Many years ago, I heard it said that Aboriginal people tread lightly when they walk because they perceive the earth as their mother, and to stomp around on her would be disrespectful. That awareness of the earth as mother has been with me ever since. I’m not claiming that I pick my way along like a water bird stalking the shallows, but I do recoil from the attitude that the planet and the creatures on it are ours to take for granted, to exploit and tread all over with indiscriminate abandon. And like many others, I have grown ever more conscious of our desecration of the natural environment, and my personal responsibility to “do the right thing”.
I do my best, within reason, to minimise my carbon footprint. No aircon, no bar fridge or freezer, small shared 4-cylinder car, lawn replaced with waterwise natives and organic vege beds laid with sub-mulch drip irrigation, all vegetable waste composted or dispatched to the worm farm.
OK, “within reason” for me might seem extreme to some. It so happens that I find the sustainable living concept attractive, regardless of any climate change factor. I don’t like waste and excess. I do like picking herbs and vegies from the back garden and cooking - and eating! - my own produce grown according to organic cultivation principles.
I do not seek to present myself as some sort of noble environmentalist making sacrifices for future generations. I am merely exercising a lifestyle choice. It is no sacrifice. And my topic here is not myself, but hard economics - specifically, in the context of installing solar photovoltaic (PV) panels. Here I come to the purpose of this self-spotlighting intro: even for people like me, practising sustainable living as far as is practicable in an urban environment, choices come down to the bottom line at some point.
Last year, I decided to investigate the viability of installing solar PV panels on the roof. With the assistance of the Federal Government’s $8,000 rebate for households with incomes under $100K per annum (for which, sadly, we qualified very easily), I assumed the PV panels would pay for themselves within a few years. It seemed a win-win, environmentally and personally - if we could afford the initial capital outlay, we could look forward to smaller energy bills not far down the track, perhaps even no bills at all! Perhaps Synergy would be paying us (such are the claims that are bandied about by some who have taken the plunge and installed solar panels).
Oh yeah? Do the homework and you’re in for a jolting reality check.
Detailed calculations follow, but to cut to the chase: installing the required minimum of six solar PV panels, it would take just over 21 years to break even! Yes, this is with the $8,000 rebate + cashing in the 21 RECs (Renewable Energy Certificates) you receive when you install six panels.
Here’s the proof of the disappointing pudding, in arithmetical black and white (those who fear indigestion or trust my maths implicitly may safely skip ahead):
Calculations in detail
1.05kW system with 6 x 175W solar PV Panels + large inverter (to allow future addition of up to 10 more panels): $13,660.00 including GST
Minus $8,000.00 government rebate
Minus $924.00 for RECS trade-in (21RECs x $44). Note: The REC rate is variable - it was $44 at the time these calculations were made.
Actual cost: $4,736.00 including GST
Western Australia’s domestic power provider, Synergy, currently charges 13.94c per unit (including GST).
A 1.05KW system of 6 x 175W panels produces estimated average energy of 4.4 units daily. At 13.94c per unit, this represents a saving of 4.4 x 13.94 = 61.33c per day.
Annually, this translates to a saving of $223.83 (that is, 61.33c x 365 days).
Cost of the solar PV panels was $4,736.00. Therefore, breakeven point is 21 years (that is, $4,736.00 divided by $223.83).
OK, the point should be made that there are cheaper solar PV panels and inverters around than those for which we were quoted. I figure you get what you pay for, and with a long-term investment like solar PV panels it makes sense to go for quality.
Even if you chose the cheapest possible options, though, you’d still be looking at about $3,000 installed - and 14 years to break even! This is for bottom-range Chinese solar PV panels, which are less efficient than top quality options and subject to more rapid deterioration over time, and a basic inverter that will not enable the addition of further panels in the future.
We wanted solar PV panels. We really wanted them. We did the calculations once, sat back bemused, and did them again. We emailed our figures through to the guy who’d quoted us. He confirmed that our figures were correct. We scratched our heads, considered this and that future scenario, and came to a regretful conclusion that it was simply not economically sensible to install solar PV panels at this time. Only an environmental idealist with money to spare or someone who hasn’t done their sums properly could logically conclude otherwise!