Midday wholesale price of electricity falls to zero in Queensland

An article by Giles Parkinson in The Guardian on 7 July reported that the wholesale price of electricity in Queensland fell into negative territory – in the middle of the day.  Apparently this has never happened in the middle of the day before. Here’s part of what the article reported:

For several days the price, normally around $40-$50 a megawatt hour, hovered in and around zero. Prices were deflated throughout the week, largely because of the influence of one of the newest, biggest power stations in the state – rooftop solar.

“Negative pricing” moves, as they are known, are not uncommon. But they are only supposed to happen at night, when most of the population is mostly asleep, demand is down, and operators of coal fired generators are reluctant to switch off. So they pay others to pick up their output.

That’s not supposed to happen at lunchtime. Daytime prices are supposed to reflect higher demand, when people are awake, office building are in use, factories are in production. That’s when fossil fuel generators would normally be making most of their money.

The influx of rooftop solar has turned this model on its head. There is 1,100MW of it on more than 350,000 buildings in Queensland alone (3,400MW on 1.2m buildings across the country). It is producing electricity just at the time that coal generators used to make hay (while the sun shines).

Yes, the wholesale price level around zero was due to the level of installation of rooftop solar PV systems by homeowners and businesses in Queensland.  But in reality it seems to me that the near zero pricecould more accurately be said to be due to the removal by the Queensland government of most of the feed-in tariff paid to solar PV producers – BUT …  there are still lots of solar PV owners on fixed term contracts and receiving reasonably high feed-in tariffs – so shouldn’t these tariffs have been reflected in the wholesale price when solar PV was dominating the market?  Or are there now so many recent solar PV installations that their low feed-in tariffs are dominating the market around the middle of the day?

Can anyone enlighten me as to how the near zero wholesale electricity price really came about?

Regardless of the confusion, it seems that solar PV is making its mark as a component of the State’s energy generation industry.  Are these low wholesale prices eventually going to be reflected in our electricity bills?

You can read the whole Guardian online article here.


Is a 100% renewable electricity supply possible in Australia right now?

Mark Diesendorf, Associate Professor and Deputy Director of the Institute of Environmental Studies at the University of New South Wales, has posted a detailed and convincing article in The Conversation this morning about the potential for a 100% renewable electricity supply in Australia.

His conclusion (with my underlining):

The renewable scenarios would be economically competitive with the fossil system either with a carbon price of A$50 per tonne of CO2 (reflecting part of the environmental and health damage from fossil fuels) or, in the absence of a carbon price, by removing the existing subsidies to the production and use of fossil fuels and transferring them temporarily to renewable energy.

That’s right: we could start implementing 100% renewable electricity generation RIGHT NOW, and with no financial burden on the economy, just a temporary shift of the political sacred cow of hydrocarbon fuel subsidies to the renewable energy sector.  In fact Diesendorf doesn’t say it, but there would be a significant positive impact on the economy from very significant increases in both temporary and long-term employment in the renewables sector.  And, you never know, when the renewable sector no longer needs the subsidy the government of the day may decide not to reinstate it for the hydrocarbon fuel sector.  Very big win for the economy and possibly the climate if that happened.

Could we do this with current renewable technologies, or would we have to wait for the development of some currently unproven approach?  It’s can all be done with today’s technology.  Here’s Diesendorf again:

“Using conservative projections to 2030 for the costs of renewable energy by the federal government’s Bureau of Resources and Energy Economics (BREE), we found an optimal mix of renewable electricity sources. The mix looks like this:

  • Wind 46%;
  • Concentrated solar thermal (electricity generated by the heat of the sun) with thermal storage 22%;
  • Photovoltaic solar 20% (electricity generated directly from sunlight);
  • Biofuelled gas turbines 6%; and
  • Existing hydro 6%.

So two-thirds of annual energy can be supplied by wind and solar photovoltaic — energy sources that vary depending on the weather — while maintaining reliability of the generating system at the required level. How is this possible?

It turns out that wind and solar photovoltaic are only unable to meet electricity demand a few times a year. These periods occur during peak demand on winter evenings following overcast days that also happen to have low wind speeds across the region.

Since the gaps are few in number and none exceeds two hours in duration, there only needs to be a small amount of generation from the so-called flexible renewables (those that don’t depend on the vagaries of weather): hydro and biofuelled gas turbines. Concentrated solar thermal is also flexible while it has energy in its thermal storage.

The gas turbines have low capital cost and, when operated infrequently and briefly, low fuel costs, so they play the role of reliability insurance with a low premium.”

“BASELOAD POWER!  You’ll need baseload power!”, I hear the coal and gas industries shouting.  Well, clearly such a system would NOT require baseload power in the form that they understand.

I like it too that he has addressed the bogie inherent in the use of biofuel powered gas turbines: the possibility that they will require unacceptable volumes of timber from forests or the allocation of unacceptable areas of food-producing farmland to grow the fuel to run them.  Keeping the gas turbines in reserve, to be used only for periods of a few hours a few times per year would mean that not only would fuel demand be low, but the fuel could be sourced from wastes over a longer period and stockpiled for later use.

Do we know whether it would work in reality?  How about on hot summer evenings, or on those cold, windless winter nights?  Diesendorf’s team used real figures from the National Energy Market (presumably the ones published daily by the Australian Energy Market Operator), to model many different mixes of current renewable energy technologies to come up with the proportions set out above.

 “Ben Elliston, Iain MacGill and I at UNSW have performed thousands of computer simulations of the hour-by-hour operation of the NEM with different mixes of 100% commercially available renewable energy technologies scaled up to meet demand reliably.

We use actual hourly electricity demand and actual hourly solar and wind power data for 2010 and balance supply and demand for almost every hour, while maintaining the required reliability of supply. The relevant papers, published in peer-reviewed international journals, can be downloaded from my UNSW website.”

 Read the full article on The Conversation.

Imported Weeds and Invasive Exotic Plant Species

The use of “weedy” species, together with the use of non-local species of unknown weediness, incites very heated debate in permaculture circles, inspiring a lot of name-calling and pseduo-science.  My own view is that the promotion of known invasive, or potentially invasive, species as part of the permaculture approach is highly irresponsible and arguments for their use are often couched in language that approaches the mysticism or spirituality that is supposedly “banned” in serious permaculture.  (You can see my views on the use of Leucaena here.)

Of course, the topic of invasive species overlaps with the consideration of “weeds” as an element of food productions activities.  I’m not going to go into that here, but the eXtension website has an excellent article on weeds in agriculture (An Ecological Understanding of Weeds) that incorporates both the negative and positive aspects of weeds in agriculture.  Well worth reading – much of it reads as if it was written by an well-informed permaculturist.  In fact the author, Dr Mark Schonbeck, is credited by the the Virginia Association for Biological Farming as combining “deep scientific knowledge, practical farming technique and policy smarts”.  I recommend googling his name – it will turn up a plethora of interesting and informative articles.

Dr Schonbeck’s article also deals with invasive species, under the heading of Imported Weeds and Invasive Exotic Plant Species.  Among other things this part blows out of the water the permaculture argument that for a species to become invasive in an ecosystem there must have been a vacant niche in the ecosystem.

Below is the text of that part of the article (with what I think are the really telling points underlined by me), but I really recommend you read the whole article for its information about the place of weeds in food production systems.  Remember that the weed/invasive species referred to are in relation to the US, though it is interesting how many are familiar to us in Australia.

Many of a region’s most problematic weeds are those that are not native to the region, or even the continent. These exotic plant species often grow more vigorously in their new habitat than they do in their area of origin, where certain soil organisms, herbivorous insects, climate patterns, and/or competing vegetation keep them in check. Kudzu (Pueraria thunbergiana), imported from Japan as a forage crop, is one dramatic example whose enormous vines can cover and kill large trees in the southeastern US. However, a small (4–18 inches) perennial weed called purple nutsedge (Cyperus rotundus), which has invaded the southern United States, causes much greater losses in cultivated crops (even sugarcane and coffee trees), and is considered the world’s worst weed (Holm et al., 1991).

Some of our major agricultural weeds were intentionally brought to the United States from overseas to provide food or forage. European colonists carried common lambsquarters (Chenopodium album) to the New World as a vital source of early season greens that prevented scurvy and other nutritional deficiency conditions. Common lambsquarters has spread around the globe and is now listed as the world’s 10th worst agricultural weed. Livestock farmers imported bermudagrass (Cynodon dactylon, 2nd worst weed), johnsongrass (Sorghum halapense, 6th worst), and quackgrass (Elytrigia repens, a major weed of vegetable crops in the northeastern US) to this country for their utility as forages. Other serious exotic weeds were first planted as flowers and other ornamentals, and subsequently spread from cultivated gardens into surrounding farmland and/or natural ecosystems. Still others arrived by accident as a seed contaminant in imported crop seed, feed grain, foods, bedding plants, or other materials.

Many exotic weeds have become “naturalized” over time, and are now part of a region’s agricultural weed flora that must be managed (not necessarily eradicated) to protect crop yields. However, some newly introduced plants growing in the absence of the natural enemies with which they evolved may spread unchecked, choking out native vegetation as well as invading pastures or cultivated fields. Imported weeds that threaten natural ecosystems and/or rangeland over wide geographic areas are designated invasive exotic plant species or invasive exotic weeds, and often become the focus of regional or nationwide coordinated eradication efforts. Examples include water hyacinth (Eichhornia crassipes) and purple loosestrife (Lythrum salicaria) in wetlands; Canada thistle (Cirsium arvense), musk thistle (Carduus nutans), spotted knapweed (Centaurea maculosa), and St. Johnswort (Hypericum perforatum) in rangeland; and autumn olive (Elaegnus umbellata) and tree-of-heaven (Ailanthus altissimus) in eastern deciduous woodlands. Classical biological control—the introduction of herbivorous insects or microbial pathogens that are natural enemies of these weeds in their native lands—has been used with considerable success to combat some invasive exotic weeds.

Arrival of a new invasive exotic weed on an organic farm is one instance that may justify efforts to eradicate the new arrival. Early detection—combined with an understanding of the ecology of the weed—is vital for successful elimination of the invader.

Edible and Useful Plants

Was just searching the internet for information on what is used to inhibit sprouting in onions (and potatoes) in Australia and came across a series of well written and informative articles on useful and edible plants by Penny Woodward.  Well worth having a look at.  She includes some unusual and interesting members of the onion family and herbs as well.  She has written a series of books (available for purchase through her website) which look interesting too.  Unfortunately she doesn’t have a subscription link to her blog, offering only advice on new material via Facebook and Twitter, neither of which I use.

Haven’t definitely nailed the anti-sprouting issue yet.  But I did discover that, like many fruits, onions can be stored for long periods before appearing in the shops.  It’s time we had a “harvest date” advice on fruit and veg.  It appears that the most common approach is some formulation of Maleic Hydrazide, often as Potassium Maleic Hydrazide.  I don’t have time to chase it up further right now, but it appears that while the potassium salt might be relatively harmless, one can’t say the same for Maleic Hydrazide, particularly in relation to its impact on aquatic organisms.  If anyone has detailed information on what is used in Australia, how it’s used, and what the impacts are please add a comment.

If you’re having any problems loading the new header photo please let me know.

Harvested – April to June

Here’s a record of the different things we harvested from the garden from the beginning of April to the end of June this year.

No weights or volumes, just harvested or not.  I can’t be bothered weighing everything that comes in from the garden; life’s too short for that sort of record keeping.  If it’s there and we need it, we harvest as much as we need.  What doesn’t get used by us gets given away – usually after a quick rush around the garden as visitors are leaving or as we leave to go visiting, with no time to weigh things; or it goes into the compost when past its prime.

And of course the produce that gets sampled as we graze different things while working it the garden doesn’t get recorded at all, even though it probably amounts to quite a lot over the course of a month.  I assume almost everyone grazes as they move around their garden.  For me it is not only satisfying, a lot of it is “quality control”.  Are the lettuce going bitter yet?  How does this tomato like growing here?

Over the three month period I’d say that something like 80% of our vegetable consumption came from the garden, which has put a big dent in our grocery bill.

Sorry about the crappy layout.  I haven’t figured out how to set up a table in WordPress yet, so this is just blocked and copied from MS Word.

Common Name April ’14 May ’14 June ’14
Arrowroot, Queensland
Basil, Italian/Sweet
Basil, Greek
Basil, Thai
Beans, Snake
Bok Choy
Chives, Garlic
Dragon Fruit (red variety)
Gai Laan
Kale, Curly
Kangkung / Water Morning Glory
Leek, Clumping
Lemon, Eureka
Lemon Grass, West Indian
Lettuce, Perpetual
Lime, Tahitian
Lime, West Indian
Luffa salad, stir fry, sponge salad, sponge sponge
Pak Choi
Parsley, Flat-leaf
Potato, Kipfler
Pumpkin, Japanese tips
Radish leaves, bulbs bulbs
Silverbeet, Fordhook Giant
Spinach, Ceylon
Spinach, Brazillian
Spring Onions/ Shallots
Sweet Potato, Orange tips
Tomato, Cherry
Tomato, Gros Lisse

Urban Farming

There are a lot of people in the world without access to land or good soil.  And I’m not talking only about landless people in developing countries.  Given the high level of urbanization in most countries and particularly in the developed world, urban farming ideas are applicable just about anywhere.

I’ve come across two great and proven ideas for “landless” farming lately.  The last was from the Accessible Edibles Project run by the Rotary Club of Rochdale, and uses recycled plastic bags (or other forms of container that can be hung from something.

from the Rochdale Rotary Club website

The method is very clearly set out in their manual and has been used successfully in many countries and at different latitudes.  The frames shown in the photos don’t need to be used – the bags can be hung from anything handy.

The other effective “landless” farming technique I’ve come across recently was developed by Roman and Janna Spur, who live in a flat in New Farm, an inner city suburb of Brisbane.  They have a great website which catalogues their approaches to sustainable living in a rental situation.

We went to their place last Sunday for a workshop on making a self-watering planter box from recycled materials (a broccoli box from the local fruit and vege shop, some 40 or 50mm PVC pipe, and a wooden skewer).  You can find an illustrated step-by-step guide here

a self-watering planter box in use [from Spurtopia website]

The planter-box workshop was followed by a fascinating presentation on the ways the family has developed an increasingly sustainable lifestyle in their rented accommodation, bearing in mind that there are limits on their ability to modify structures and systems, and that they want to be able to take their sustainable “infrastructure” with them if they move.

These guys are truly inspirational and I highly recommend their website and workshops.


The Foss and Holmgren Presentation

We went to the presentation by Nicole Foss and David Holmgren in Brisbane on Friday last week.

Very well attended, with a main lecture theatre pretty well packed – maybe 200 people.  There were eight people there from the Lockyer Valley whom I recognised and quite possibly more whom I didn’t recognise.  Pretty impressive, considering the massive disparity between the population of Brisbane and that of the Lockyer Valley.

Nicole Foss’s talk was absolutely riveting, starting with an overview of the history of money and the way that it has been expanded by the incorporation of debt/credit into the “money supply” and the risks that this poses.  She moved on to energy resource issues and linked this to the money supply (debt) through the cost of finding and producing the remaining “difficult” fossil energy sources, concluding that most of the hard to access fossil fuels will not be economic to produce.  The thread running through the presentation was the cyclical nature of the economy and the fact that massive levels of debt, coupled with the interconnectedness of the globalised economy and energy shortages/high energy prices, mean that sooner or later (and very likely sooner) there will be a depression cycle from which the global economy will not be able to recover.

Not all of it was as gloom-and-doomish as that may sound.  Foss gave examples of broad strategies for weathering the storm.

Of course this summary cannot possibly do justice to what was one of the most well delivered, highly informed, logical, well structured and thought provoking presentations that I have ever had the pleasure of listening to.  We came away with a lot of food for thought, and a resolve to review our sustainability planning.

She set the scene perfectly for David Holmgren to step in and elaborate the ways in which permaculture can contribute to creating a way through the economic (and social) breakdown that is coming.

What he started with were a series of bland generalisations, some of which touched on areas Foss had already covered, though some of what he said seemed strangely at odds with what she had presented.

The major part of his presentation though was an attempt to breathe life into his Aussie Street  scenario.  For those who haven’t seen it, this is a series of morphing diagrams tracing the evolution of households on four house blocks in an Australian suburban street.  It is long, barely entertaining, and the ratio of stimulating ideas to slightly cute waffle is very low.  We first saw it about eight years ago, and neither of us could decide whether there was actually any new material in Friday’s presentation.  As an illustration of the application of permaculture principles to suburban planning and lifestyle it can only be described as weak.  As a follow-up to the opportunity that Nicole Foss had set up for someone to highlight the role that permaculture can play in dealing with the coming disastrous wind-down of the economy and associated resource issues, Holmgren’s presentation was a massive lost opportunity.

We kept thinking, there’s got to be more.  A friend of ours said later, “I just wanted to throw things at him to wake him up to what he needed to be saying”.

But if you can get to the the Melbourne presentation on July 15, don’t miss it.  This is a chance to hear Nicole Foss give a truly remarkable overview of where we are headed and why.  If you are thinking of going to the Hobart presentation (Holmgren without Foss) on July 19, my advice is don’t bother.