1. Get Williams books. I think there are two.
2. Figure out a way to get Pease’s columns from Electronics Design archives.
3. Download all the old Linear Technology App Notes while they are still available from Analog Devices.
4. TI has great app notes too, and software.
5. Learn LTSpice, perhaps the best engineering freeware ever.
I was interested in working in the tidal space at the time and this was the best book to start with.
I was also reading an amazing set of papers on horizontal axis marine current turbines by Batten and Bahaj [1]. That was in 2009 so not sure what progress the field has made, but they kinda blew my mind at the time.
It has informal and approachable style and even has a companion study book full of experiments. [1]
One of my favourites from my university days was also Introduction to Heat and Mass Transfer. [2]
Universe is a great introduction to Astronomy [3]
Wind Energy Handbook is also a comprehensive introduction to... well I think you can guess. [4]
[1] https://learningtheartofelectronics.com/
[2] https://www.abebooks.co.uk/9780471457282/Fundamentals-Heat-M...
[3] https://www.goodreads.com/book/show/705558.Universe
[4] https://onlinelibrary.wiley.com/doi/book/10.1002/97811199927...