The consistency with which three sisters seek to make The Scarlet, which they opened in 2009 on the Cornish coast, into Britain’s greenest hotel is admirable. Wind energy generates the electricity, biomass provides heat, and plants not chemicals clean the saltwater pool. The concept carries through to the restaurant. The breakfast menu changes daily, featuring organic regional items. The 37 rooms, furnished in calming hues with natural materials, open to the sea. There is an omnipresent sound of the surf in which surfers pursue their audacious game with the waves.