The primary sources of renewable energy incorporated into the master plan include tidal lagoons, photovoltaic solar arrays and wind turbines. Secondary sources such as ground source heat pumps and photovoltaic facades will be a requirement for the Bll2009 design brief.
Wind Power
Shoebury-Wix lagoon is in proximity to the Kentish flats wind farm (30 turbines) and the London array (341 turbines) and is an ideal location for taking advantage of this natural resource. 10 x 3.6MW Siemens turbines with a 107m rotor diameter have been positioned in shallow water, away from the main navigable channels to the north of the master plan at 700m centres. In all this these would generate 12.6MW, or enough energy for approximately 9500 homes.
Shoebury SEGS has a dual purpose renewable energy source. Positioned within a 20 hectare lagoon will be 118,000m2 of ground mounted photovoltaic solar arrays. These 10m x 5m panels will rotate to track the suns optimum path at all times of the year. Mounted on columns that are standing in water, they will be maintained from a network of 3m wide floating pontoons.
A PV system in the UK produces between 700-950 kWh for each kWp installed if there is no shading. The actual yield will depend on location, type of panel, inclination etc, and a tracking system will increase efficiency. Using a figure of 900kWH for a very large array located in the S.E of England, a 1m2 panel will yield approximately 0.13kWP, and so the Shoebury SEGS array 118,000m2 array would have a capacity of 15,340KW and an output of 13806MWh/y of electricity.
All the buildings being designed for Build LONDON Live must have at least 20% of their south facing facades given over to solar cladding or tiles. The cumulative area in m2 will be calculated using BIM techniques once the models have been received. However, for a building mounted system the yield is likely to be lower since orientations etc. cannot easily be optimised. Here then, a yield of around 800kWh/kWp, or around 104 kWh/m2/y will be the norm.
Main Tidal Lagoon
The site is ideally situated to generate energy from tidal lagoons and two locations have been defined. A primary 113 hectare lagoon is situated to the west of Southend pier, and a smaller 20 hectare lagoon is located within Shoebury SEGS Island (above).
The main lagoon consists of a rubble mound impoundment structure on the foreshore that will appear to be a low lying rocky island. Low-head hydroelectric generating equipment in the impoundment walls will generate reliable and predictable power as the tide flows and ebbs. The main lagoon is 600m in diameter, roughly 7.5m wide and will protrude 500mm above high water springs. The powerhouse containing the turbine/generator set would be located underwater inside the impoundment wall and connected to an existing substation onshore via and an underwater cable. The turbine is rated at 2.3MW, which in the UK is adequate for approximately 1,700 homes.
A second lagoon is located
on Shoebury SEGS and its basin covers 19 hectare - enough to generate
0.4MW or about enough energy to power 300 homes.
Tidal Electric www.tidalelectric.com
Tidal lagoon technology consists of an offshore impoundment structure that sits on the seabed in a tidally-affected area of the ocean. Conventional low-head hydroelectric turbine generator sets are installed on the seaward side of the structure and utilize the head created by the variable water levels caused by the tides to generate power. The costs per unit output decrease as the size of the impoundment increases, so larger lagoons will be most profitable. The components of the technology are mature, durable, and highly efficient. This is not one of the many experimental tidal stream devices. Nor is this a wave power device. Tidal Electric’s technology is conventional low-head hydroelectricity sited in an unconventional manner in offshore sites. The design life of the impoundment is 120+ years and the design life of the performance-guaranteed equipment is 50+ years. Tidal lagoons are a long-term, low maintenance, carbon-free, technology risk-free alternative energy source. For more information visit www.tidalelectric.com.
