Translation:Last year, they stopped using energy from coal.
Skočit means 'jump, leap, ...' :)
Skončit means 'finish, end, terminate...' I don't think it can be followed by a verb in Czech, you need to use nouns or verbal nouns: skončit + acc / s + ins
Přestat means 'stop, quit (doing sth)' It's followed by either a verb or by s + ins
Přestát means 'endure, come through' Followed by acc.
Pay attention to accents ;)
Přestal pracovat. 'He stopped working.' or Přestal s prací. 'He stopped the work.'. To put it simply, he stopped working to take a bite of his sandwich. He's not done yet.
Skončil práci. 'He finished the work.' while Skončil s prací. is closer to 'He is done with/finished working/the work.' I'd say that in this case, the first one is more about a single piece of work, the second more about a process (of working).
As an endnote, the noun is práce; it loses the accent in some cases, don't let that confuse you.