From 6th April, new regulations for England allow certain microgeneration equipment to be installed on, or within the curtilage, of buildings other than dwellings, without the need for a specific application for planning permission.  The new rules confer permitted development rights, (subject to certain criteria), for the installation of solar panels, ground and water source heat pumps, biomass heating system flues and combined heat and power system flues.  Buildings on agricultural or forestry land will be allowed to house microgeneration equipment, and in particular to house hydro turbines, biomass boilers and anaerobic digestion systems, and to store associated waste and fuel, as long as the fuel or waste is produced on the agriculture or forestry land or by the boiler or system.   See

http://www.legislation.gov.uk/uksi/2012/748/contents/made

Rules on permitted development for installing microgeneration equipment on domestic properties in England came into force on 1st December 2011 www.legislation.gov.uk/uksi/2011/2056/pdfs/uksi_20112056_en.pdf