Energy Matters Forums

[karlajensen]

An interesting point that I had not previously considered.

Japan is ~same size as VIctoria but has 126million people. Thats an energy demand approximately 5 times Australia before you consider they have the second largest economy in the world -read lots of heavy industry.

Australians as a whole need to get our heads out of the sand and start pulling our weight.

Over here in W.A. us sand gropers use 130 million litres of desalinated water each day - for a population of just 1.7million people.
That is 76L of water per person per day and desal represents only 17% of our water supply.

How is this possible? WE WASTE IT

How much energy do you think desalinating water takes
Lets do a little poll

is it
A) 10KW/hrs /litre
B) 5KW hrs /litre
C) 100Litres / hw/hr
D) 1KW / 1 Litre

That just blew my carbon footprint out the window my average is better than most but today is the day I change -during winter its under 200L/day for a family of 5 in summer it has been closer to 1000L/day.

I do have drought tolerant plants bet even they are distressed -we've had ~20mm rain since December and
had almost 3 months with daily temps >30 (couple of days only made 29).
-Yesterday we had 11hours of what is classed "Peak Sun"

In conclusion even if we think climate change isnt happening we still need to change our ways

[zzsstt]

You've only just realised this?

The BASIX benchmark in NSW for potable water usage is 90,340L PER PERSON per year. That's 250L per person PER DAY.

Two points:

1/ There is no requirement for anybody to use any reticulated water. Everybody living outside towns and cities uses tank water, captured from their roof. We (family of four including two young kids) lived in a small house with only about 90sqm of roof, and an 22,000L water tank through 3 years of drought and we only resorted to having water delivered (14,000L each time for $220) 3 times. By "average" standards, that 14,000L delivery would last a family of four only 2 weeks. We did not have "water saving" taps, showers or toilets, nor did we put any particular effort in to being economical or experience any hardship. There is no reason why the vast majority of people shouldn't have a water tank and supply all their own domestic water. In fact I struggle to understand HOW people manage to use 250L per day!

2/ The least appropriate solution to the problem is to use it as a marketing ploy to sell more products. "Water saving" devices are called "TAPS". You turn them on only to the flow required to do the job, and you turn them off when you are not actively using the water. A "normal" tap turned on a fraction to wet or rinse a toothbrush, then turned off uses only a few ml of water. A reduced flow "water saving" 2l/min tap turned on full for the entire 2 minute duration of the tooth brushing process uses 4L of water. But, once again, selling a new product (whether it works or not) makes money, which is the aim of the process......

[karlajensen]

We've kinda hijacked the thread now
Point being with 126 million people and no natural resources of your own to speak of you need energy with very little footprint

Not that I just realised the real cost of water (or how much we use)
Our place in the 'burbs of Melbourne we only* used rainwater and that was just a 5000L tank which we ran out only on a couple of occasions of 50+ days with no rain.
*almost - we did use 20L/day from mains supply as there was one toilet I couldnt hack into the supply for and the wife wanted mains water in the kitchen for drinking)

I also realise that us WA folks built a 78MW wind farm to cover the power for the desal but how much it actually covers I dont know. http://en.wikipedia.org/wiki/Emu_Downs_Wind_Farm

I know I have been keeping the garden alive and the front lawn green but that has to change.

All my household water gets recycled in some form or other -bucket in shower goes into clothes washing machine
-front loader which gets collected in buckets and used on garden. I collect cold water in the kitchen whilst I wait for the hot to arrive, use that in filter jug or watering food plants.

[Gordon-Loomberah]

We've kinda hijacked the thread now

indeed

I've brought out my shiny new moderation stick and split the topic, so it is no longer off-topic/hijacked

[karlajensen]

thanks Gordon!
I was trying to figure out how I could do it simply but it looks like your method works a treat.

[munter]

Interesting topic. The Australia Institute has suggested that the energy intensity of Sydney desal is 5kwhr/kl. Presumably that is just the desal component and transmission is additional. Studies have also been done on the energy intensity of rainwater systems and the results show a very wide range (up to 5kwh/kl) but more commonly about 1.7kWh/kL. (See this link http://www.water.anu.edu.au/project/auscew/pdf/policy_forums/sydney/Retamal_Systems_thinking_and_virtuous_circles.pdf)

I have no idea how people manage to get through 250L/person/day. Our consumption is down to 100L/day of mains water for all three people in our house. While we have rainwater tanks, we only use that water for the toilet, the washing machine and the garden. Our everyday life is completely unaffected by the use of rainwater.

[karlajensen]

I have discovered how our families water use has got out of hand.

-Our reticulation system -which I have done several upgrades to reduce water use, drippers, caps, etc
still uses 60l/min for the front lawn, 60l/min for front garden, 45l/min for rear side south, 35l/min for rear side west, 40L/min for lawn rear, 45l/min for garden rear nth.

All of those 6 stations at 7 mins a pop = roughly 2000L of water twice a week

I have been running it basically manually for a while so time to do it properly and re-program.
As the "soil" over here is basically sand the water travels through it very quickly.
hence longer waterings are not as beneficial as one might think.

I think I'll go for my two watering days at 2mins morning, 2 mins night which will almost halve my garden water consumption.

[Gordon-Loomberah]

... the front lawn... the rear lawn...

There's your problem!

While they may look nice in a traditional kind of way, and are easy to maintain in the places where they were invented, ie Europe, UK, they are just not suitable for the dryer regions of Australia. As Karl points out, they require huge quantities of water in hot weather. I think we need to look at covering areas that have been traditionally maintained as lawns with dry-tolerant native plants, on a massive country-wide scale, if we want to have sufficient water for more important uses as a nation. Buiding more/bigger dams doesn't really solve the problem of low rainfall.
When you survive on tank water alone, careful management of the limited water resource quickly makes clear what is sustainable.

[zzsstt]

There's little point in tiny waterings. If there isn't enough water to keep the grass alive it will die, so a few litres a week is actually more wasteful because it doesn't even achieve a positive result.

The answer to the problem is gravel. It costs a bit to "install" but after that it's all positives. It is fireproof, the snakes don't like crossing it, it has a minimal water requirement (a couple of litres every two/three weeks, mixed with RoundUp!) and you can hear anybody approaching your house. If you get the depth right it will suppress most weeds and provide an all weather surface - no mud! If you get the size right (I like the one they call "Denman Stone") it is not too uncomfortable to walk on. If you want some greenery, you can put large pots on your gravel, it's easy to bury/hide the irigation pipes and any surplus water runs through the gravel and away. Unlike concrete, when it rains the water simply soaks in to the ground as it did previously, so there is no need to create drains.

The only downsides are that if you have "offroad" tyres it does tend to migrate via getting stuck in the tread, and it can be annoying if overhanging trees drop their leaves and cover it, though no more so than with a lawn.

We bordered ours with (mostly) old vineyard trellis posts to keep it separate from the surrounding areas. Vineyard trellis posts are normally treated pine, but as I don't intend eating the gravel any leaching doesn't bother me. In fact as they are either broken posts or posts from vineyards that have been torn out, they have already been weathered for many years and I doubt there's much leaching!

Further from the house, where the fire risk isn't so important, a thick layer of mulch suppresses weeds and looks OK. Our local "professional chainsaw wielding maniac" provides us with chipped native trees - he clears them for the council, chips them and then sells them (unless you're a mate!) as mulch.

Beyond the gravel, plant native (and LOCAL!) trees in the mulch, which need no watering after establishment. If the odd one dies, leave it in place as a reminder to the others what will happen if they don't grow......

Then add a vegetable garden, which is a worthwhile use of water because it is productive. To maximise water efficiency, use raised beds with quality potting mix, and try to shelter them from the wind. A few years ago I got my local tank-maker to build us some oval tank sections, 1 sheet high and without tops or bottoms. He looked at me as though I was mad, even after I explained their purpose. They're still going strong, and the tank-maker now advertises them for sale in the local hardware store!

[bashworth]

Its not just the clean water that adds to the Carbon footprint.

It also the waste water if its discharged to a sewer. To get to the treatment plant it goes it probably has to go through several pumping stations (as no one likes to live next to the sewerage works). Modern treatment plants are also significant users of power.

The old treatment plants used to have fairly low power use but as the discharge quality has gone up the electricity used by the plants has quadrupled.