In the energy Dashboard, you can configure a price per “kwh” you are using from the grid.
As well - as a price per kwh when you export to the grid.
But to be fair - even the power you are using from your solar does have a cost factor…
Usually: the price for buying and installing / expected production * years…
In my own case - the price per kWh which I do use on my own is “round about” 0.098 € / kWh… and on top of that I need to pay 19% tax (yeah … germany 
)
But:
It would be great, if I could add the “price per kWh” for my own solar Energy to the energy dashboard, too… how much this is, needs to be calculated by everyone individually.
This would make the cost-calculation more accurate.
It would also alow some comparison features:
What you pay → Import + Own Costs vs. What you would have payed with onyl grid import (since we already have that price-tag)