What’s around – mid September 2012

The biggest event in the garden in the last month has been the flowering of our poplar gum, plus the paperbark, macadamia and bottlebrush. All attracted their quota of nectar-feeders – birds and flying foxes as well as insects.

The weather news is simple: we had a little bit of rain which triggered the flowering of our trees, and since then we have had rather warmer nights and slightly warmer days, with slightly higher humidity. Temperatures are now consistently dropping to 16C overnight (not 8 or 10) and going up to 28 in the daytime, and I do mean ‘a little bit’ of rain – the BoM recorded 1.4mm on August 20 and none before or since. The invertebrates have responded to the warmth and food with a surge in numbers and variety:

Butterflies and Moths (Lepidoptera): numerous Chocolate Soldiers and Eurema; a few Varied Eggfly and Evening Brown; and visiting Cairns Birdwing, Orchard Swallowtails and Ulysses. Magpie Moths are common again, and I loved the Zodiac Moth on the poplar gum. Nearer ground level, I spotted a pretty white moth, Amerila rubripes. It does have a ‘common name’ – Walker’s Frother but it’s not well known enough to be a genuinely common name.

hairy orange caterpillars
These very hairy caterpillars fell from the poplar gum and ended up on a weirdly photogenic blue textured glass louvre

Flies and their relations (Diptera): Tiger craneflies are abundant, to the extent that I saw half a dozen mating pairs in half an hour one morning, and the orange-headed Plecia flies are also mating. Our tiny metallic Dolichopodidae are as common as ever, and there are a few blowflies too. Mosquitoes? Yes, unfortunately, but not too many.

Paper wasps on a chain of nest cells
A new, small paper wasp nest. Its structure is enough to identify the wasps as Ropalidia revolutionalis

Wasps, Bees and Ants (Hymenoptera): Honey bees came to the flowering trees and various native bees are also around. The small parasitic wasps (Braconidae) are back, and so are paper wasps and mud-daubers.

Spiders and other Arachnids: The orb-weavers suffered housekeeping agonies from the poplar gum as flower debris kept falling into their webs, making them useless for trapping prey. Spiny spiders and the Silver Orb-weaver are the commonest at the moment, with a few St Andrew’s Cross spiders for variety. Jumping spiders, Lynx and flower spiders are all to be found, too.

Others: A praying mantis was resting on our lounge-room wall last night and I have seen a few dragonflies cruising through our airspace. There very few grasshoppers of any size or variety but lacewings, both green and brown, have been attracted to our lights in the evenings. Of the Hemiptera, my little aqua-legs sap-sucker is back and I have seen a few others; not many, though, and I suspect they are waiting for more new greenery.

Last monththis time last year

Big sky over Ross River

high cloud over beach at Ross River estuary
Big sky over Ross River estuary, looking roughly southeast towards hills between Mt Elliott and Cape Bowling Green

Ross Creek runs along the edge of the city centre and past Reef HQ Aquarium so I know it well. However, I rarely visit the mouth of Ross River on the other side of South Townsville.

I was in the vicinity last week to recycle some old computer gear so I continued down to the end of Boundary Street for a walk on the beach. The river mouth is very shallow, with wide stretches of sand and extensive mangroves. I enjoyed the clouds, and a couple of Whistling Kites soaring above me. One came close enough for a pleasing photo:

brown hawk soaring overhead
Whistling Kite, Haliastur sphenurus

Down at ground level I found a sleek grey and black wasp going about its business. It turned out to be a Spider Wasp (Pompilidae) and you can see it here on Flickr.

Wildlife Carers’ open day

North Queensland Wildlife Care Inc. are having an Open Day in Aitkenvale on Saturday 29 September.

  • Meet their dedicated and experienced carers
  • Find out more about our local native wildlife
  • Learn first aid for injured wildlife
  • Learn about what it takes to care for injured or orphaned wildlife through to release

All proceeds for the day go towards feeding and rehabilitating wildlife.

I don’t know the group, although I suspect some of its members have ended up caring for injured animals we have rescued from time to time, but this sounds like an interesting and worthwhile event. For more information, visit their website http://www.nqwildlife.org.au/ or download a flyer (pdf).

Nocturnal visitors

I was thoughtless enough to leave a window open and a light on in my study on Wednesday evening and by the time I noticed, there were dozens of little bugs around the light and resting on the ceiling. There were several green lacewings, at least one brown lacewing, a creature I thought was a katydid but turned out to be a cricket, some bugs which looked like small pale mosquitoes but were non-biting midges, many tiny moths and flies, and miscellaneous others. Here are some of them.

cricket looking like brown grasshopper
Cricket (Gryllidae, perhaps Amusurgus sp.), about 12mm long not counting the antennae (click for larger view, as usual)
green lacewing
Green lacewing (Neuroptera, Chrysopidae) resting on ceiling
Not a mosquito but a non-biting midge (Chironomidae). Love the feathery antennae!
Another non-biting midge, Chironomidae
orange and black fly
This looks like it could be a wasp but it is a fly (Diptera, Plecia sp.)

These five all look roughly the same size on screen but in real life the midges are only 4 – 5 mm long and the others are two or three times their size.

The room has a resident population of spiders and they benefited from the influx of prey. The fly here is not a house fly but about half that size, so the spider is correspondingly minute.

spider and fly
Daddy long-legs with an incautious fly.

Going Solar: FAQ’s

Created December 2011, updated September 2012: We spent a lot of time tracking down the facts in mid-2011 before we were confident that going solar was a good thing for us to do. I updated the information in December 2012 in preparation for another installation the family was planning and presented it here on Green Path in the hope that it would be useful to others contemplating the same action. I have now (September 2012) updated it again, mostly because of drastic changes to Queensland incentives. Major changes are in bold.


Both national and state governments have incentives to encourage our move to renewable power generation, while the federal incentives also reward any steps we take to reduce power consumption.

Federal Incentive: RECs or STCs

The federal government, through the Small-scale Renewable Energy Scheme (SRES), gives an up-front lump-sum incentive payment calculated on the amount of energy a solar PV system will notionally produce over its lifetime.
The scheme aims to:

  • encourage the additional generation of electricity from renewable sources;
  • reduce emissions of greenhouse gases in the electricity sector; and
  • ensure that renewable energy sources are ecologically sustainable.

This is achieved by:

  • the creation of online certificates by eligible renewable energy sources based on the amount of electricity in megawatt hours (MWh) generated by a renewable energy power station, or small-scale solar panel, wind or hydro system; or displaced by a solar water heater or heat pump; and
  • placing a legal obligation on electricity retailers to purchase and surrender a certain amount of these certificates each year. The trade in these certificates thereby provides financial incentive for investment in renewable energy.

In practice, this up-front incentive usually appears as a discount on the quote from your installer, who takes the certificates and on-sells them.

When we installed our own system, RECs were issued at five times the expected 15-year output in megawatts for installations up to 1.5 kW and one time (same number) for anything over that. They are now called STCs and credited at twice (same number) for installations up to 1.5 kW and one time for anything over that. The discount for a 1.5 KW system has therefore dropped considerably. At the same time, however, component prices have dropped so the net cost increase is not so significant.

For more information on the federal scheme, see The Small-scale Renewable Energy Scheme (SRES) at http://www.orer.gov.au/About-the-Schemes/sres and RET Frequently Asked Questions at http://ret.cleanenergyregulator.gov.au/Frequently-Asked-Questions/all-faqs

State Incentive: Feed-in Tariff

The other incentive is the feed-in tariff from Qld Gov’t via Ergon, who pay a certain amount per kWh for power fed into their grid. The payment goes through the power bill.

The bad news is that the Newman LNP government slashed the feed-in tariff for new customers as of July 2012, from 44 c/kWh to a mere 8c/kWh, and has said that, “The 8 cent tariff will end on 1 July 2014. However, the Government will also review the 8 cent tariff by 1 July 2013 to ensure the rate remains appropriate for Queensland,” which sounds like code for, “We will abolish it altogether if we can get away with it.”

Fortunately for early adopters like ourselves, existing customers will continue to receive the 44c feed-in tariff until 2028, “providing they maintain their eligibility for the scheme,” which basically means not changing the account name. That is, if the house is sold or rented out, the feed-in tariff lapses.

Our system is producing just over 6 kWh/day. If it all went in to the grid at 44 c/kWh it would earn us $2.60 per day; if we used all of it, it would save us $1.30 per day by replacing Tariff 11 power at 23.7 c/kWh. Our net benefit must therefore be somewhere between those figures, and in fact it has averaged just under $2.00 in its first full year. (Summary figures for the first full year of operation are here and month-by-month figures are here – scroll down to the comments).

Limits of incentives

  • Basically one system per property and a maximum of 5 KW per system.
  • The Federal incentives dropped in the middle of 2012, when the multiplier for small systems dropped from 3 to 2, and will drop again in July 2013 (see “What are Solar Credits” here).
  • The feed-in tariff is guaranteed to stay the same for 20 years for people who signed up before July 2012 but there is no long-term guarantee for new customers. 

Rental properties

The federal subsidy is availabe to owner-occupiers and landlords alike. So is the state’s feed-in tariff, except that the payment goes to the person whose name the power bill is in – normally the tenant, in which case the landlord would have to negotiate with the tenant to receive any benefit.

Payback time

In December 2011 I said:

These figures make payback time for our 1.5 kW system 4.5 yrs and for a new system like ours about 6.5 years. That’s not bad, but a 5 kW system is mostly a solar farm, since no extra power would be used by the household. On the same domestic consumption, export to grid would be 6000 kWh / yr and pay the owner $2650 p.a. as well as saving $200 p.a. off the normal bill. On the other hand, it will cost more – about $14 000 – $15 000. On these (very rubbery!) figures, payback time is still, surprisingly, in the 5 – 6 year range.

I haven’t done all the calculations again but ‘solar farming’ has obviously become far less attractive since the state feed-in tariff dropped in July 2012: that $2650 p.a. would become $480. 

Stand-alone capacity

Grid-connected systems don’t usually have any stand-alone capacity. One installer told me the Australian standards for grid-connected inverters mandate automatic shut-down when mains power drops out. The only way to give your system stand-alone capacity is therefore to install a second inverter (a stand-alone model) and a rack of batteries, for a total cost far greater than the cost of a portable generator and a generator input plug on the main switchboard.

Is PV Solar the best thing for me right now?

This question was answered separately on Oct 22, 2011, here; I haven’t updated it since then, mainly because it still all seems to be correct. In fact, the potential benefits of energy savings seem greater now in comparison to the potential benefits of installing solar power, since the incentives for solar have dropped.

Accredited Installers

Listed here: http://www.solaraccreditation.com.au/acccec/consumers/findaninstaller

Coming Technology

The current monocrystalline and polycrystalline cells are both mature technologies and radical improvements seem unlikely. Amorphous and thin film technologies are newer and potentially cheaper per watt but less efficient (i.e. you need a bigger area to make the same amount of electricity) at this stage and are apparently not really worth considering for domestic installations. See http://en.wikipedia.org/wiki/Low-cost_photovoltaic_cell for regularly updated information.

Flexible cells are coming – there has been a demo set-up at Townsville airport for a year now – and may have their uses but don’t seem particularly relevant to fixed installations. For something further out, look at these printable and paint-on solar cells.


The three big sites for authoritative information are the Clean Energy Council (the peak industry body in Australia), the federal government’s Office of the Renewable Energy Regulator (ORER) and (for Queenslanders – I assume other states have similar sites) the Office of Clean Energy which has a more people-friendly page at Do the Bright Thing. The solar PV guide (pdf) from the Clean Energy Council is good introductory material, but there is plenty more on these sites.

The Desert Knowledge Australia Solar Centre (DKASC) is a demonstration facility for commercialised solar technologies operating in the arid conditions of Alice Springs, Central Australia. This page is a fun introduction to it.