example the concept of “The Great Aerial Ocean”, which is how he describes our atmosphere. And when you think about it, it is quite true. The atmosphere supports all life on the planet, as does the water based ocean for marine life. And the shame of it all is that we are polluting both at an alarming rate!

I have posted the video of his speech below so that you can experience it as well. It goes for about 39 minutes.

The man really inspired me enough to purchase his book “The Weather Makers”, and to keep going on my journey towards a sustainable lifestyle. What a way to spend my 43rd birthday, and is one that I will never forget!

Reducing Food Miles Part 2

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Gavin Webber veggie patch

What are food miles? This is a question I get asked on a regular basis. I consider food miles to be not only the distance that the food has travelled from garden fork to dinner fork, but all of the CO2 emitted during cultivation, harvesting, transport, storage, and sale. All of these steps in the process use large amounts of oil and energy, therefore contributing to climate change. So grow your own food and reduce food miles!

This was one of the two reasons I chose to grow my own food. The other reason was that I didn’t want my food to be contaminated with herbicides, pesticides or be genetically modified. I was sick of the lack of taste from supermarket bought fruit and vegetables, all bland and picked far too early so that the grower could be first to market and get the best price. How many times have you bought expensive produce, only to find that it tastes horrible! Far many times, as far as I am concerned.

Two great books that helped me to decide how and what to plant were “The Australian Fruit and Vegetable Garden” by Clive Blazey, and the “Organic Gardener” by Jeffrey Hodges. They taught me about how crop rotation works, what vegetables to plant in what season, how to compost successfully, and the science of mulching. I highly recommend each of these books for anyone starting out in growing your own food.

I knew that planting in May was not the best time to sow, and that being late in Autumn 2007 it was better to plant seedlings where possible. So it was of to Bunnings (our closest nursery) to buy a selection. I only chose what I thought the kids and Kim would eat, so as to cut down on wastage. I planted broad beans, snow peas and peas in the first bed; beetroot, carrots, spring onions, and Spanish white onions in the second bed. In the third I planted green dragon broccoli, mini cauliflower, Savoy cabbages, red cabbage, and Brussels sprouts (big mistake). In the fourth and last bed I planted a herb garden but soon moved all the herbs to large pots so they were easier to manage. I replaced the herbs with a second crop of broccoli of a different variety, and a few more cabbages. Ben loves broccoli, hence the reason I planted so many.

Everything was successful and I harvested gradually over the next few months. The snow peas were first and we couldn’t stop grazing straight from the bush. The only vegetable that didn’t make it to the table was the Brussel sprouts for two reasons a. no-one liked them except me and b. the heads didn’t form properly, so I broke them up and added the plants to the compost.

I can positively say that all of my organically produced food tasted fantastic. Fresh, crisp carrots, eye watering onions (I pickles 50% of them) and mouth watering broccoli. I could go on forever about the taste, but I won’t, however I do urge you to grow your own vegetables if you have the room. Even in pots if you have a balcony! There is very little maintenance if you mulch well and I watered from the rainwater tank about three times a week depending on the frequency of the natural rainfall. I would say that between the planting and harvesting, I would spend about five hours a week working in the veg patch. Not much of a sacrifice, and much better than watching the rubbish available on the television these days.

Lastly, I found that I got back in touch with the cycles of nature. I became more aware of weather cycles, and could pick a rainy day without Met Bureau’s assistance and i just felt good to be outdoors and nurturing all of my plants.

It felt good to be green.