Rooftop Solar Part 1 – where do I begin? (off-grid guide)

04/12/2024
By Ray Shaw
In Featured Guides

Rooftop Solar Part 1 is the first of a four-part series about the journey to installing rooftop solar. We will cover when you need solar, what solar you need, and whether the promise lives up to the marketing hype.

Some 3+ million Australian homes now have rooftop solar, mainly because energy costs are skyrocketing and the push to renewable energy is straining the electricity grid.

Never before has Australia faced the possibility of total power loss, power rationing, and unexpected blackouts. We are not going down the renewable versus coal/gas versus nuclear baseload argument but looking at what Joe and Jane Average can do to ensure continuous supply.

Rooftop Solar Part 1 is a 4-part series that will explore everything from the decision to go solar to a few months after, where we assess whether the economic and supply benefits outweigh the initial capital cost. It follows my journey and friends who have opted for rooftop solar, with and without batteries.

My journey started in 2019

It started when South Australian-based Embertech asked me to review its Emberpulse energy monitoring system. This system comprises a visible Emberpulse alert light that goes from green to orange to tell you immediately if you are using more energy. For the first few months, we frantically switched things off when it was angry orange but gradually learned to schedule stuff like the dryer or dishwasher during off-peak power. It made us energy aware.

There is also a handy EmberIq Smart Plug that can measure individual appliance energy use. This was instrumental in the decision to replace a 2-star fridge with a 4.5-star and 60 x 50W halogen downlights (3000W) with 60 x 5W (300W). Those two changes alone saved hundreds of dollars a year.

Behind the scenes, it is a cloud-based Pulse Analytics system that has most Australian energy plans and records your energy use. It then generates reports that help you determine whether you would benefit from solar panels and, optionally, a battery.

Since its installation in 2019, all that data has graphically shown how much energy is used each day/week/month/year, peak and average loads, and, importantly, baseload (how much you use with most things turned off), average load, and peak load (how much you need to power the home with most things on).

This year, our average consumption was 742.9 watts per hour, with the peak load at 5,595 watts (during summer, we had a ducted air conditioning unit). Significantly, our consumption grew from an average of 490.8 watts per hour in 2019.

If you want to read my Emberpulse 2019 journey, it is over at GadgetGuy’s site.

Data is power

I had Emberpulse to guide me, and in 2022, at the height of Covid and working from home, it indicated rooftop solar was the best option.

Most people only have the quarterly electricity bill, which should show how many kWh (kilowatt hours or 1000 watts for an hour) you use and compare it to the same period last year. That is not the whole story because that power is charged at (these are at 12/24 and expected dramatically rise in 2025)

Peak (Approx. 60 cents per kWh)
Shoulder (Approx. 35 cents per kWh)
Off Peak (Approx 30 cents per kWh)
Daily Supply Charge (around $1-$1.20 per day)

In 2019, power was 25 cents for peak, and daily supply was 75 cents. A typical summer quarter costs $400, now $800.

The big lure – Go solar and get feed-in payments

From 2019-2023, the lure was that rooftop solar could pay for itself in a few years from the generous energy feed-in tariffs of 10-20 cents per kWh exported to the power grid. A cheap 5kW solar system cost around $5000, and online calculators showed payback in 5-7 years. Batteries were expensive and, on a feed-in tariff basis, had far longer payback periods – often more than the battery’s lifespan.

Well, we now have over 3 million homes with rooftop solar, and the feed-in tariff is about 0-5 cents, with many capping feed-in to 3.5-5kWh per day. Most states are looking at remotely switching off feed-in when the grid does not need it, reducing feed-in income to a trickle. Conversely, this makes a battery more desirable.

The rationale for rooftop solar has moved from how many dollars you can save to how much energy you can create and intelligently use to power the home, EV, pool pump and maximise ROI. This is even more critical for all-electric homes that need guaranteed, constant supply.

OK, I want rooftop solar – enter the Cowboys

Like most people, I was drawn in by the sports or celebrity-backed solar panel installers with giant TV advertising budgets and incentives to order today. Unlike most people, I wanted to know more about the technology before committing. The answer from most companies is a condescending paraphrase: “You want the truth. You can’t handle the truth.”