Well I can't write an essay but I can give you some points:
-Renewable electricity isn't much(1 wind turbine can only power THREE houses)
-It looks really ugly(Just imagine a beautiful bay then you stick some wind turbines in the sea and it instantly looks ugly)
-Too expensive to build(solar panels are not cheap)
There's also another reason I didn't write your essay, it's because I suck at writing essays. I always end up putting a bunch of fancy and bombastic words that the teacher doesn't understand so she marks it wrong. I'm really sorry!