The devil's children
Peter Dickinson
After the mysterious Changes begin, twelve-year-old Nicola finds herself abandoned and wandering in an England where everyone has suddenly developed a horror and hatred of machines.

by John Christopher (1978)
In this first in a trilogy of twenty-third-century England, young Clive Anderson, unjustly imprisoned in an attempt to mold him into a docile member of society, escapes to the Outlands and is befriended by Wild Jack's outlaw band.
Peter Dickinson
After the mysterious Changes begin, twelve-year-old Nicola finds herself abandoned and wandering in an England where everyone has suddenly developed a horror and hatred of machines.
Mark Walden
Sam awakens to see strange vessels gathered in the skies around London. As he stares up, people stream past, walking silently toward the enormous ships, which emit a persistent noise. Only Sam seems immune to the signal. Six months later, he is absolutely alone.
Nick James
In 2095 when a fifteen-year-old slacker discovers that he has the power to control Pearls, fragments of space debris that are a dying Earth's most important energy source, government forces work to capture him.
Keith Laumer
Description from [goodreads][1]: > When Legion meets a strange old millionaire called “Foster,” he doesn't know that his whole life will never be the same again. For “Foster” has a strange story to tell. Part of his story is contained in his diary, which not only describes things in the very recent past, but goes back for centuries. . . > > Foster has hired Legion to help him regain his lost memory. Then both men are suddenly attacked by alien powers. They flee to Stonehenge in England where they discover a strange control chamber deep in the ruins. > > They succeed in bringing down to earth an alien space ship which has been in orbit for thousands of years. Eventually they both become captives. . . on another planet. [1]: