When will solar power systems be cost effective enough to ‘pay for itself’ within a few years?

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Karajan, Armenia

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Question by Mitch Rawlings: When will solar power systems be cost effective enough to ‘pay for itself’ within a few years?
Solar power systems are inherently expensive, and even living in a hot sunny climate, It will take over 20 years for the cost of the system to have paid itself off in terms of reduced power bills…
Technology is always evolving, getting more efficient, cheaper, smaller, more powerful … what are the next steps for home use solar power generation? and when will a system be cheap enough to buy that it will have been ‘paid off within a few years’ (not 20)

I heard that using photosynthesis processes from plants can be combined into an electricity generating paint, more efficient than silicon cells now, whens this coming out? what other technologies are there?

Feel free to answer in the comment section below