Buckinghamshire-based G2 Energy has connected almost 1GW of renewable energy to the National Grid since 2011. It designs and installs electrical connections for solar farms, wind turbines and anaerobic digestion plants, and its customers range from landowners to commercial developers. It has constructed more than 100 wind turbines nationwide, including designing and building the foundations, and has also connected more than 90 large solar farms to the grid. Under founder and chairman Gary Gay, 59, sales grew to £32.3m this year, and it forecasts growth for next year despite cuts in subsidies for renewable energy.