Electrical transformers and switchgear step-up the voltage from the batteries and generators to match the 275 kV National Grid voltage at Tilbury substation. The flue stacks from the engines may be grouped together; the stacks will be 40 metres tall. The engine building will be 20 metres high and the battery building up to 10 metres high. It is envisaged that advance works will start in 2020; main construction work will start in 2021 and take 18 months to six years in total over several phases. The plant will have a design operational life of 35 years. The Tilbury Green Power plant is an operational electricity generating facility which uses wood as a fuel source. The plant is owned and operated by Tilbury Green Power Limited. The plant is located within the Port of Tilbury, Essex. There are two phases of development: Phase 1 is a 40 MW waste wood power plant; and Phase 2 is a 20 MW Solid Recovered Fuel power plant. Only Phase 1 has currently been developed; construction started in August 2015 and the plant was commissioned in early 2019. The plant utilises about 270,000 tonnes of waste wood to produce up to 319,000 MWh of renewable electricity each year. Wood is processed onsite to produce wood-chip which is burned in a single travelling grate boiler to produce high pressure steam. This steam passes through a single steam turbine to generate electricity. Electricity (at 132 kV) is supplied to the National Grid via a 4.5 km underground cable to the existing 132 kV substation at Tilbury. Flue gases from the boiler are treated by emissions control technology including Selective Non-Catalytic Reduction (SNCR), fabric filters, and dry lime and activated carbon injection. Exhaust gases are discharged via a 100 metre high stack.