The 45-year-old construction worker admitted to the bomb attacks and was found guilty for dangerous bodily harm and violating German weapons law.
The Darmstadt court called his actions an “incomprehensible crime,” but did not believe they constituted attempted murder.
“I am a militarist,” he told the court.
The man, identified only as Jürgen K. set off an explosion at a single-family home in Viernheim, a town near Mannheim, slightly injuring the father.
He then set off an explosion in Weinheim, some five kilometres away in Baden-Württemberg, but caused no injuries.
He fled and barricaded himself in his nearby apartment wearing camouflage and a gas mask. From there he called police and threatened further explosions.
A tense 28-hour stand-off followed, with some 500 police and emergency workers evacuating the area and surrounding the building. On August 20, he surrendered and was arrested by special commando officers.
Police later removed several trucks full of explosives and weaponry from his home.
The man felt his victims had fleeced him with bills.