The 10 dumb myths of solar installers #10 You can’t split arrays on different inclinations Yes it can be done. Sure there is a loss of output (in technical speech, a cosine loss leading to voltage mismatch dynamics because of different MPPs within the series strings) but this must be balanced against other benefits in, say, reduced installation cost and the ability to fit more panels on a roof. The CEC guidelines say a maximum of a 5% difference in inclination, yet most installers won’t even do that. In reality the guideline should be scrapped or increased to a higher figure more like 15%, as long as the consequences are understood and explained to the customer and the economics of a larger system outweigh any losses per capacity invested. Please bury these myths for everyone’s benefit By burying these myths, Australians will be able to buy a lot more solar panels,….

The 10 dumb myths of solar installers #9 Frames should be used to ensure panels are optimally tilted to the North No, this is old thinking. Adding the cost of 20 or 30 cents per watt to a system that costs $1.00 per watt so the the panels are ideally tilted to eek out every bit of output from a panel is a complete waste of money. With the exception of completely flat roofs where build-up of dirt and grime will be a real problem, flat racking is the go. If space permits, you could instead install 30% more panels for the same price as using tilt framing. Better to install more panels than frame – because that creates economies of scale and brings the cost of panels down in the future! Next: 10) You can’t split arrays on different inclinations Previous:8) The electricity network distributor won’t allow oversizing beyond their inverter size limit

The 10 dumb myths of solar installers #8 The electricity network distributor won’t allow oversizing beyond their inverter size limit Wrong again for most network distributors. Yes, Ausnet in Victoria has this stupid rule and they should hire some electrical engineers with competence to help them out. But Citipower/Powercor, Jemena and United Energy in Victoria all allow oversizing as do network operators in WA, SA, Queensland as well as some distributors in NSW. So if distributor Jemena says you can have a 10kW capacity inverter installed on a single-phase then as long as it’s compliant with Australian Standard 4777 you can attach panels with capacity of 13kW, 15kW or even more. Also by not going beyond a 10kW inverter you slip in under their rule of automatic pre-approval Next: 9) Frames should be used to ensure panels are optimally tilted to the North Previous:7) You shouldn’t put on more panel capacity than the output of your….

The 10 dumb myths of solar installers #7 Let’s be straight – it’s better economics to oversize the amount of panel capacity relative to the inverter (see Reasons to supersize your solar for why this is the case). All systems should be oversizing 150% panel capacity to inverter output. Unfortunately the Clean Energy Council (CEC) guidelines undermine good solar system economics. They currently only allow 133% oversizing of arrays, after which you forgo eligibility for the government STC rebate. However provided you are prepared to do the project in two passes, claiming the STC rebate only for that capacity up to 133% of the inverter capacity, this is entirely legitimate. Most importantly it can be done safely and within electrical codes and regulations. Yet what’s even more ridiculous is that many installers come up with arbitrary constraints that they’ll only do 15% oversizing on the north. Others even incorrectly claim that you’re not allowed….