This will probably be one of those "crystal ball" questions. But are solar panel prices likely to drop in the future, stay the same, Or go up in price like how everything else seems to increase in price.
Partly why I ask is that supposedly new rules have come out to do with solar panels. Which mean that new ones are now more expensive. And the old models are now available at cheap prices. (presumably until the old stock has sold out).
Also I have seen people claim that solar panels typically cost around $1 per watt output. They didn't say whether that is US$1, NZ$1, or $1 +GST ect. Yet they normally seem to cost way more than NZ$1 per watt. So what is typical pricing, So I know when to jump at a good offer. Guessing that quality will also vary. But virtually all sellers seem to offer 20+ year warranties. So Im unsure how to judge them beyond the reputation of the seller (Big company Vs someone on Trademe)
I haven't even decided what solar system size I want. I could just get a MPPT charge controller. And use it to charge up my existing 12V UPS system, which is 2x 100AH deep cycle batteries. Which provide power to the Router, fibre ONT ect. And are currently charged by a constant voltage charger that runs on offpeak mains power. Guessing would probably need approx 1KW solar array size to get good charging in cloudy weather. Also allowing for a scenario where the mains is dead for ages in a disaster.
Or go big - more batteries, Add a big inverter - probably around 5KW, and of course more solar panels. I would consider consider using the solar PV to feed an element in the hot water cylinder, but I have an existing solar hot water system.
Guessing the answer would probably be - Do nothing. As solar will never stack up on a purely financial point of view. Due to already having solar hot water, and getting cheap offpeak power with Flick Electric. But having a backup power system would have a big value in a disaster. Yet I could just buy a diesel generator and lots of diesel instead. If the only consideration was backup power. Problem is that generators are noisy, And would be inefficient for me as average current draw for my house is low. But I have things like water pumps and fridge compressors that still have big switch on surges. So load profile better suits a battery / inverter setup.