A man who torched his car in Wellington's busy Cuba Mall on election day last November in a protest about the banking system has avoided prison.

Christopher Charles Palenski got eight months on home detention and 160 hours community work when he appeared for sentence in Wellington District Court today.

The unemployed 40-year-old had pleaded guilty to a charge of arson knowing that danger to life was likely to ensue, and also admitted two charges of threatening to kill arising from hoax bomb threats by telephone four days earlier.

The Crimes Act arson count carried a maximum 14 years in prison.

A psychiatrist's report outlined a significant history of mental health problems including recurrent depression and, most likely, bi-polar affected disorder, said Judge Susan Thomas.

Described by the psychiatrist as a "considered, serious and reflective man'' and a one-time "carbon warrior'', Palenski's aim was to draw media attention to the Reserve Bank and fractional banking.

About 10am on November 22, he rang the Wellington police emergency number from a public telephone booth.

"Listen carefully,'' he instructed, before saying four devices would be detonated at noon in the Rural Bank and the New Zealand Stock Exchange.

Palenski then went to watch the response by emergency services, including police with sniffer dogs, said the judge.

Four days later, he drove his car to central Wellington's Cuba Mall and spray painted a protest about fractional banking around the vehicle.

Telling nearby pedestrians he was going to make it disappear, Palenski ignited flammable material inside the car, causing an explosion which sent him reeling backward and engulfed the vehicle, shattering the windscreen.

Shocked bystanders were warned the car was full of petrol and he instructed them not to put the fire out.

Judge Thomas said Palenski's premeditated actions posed a significant and potentially fatal risk to the public.

He now accepted they were "stupid and irrational'' and could have harmed people. He told police he did not think the car would explode the way it did.

The judge accepted his remorse was genuine but described him as highly misguided.

Palenski had a strong support network in the community, including a number of churches, but had not had any contact with mental health services.

She made it a condition of his sentence that he attend psychiatric assessment and any treatment or counselling as directed.

- APNZ