First thing not mentioned is the Feed in Tariff stopped for new installations a couple of months ago. Second, the notion that you have to export it all and then buy back is nonsense - we have had a wind turbine for eight years now, so I have some idea of what I am talking about. Except we don’t have any solar panels - we are getting a quote but it won’t be economic to do.
I would like batteries but they are not financially viable - v hard to find out actual figures, but in terms of carbon footprint batteries are pointless as using your own renewable electricity rather than sending to the grid at the margin just means someone else using a dirty supply. The green benefit is from generation not use (although there are some transmission losses). I understand the latest battery systems do permit continued supply in a power cut though
I think there will be new arrangements in time with the grid wanting to buy electricity from you at peak times and happy to sell at cheaper prices off peak - that may work with car batteries and / or Tesla power walls and the like, but not here yet