Going Solar: Malcolm

As I said at the end of June, I think real-life examples may help to sort out the truth about domestic solar power from the hype. Here is the second of two recent Townsville installation stories. My own solar installation was not as straightforward as David’s but that may make it more useful for some readers. 

We have lived in an older high-set weatherboard house (about 1950, a product of the post-war building boom) for nearly twenty years. When we decided to install a photo-voltaic (PV) system, we had to deal with a main switchboard as old as the house, mature trees surrounding and shading the house, and the need to work around our existing solar hot water system.

Malcolm's house from the South-East
Mature trees: The house from the South-east, with Poincianas on the footpath in front of an even taller Poplar Gum just inside our fence and an under-storey of Frangipanis (leafless in winter). The Macadamia and Paperbark (the tallest tree on the left of the picture) on our southern fence and the Mango in the the back corner of the block are not so visible but should not be forgotten.

Every PV system installer who quoted for us told us that we would have to replace our switchboard. We were neither surprised nor particularly disappointed but it did encourage us to choose a company which has always done general electrical work and has recently added solar installations to its business, rather than a PV-only company, since we figured we could be sure the switchboard and solar system would be done together and work together. Since we were upgrading the switchboard anyway, we switched our solar HWS booster and the pool pump to tariff 33 (off-peak) to save ourselves quite a bit off our electricity bill quite apart from our solar savings (and yes, I know we probably should have done it years ago). The cost for all that work was $2000.

We opted for a 1.5 kW panel array, the usual entry-level configuration, but a 3 kW inverter so that we could add panels later without needing to upgrade anything else. The cost for the system was $3500 – not quite the cheapest quote, but all three were within a couple of hundred dollars of each other (and of David’s cost). The house faces East so our North-facing roof is relatively small to start with and (reasonably enough) our solar HWS panels and tank were right in the middle of it. The PV panels therefore had to face East or West, since South is the worst possible direction. East gets the most shade, so West it was. Installers’ estimates of the reduction in output as compared to a Northern aspect were in the 7 – 10% range, nothing we couldn’t live with.

Installation, in mid May, was not as smooth as we would have liked. The switchboard was no problem at all but the solar team were in the middle of the rush to get systems in before the federal government rebate dropped and made a couple of significant mistakes, installing the wrong inverter and installing the panels too low on the roof. To their credit, they fixed them willingly enough, but it took a while.

The percentage of generated power which we didn’t need should have been feeding into the grid and earning us money right from the day of installation, but Ergon also were swamped by the rush of people installing systems before the incentives dropped. An essential piece of paper went astray, and after it was found there was still a backlog of installation work, so that in the end there was a delay of exactly three months between installation and hook-up. It was irritating and disappointing but it doesn’t matter much in the long run: we can have lost no more than $100, which is negligible over even the first five years.

Our latest quarterly account (May – July) has been affected by far too many changes to give us a clear indication of the benefits of the PV system but we do know we have saved about $50 by putting the pool pump on the off-peak tariff. (We haven’t even used the HWS booster so there are no savings yet from that change – hot water can’t be any cheaper than free! – but we will get the benefit during the Wet season.)

Since the system was properly completed we have been getting a daily output of almost exactly 6 kWh. Taking seasonal factors (see my first comment to David’s story) into account, that happens to be roughly what we expect our long-term average to be. If it all went in to the grid at 44c / kWh it would earn us $2.60 per day; if we used all of it, it would save us $1.25 per day by replacing Tariff 11 power at 20.7c / kWh. Our net benefit is therefore somewhere around $2 per day, or $180 per quarter.

All in all, making the best guesses I can for the unknowns, pay-back time for the whole project (PV system and switchboard) looks like being in the 5 – 8 year range. That’s perfectly acceptable in itself and, like David, we are pleased with the value it has added to the house. Of course, if the electricity tariff rises (hands up everyone who thinks it is going to fall? No, my hand didn’t go up either), pay-back time will drop accordingly.

(A slightly different version of this post was published in Reef HQ Volunteers Association newsletter, Waves, for September 2011.)

Going solar: Ravenswood and elsewhere

My wife has recently returned from a holiday in Europe (Germany, France, and northern Italy) and says that solar panels are all over the place there. She found the sight of centuries-old farm sheds with panels gleaming on their roofs quite amusing, and also noted that people were ‘not just putting up a few panels, as we do, but covering the whole roof.’ All good to hear.

While she was over there, I visited Ravenswood, which is quite a contrast. They do have solar power in common, though. Here’s a house in town, an older place (note the single-skin weatherboard construction) in a well kept garden:

House in Ravenswood with solar panels on roof
Old and new: the house is probably a century old.

Meanwhile, back here in Townsville, I’m still waiting on our first electricity bill since installation of our own system. When I get that, I will write up our experiences as a companion piece to David’s story.

Going Solar: David

There has been a lot of talk about domestic solar power systems in the last year or so but most of it seems to be coming from governments, suppliers and others who may have vested interests, so it’s understandable that we listen to it with a degree of scepticism.

I thought a real-life example or two may help to sort out the truth from the hype.   Sometime soon I’ll post my own story, of the installation on our own older high-set house in Mundingburra. Meanwhile, here are the experiences of David and Kate, a young professional couple living in a small modern house in the new suburb of Douglas. In David’s words (and with my thanks to him for allowing me to quote him):

Our 1.52 kW solar power system was installed by a specialist PV company in March 2011 and the entire process has been extremely smooth. The installation was performed amazingly quickly, with about six staff working together to place the panels on the roof, provide conduit from the panels to the solar inverter through our roof, and rewire our switchboard. The whole process took only a few hours to have everything in place and signed off.

After the installation, on an average sunny day, we would see generation of at least 7 kWh, even reaching 8.5 kWh on our best day. Through this, we were seeing our power usage at home more than negated, with our meter steadily going backwards. That said, we’re not a typical situation since we only have two of us at in the house, we work 9 to 5 on weekdays, have a two-storey, north-facing house with a perfectly angled roof and no trees nearby, and are extremely power efficient around the home with LED halogen-replacement lights and gas appliances in use.

After the installation, we applied to Ergon Energy for a new electricity meter so we could get the bonus feed-in tariff. Unfortunately, this process took nearly two months of waiting – but given the recent cyclone and number of people purchasing solar panel systems, that was understandable. In late May 2011, our new meter was installed and we’ve been able to watch how much we’re saving off our power bill. Because we use so little power during typical days, most of our generated power goes into the grid at 44 cents / kWh, and we’re therefore making a fair amount of money.

As a rough indication, our new meter has been in place for just over a month, we’ve pushed around 140 kWh into the grid at 44 c/kWh and we’ve only used 108 kWh at 22 c/kWh, giving us a credit of about $38 so far. This works out at around $2 per day in credit, after paying for power usage. So, since our previous year’s power bills were approximately $700, we should be looking at a net benefit of over $1200 per year (and that’s taking into account air conditioning during summer days). Our system cost was $3300, so it’ll pay for itself in no time, not to mention the value it has added to the house.

We’ve changed our lifestyle a little with the solar as we try to do washing, dishwashing and similar powered activities when the sun isn’t shining – either early in the morning or in the evening – to avoid using our solar power and losing out on the bonus. Aside from that, we just keep being electricity conscious and turning off everything we can when it’s not in use.

We’re still waiting to receive our first power bill after the new meter was installed but our previous bill (i.e. after the panels were installed but before we started getting the feed-in bonus) saw our power bill halved just by having the solar panels installed for a third of the billing period.

Kate and I are very thorough with planning so we made sure we knew what we were getting, and we made sure to have the panels in the right place, etc, etc. Aside from the slow Ergon hook-up, we’ve had no problems at all. Anything we didn’t expect? We didn’t really expect we would be saving so much!