Hothouses' biggest cost is usually the energy it takes to keep them hot, so growers naturally look for ways to cut that growing bill. Grower-entrepreneur Jaan Vion in the quaintly-named Dutch town of Beetgum is switching his boiler from natural gas to a 25% more efficient wood-fired CHP, and he's the first in Holland to spring to use a system that captures the CO2 generated from the exhaust and after "scrubbing" pipes it back into the greenhouse as a stimulant to help the peppers grow. Vion's is no rinky-dink project - the boiler is 5 MW in capacity and uses 2.6 tons(!) of wood per hour - to support 8 hectares of pepper production. A tomato grower in Sweden and a Canadian greenhouse will soon get the same system. Via PrivataAffarer (Swedish)
In Scandinavia it's almost a given that the shiny, gorgeous, and expensive red and yellow peppers (for some reason there are few green ones) at the grocery store are imported from Holland, the land of the never-ending greenhouse. So peppers aren't the best local, sustainable mid-winter choice, and in fact they aren't even available at the all-organic eco-store this season. But sometimes a potato, a parsnip or a beet just can't cut it.