How did the Faroese heat their houses?

Question

As Faroe Islands' "low temper­atures during the growing season, stormy winter weather, and variable winter temperatures are unfavourable for tree growth", there are hardly any trees on Faroe Islands. What have the Faroese used as fuel to warm and light their houses with?

I am asking about period before the Faroese started importing fuel from other places.

Answer 1

They used local peat

In the past driftwood was avidly collected and used for building and furniture rather than burned; heat was provided by peat cut from ground outside the settlement and dried through the summer in peat drying huts that are dotted around the landscape.

^{Visiting the Faroe Islands}

Also

A couple of generations ago the faroese were still living in their turf-roofed, peat-fired, tarred wooden houses and were wearing their national costume as they had done for centuries.

^{North Atlantic Maritime Cultures: Anthropological Essays on Changing Adaptations}