It’s been just under three months since the team from BREC Energy installed 13 solar panels on my roof, and I’m now the proud owner of a 5.33 kW rooftop solar system!
This system is capable of generating up to 22 kWh of power in an average day, which is almost double our household electricity needs — amazing! In real terms though, based on our actual energy use patterns, the system should account for about 36 per cent of our total energy consumption, with 64 per cent still required to be purchased from the grid (because like most households, we still use a lot of energy at times when the sun is not shining).
So, did these predictions hold up? Have I saved any money at all on my power bills? And what else have I learnt since making the big investment on rooftop solar?
Here are my honest thoughts and key takeaways from this whole experience!
How much solar are we generating and actually using?
I was amazed to find just how accurate the solar provider’s calculators were about our energy use, and predicted solar consumption.
Over the past three months, our solar energy has accounted for an average of about 30 per cent of our total household energy consumption. Also, on a month by month basis, our solar use has steadily increased each month, from 26 per cent of our overall energy in July, to an impressive 41 per cent in September.
Why? Well, I’d like to think its partially because we’ve learnt to adjust some of our energy use and make the most use of our electric appliances when the sun is shining… but, really this increase is mostly because we’ve had more sun in September! As the summer months roll on, we’ll likely see the percentage increase again, before decreasing in the winter months.
What has this meant for our electricity bills?
This is a tricky one. To be honest, we haven’t seen a significant decrease in our energy bills. When comparing June – September 2022 with June – September 2023, our energy bill is pretty much the same (around $300 for the quarter). But, how can this be, since we’ve reduced our energy consumption from the grid by at least 30 per cent?
The simple reason is, energy prices across Australia have increased significantly over the past year.
Our average daily energy use is down from 10kWh/day to around 7kWh/day, but we’re still paying an average of $3.25/day for electricity, compared to $3.27/day for the same period last year! So we’re paying roughly the same amount each month, for 30 per cent less energy.
The only positive we can take away from this, is that we would be paying 30 per cent more this year for electricity if we hadn’t installed solar due to price rises. I’m calling that a win!
How has having solar impacted our energy use at home?
One of the coolest things about installing solar has been getting access to real-time monitoring of our solar system via an app called My Solar Edge. This app came included in my solar-set up costs. It’s so interesting (and fun!) to open the app at any time and see exactly how much solar is being generated on my rooftop, how much of it we’re using, and how much of it goes un-used (and sent back to the grid).
One excellent outcome of this is that we are much more aware of our household energy consumption now. It was previously invisible and is now something we take an active interest in.
Electricity no longer feels ‘infinite’, and that’s a good thing! I already have a clear sense of exactly how much energy our household needs, and how much we’re capable of generating at home. It’s really helped to shift my perspective on our energy use more broadly. The app is so simple to use and it has also become a great tool to teach my seven-year old daughter about energy use and renewables.
What do we save/earn by selling power back to the grid?
You’ve probably heard the term ‘feed-in tariff’ — this is the credit you receive back from your energy provider, for any unused electricity you send back to the grid from your solar system. Also known as a ‘buy-back rate’, it’s usually a set rate per kilowatt hour (kWh) that you receive as credit on your electricity bills.
The problem is, energy prices vary greatly based on-peak and off-peak timing, and since every solar system in Melbourne is making large amounts of excess energy at exactly the same time (i.e. when the sun is shining), the grid is flushed with excess solar power at these times. It means you’re pretty much guaranteed to get very low ‘buy back’ prices for any energy you send back to the grid on a sunny day!
Unfortunately, these feed-in tariffs are so low the credits we earn by feeding energy back into the grid are pretty negligible. It makes a strong case for investing in a battery, which brings me to my final point…
What do we think about installing a battery, now that we know what we know?
The idea of a battery definitely seems more appealing now that we can see how much energy we are generating every day that we’re just not able to use. It feels as if we’re ‘wasting’ around 70 per cent of everything we’re generating (although that isn’t strictly true, since it is going back into the grid, which means someone, somewhere will be using it!).
According to our solar provider’s calculations, if we did have a battery our rooftop solar would cover more than 90 per cent of our household electricity use! That would be pretty amazing.
Right now, the investment in a battery is still too great for us to seriously consider it — we’d be looking at over $10k to do this.
However, having become more aware of my energy use, the appeal of a battery for our household has become more ‘holistic’ and less about pure financial payback. After all, the benefit of installing a battery isn’t just saving money, there is a strong incentive around just being a more energy efficient household, and reducing our reliance on fossil-fuels and the grid. So we still may consider it in the future!
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