As someone living there presently rooftop solar is massively subsidised and an obvious choice given our near year round sun. A standard install is approx. $5k AUD ($3.5k USD) and will produce 30kw/h or more on a sunny day, this means a summer energy bill is around $100 for the 3 months (those that locked in higher buyback rates can even make money off the provider in summer).
We just need better/cheaper storage solutions, as a $10k Tesla battery just doesn't stack up.
Solar is subsidised here, but not massively anymore - it's more the huge demand and pretty competitive market that keeps things cheap I think. My 6.6 kW solar system had a subsidy of about $1,750 so I paid around $6500, and unfortunately when I installed it (2019), I was already about six or seven years too late to get locked in feed-in pricing (and it's already dropped since I installed the system). Panels are a bit cheaper now so yeah 5 kW for $5K is definitely in the realm of possibility but the rebate is dropping over time.
Back in the early 2010s, it was very heavily subsidised for sure, my father managed to get in then and even with a system half the size of mine he hasn't paid for a power bill since... The system was a lot more expensive to install per kilowatt then but the feed-in tariff he gets is insane and is still locked in for another five years or so...