Complex sentence: Two factors make the Power Station unusual, and have both played their part in its chequered history; it is sited in a pristine World Heritage Area, and the power station itself is an impressive feat of engineering, but not without its technical problems.
Split into simpler sentences: Two factors make the Power Station unusual, and have both played their part in its chequered history. Secondly, the power station itself is an impressive feat of engineering, but not without its technical problems.