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 off-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.

Water from the Sun

windmill on skyline
A windmill on the edge of Hughenden in Western Queensland

Much of Western Queensland has always depended on underground water and for years a windmill on the horizon was a traveller’s first sign of the next homestead. That’s gradually changing now, however.

Free, non-polluting, renewable energy from the wind was first challenged by diesel pumps decades ago; they were cheaper to install and easier to maintain but had the disadvantage that they needed regular refuelling at a significant cost in dollars and (unless the pump was near the house) time. Then there were mains-powered electric pumps – so long as the bore was close enough to a power-line that running a wire to it was feasible. Now solar power is taking over from all three. It has the advantages of windmills – endless free power, anywhere – and it has quite recently become cost-competitive with all three older technologies.

When relatives built a house on Hervey’s Range thirty-odd years ago the only bore was half a kilometre away and they chose to run a power line through the scrub to an electric pump. It served the house well until cyclone Yasi came along and knocked over a few of the termite-weakened power poles. Replacing the line wasn’t an automatic decision since a new one would be expensive and would still be vulnerable to termites and storms, while the pump itself was old enough that replacing it was on the horizon anyway. The family chose to run the pump from a portable petrol generator – taking it to the pump every time the tanks needed filling – while investigating other possibilities.

In the end, a new overhead power line was going to cost about as much as a whole new solar pump system while an underground power line was prohibitively expensive so solar it was! A complete kit was ordered: panels, mounting frame, pump, and controller. Batteries and inverter? No and no: the pump simply runs when the sun shines and stops when it doesn’t so there’s no need for any storage. (More correctly, there’s no need to store electricity because the water tank above the house stores the pumped water instead.)

Installation was straightforward and was all done by unskilled family members. A couple of us dug a post-hole and cemented a steel pole in place, then returned a week later to remove the old pump, assemble the kit according to the instruction booklet and connect the new pump to the existing pipeline.  It all took less than a day.

solar panels on pole
The completed solar pump set-up
control box under solar panels
The whole of the control gear.

The black box up on the H-frame is the isolator switch and the bigger one on the post is the control box – and that’s all there is. The only other component is the pump, six metres down the bore at the foot of the post.

This is very early days in our experience of the new system but so far, so good. It pumps for four or more hours per day and when the panels are getting full sun it pumps enough water to run four sprinklers up at the house. It costs nothing to leave it running so that’s what we’ve been doing, making up for a long spell when the garden got less water than it needed.

This installation is only one small example, of course, but it points to two larger trends – one positive, one a little sad. The good one is that solar power is now a genuine alternative to fossil fuels in yet another application. The sadder one is  that all over inland Queensland, windmills are going the way of the blacksmith’s forge.

Sustainable Christmas

Best wishes to all my readers for Christmas and the coming year. May your Christmas be happy and may the coming year bring a global shift towards peace and sustainability.

tree with solar panels nearby
Townsville City Council’s solar-powered Christmas tree in Flinders St Mall

This municipal Christmas tree is lit at night by energy from the pair of solar panels beside it. It’s a small step, to be sure, but if we take enough small steps we can travel a long way.

Green Path has been updated less regularly in the last few weeks than I would like and that may not improve for a little while as we enjoy family and friends’ company over Christmas. However, we should be back to normal (which I think of as updating two or three times per week) soon after that.

Solar powered family car

The Dutch solar car (photo from Clean Technica)
The Dutch solar car (photo from Clean Technica)

This is really just a footnote to my previous post but it’s too good not to share: a Dutch team has built a family-sized, street-legal car which runs completely on solar power and (even in Holland!) can be expected to produce twice as much energy as it needs for normal use and then (bonus!) feed the excess back into the grid when parked at home.

Here is a short BBC report – http://www.bbc.co.uk/news/world-europe-23339794Clean Technica has run two reports on it as well – this one with a follow-up video here.

Renewable energy in Europe

My holiday in Europe is beginning to fade from memory but there are still one or two subjects relevant to the concerns of Green Path that I would like to discuss. One of them is the visibility of renewable energy production. Rather than follow our itinerary I will work from North to South, so I begin in Scotland.

Wind power in Scotland: a view of Ardrossan from the Arran ferry
Wind power in Scotland: a view of Ardrossan from the Arran ferry

The most visible of the renewable energy sources was wind power. As we drove from Ayr to Edinburgh (clear across the width of Scotland but only a couple of hours in the car), a row of windmills was often in view on a hilltop or ridge; sometimes half a dozen of them, sometimes bigger groups as in the photo above. I noticed one rural enterprise (a piggery or chicken farm, perhaps – one huge shed, anyway) had gone it alone, with a two-bladed windmill rather smaller than the commercial units.

house with solar panels
Solar power at Doonfoot, just South of Glasgow

Solar power was obviously not so popular – and for really obvious reasons when you think about variability of day length this far from the equator and then factor in the reputation of Scottish weather. The example above is one of only two or three I saw in a town of several thousand houses.

Generator house
Older renewables – hydro power at Loch Lomond

Hydro-electric power is still in use and we saw two installations – this one feeding into Loch Lomond (1940s) and another at Loch Doon (1930s).

We didn’t spend any time in Holland but wind power was part of the scenery as we flew into and out of Schiphol on our way from Frankfurt to Glasgow.

Wind power in Holland: a neat row of windmills along the canal as far as possible from the neat rows of farmhouses
Wind power in Holland: a neat row of windmills along the canal, as far as possible from the neat rows of farmhouses

A constant complaint about wind power here in Australia is that the windmills “intrude on the landscape” or words to that effect, but after a week or so in Scotland I’m ready to say that’s nonsense: once the first strangeness wore off, they were no more intrusive than buildings or a row of pylons, and they are actually rather graceful.

Germany has invested more in renewable energy than most countries but it wasn’t at all obvious to us in Frankfurt or Heidelberg or on a side trip to a wine-growing region on the Rhine. Local conditions again need to be taken into account, and in Frankfurt we need to consider the nature of the housing stock.

blocks of apartments
Typical residential streetscape in Frankfurt

Most people live in apartment blocks like these, and one consequence is that the amount of roof space per household is one quarter of what it would be in a Australian suburb with its single storey houses. And most people rent their apartments, so they have no reason to invest in a roof-top system, even if they could get permission. Furthermore, Frankfurt is not the best part of Germany for solar power (see map).

Wikipedia’s article on renewable energy in Germany reveals that several technologies are contributing significant amounts of power – as of 2010, wind (about 50 000 GWh) was followed quite closely by biomass, hydro, photovoltaics and bio-waste (about 7 000 GWh). That, to me, is healthy, since (1) we need to take advantage of whatever is most readily available, and (2) a spread of sources will maximise energy security.

Finally, Turkey seems to be in catch-up mode. Again, local solutions will reflect local conditions. Hydro-electric and geothermal power is relatively well developed already, and solar power will be far more attractive than in Scotland but is presently limited; passive solar hot water systems are fairly common but photovoltaic systems are not (see wikipedia again).