At Ratcliffe, High Efficiency High Pressure turbines are used which achieve 93% efficiency. These turbines make the generation process more efficient by requiring less steam than a traditional High Pressure turbine to generate a given load. The less steam is required, the less water needs to be fed into the boiler to be heated so the less coal needs to be burnt. As a result, the amount of ash and emissions produced is lower and our environmental impact is reduced.

Their increased efficiency is due to their blade and seal design. The   High Efficiency High   Pressure   turbine consists of two rows of blades with seals attached - the inner blades are fixed, whilst the outer blades rotate. The seals force the steam through the blades preventing any from escaping.

In traditional High Pressure turbines the inlet (or first stage) consists of one impulse stage and thirteen reaction stages. The High Efficiency High Pressure   turbine only has reaction stages -   half of the pressure drops over the fixed blades and   the remaining pressure drops over the moving blades. This means that the force on the rotor is a combination of changing direction of steam flow and changing velocity of steam.