Required reading:

Schubert, S.R.; Pollak, J.; Kreutler, M. (2016): Energy Policy of the European Union, 92 - 143.

Supporting literature:

Rayner, T.; Szulecki, K.; Jordan, A.J.; Oberthur, S.(ed.): Handbook on European Union Climate Change Policy and Politics, 23-67, 129-142. (The book deals with climate policy, however, given the interconnectedness of this policy and energy policy, the above chapters are very applicable to our purpose). 

https://www.elgaronline.com/edcollbook-oa/book/9781789906981/9781789906981.xml