Last year we bought a house in Perth - one with 6 solar panels on the roof and a German brand of inverter. It was quite exciting for me as I had never owned a house with solar panels before. Being a bit of a 'Greenie' I felt like I was doing something positive for the environment. And when you live in one of the sunniest places on earth, it just seems like the right thing to do. However, it turns out my electricity bills were pretty ugly, and I was getting next to nothing for selling energy back to the grid. So began my journey... or should we say my 'Solar Sojourn'.
With the help of Google I chose two well-reviewed companies and received quotes from both. The pricing and product offering was very similar from both and in the end I went with gut-feel to make my choice.
Here are some things I have learnt so far:
Lifespan: While there are loads of good options for photo-voltaic solar panels, the key price differentiator is lifespan. The cost of a system guaranteed for 12 or 15 years is significantly more expensive than a system guaranteed for 25 years. I ended up choosing the more expensive option since I plan on keeping this property long term, and I like to think long term in general. Plus the fact that old panels end up in landfill made me want to extend the life of the panels as much as possible.
Orientation: Most people default to north facing panel arrays in the southern hemisphere, which makes sense, but (depending on the angles of your rooftop) you can also choose to mount them facing north-east or north-west. Since the sun rises in the east you can choose east-facing if you need more power generation in the mornings, or west-facing if you use more power in the afternoons. This was an easy decision for me - I would like to freely run my air conditioners on hot summer afternoons! Ideally we would also run our dishwashers and washing machines in the afternoons too, but this would require a bit of an adjustment
Batteries: Adding a battery to store power more than doubles the cost. All the articles I have read suggest waiting 2 to 6 years as battery technology is evolving rapidly at the moment - unless of course you live in a place with an unreliable grid! I think batteries will play an important role in distributed power storage in the future, and I plan to write more blogs about this (bet you can't wait!)
Sizing: I opted for 6.6kW of panels with a 5kW inverter. This should be more than sufficient for our household needs - even if we are all driving Electric Vehicles in 5-10 years time. My teenage kids will also have left home by then too (?) so our household power needs should be less. Apparently it is difficult to add on extra panels, so generally it is suggested that you max out your roof space with panels to future proof your system, but there are some practical limits here.
Cost: I ended up choosing a 6.6Kw REC PV panel system for around $5k after govt rebate of $3.3k. The payback period is expected to be around 3-4 years as my savings predictions are $1.5k per year.
I am currently eagerly awaiting the installation and will blog again to share my installation experience and learnings!
Until next time!
Doug
aka The Regeneralist
Our house came with a small 1kW system and I love tracking how much we generate and compare to what we draw from the grid. The inverter came without the wifi connector, so I added it and can now track it on an app. I also installed a system to track the mains meter, so can track everything on my phone. I think this connectivity is something also worth considering (maybe too late now), so you're not blind to your energy consumption and can get a feel for what your appliances are using & when.