Nguyen Duc Long, 24, of Gia Lam District was found guilty of destroying public assets by a Hanoi court on Wednesday.
It also ordered him to pay VND802 million (US$32,460) to compensate the loss.
On Dec. 12, 2022, power was cut off to his house since Long did not pay the electricity bill.
At around 4 a.m. on Jan. 4 last year, a few days after that, he was irritated by street lights shining into his house and so he set fire to a mat and took it to the substation 100 m away.
Then he returned home and took wooden planks from his bed to fuel the fire before going back to sleep.
Local residents rushed to put out the fire.
According to the police, Long was a marijuana user but was in full control of his behavior when committing the crime.