Planning a renovation, or new build? Wondering about how best to integrate solar?
Read on my friend, and we will try to help. As always, if you get stuck, contact us.
What size should I choose?
Here is what you need to know about system size: as your solar system gets bigger, every additional panel gets cheaper. The $/kW price drops by roughly 10-15% for each extra kW as you go from (say) 2-10 kW.
But a bigger solar system means more energy being exported to the grid, for which you are paid a “feed in tariff”. Feed in tariffs are usually (much) lower than the price you pay for electricity from the grid. So, a bigger system is proportionally cheaper, but the value of the energy you generate might be lower. So what's the right size for you? Try our calculator and find out which system matches you needs.
How to design your system?
Whether north, east, west, flat or pitched, just about any roof can handle some amount of solar.
The main thing to consider with your roof is will it be free from obstruction? Skylights, complicated roof lines, chimneys, or even an evaporative air-conditioner unit could end up being the difference between a neat and clean solar system design, and a convoluted one.
Before you say “yes” to a design, here is what you need to know:
Solar panels produce up to four times as much energy in summer, as winter. You want your panels in clear summer sun. However, a bit of winter shading is not the end of the world.
East-west panels typically produce 10-15% less energy each year than panels facing north. But this energy will be more spread out over the day, which might better align with your consumption (i.e. mornings and evenings). Even south is only 25% less than north, so worth considering if you're short of roof space, or going for the biggest system possible.
“If you have the option, make your rooftop solar friendly. A large unshaded (ideally) north roof makes it easy to install a large solar system, while complex hip roofs, vents, antennas and chimneys may limit your options.”.
How to coordinate solar on a new build or renovation
It might seem simpler to let the builder handle everything... But if your builder and their contractors don’t have solar experience, this could end up being more complex and costly. Small details, like where your switchboard will go, are important to agree up front, as this will determine your inverter (and maybe battery) location.
If in doubt, your solar supplier should have the final say on anything solar related - this includes cable sizes, where roof, ceiling or wall penetrations will need to be, and anything safety related on the solar install. There are extra electrical standards for solar that don't otherwise apply to household wiring, so it's important that an electrician with solar experience is involved.
Integrate with an all-electric home
The cheapest, cleanest energy you can supply and consume is the solar energy coming from your roof.
Going all electric also saves costs and hassle, avoiding the need for additional gas plumbing, and avoiding gas connection charges for the rest of your days - that alone could easily be more than $3,000 over ten years.
In a modern home, it is easy to supply the bulk of your energy needs with rooftop solar. So, what does an all electric fit out typically look like?
Hot Water: A high-efficiency heat pump can be scheduled to run during the day, to absorb excess solar production.
Heating/Cooling: Reverse cycle split-systems give you heating and cooling where you need it, when you need it. You can even run multiple head outlets off the one heat pump unit, to heat multiple spaces. The heating and cooling load of a new, well designed home will be far smaller than the "average" home - in fact it could be less than half as much. So you may not need as much heating and cooling as you think. You can even run all-electric hydronic heating and cooling.
Cooking: Induction cooktops are efficient, safe, and easy to clean. Even standard electric cooktops are efficient and effective (trust us, they aren't what they used to be).
“Cheaper, cleaner, safer and simpler. When it comes to new builds, gas is on the way out, and going all-electric is in.”.
Inverters sit between your solar panels and the grid, making sure power flows the way it should without causing problems for your home, or the grid. This makes the inverter the weak link in your solar system. If it fails, your system goes down. Or, if you buy a good quality one, it could be the strongest link!
We always recommend going for a ten-year parts and labour warranty on your inverter and our go-to recommendation is Fronius. A solid product, with reliable local support (even the best inverters can fail). SMA, SolarEdge and Enphase are also excellent options, with the latter two being particularly suited to situations with shading or complex layouts.
Monitor your solar performance
Ask your solar supplier for a monitoring system, so you can easily track performance and identify any issues.
These are often free to install and setup. They come with the inverter and can be programmed to provide automatic alerts when a fault is detected. Some have add-ons to monitor consumption as well.
This comes in handy
when trying to make your home more efficient, and aligning usage with
times of maximum solar generation, so you can save even more!
If you expect some shading on your solar system, particularly in summer, it could be worth considering optimisers or microinverters. If an individual panel is shaded, this can affect all the other panels connected.
Think of a kinked garden hose - one small obstruction and the flow is limited along the whole length.
far as brands go, Tigo is a good option when a couple panels have
shading - at about $80/panel, as an add-on to a standard string inverter
SolarEdge is another good optimiser option, where an optimiser is installed on every panel, while Enphase is the market leader in microinverters - expect an overall price premium of 25% for these.
Choosing a solar panel brand
comes to solar panel brands, it is hard to know where to start. Chinese
brands dominate, and while there are a few suspect brands, the larger
players can generally be relied upon. The following are the biggest
manufacturers, which we are happy to recommend.
- JA Solar
- Canadian Solar
There are a few premium brands worth considering, albeit at up to double the cost. They tend to offer longer warranties and higher efficiencies. These include LONGi, Winaico, REC, LG and SunPower.
Choosing a solar retailer
There are 400+ solar retailers in Australia. How do you pick a decent one?
While there are constantly new players in the solar industry, it's safest to go with a company with an established track record. We pre-qualify companies with a robust financial position, diligent compliance obligations (e.g. insurance), and demonstrated commitments to quality and customer service.
Companies with pushy sales people, who dodge questions, are often a warning sign. At BOOM! we conduct extensive due diligence on the suppliers we work with to ensure they'll deliver on what they promise.