In fact it's pretty bad these days.
A good link to calculate the ROI of a machine:
https://bitcoinwisdom.com/bitcoin/calculatorYou have to enter all the parameters of your machines, electricity costs ... in the left column (mining settings and hardware infos). The only unknown is the rate of increase of the difficulty step. But this setting is critical in determining the ROI. It was hard raised in recent times, but I hope that it will calm down, below 5%, otherwise it will be very difficult for many people.
Be careful because I think this calculator ignores the halving effect.
I do not know how you do. In my case I bought my last S7 miner early February. While it's fully operational, the income I draw not just compensates for the decline in purchasing prices, while I have my free electricity (hydropower)... For now, I would have done better not to buy it, I would have earned more by keeping my BTC ...
I do not think that solar panels are a good solution, unless you get it very cheap. The problem is that effective miners must run 24/24 hoped for profitable before they're obsolete. So you need to have your solar panels produce for less than the price of the mains network, otherwise it is not profitable. Knowing that a large part of the electricity will come anyway from mains, over one year, the solar panel will be between 5 and 30% depending on where you are (it has many) At my home in France, that would 12% one year average , only...