Friends of mine had a weekender in the country with only solar power. Problem was it was unreliable and often found the power went off which meant the fridge stunk to high heaven when they went there. In the end they installed an answering machine on the phoneline and called it daily to ensure it answered which meant the system was working. When it didn't answer it an unscheduled trip. Today's inverters are still unreliable and fail within 5-10 years and need replacing at a cost of a few grand. The people selling systems don't mention that. Cost for my friends was $20k+ so I can't see how you have got away for a few grand. Even today for a basic PV/battery system you are looking at $23k going from the ads.
The only way I see you doing it for that money is a wood burning stove, solar hot water without backup, no aircon, maybe a gas fridge or a esky style electric fridge used by campers.
Let me know how close I am.
PV panels are currently 15% efficient so I agree that they can be improved but even the ones used by NASA in space which are super expensive are only 40 odd % efficient. If the efficiency can be doubled then the roof space required could be halved.
Battery chemistry and costs still has a long way to go as well.
And both PV's and batteries drop their efficiency by 1% a year so after 20 years they have dropped their output by 20% and will most likely need replacing after another 10 years. You know that from using a mobile phone.
Of course replacement costs will go down but labour costs will go up.
Also, we should keep in mind those properties that for one reason or another can't install PV panels and will be subject to electricity price fluctuations and the owners have a voice. More than half the population in some cities will be living in multiple dwelling buildings sooner or later so I can't see costs getting out of hand when you consider the coal burning power stations are fully written off.
I'm not against green energy by no means .... just being a realist.
