1. Barford Power Station St Neots Community College Sixth Form Visit, May 2008

2. Key Points The combined cycle power station is on the site of the old Barford A station, about 1.5 km from the school. Two gas turbines drive generators. The waste heat from the turbines is used to heat water in a boiler. This drives a steam turbine. These are some pictures of what is there.

3. The back up This is a turbine from a jet aeroplane that can provide the power for a “black start.

4. Where the electricity leaves

5. Closer up to the black start turbine.

6. Air intake for the turbine FiltersReally thick wires Transformers High voltage wires

7. Output Transformers They are huge. The electricity comes in at 25 000 V, 15000 A. It leaves at 132 000 V, 2800 A. With the lower current and the bigger voltage, the wires don’t get so hot.

8. Fuel The power station is fired using North Sea gas. You can see the massive pipes through which the gas comes. Thousands of cubic metres are used every day.

9. Water Supply The water comes from the St Neots supply

10. Dimineralisation The water has to be very pure, otherwise it will damage the boiler and the turbines St Neots water is very hard, and the minerals have to be removed completely.

11. Cooling Water The water in the boilers is recycled lots of times. It is cooled by cold river water. You can see the huge pumps that pump the river water. The river water is returned to the river. It does not get dirty. Huge pumps

12. Big wires carrying electricity from the generators

13. Under the Boilers The boilers are huge boxes in which there are lots of pipes carrying water. The green pipes carry cool, clean water to the boiler. The boiler is heated by the hot exhaust gases from the turbine.

14. The Condenser This condenses the steam under the turbine. This gets even more energy from the steam. It makes the power station more efficient.

15. The Turbines The turbines turn at 3000 rpm. They have lots of blades that turn in the steam. Each blade costs about £10 000. If they break, the turbine “has a haircut”. This is very expensive.

16. The Generator You can see how big it is. The electricity is generated in coils that surround a rotating electromagnet. The voltage is 25 000 V; the current is 15 000 A. The power is equivalent to 100 electric locomotives