The contract award will see Amey deliver the design, installation and construction of two new temporary substations to support the delivery of the Chiltern Tunnel south portal.
The first will connect to the Scottish and Southern Electricity Network power grid and transform voltage levels from 132kV to 33kV.
A second, primary substation will then drop these voltage levels further from 33kV to 11kV ready for the distribution of power to the tunnelling equipment required for the Chiltern Tunnel.
This will be built by the Align JV of Bouygues, VolkerFitzpatrick and Sir Robert McAlpine.
Amey CEO Andy Milner said: “The HS2 programme is an exciting piece of work for us and is testament to the skills and expertise of our long serving and dedicated workforce.
“The construction of the new substations will enable us to provide power to support the delivery of the Chiltern Tunnel for HS2.”