One of the Lockyer’s major farming enterprises depends on solar PV power

No doubt most of us are familiar with the climate sceptics, large energy companies, and both major political parties pouring scorn on the potential for solar power to make a significant contribution to our energy mix.  It’s a tired but oft-repeated refrain.

However, I’ve just come across an example from the Lockyer of a large-scale agricultural application of solar photovoltaic energy that is not only working, but has been shown to make good economic sense.

Linton Brimblecombe and his family have been farming in the Locker for almost 130 years.  Linton is known as one of the most successful and forward-thinking farmers in the Valley.  He and his wife have a 1,700 acre property at Forest Hill that grows sweet corn, green beans, onions, broccoli, beetroot, seed and grain.  There are 900 acres of irrigated land.

By 2009, Linton had recognised that not only were prices of major inputs (diesel, fertilizer, labour, etc.) increasing rapidly, but that climate change was affecting the nature of farming in the Lockyer.

Here is Linton’s take on using solar power in large-scale agriculture.  It is from the Climate Kelpie website‘s “ask a farmer” section where he provides a detailed overview of his response to changing climate.

In 2010, my brother and I decided to invest in solar panels to generate electricity for our farms in St George and the Locker Valley.

For us, it made good economic sense and was just another way of protecting our business against foreseeable changes in power costs, not to mention the touted carbon tax, which was a bit of an unknown.

After a bit of research we realised that solar panels were not widely used in our areas and, if they were, they were often attached to sheds and were not being used as effectively as they could be.

Luckily we were able to source a very handy engineer who was able to knock us up a system which was able to track the sun as it moves across the sky. This meant that the panels would always be in full sunlight and would be able to generate max power. The solar panels are connected to an axle which a small, self-sustaining motor turns hourly.

So far we can generate 270 kilowatts a day during summer and about 170 kilowatts a day during winter, which is more than we need to power irrigation pumps, our sheds and houses. Whatever is left, we sell back to the grid.

People always ask me whether it is affordable and sustainable. Given electricity prices at the moment, we predict it will probably take about 5 years to pay for itself.

Like everything new, panels will get cheaper as the technology becomes more used and supply becomes greater—so I only foresee that in light of growing power prices, solar is a cheap way to secure and sustain your business, not to mention that it is good for the environment.

While the government kowtows to the fossil fuel miners and power generators, handing out billions of dollars each year in subsidies for miners while cutting subsidies on renewable energy installations, real people are getting on with future-proofing our industries and homes by switching to renewable energy.

Wicking pots and beds

Wicking pot with garlic, basil and clumping leek

We first started to investigate wicking pots during a seven-year drought we experienced between 2001 and 2008. At that time we were dependent on one 3,000 gallon tank for all our water needs, including the garden, though we were recycling treated greywater to the fruit trees for part of that time.

The theory behind wicking beds is simple.  Water will generally wick up most soils to a height of around 300mm.   So if water is supplied to the plants via a reservoir under the soil layer, then it will wick up the soil, and if the soil surface is more than 300mm above the water then the surface will not be wet, and there will be little or no evaporation.  Thus the only water that should be lost is what passes through the plants by transpiration.

Because this was a bit of an experiment we decided to try it first with pots, before moving on to a wicking bed, though we did make the base for the wicking bed at the same time we made the first wicking pots.

My first impressions when I thought about the design of wicking pots / beds was that it seemed like the perfect situation for creating anaerobic processes (i.e. without oxygen) that could result in some pretty horrible smells, not to mention bad impacts on the plants.

Using half a 200 Litre barrel

The first design had a drain approximately 100mm above the bottom, so that excess water (e.g. rain, or forgetting to turn the hose off when filling the reservoir) didn’t flood the roots of the plants for too long.  Just in case this drain got blocked or could not cope with the heavy storm rains we get from time to time, another drain was added above this.

Reservoir recharge pipe

The recharge pipe is made from some off-cuts of 90mm downpipe and a spare elbow, with holes cut in the bottom to allow an even distribution of water.

The bottom section was then wrapped in weed mat to keep soil and roots from getting into the pipe.

Wicking pot with recharge pipe and upturned plant pots to provide voids to make more space for water storage

Test of wicking with soil mix

Before the pot was filled with the intended medium a test of its wicking capacity was done using some cut-off soft drink bottles – the wicking height was pretty close to 300mm.

For the first trial I filled four pots with a sandy loam with a good amount of compost and some coconut coir fibres to increase the water retention capacity.  Early results were very encouraging.  Plants thrived, and on hot days when the same plants in adjacent non-wicking pots were wilting, those in the wicking pots were showing no signs of stress.  But then, after about four weeks, things started to go wrong.  Leaves of tomatoes and basil started to lose their rigidity, going a dark green colour and “collapsing”.  Those species that didn’t show these symptoms just failed to thrive.

I removed the plants from one pot and dug out the soil.  Before I got to the saturated layer there was a very strong smell of rotten eggs. Hydrogen sulphide – the tell-tale sign of anaerobic processes.  When I did get down to the saturated layer I was surprised to find some areas of shiny black soil – pretty clearly some kind of metallic sulphide deposit, and a sign of extreme anaerobic processes.  Much worse than my early misgivings had led me to expect.

What to do?  Clearly there were likely to be two aspects to the problem – a primary cause:  no, or too little, oxygen was getting to the saturated layer; and a secondary cause: too much nutrient in that layer, leading to rapid consumption of any oxygen that did reach the saturated layer.

I’d been reading about water treatment processes and about biochar at the time, and both of these mentioned the way in which the capillaries in charcoal provide habitat for an amazing range of organisms that consumed excess nutrients as well as promoting healthy soil.  Maybe charcoal would make a good medium for the saturated layer, and could possibly be combined with a routine of regularly changing the water in this layer so as to drain away any developing anaerobic products.

But what about stopping nutrients from moving into the saturated layer?  Adding plant food at the top of the soil layer wouldn’t meant that it would find it way to the saturated layer, or at least not in large quantities.  And if water could be prevented from moving downwards then there would be less likelihood of downward nutrient movement.

Possible solution:  Keep the reservoir full, only provide plant nutrient at the top of the soil layer and water it in only after the reservoir had been filled.  Draining the reservoir every few weeks (add another drain with a tap at the bottom of the wicking pot) should help prevent an anaerobic situation from getting out of control.

But why don’t most other people seem to experience this problem.  I suspect that it is because the surface to soil volume ratio in the plastic barrels I am using is much less than one finds in, for example, a raised garden bed, a bath tub (often used for wicking pots), or a wicking bed.  That higher surface area to soil volume ratio allows more oxygen to penetrate to the saturated layer.

Some people do report bad smells – have a look here, and at the response by Scarecrow (who knows a thing or two about gardening generally, including wicking beds).  She says: “When I built the in-ground beds I filled the base (‘pool’) area with sand or a sand and gravel mixture. There is little organic matter in these mixtures so there is little to ‘break down’ to cause odours.”  So my theory about anaerobic decomposition of nutrient in the saturated layer is probably right.

By and large this has been successful, as can be seen by the photo above of the garlic, basil and clumping leek.

Tomato, rocket and another lettuce variety

Pak Choy, Zuccini (courgette) and Spring Onion

Does anyone know what the plant in the foreground is in this photo?  It was given to me as gai laan (Chinese broccoli) but so many people have told me that it isn’t gai laan I’m now convinced.  Some Indonesian friends (who showed me real gai laan to convince me this isn’t it) call it “chi asem”.  I can’t find an English name for Chi asem, but I suspect it is non-hearting Chinese cabbage (wombok) [I later discovered that it is Pak Choy].  It loves wicking pots, as do spring onions.

Zuccini grows really well too, and flowers and sets fruit, but then the small fruit goes rotten and drops off. Too much water?  Wrong pH?

In general it seems that plant roots move downward in wicking pots till they reach their optimum level of saturation and oxygen.  As you might expect, water plants do particularly well.  I’ve currently got water celery (Oenanthe javanica) in a wicking pot and it is thriving.  This plant can grow in water or in damp soil, though in water it has a less bitter taste and its “celeryness” is clear. [We stopped growing Water Celery when the extent of its “weediness” became clear].   Kangkung (Water morning glory – Ipomoea aquatica) also does well.  In Southeast Asia it grows in damp soil or in water with its stems floating on the surface.

Here are a couple of links to more information on wicking pots and wicking beds:

An unexpected bushfire

The weather last Friday morning was quite unusual.  In fact I was commenting on it at the time in a blog post I was writing over at the Helidon Hills Smokespotters web site.  The general feel of the morning said “Fire Danger”, even though the actual Forest Fire Danger Rating was only High (we have six levels of Fire Danger Rating – Low/Moderate, High, Very High, Severe, Extreme, and Catastrophic).  Over the space of half an hour the temperature had climbed a few degrees C, while the Relative Humidity had dropped about 10%.  This was largely caused by strong dry winds coming in from the north.  On the Smokespotters blog I’d finished the post with a plea to the Smokespotters group members not to be lulled into a false sense of security just because 5,000ha in the southern Helidon Hills had been burned out in a fire in late October – there was still about 30,000ha of bushland unburned.

I haven’t posted anything on that fire yet.  Dealing with the fire took up a whole week, then putting everything back in order here and getting our lives back on track (not to mention recovering from the exhaustion from the previous week) took another week.  But I will post something about it  soon.

Having finished the Smokespotters blog post I took a break for lunch.  Our kitchen bench is by a window that faces south, looking across the western half of our forest down to Lilydale Creek, the Lockyer National Park and the back parts of the blocks of two neighbours and up to a distant ridge.  While we were making lunch there was no sign of smoke, but 15-20 minutes later when we had eaten and came back to clear the bench the view that greeted us was of a dense area of boiling smoke in the vicinity of the Creek.

A “zoomed” photo of the fire about 30 minutes after we first saw it, and less than an hour after it started. It now has two clear “fronts”, one driven by the wind and burning strongly in the distance and the other, closer, burning into the rocky bed of Lilydale Creek

My immediate impression was that someone must have lit this.  There is nothing there other than bush, much of it with dense Lantana, and a dam with a water pump at the back of one neighbouring property.  I jumped into my fire-fighting gear (thick canvas jeans, a heavy cotton shirt, and a thick cotton hat) while Hanneke phoned the neighbours whose house was nearest to the fire to alert them and then emergency services on 000 and the local Rural Fire Brigade.  The neighbours were already on their way to investigate.  Like us, they had seen smoke where ten minutes before there had been nothing.  Thinking that they might need help, and also that I might find the ignition point, if not someone who had lit the fire, I grabbed my camera and a Rakhoe (a very effective fire-fighting tool, long-handled, with a wide hoe blade on one side and a coarse rake on the other) and headed toward the fire.

Luckily for me it had burned down into the rocky bed of Lilydale Creek and I was able to cross into the burned area where the fire-front had gone out on against the creek bank.  Navigating largely by the locations of the fire fronts (about 80m on each side) and the slope of the land I came to the neighbour’s fence, luckily at a point where a small section of the fire had burned out against their track, allowing me to cross into the unburned area.

I spent the next couple of hours helping to put out spot fires and checking for embers in and around the house and workshop.  The wind had picked up even more, and there were “floaters” of burning bark and leaves dropping fifty metres or more from the fire front.  We were lucky that they had done a lot of work preparing their property for the fire season, with a number of tracks acting as containment lines, and wide areas of short, mowed grass around the house.  Even so, with the flames periodically blown horizontal by the wind, the fire was easily jumping tracks three metres wide.

In the 38 degreeC heat, low humidity and dry winds patches of grass and leaves which had been extinguished with water were re-igniting within 5-10 minutes.

A small section of the fire front about two hours after it started. This was directly up-wind of the neighbours’ house, but by this time there was a fire crew on hand.

No fire trucks were able to reach us for around an hour because it was too dangerous for them to drive through the flame and smoke along the narrow access track. Two volunteer fire-fighters did make it through on foot to check that we were alright.  It must have been a hellish trip through the dense smoke and wind-driven flames.

Two other houses were in the line of the fire after it swept past us, but being closer to the road they were more easily accessible by emergency crews and no damage was done to them.  By the time I was able to get a lift home with one of the neighbours it was late in the afternoon.  On the way, we discovered that the fire had burned about 400 metres against the wind to our access track, and was being monitored by the crew of a fire truck so as to prevent it from getting across into a large area which we had kept the October fire out of.

Arriving back home I discovered that the fire was also making its way up into some areas in the National Park which I hadn’t realised had escaped the October fire.

4.45pm – the fire has burned into the National Park to the south of our place

As the fire near the creek-crossing burned along the edge of our track it set alight the bark of a couple of very tall Angophora trees.  These are a distant relative of the eucalypts, and this particular species has a thick, cracking and highly flammable bark that can burn for hours.  The fire raced up these, reaching a height of 25 metres or more in minutes.  Then, for hours burning flakes of bark fell from high in the canopy, breaking up as they fell and drifting with the wind with the potential to land across the track in unburned areas.  By this time there were eight or ten fire crews scattered around the area, so we asked one of them to come in and hose down the tree.  Of course, even with the pressure from their pumps the jets from their hoses could not reach more than half way up the trees, but at least this reduced the risk quite a lot.  In addition they covered the potential drop zone on the other side of the track in foam to reduce the chances of ignition there.

Burning bark of an Angophora on the edge of our track – this shows only abut two-thirds or less of the height to which it was burning.

We arranged for one of the fire crews who were going to stay in the area mopping-up to keep an eye on this  during the night and we drove down to check it ourselves every couple of hours until midnight.

In the end it seems most likely that the fire had started somewhere along Lilydale Creek, from a burnt log or dead tree that had been quietly smouldering since the October fire nearly three weeks before, and had flared up in the high temperatures, low humidity and strong winds that day.  The same thing had happened a couple of months before in another part of the Hills, and in both cases there had been more than 60mm of rain since the earlier fire.  In fact, parts of this fire were still smoking 36 hours later, after more than 100mm of rain had fallen in a four-hour period.

Pumpkin greens

Part of our pumpkin management is to pinch off the growing tips once a runner has reached a certain length.  This forces them to put out additional branches, providing  more sites for flower production.  We then use the tips as a vegetable, either steamed or stir-fried.

Fresh pumpkin growing tip

However every year we have self-sown pumpkins coming up in garden beds or anywhere else that we use our compost.

“Rogue” pumpkin seedlings

Until now we have just weeded these out, though sometimes we move them to where they can usefully grow or pot them up to give to friends.  This morning I was doing something else in the garden and my eye was caught by the sight of a fresh, bright green new pumpkin leaf.

New pumpkin leaf

Curious, I picked it and ate it.  Delicious!  Fresh, sweet, full of flavour.  Wow.  I would not have suspected that a leaf that size would be tender and sweet.  We now have a new vegetable, and wherever possible the volunteer seedlings will be left in place for a while so we can harvest the young leaves.

We have a new variation on pinching the tips off the pumpkin vines to promote flowering.  Meg McGowan suggested restricting each vine to one square metre – she finds it promotes much more productivity.  We are trying it this pumpkin season.

Not sure whether climate change is really happening in Australia?

If you feel uncertain whether climate change is happening in Australia (as distinct from just climatic variability) then the ABC’s Catalyst program has just released a report that you should see.  The climatic data is set out in detail, using 100 years of Australian weather records in most cases but relying on  high quality data sets identified by the Bureau of Meteorology.


The title of the report is Taking Australia’s Temperature, but in fact it looks at a range of parameters, not just temperature:

  • (temperature: maxima and minima, changes to annual temperature cycles;
  • precipitation – rainfall and snowfall: regional increases and decreases;
  • sea level: changes since the 19th Century (1841 in Tasmania, 1897 in southwestern Western Australia); and
  • sea temperatures: changes and specific warming events.

For an evidence-rich, bias free (in my opinion at least), easy to understand, Australia-relevant presentation of the data you can’t go past this report.

This is a blog about living sustainably in the Lockyer Valley Region, so why am I posting on climate change in Australia?  Because being able to live sustainably does not depend on only local factors.  Everything we do happens in, and is influenced by, a wider context.  If we are not aware of and up-to-date with that wider context there is a good chance that it is going to frustrate our efforts to live sustainably.  That’s one reason.  A better reason is that climate change is very difficult to discern at local scales.  Relying only on what we observe in the Lockyer to make up our minds on climate change is not reliable.  Put simply, you can’t arrive at a valid conclusion if you rely only on local observations – or on data over very short time scales.

Lockyer up with the best in Australia on level of solar PV power installations

A new report by Sunwiz has revealed that the Federal electorate of Wright (containing all or most of the Lockyer Valley Region) has the highest number of domestic solar power installations (solar PV plus solar hot water) of any Federal electorate in the country.  SunWiz has performed an analysis of Clean Energy Regulator data as of 1 October 2012 to identify the top solar electorates.

The electorate of Wright has a total of 26,417 installations, made up of 16,420 solar PV and 9,998 solar hot water systems.

Of course, raw figures on the number of installations in an electorate are not particularly meaningful, given that there is some variation in household numbers per electorate (though electorates generally have populations of around 150,000).  The percentage of households with solar installations (known as “penetration”) is a much more useful number, both for comparison and for revealing the level of uptake of renewable energy at the household level.

Wright figured 6th in level of penetration of solar PV (out of 150 electorates) with a penetration level of 20% – one in five dwellings (the national maximum was 23%) and 15th in solar hot water with 12% – one in eight (national maximum 21%).

The electorate of Wright encompass an area stretching from the western Gold Coast through the rural areas left out of the more urban electorates between Logan City and the NSW border, before curving northwest to include the Lockyer Valley Region west of Ipswich. As well as the western edge of the city of Gold Coast, Wright includes the towns of Beaudesert, Jimboomba, Boonah, Gatton, Laidley, Hatton and Helidon (ABC 2010 election web site).

Given its location, Wright may not be what you would think of as a particularly Green electorate, and it isn’t, though there was a significant swing to the Greens in the 2010 election.  Conservative parties (LNP, ALP and Family First) – yes, I’ve identified the ALP as a conservative party – got over 80% of the vote.  The voting pattern in that election was:

How does the Lockyer Valley Region fit into this solar power picture?

Census records for the Lockyer Valley Region do not include solar PV installation data.  However it doesn’t seem unreasonable to take the 4343 postcode area as a proxy for the Region.  As can be seen from the map below, it clearly takes up a significant proportion of the Region.

The Sunwiz analysis is based on postcode data (their methodology is explained at the foot of the web page reporting their findings), but understandably in a national report they do not provide the separate postcode data.

The Clean Energy Regulator’s web site includes detailed data on “small generation units” (= solar panel installations) for each postcode area.  In the 4343 area 677 units had been installed as of October 2012, with a total generating capacity of 2,012 kW.  The total is likely to be higher than this because the data is based on registration for Renewable Energy Certificates, which can be done up to 12 months after installation.

There were 3,610 occupied private dwellings in the 4343 postcode area at the time of the 2011 Census.  This suggests a “penetration” of solar PV power of 18.7%.  However, solar power is seldom installed on apartments, flats, and similar, and is much more likely to be found on private houses, of which the Census recorded 3,190, leading to a penetration level of 21.2%.  It seems fair enough to say that the solar PV penetration level in the 4343 postcode area is between 18.7% and 21.2%, and that the level for the Lockyer Valley Region is probably in this range.  (There were 11,900 private dwellings, and 11,200 occupied private houses recorded in the Region in the Census, so the 4343 figures represent 30.3% and 28.9% respectively of these totals. Seems like a pretty good sample).

What this means is that the penetration level for solar PV power installation in the Lockyer Valley Region (around 18.7-21.2%) is clearly of the same order as that for the larger Wright electorate (20%) and close to the highest penetration rate in the country (23%).

The Soup Kitchen is open again

Following the bushfire (more on this later) that burned out about 80% of our bush 13 days ago, there is very little food for the our wallaby population.  As in the 2009 fire, we have set up a “soup kitchen” to tide them over until enough grass comes through to feed them.

The menu is simple: water (we always put out water pots for them because it is very dry here on the sandstone ridge), pony pellets, and racehorse-grade lucerne (alfalfa).  They much prefer the pony pellets over the lucerne, which is OK with us as the pony pellets cost $10 per bag, while the top-grade lucerne is $10 per bale wholesale and would not last as long as a bag of pony pellets if they decided to eat it.  Any leftover lucerne will make good mulch for the garden.

It’s hard to know how many wallabies we are feeding. They come and go for much of the day and all night, but there are four feeding stations, and there are sometimes 3-4 animals at each at the same time.  Probably nearly half of the females coming to the food are carrying well advanced joeys in their pouches.

Female Red-necked Wallabies at a feeding station

We set up a couple of camera traps (trail cameras) to check whether we are also feeding pigs and deer, but so far there aren’t any signs of them at our feeding stations.  We can see by their tracks that they are moving through our property from the National Park (also burned out) to get to the stone-fruit orchard next door.  The windfall fruit lying on the ground there are a favourite of the pigs, and the succulent leaves on the trees  attract the deer.  Our pony pellets and lucerne probably can’t compete with either of those.

One thing we did discover was that at a certain age the young male Red-necked Wallabies get around in a group.

A “gang” of young males takes over a feeding station.

In addition to checking for feral animals, the camera records provide us with great entertainment in the form of interactions between the wallabies, confrontations they have with possums, and views of joeys (baby wallabies) hanging their heads/tails/legs out of the pouch.

Wallaby vs Possum stand-off

Even the possums get possessive about the feeding stations sometimes.

Mother Brush-tailed Possum defends the feeder (and her young one) from an interloper

Some surprising things get into the camera trap images.  The data on the bottom right of the photo shows date (ddmmyyy) and time.

A bat zooms over one of the feeding stations – possibly a Flying Fox (one of the Megachiroptera).  Its image is distorted by the relatively slow shutter speed.

There is “green pick” coming up already in the burnt areas, and some of the wallabies are starting to feed there, though it would be hard work for a mother with a large joey in the pouch or “at-heel” to get enough of this to sustain herself and the joey.  Some of the females will have a joey at-heel but still getting milk from the mother, another in the pouch, firmly attached to a nipple, and another in the early stages of gestation, and their nutrient needs will be even greater.

We’ve had 69mm of rain since the fire went through, so the grass should come back relatively quickly.  We plan on starting to gradually reduce the food we supply in the next couple of weeks.