Is there anywhere where people are using solar panel miners to run miners with them ?
Yes, if you browse through this mining section than you will find related information. Since electricity is quite expensive in most of the countries, only option now left is utilize solar power to mine bitcoins
but it needs initial investments higher than normal mining methods. Exactly! And that's why it is almost impossible to have ROI with solar panels. Many people in those threads are talking about it. Only if you manage somehow to get solar panels free or for very low price (mybe used ones?) you might consider using them.