Going solar is not for everyone

In the early days of this blog I wrote about whether going solar is always the best option and I have just revisited that question in real life after a Melbourne friend asked me for advice. Things have changed since I wrote that post – two and a half years is a long time in renewable energy development – so I thought that presenting her query as a case study might be worthwhile. Here it is; I have changed her name and lightly edited our emails for clarity, but that’s all.

solar pv advertisement

Paula lives alone in a unit in Northcote. She works as a nurse but is looking forward to retiring in the next five years and, sensibly, wants to set herself up for retirement by reducing her future expenses, which is where the thought of solar power came in.

She saw ads like the one at left and spoke to a salesman who recommended a 2.5 kW system on the roof of her garage, the biggest that would fit there, for a net cost to her of nearly $4000. He promoted it on the basis of how much it would reduce her power bills but she had second thoughts, writing …

I have gas ducted heating for winter and the air-conditioner is the cheaper-to-run evaporative type. My hot water service is gas. I rarely use the dishwasher, and the fridge and freezer are usually full so not a lot of power is used there. It is true I use my clothes dryer twice a week but apart from that it’s hard to see where the power goes.

I use lamps at night except in the kitchen and don’t have lights on all over the house, and I am in the process of replacing all the down lights with LEDs – which leads me to wonder how much can be saved.

Apart from the obvious long term considerations I’m starting to wonder how much of a good idea this is.

I asked her to send me a copy of her power bill and the solar power proposal, and took it from there:

Hi, Paula,

Thanks for sending the documents. They confirm what I was already beginning to think and, from your “I’m starting to wonder”, you were too: that going solar may not be the best thing for you.

(1) Looking at the pie chart showing average Victorian enargy use patterns on http://www.sustainability.vic.gov.au/services-and-advice/households/energy-efficiency we find 16% goes on water heating (but you’re using gas) and 32% on heating (but again, you’re using gas). That means only half of your total energy bill goes to electricity, and agrees with the fact that your current electricity consumption is pretty low – around 60% of a typical one-person household’s use. It also means, of course, that reducing it can’t save you anywhere near as much as it would if you were all-electric.

(2) The feed-in tariff you can get from a new solar PV system is only 8 c/kWh. Any PV power you generate but don’t use during the day only makes you 8 c/kWh (that’s what they pay you for it). Any power you generate and do use makes (saves) you 27 c/kWh (it’s free but that’s what you would have paid for it).

While you are working, the only electricity you use during sunlight hours most days of the week is keeping your fridge ticking over. That is far less than the 2.5 kW the PV system will put out, so 90% of your PV system output is only going to be worth 8c/kWh to you. And what’s the output going to be? Maybe 7.0 – 7.5 kWh per day, or 2700 kWh per year; at 8c, that’s only about $200 … not a great return on your investment.

(3) When you retire, you will probably run the air-con a fair bit during summer so more of the PV output will be worth 27 c/kWh to you (probably more than that, actually, since power prices are only going one way – up!). But your air-con probably doesn’t use 2.5 kW anyway, so a smaller system (1.5 or 2.0 kW) will be a lot cheaper and give you almost as much benefit.

(4) There is no particular advantage in installing solar PV now rather than in two or five years’ time. A few years ago, feed-in tariffs were set high to encourage people to install systems but those days are gone. Meanwhile, component costs are still dropping and the technology is still improving, so you will probably get more bang for your buck in a few years’ time.

As you know, I am pro solar and anti fossil fuels but I think in your present situation a solar PV system, especially one as big as the one you’re looking at, is not worthwhile. That could change when you retire, but there’s no reason to install a system ahead of that time and a few reasons to leave it until that time.

And if you do decide you still want to go ahead now, please (1) go for a smaller system, probably 1.5 KW, and (2) shop around, since $4000 for a 2.5 KW system seems a little bit on the high side.

Meanwhile, your best money-saving tactics centre on minimising waste – not over-heating your house or your hot-water, not over-cooling your house in summer, turning off appliances which are perpetually on stand-by, improving insulation, etc. http://www.sustainability.vic.gov.au/services-and-advice/households looks like your best resource, but you probably know most of it anyway.

That was enough to confirm Paula’s doubts and she decided not to proceed with the installation but I kept on thinking about the issues.

One thought: by the time she retires, the technology may have changed enough that she might go solar in a different way. For instance, she may be able to buy a plug-in electric vehicle as well as a solar PV system and use the batteries of her car as storage for household power. This kind of integration has been trialled for at least five years and must be ready to go mainstream soon.

Another thought: the 8c feed-in tariff seems way too low to be fair, and if and when that gets sorted out the long-term level for feed-in tariffs may be half to two-thirds of the retail domestic tariff, i.e. 16c on current rates. The library which lives behind my computer screen (I love the internet!) backs me up on that: RenewEconomy says:

Are Australian solar households getting ripped off?

Households in Australia adding solar PV arrays to their rooftops have an important question to ask themselves: Are they getting a fair deal from their local utility for the solar power that they export back to the grid?

Why is it, they might wonder, that households in regional Queensland which pay 26c/kWh (even after state-sponsored subsidies) for their electricity from the grid will get just 6.321c/kWh for their solar exports? In some areas, such as south-east Queensland or NSW, there is no obligation to pay households at all.

Yet in Minnesota, a state in the US (think of the film Fargo), households which pay a retail electricity rate of just 12c/kWh are being offered 10.9c/kWh for the solar that they export back to the grid.

In turn, that page references another RenewEconomy article called, Could a 500-house community go off-grid? which says, “Last year, a CSIRO study suggested one-third of consumers could go off-grid by 2050, based on the prospect that it would be economic for [individual] households and businesses to do so from around 2030 onwards,” and says that it’s economic right now for new housing estates to set up their own of-grid power supply.

Those pressures are going to radically transform the economics of electricity supply in much the same way that the internet has transformed (“trashed” may be a more accurate word) both print media and the post office. Utilities will find distribution costs per customer rising inexorably as customers go off-grid, and the resulting increases in supply charges will drive ever more customers off-grid – unless, perhaps, companies entice them to stay by offering very generous feed-in tariffs

There are going to be big changes and they are going to come more quickly than anyone would have predicted a few years ago.

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Big Crystal Creek

view of forested mountains

Looking up towards Mt Spec

Last Sunday we went for another walk in the bush with the local Wildlife Queensland people – a bit further from home than our first, and more interesting in that it took us to a place we knew about but hadn’t visited before. We know Paluma, and Little Crystal Creek on the road up the range to it, but had somehow never diverged from that road to visit Big Crystal Creek and Paradise Lagoon. It’s easy enough: turn off the highway as if you’re going to Paluma but then follow the signs (about 7km) to Big Crystal Creek instead of turning left to go up Mount Spec to Paluma.

two yellow-fronted birds on branch

Lemon-bellied Flycatchers

We parked at the Paradise Lagoon picnic ground and walked up the road to the Water Slides area. WQ will  soon have a full report on the walk (it is here) so I will concentrate on the bugs and leave most of the plants and birds to them. I’m still going to put one bird photo here, however, just because the birds were obliging enough to pose for a series of portraits (as usual, click on it for a full-size image).

As well as these Flycatchers (Microeca flavigaster) we saw a tiny Scarlet Honeyeater and several other birds. Insects and spiders were also abundant, from the mantis and preyed-upon grasshopper I spotted before we even left the carpark, to the grasshoppers preying upon flowers of the native hibiscus (see them here), to the spiders waiting patiently in their webs above the fast-flowing rocky stream. There were lots of butterflies, too - we saw Blue Triangles, Clearwing Swallowtail, Common Crow, Eurema, Common Eggfly, Blue Argus, a Pierid which was probably a Migrant, and an orange butterfly which may have been an Australian Rustic – but they are all species which I have already photographed lots of times and I didn’t try too hard to catch them this time.

spotted beetle

Acacia Longicorn Beetle on twig. They eat bark, so this one is probably responsible for the damage we see here.

mantis with a grasshopper

Mantis and prey

A slender spider, Tetragnathidae, suspended above rushing water

A slender spider, Tetragnathidae, suspended above rushing water

Another slender spider, Cyclosa species, in its web. The strand of 'rubbish' consists of egg sacs (near top), spider and (lower middle) and camouflage including prey remnants

Another slender spider, Cyclosa species, in its web. The strand of ‘rubbish’ consists of egg sacs (near top), spider  (lower middle – head down and with front legs extended) and camouflage including prey remnants.

We returned to Paradise Lagoon picnic ground for lunch and a short walk to the swimming hole:

rocky swimming hole

Paradise Lagoon

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I’m still spending a bit more time on Facebook than I really should but it does mean I’m still collecting some clever and thought-provoking graphics. It’s a bit like beachcombing (but without the sunshine and fresh air), actually, in that if you pick up enough shells and pebbles you can make pretty patterns with them, or with a selection of them. It’s also like beachcombing in that you hardly ever know where your finds have originally come from; as before, I would like to give the creators of these graphics credit (and link to their sites) but I simply don’t know who they are.

These three go together quite interestingly, I think:


do nothing

first they ignore

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More arboreal ants

two ants on branch

Two ants from the first nest – a soldier (above) and a worker

Frangipanis are deciduous tropical trees with – as everyone knows – beautiful flowers, and they are deservedly popular in Townsville gardens. A few days ago I was trimming small dead branches from ours and was vividly, and almost painfully, reminded of the fact that dead branches are hollow and nature abhors a vacuum – that is, small creatures enthusiastically adopt hollow branches as nests.

The creatures in these branches were ants, and I found two different species. Two residents of the first are shown above and yes, they are big ants. The soldier must have been about 15mm long and it had a huge, heavy, big-jawed head in proportion. They weren’t just casual visitors to the branch, either, but long-term residents raising the next generation inside the hollow as I proved by knocking the branch against a post and seeing eggs fall out:

ant and eggs

A worker from the first nest trying to rescue eggs

The ants in the second nest were much smaller, perhaps 10mm long, and prettier. They were also more agitated, moving so fast that it was almost impossible to get a photo.

silver-charcoal ants

Ants from the second nest

When one of them did stop to investigate a hole it bent forward in such a way as to show off its spiny body:

ant on branch

Investigating a hole

This spines are enough to identify it as a Polyrhachis species, but (as this page shows) we have well over 100 species in that genus in Australia and I haven’t tried to narrow it down.

To answer a couple of obvious questions …

  • My reminder about vacuums was ‘almost painful’ because I very nearly got bitten by soldiers of the first nest.
  • Carpenter bees also adopt frangipani hollows as nests (this one wasn’t smart enough but will give you the idea).
  • Our other ‘arboreal ants’ are the two species which make nests by sewing leaves together – Rattle Ants (another Polyrhachis species) and the very familiar Green-ants.
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March in March and Earth Hour

A few months ago I wrote about how good it felt to be part of a large group of like-minded people standing up for the environment. We have two opportunities to repeat the experience in the next couple of weeks – March in March this Sunday (16th) and Earth Hour two weeks later, on Saturday 29th.

The route of Townsville’s March in March is along the Strand, from Burke Street Headland to the Rock Pool; people are asked to gather on the headland at 9.00am. Full details are here but that page doesn’t give much of the rationale for the protest. This article in The Age gives the background – sympathetically but from outside the movement, which is what one should be able to expect from a responsible news organisation.

If you’re not in Townsville, look here for your nearest gathering. If you can’t get to one, you could send Mr Abbott an email to tell him what you think he’s doing wrong.

Townsville’s big gathering for Earth Hour is also on the Strand – in Strand Park, in fact. Townsville City Council – who deserve kudos for this, for Eco-Fiesta and for many other sustainability initiatives – invites everyone to an event which begins at 3.00 pm:

The Townsville Earth Hour and Resilience Expo will bring together different organisations and business to showcase the actions people in Townsville can undertake to go beyond the hour and build resilience in the community. The event will culminate in a public screening of the “lights out for the Reef” documentary. People are encouraged to come down and set up a picnic rug to enjoy the public screening.

More information here. If you’re not in Townsville, look here for a gathering near you.

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