Looking for solar and / or batteries? How to get value for money and not get ripped off.
I often see people asking the same questions about solar and battery storage. I've been watching the industry and have formed my own opinions as well as providing some common industry knowledge.
Expensive isn't necessarily good.
Good isn't necessarily expensive.
If you're one of the few still getting 44c per KWh for solar exported to the grid, that expires on July 1 2028 (QLD).
Some companies will want to try and sell you certain brands and products where they receive money in exchange for promoting such products.
They may even run groups on Facebook and censor anyone who disagrees with them or has other verified ways to save on power bills.
I'm independent. I don't receive any money.
I wouldn't recommend something I wouldn't put on my own house or spend more money than necessary unless it's actually worthwhile.
Solar panels: Cheap out or splash out?
It all depends on your house.
Hail storms are the biggest threat to solar panels, although most panels have decent glass on them these days.
If you have a low set single storey house, you only need cheap panels. They're easy enough to replace.
If you have a house where roof access is difficult (such as a two storey house, particularly with multiple roof angles), I would recommend spending the extra money on heavier panels as you don't want to be getting up on the roof to replace them any time soon. The labour for these sorts of installations will be noticeably more expensive.
Shadeproof solar panels:
Some solar installations produce next to no power when one panel is partially shaded by trees.
Other solar installations continue to produce a reasonable amount of power even if half of the array is shaded by trees.
Some solar panel manufacturers include bypass diodes in the junction box of their solar panels. These usually only cost a few dollars more per panel.
Ask your installer about shadeproof panels and that the solar panels have bypass diodes in their junction box.
Pigeon proofing:
Pigeons nest under the solar panels and if left unchecked for long enough can damage your roof. You can get mesh (UV stabilised plastic, or stainless steel) and solar clips to mount the mesh along the edges of the panels. Drilling screws into the solar panels is likely to void their warranty and may even potentially present an electrical hazard. Never used galvanised steel mesh as it will corrode and damage your roof.
Which brand and type of inverter?
I have two systems on our house. One has a basic Fronius inverter, and the other is a hybrid inverter (it has a battery connector port on it and a sensor around the incoming mains cable from the street).
I've had a hybrid inverter system for several years now and tested various battery configurations.
The hybrid function of the original inverter failed under warranty and I got a replacement under warranty. The hybrid function of the replacement inverter died just outside of warranty also. Its features were reasonably flexible.
I got a different brand inverter, upgraded to LiFePo4 batteries, and noticed its features were even better than the original brand inverter. I was later going to buy another one of the same to replace the basic Fronius inverter, only to find it had been discontinued. The newer version was crappy and compatible with a very limited range of battery systems - if the controller system fails, you're screwed.
Then began my dilemma. I spent a few nights researching every brand of hybrid inverter out there by reading their installation manuals.
Most of the hybrid inverters had the same battery compatibility problem.
I eventually stumbled upon a brand / range of inverters which offer a wide battery compatibility. You're not forced to use an external BMS controller if you don't want to, you can program the battery parameters into the inverter and it will offer protection that way.
The brand I'm talking about is Aforenergy. They have Australian suppliers and their inverters are Australian approved. They offer single phase and 3 phase inverters in various sizes to suit your needs.
I'm not receiving any money for promoting these. Unless other manufacturers lift their game, I wouldn't recommend anything else. It's as simple as that.
Aforenergy is mentioned on SolarQuotes if that prominent website takes your fancy.
South facing panels?
Most systems face north. The Sun tracks along the north in winter.
If you're in the northern half of mainland Australia, you can get away with also installing panels on the south facing roof (if it isn't too steeply pitched), as the Sun tracks slightly along the south during summer.
Building a new house?
Best to design it for off grid.
Orient the roof so that it's either split East / West, or a single aspect facing North. The closer you are to the equator, the less pitch the roof should be.
You can never have too many solar panels.
Use single phase if it's only a small house (4 bedrooms max).
Use 3 phase if it's a large house and / or you have long cable runs (3 phase has less voltage drop).
The Aforenergy inverters can be used off grid and are weatherproof, or you can get a non-weatherproof one from AliExpress.
Getting battery storage?
It's usually a matter of replacing your existing inverter with a hybrid inverter and mounting a battery box beside the inverter.
You don't need to replace the whole solar system but it would be helpful. You can never have too much solar. The newer panels have a higher energy density per square metre.
Unless your house is brick, you'll need a fire barrier between the battery system and the wall of the house. A sheet of flat Colorbond will be sufficient and is cheaper than the fiber board they usually recommend.
What type of battery is safe?
Lead Acid - These are obsolete now and the "Deep Cycle" models have a Depth Of Discharge of about 20 - 25% and require maintenance. They produce hydrogen gas (explosive - requires ventilation) but other than that they won't catch fire. They take up a lot of room and if cared for, only last 10 years.
Lithium Ion (Li-Ion) - Avoid like the plague. Many solar batteries on the market use this type of battery chemistry. They may catch fire if incorrectly charged / discharged or exposed to direct sunlight / excessive heat. Great for burst loads such as power tools. Identifiable by its cell voltage of 3.7V per cell.
Lithium Iron Polymer (LiFePo4). Relatively safe. Their lifespan decreases the further you discharge it. I recommend a Depth Of Discharge of no more than 80% (20% State Of Charge) and in theory you should be able to get 15 - 20 years out of them. Generally not suitable for burst loads such as starting engines. Identifiable by its cell voltage of 3.2V per cell.
Sodium Ion - Buy if you have the money to spare. These are the safest and are new to the market. They can be used for burst loads such as starting engines. Identifiable by its cell voltage of 3.1V per cell.
Where to mount the battery / inverter?
Where it is least likely to be affected by direct sunlight. If this isn't possible, you'll need a shade cover / cloth to cover them (while maintaining ventilation).
Switching DC isolators?
Switching off: Make sure you switch off the AC side of the inverter first. Switching a DC isolator under load may lead to corrosion / disintegration of the switch contacts and eventually an electrical fire. DC is much harder to safely interrupt whereas AC crosses zero 100 times per second and so the arc within the switch extinguishes.
Switching on: With the AC side switched off, switch the DC side on. Then switch the AC side on.
Solar and battery is half the battle.
Ensuring your house is energy efficient is also a must.
Insulation in the roof is a must have.
Insulation in the outer walls of the house is helpful.
Double glazed windows or window tinting reduces heat loss.
Unsure? Contact someone with a thermal imaging camera.
Expensive isn't necessarily good.
Good isn't necessarily expensive.
If you're one of the few still getting 44c per KWh for solar exported to the grid, that expires on July 1 2028 (QLD).
Some companies will want to try and sell you certain brands and products where they receive money in exchange for promoting such products.
They may even run groups on Facebook and censor anyone who disagrees with them or has other verified ways to save on power bills.
I'm independent. I don't receive any money.
I wouldn't recommend something I wouldn't put on my own house or spend more money than necessary unless it's actually worthwhile.
Solar panels: Cheap out or splash out?
It all depends on your house.
Hail storms are the biggest threat to solar panels, although most panels have decent glass on them these days.
If you have a low set single storey house, you only need cheap panels. They're easy enough to replace.
If you have a house where roof access is difficult (such as a two storey house, particularly with multiple roof angles), I would recommend spending the extra money on heavier panels as you don't want to be getting up on the roof to replace them any time soon. The labour for these sorts of installations will be noticeably more expensive.
Shadeproof solar panels:
Some solar installations produce next to no power when one panel is partially shaded by trees.
Other solar installations continue to produce a reasonable amount of power even if half of the array is shaded by trees.
Some solar panel manufacturers include bypass diodes in the junction box of their solar panels. These usually only cost a few dollars more per panel.
Ask your installer about shadeproof panels and that the solar panels have bypass diodes in their junction box.
Pigeon proofing:
Pigeons nest under the solar panels and if left unchecked for long enough can damage your roof. You can get mesh (UV stabilised plastic, or stainless steel) and solar clips to mount the mesh along the edges of the panels. Drilling screws into the solar panels is likely to void their warranty and may even potentially present an electrical hazard. Never used galvanised steel mesh as it will corrode and damage your roof.
Which brand and type of inverter?
I have two systems on our house. One has a basic Fronius inverter, and the other is a hybrid inverter (it has a battery connector port on it and a sensor around the incoming mains cable from the street).
I've had a hybrid inverter system for several years now and tested various battery configurations.
The hybrid function of the original inverter failed under warranty and I got a replacement under warranty. The hybrid function of the replacement inverter died just outside of warranty also. Its features were reasonably flexible.
I got a different brand inverter, upgraded to LiFePo4 batteries, and noticed its features were even better than the original brand inverter. I was later going to buy another one of the same to replace the basic Fronius inverter, only to find it had been discontinued. The newer version was crappy and compatible with a very limited range of battery systems - if the controller system fails, you're screwed.
Then began my dilemma. I spent a few nights researching every brand of hybrid inverter out there by reading their installation manuals.
Most of the hybrid inverters had the same battery compatibility problem.
I eventually stumbled upon a brand / range of inverters which offer a wide battery compatibility. You're not forced to use an external BMS controller if you don't want to, you can program the battery parameters into the inverter and it will offer protection that way.
The brand I'm talking about is Aforenergy. They have Australian suppliers and their inverters are Australian approved. They offer single phase and 3 phase inverters in various sizes to suit your needs.
I'm not receiving any money for promoting these. Unless other manufacturers lift their game, I wouldn't recommend anything else. It's as simple as that.
Aforenergy is mentioned on SolarQuotes if that prominent website takes your fancy.
South facing panels?
Most systems face north. The Sun tracks along the north in winter.
If you're in the northern half of mainland Australia, you can get away with also installing panels on the south facing roof (if it isn't too steeply pitched), as the Sun tracks slightly along the south during summer.
Building a new house?
Best to design it for off grid.
Orient the roof so that it's either split East / West, or a single aspect facing North. The closer you are to the equator, the less pitch the roof should be.
You can never have too many solar panels.
Use single phase if it's only a small house (4 bedrooms max).
Use 3 phase if it's a large house and / or you have long cable runs (3 phase has less voltage drop).
The Aforenergy inverters can be used off grid and are weatherproof, or you can get a non-weatherproof one from AliExpress.
Getting battery storage?
It's usually a matter of replacing your existing inverter with a hybrid inverter and mounting a battery box beside the inverter.
You don't need to replace the whole solar system but it would be helpful. You can never have too much solar. The newer panels have a higher energy density per square metre.
Unless your house is brick, you'll need a fire barrier between the battery system and the wall of the house. A sheet of flat Colorbond will be sufficient and is cheaper than the fiber board they usually recommend.
What type of battery is safe?
Lead Acid - These are obsolete now and the "Deep Cycle" models have a Depth Of Discharge of about 20 - 25% and require maintenance. They produce hydrogen gas (explosive - requires ventilation) but other than that they won't catch fire. They take up a lot of room and if cared for, only last 10 years.
Lithium Ion (Li-Ion) - Avoid like the plague. Many solar batteries on the market use this type of battery chemistry. They may catch fire if incorrectly charged / discharged or exposed to direct sunlight / excessive heat. Great for burst loads such as power tools. Identifiable by its cell voltage of 3.7V per cell.
Lithium Iron Polymer (LiFePo4). Relatively safe. Their lifespan decreases the further you discharge it. I recommend a Depth Of Discharge of no more than 80% (20% State Of Charge) and in theory you should be able to get 15 - 20 years out of them. Generally not suitable for burst loads such as starting engines. Identifiable by its cell voltage of 3.2V per cell.
Sodium Ion - Buy if you have the money to spare. These are the safest and are new to the market. They can be used for burst loads such as starting engines. Identifiable by its cell voltage of 3.1V per cell.
Where to mount the battery / inverter?
Where it is least likely to be affected by direct sunlight. If this isn't possible, you'll need a shade cover / cloth to cover them (while maintaining ventilation).
Switching DC isolators?
Switching off: Make sure you switch off the AC side of the inverter first. Switching a DC isolator under load may lead to corrosion / disintegration of the switch contacts and eventually an electrical fire. DC is much harder to safely interrupt whereas AC crosses zero 100 times per second and so the arc within the switch extinguishes.
Switching on: With the AC side switched off, switch the DC side on. Then switch the AC side on.
Solar and battery is half the battle.
Ensuring your house is energy efficient is also a must.
Insulation in the roof is a must have.
Insulation in the outer walls of the house is helpful.
Double glazed windows or window tinting reduces heat loss.
Unsure? Contact someone with a thermal imaging camera.