This growth in energy production is also reflected in the number of renewable facilities. Between 2017 and 2018, all methods of renewable energy generation (excluding landfill gas) had seen an increase in their number of sites, with an overall growth of nearly 21,000 plants. Unsurprisingly, solar PV sites were by far the most numerous, at over 957,000 installed, offering a cumulative capacity of 13.1 gigawatts as of 2018. By comparison, hydropower plant capacity remained relatively stable in the past ten years, with 4.6 gigawatts installed by 2018.
In terms of utilization efficiency, sewage gas has the greatest load factor of all renewable sources in the UK. The annual average noted only slight fluctuations, between 41 and 46 percent. By comparison, figures for landfill gas declined from nearly 60 percent in 2010 to 42 percent by 2018, showing that peak demand for said energy source grew quicker than average consumption.
Both sewage gas and landfill gas are a form of bioenergy. The term also includes power sourced from waste combustion, animal biomass, plant biomass, anaerobic digestion and co-firing with fossil fuels, although the latter was nearly phased out by 2018. Bioenergy is the second greatest contributor to renewable electricity generation after combined wind power, producing 34,758 gigawatt hours worth in 2018.