The flaw? Sorry we need to do more maths
So, you have 10kW (10,000kWh) per year production capability, and you are using around 2,000kWh (5kW x 365 days) leaving 8,000kWh to feedback to the grid.
A smart meter feeds excess power generated from your solar panels back into the grid. The greedy energy retailers only pay FiT (feed-in-tariff) of about 11-12 cents per kWh so at best that 8,000kWh excess could yield around $1,000.
Solar is a no-brainer if:
- You correctly match the system size to your maximum daily use
- You get maximum efficiency from it, e.g. it is not a poorly installed cheapie!
- And you are using lots of power during the day – payback time can reduce if you run air-conditioning or charge your Tesla.
- Solar makes no difference at night unless you have a battery to store that excess capacity
But you get the drift – match the solar system size to expected daily use, do not oversize it unless you plan on increasing energy usage over time or getting battery storage, and do not expect much FiT income. In other words, you are paying the capital cost of becoming a mini-generator for your needs, and you will eventually get that back.
Rule One – the only rule – data is king and will tell you when is it time to go solar .
Our Emberpulse meter (about $500 installed) is the simplest way to help you get the right size solar system as it gives accurate hourly usage and cost data. And when you get a solar system, it will tell you if it is performing as it should – more on that later.
Why are solar salespeople talking about shorter payback times and saying you can get a solar system worth $10K for $5K?
They are factoring in a 5% year-on-year compound increase in power costs over 25 years. So, what costs $1 today will cost $3.50 in 25 years. That 3.5X factor is one explanation on why they can claim faster paybacks, but in reality, without the power data from your home, they don’t know with proper accuracy what the payback is.
But with governments trying to reduce artificially high energy costs (they are about three times what they should be) and new homes being more energy-efficient, that 3.5X argument is very thin.
It is a colossal mistake to theorise before you have accurate data specific to you. Hint – get an Emberpulse meter before you consider solar and definitely before you consider a battery. More on this later.
On the second point, Australia has a solar rebate scheme where STCs (Small-scale technology certificates) apply for installing a solar system. Depending on how large your system is, and where you live, the number of STCs you are eligible for varies (you can calculate that here), and therefore the amount of your rebate varies. Solar panel installers can turn STC’s back into money – you cannot.
See below how the industry is propped up by government incentives. It is probably cheaper than building more power stations. And note the real cost of a 5kW system (admittedly in 2012 and in US$)
The STC scheme is phasing out progressively by 2030. So, if you are going solar, do it sooner rather than later.
What are the issues with solar?
Recently news.com.au stated one of the big problems with the solar scheme is that despite guidelines and accreditation, dodgy panels are coming in from overseas disguised as approved products, leading to potential fires and electrocution risks. Its estimate is 25% of systems have serious faults. Kind of reminds you of KRudd’s pink batts insulation scheme all over again.
Build.com.au states that the lack of clarity in requirements for solar installations makes it difficult to judge how serious the NSW inspection results are (20% of installations were deemed dangerous, and 60% had less serious deficiencies).
I think news.com.au is exaggerating, but all too often shoddy installers con bargain-chasing householders over the panel or inverter quality/efficiency and installation can be sloppy. The biggest issues are:
- Shoddy so-called Tier 1 panels from companies that will not be around to honour generous warranties
- Penetration of the roof can cause leaks in the ceiling.
- Use of the wrong types of cables for run lengths.
- The wrong sized inverter for the installation.
- Poor placement/angle reducing power efficiency even more. Unless you have a perfect north-facing roof, you will not achieve maximum energy generation. I have never seen a shonky installer tell you that. Ideal panel mount is North Facing (0° Azimuth and 20° from horizontal).
- Bargain hunters thinking that all systems are the same – the cheapest is not the best, and you need to take a long-term view.
I would really like the Government to provide independent certifiers to check installations and withhold STCs until the job is perfect.
If you have a spare 10-minutes, the video below shows the horrors of cheap so-called Tier 1 panels where warranties are useless as the installers or the panel’s manufacturer or both have gone out of business.
Not wanting to push Emberpulse meters but ask the installer if they are Emberpulse accredited and if so, you can count on a fair deal and good quality.
Solar panels lose efficiency over time
I have seen some dodgy 250-300W, 60/120 cell, P-type, Poly, PERC, Shingled and Multi-busbar panels claiming to be ‘Tier 1’ (there is no such grading – it is marketing hype). These have low power generation efficiency (<20%) and worse, less than 50% of that efficiency, (e.g. 10%) after just a few years.