The 10 dumb myths of solar installers
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 to oversize and it wouldn’t get past the electrical inspector/authorities.
Oversizing changes production over the day from a bell curve to a table top (much like an intermediate power station) which is better for solar owners by maximising self-consumption, but also customers without panels and the network operators.
Next: 8) The electricity network distributor won’t allow oversizing beyond their inverter size limit
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