June 13th, 2019
Owner Builders and Solar Power
Over the last few months, several of my owner builder students have been asking what I know about solar.
Fact is, I actually do know a little, having recently installed a 6.5 kilowatt system at my own home.
6.5 kilowatts is 24 panels and the single inverter which sits nicely on my West North West facing roof.
Owner builders need to consider several things if they are looking to install solar.
Firstly, as an owner builder, you are not legally allowed to do any of the works associated with the installation of your solar system, unless of course you are a licensed electrician with solar accreditation. That should be obvious.
The second thing is deciding what size system will best suit your needs. Thee is some confusion out there generally as to how big a system you can install, with many owner builders thinking that 6.5 kilowatts is the maximum for a single residential property. Fact is you can go bigger but they need to be separate systems.
My son has two systems, that means two inverters and around 48 panel to generate the level of power that he wanted to achieve. He is a licensed electrician and does run a solar installation company, so he did have a slight advantage.
Other factors that should be considered are how and when you use your electricity, what your exposure to sunlight is and what type of roof you have.
How an owner builder will use their electricity is important, particularly because the rebates given these days is far lees than in previous years, so your aim should be to use as much of the electricity that you produce. Retail prices of between 25 to 40 cents per kWh are typical and sales back to the grid will yield you around 16 cents.
If your place is electrically ‘noisy’ through the day, then it makes sense to generate and use as much as you can during daylight hours. We advise our owner builders to run pool pumps, washing machines and dishwasher during peak production times to get the best out of their systems.
The ideal orientation is close to North for these latitudes and the angle of installation can be optimised by matching the latitude so for someone in Cairns they would set the panel pitch at around 17 degrees, 27 degrees for Brisbane and 38 degrees for Melbourne. Owner Builders should check that this is correct, because it may be old thinking and the technology has come so far that it may not still be relevant. That’s the way it was taught to me anyway! (Fraser?).
In any case there are other factors like shade from trees and obstructions that will affect exposure and hence production.
Owner Builders need to be aware that not all panels are equal and that a cheap system may be a nasty system and not provide the same output as a good quality set up.
Of course, the question most often asked is how much will I save?
Well it depends on all the factors I have mentioned above but as a guide, and by my owner experience, the 6.5 kWh system that I have installed has reduced my power bills by around 70%. This is inclusive of a 28% discount I got by changing suppliers at the same time.
So, owner builders need to shop around and get the best deal not only from the installation companies but also through revisiting their retail supplier.
Hope this demystifies solar installation to some extent.
Best Regards and Happy Owner Building
I have a problem with amount you have to outlay to have solar power installed with battery back up. For a system to run a house you could be up to 30k. Also they the panels corrode break down were to they go to be recycled not all parts of panels can be recycled. You don't take them to land fill that is wrong. Batteries need a lot more development if they are like car batteries they only last 3 years. I see a lot of environmental issues surrounding these solar installations.. Low Emission Coal Fire POWER stations for reliable and cheap power also solar does not cut it for manufacturing
Solar is a viable option. However, emerging technology is developing solar batteries which stores energy for 24 hour use. Research is required to understand the best options for each household.
I love my solar.
We are also in a situation where it is considerably cheaper to install solar than connect to mains power.
My advice is to do the maths. When I installed solar I calculated that the payback time for the panels was 4 - 5 years but a battery was 10. From this, I decided to install the panels and hold off on the battery until price allows for a faster payback.
Unfortunately most people don't understand the value of proper orientation of their solar panels. when we were getting 60 cents per kWh (gross metering) an orientation of direct north was great, but now with net metering, a combination of east, north and west is more efficient. Most appliances (washing machine, dryer,A/C unit will draw from 1 to 3 kWh. A 6.5kw system will provide 1 to 3 kw constantly from sunrise to sunset. Running these devices over the course of the day means that the P.V. system will adequately supply them resulting in no cosumption of power from your supplier. Think about your roof design when building.
We have installed solar in our home and the bill is amazing. We are just about to change providers as energy australia plans are terrible, with the new plan we should be in credit. Have considered a battery just seeing how the prices go over the next 6 mths but if the talk of energy companies starting to charge to give back to the grid (because they dont have capacity to store) then a battery is the way to go.
We have just had a 6Kw solar system installed today. The roof faces north. it is replacing a old 2Kw system. I look forward to the savings this coming summer!!
We had off grid solar on the house we lost to the 2019 fires and plan to be off grid again. Technology has moved on from "state of the art" 2000 systems (980w of panel and 1500w inverter output with lead acid 24v batteries) which lasted 19y to 20kw Li batteries and min 5kw inverter output. There have been some hard lessons learnt on the robustness of some components in our environment. We had a series of errors on the inbuilt battery management system which we could not access to resolve because we needed an active internet connection. It has taken the solar installer several months to configure the charge controller and batteries to prevent the battery from shutting down to protect itself. We also changed the battery to a slightly older technology that can handle the extremes of our temperature range (-7 C to +36 C) without need to provide a temp controlled environment.
so is it actually worth it to get a solar system?
good to know about solar. actually I was interested install one with battery pack
Different plans are worth looking into. With a smart meter our off peak rate is available to the whole house and not just hot water. This means we can buy for 18 cents guarantied at night and sell for 21 cents during the day and not need to think about cloudy days.
I have to put on Solar panels to pass the BASIX here in Dubbo. I plan to set it up so all my power items like pool filter, hot water, air conditioner etc are set to run during the charging hours. Also I will wait till the price of battery panels is reduced more in price. If you look, the price of solar panel has plummetted in the last 5 years
I recently installed solar and love it and such a reduced bill.
I like the idea but for me I don't think it has hit its peak and is outdating to fast so for now I'm just selecting higher energy efficient devices
If anyone is looking at installing solar, have a look at a website 'Solar Quotes'. It's managed by Finn Peacock & it's very informative. I've put solar on in NSW and with the help of this website, the decision making became a lot easier.
Again a very interesting read, Rick. Regarding solar panels for rooftops it all depends on how much electricity you are using to whether or not the investment is worth it or not. Again I personally encourage anyone to install rooftop solar panels if they can. It is a great way to lower carbon emissions and go off the grid if you can.
I'm wondering about battery packs. As far as I know we are not yet able to store solar energy ourselves. Will this change in the near future? We have solar on our Airbnb as the building is old and has restrictions on how much insulation can be installed. Begin an air bib we had to make sure it was well climate controlled so we opted for split systems and solar panels. So far so good. Bills are extremely cheap for what we are using. Its fantastic. We are yet to put solar on ours. Have to keep save our $$ to do it. Feels so good to be something helpful environmentally too.
Great read. I am putting a solar system and battery into our new property.Any recommendation of brand
Interesting read. I've been looking into it and the biggest issue is the export limitation by the grid. On single phase, that's near the 6.5kw system you had installed. But if you upgrade to 3 phase, then you can generally export a minimum of 15 kw, with some providers letting you export more.
Good to know
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Rick Heaton is a Building and Construction Industry professional with formal tertiary qualifications in management and training.