Joining 2 million other Australians with a 6.5kW solar install

    This week, I joined the more than 2 million Australians and added solar to my home. Personally I went with a 6.5kW solar system, which is right sized for our household power needs today, and into the future.

    Our solar system includes:

    • 20 x SunPower 325W P-series All Black Mono Crystalline modules (SPR-P19-325) with 25 year product warranty and 25 year lineal performance guarantee
    • 1 x SolarEdge HD Wave 5kW solar inverter (SE5000H)
    • 20 x SolarEdge P370 DC Optimisers with: 12 year product warranty on inverter + 25 year product warranty on DC optimisers
    • Optional “Black Pack” – All associated mounting hardware and isolator shrouds to be supplied in a black finish for added aesthetic appeal.

    For those who haven’t yet been through the process, there’s plenty of things I’ve learnt along the way that could benefit others. You can get started by reading my background post on how I chose the right system and the costs associated with getting solar installed.


    Wednesday last week I received a phone call from Kdec to ask if Friday would suit as an installation date. I confirmed it did and we were locked in. Around 7.30am the expected knock at the door arrived and the safety scaffolding company began work to keep the installers safe while on our roof.

    There was really 10 elements to the installation process, they are:

    1. Install mounting hardware (solar rails etc)
    2. Install 20x DC Optimisers on back of panels
    3. Install of the 20x Solar Panels
    4. Install Solar Isolators
    5. Run cabling from panels to inverter
    6. Install Inverter in the garage
    7. Install Inverter breaker in the switchboard.
    8. Testing
    9. Handover

    This is definitely not just a case of whacking some panels on the roof and calling it a day. This process is like performing brain surgery on your electricity connection to the grid.

    Adding solar means the electricity provider needs the capability of turning off your solar production to the grid, in the event there is work being done on the lines as this could be dangerous for maintenance personnel.

    In the planning stages of our solar system, Kdec had calculated the optimal panel distribution on our roof, which meant 12 of our panels run along the sunny side of our property, with the remaining 8 positioned on the rear of our house. This split layout, combined with our orientation, will extend the hours per day that our solar system is capturing energy.

    By the early afternoon, the installation was complete. I headed outside for a chance to see the panels on our roof for the first time. I have to say, I was seriously impressed at the visual appearance of the panels. While aesthetics certainly don’t matter as much as their performance, we spent up for a nice façade on our home, so I try really hard now to avoid things that would detract from that.

    The optional black pack, combined with the SunPower 325W P-series All Black panels is a killer combination, especially against our dark Colorbond roof. I’m happy that our panels compliment our home, rather than stand out like most cheaper, blue panels with steel surrounds.

    When it comes to the inverter install, I decided I wanted to have it inside to protect it from the weather, and the wall right next to the Tesla Model 3, seemed like the perfect position.

    Massive props to Alex from Kdec, his install of the SolarEdge 5kW solar inverter (SE5000H) is extremely clean and judging from photos of others online, one of the best in the business. This is something I will see as I pull into the garage, each and every day and now serves as a great little reminder that we have solar and as I walk inside our home and start using power, it’s coming from the best place possible, the sun.

    Selecting a Solar plan

    When you’re just a consumer of energy, signing up for an electricity plan is fairly straightforward, but when you move to become a solar generator as well, things get complicated.

    Selecting the best electricity plan is no longer a task of finding the best rate across energy retailers, instead, you have to do some calculations. If you’re like me, you can bust out Excel and get to work, or if you’re after something easier, then you should head to Solar Quotes where they have an Electricity Retailer Comparison (currently in beta).

    It’s important to check that the rate you pay to use power and the daily service charge is as low as possible, and the amount you get paid to supply energy to the grid, is as high as possible.

    Here’s the gotcha, there is no golden plan that has the best of all 3 of those parameters. Essentially you end up paying a higher rate to use power when you get solar, something that took me a while to wrap my head around. The key here is to focus on the end game, that final bill.

    For those of us who live in locations that get plenty of sunny days per year and sunny hours per day, then chasing the highest FIT will almost always overcome any small growth in usage charges of service charges.

    The Feed-in-Tariff (FiT) is also not straightforward, it can be if you’re willing to accept an OK plan, but if you’re chasing the best, then you need to run the numbers. The FiT comes in two varieties.

    The first option is to go with a flat rate, usually around 0.12c per kWh, but some providers have this as high as 0.20c per kWh (which annoyingly isn’t available in all locations).

    The second option is Time of Use FiT which features different rates for peak, shoulder and off-peak times. This means calculating how many hours are contained in each of those windows and how much power you’re likely to consume during those windows of time.

    Most electricity bills now feature your average daily usage in kWh, as well as your average daily cost. That information is pretty handy, until you have to break it down per hour, which is a lot harder to account for. Also remember you’re power needs are likely to change over time. Get a new dishwasher, add a TV, new computer, etc, it all adds up, especially if that addition is another human.

    Our solar provider was KDec Electrical and Solar (tell them Jason from techAU sent you), who provided us with a performance estimate for the new system. I expect the real-world number to vary a bit given there are so many variables to consider, like the number of sunny days, energy price rises and the feed-in tariff you select.

    The estimated generation varies a lot based on the month of the year. The maximum expected production is in the month of January and is expected to be around 40kWh. Contrast this with the minimum expected generation in Jun, with around 10.5kW.

    Given this variance, I chose to average across the year in my calculations, understanding the regular 92-day bill cycle will vary from these numbers. An average of 24.45kWh per day throughout the year is a great benchmark to start running some calculations.

    Let me break down the structure of my Spreadsheet.

    1. Current usage (Used previous bills to enter this info)
    2. Estimated Generation (Based on installer’s predictions)
    3. Feed in Tarrifs (Enter details of potential energy plans)

    To calculate your resulting financial position (also known as your bill), we’ll need to look at the following:

    • Total Energy consumed per day x Daily Rate
    • Total Energy produced per day x Feed in Tariff
    • Total supply charge per day

    This set of data will allow you to calculate the daily, monthly, quarterly and annual cost of what your bill will drop to or the income you’ll make from sending back more power than you consume.

    From here you should have a fairly straightforward runway to generate a return on investment for your solar purchase. To get at this number, simply calculate what you would have spent on power in a given year, to the new predicted number. Divide this number by the price you paid for your solar system and you’ll see how many years it’ll take you to start making a net profit.

    Personally, the payback period is expected to be around 3 years, but you don’t have to wait 3 years to start making savings. From your first bill after adding solar, you should see a substantial reduction in your energy costs.

    I worked out this will be the first time I’ve changed power providers outside a property move, for many others, this is also likely the case. I’m keen to avoid any outages when the changeover happens if I do move from my current provider, Energy Australia.

    I called them to confirm and they inform me that the solar installer submits the paperwork to them. After being reviewed, I’ll receive a text message inviting me to choose a new electricity plan. At this point, I’ll have to make the decision to stay or leave the current provider.

    Part of that review process involves the upstream electricity wholesaler who needs to confirm the grid (transformers in the area) are capable of receiving the power from you. Most of the time, I expect the answer to be yes, but there is a scenario where the number of houses with solar in a specific neighbourhood, outpace the infrastructure required to enable power to flow in the opposite direction.

    Our SolarEdge inverter is up and running and the panels are collecting power, which for the next week or so (until we change plans) is flowing back to our power company and we’re making $0. There’s really no way around this, the process which involves at least 3 businesses, the installer, the wholesaler and the retailer, talking to each other before activation.

    Monitoring solar with a mobile app

    Before the installation, I knew our inverter had no external display, it doesn’t need one, as you connect to it via your smartphone. What I didn’t know is that your installer configures the account and adds permission for you to use it.

    This feels a little weird, given you bought the inverter, you’d think you’re account number 1 and give access to them, but it doesn’t work that way. The benefit of your installer having access is that they can monitor the system for any faults and will often alert you before you even notice.

    Our installer showed me the details on his phone, demonstrating that our panels were collecting energy which is great. Not it’s just a matter of waiting for an email to activate my account and signing into the mobile app. With our system, we’ll be able to see the production of each panel, which if you’re a data nerd, is like heaven.

    The final calculations

    You know that saying, you have to spend money to make money.. well solar may be the best example of that.

    If everything goes well, we could be looking at a 90%+ reduction in our electricity costs. Given we chose premium panels, they have a 25-year guarantee, which could leave us more than $60k better off over the life of the panels. When you take all that into consideration, investing in solar looks like one of the best investments a homeowner could make.

    I’ll be posting in the future about monitoring the panels through the mobile app, as well as more details on real-world production versus predictions.

    Jason Cartwright
    Jason Cartwright
    Creator of techAU, Jason has spent the dozen+ years covering technology in Australia and around the world. Bringing a background in multimedia and passion for technology to the job, Cartwright delivers detailed product reviews, event coverage and industry news on a daily basis. Disclaimer: Tesla Shareholder from 20/01/2021

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