Hi Joe,
Below are the links with details on calculations and a case study. We include the embodied impacts of solar panels and simulate the carbon credit for feeding renewable energy back to grid by assuming today´s grid coefficient or a grid decarbonisation scenario. EN15978 says to report export energy (D1) only after all annual on site demand (B6) is met by renewable supply. Happy to organise an online chat to run through an example together if you like.
Cheers,
Henrique