The eStorage project

1. The eStorage project WP1 Presentation 28/10/2013 Henri Jacquet-Francillon - EDF

2. eStorageproject : WP1 Objectives and organisation Objectives : Demonstrate the feasibility and benefit of converting a large fixed speed pump-turbine into a variable speed machine: Le Cheylas PSP unit 2 (240 MW) Evaluate the likely benefits of such conversion, Monitor results from the demonstration plant and provide data for WP3 Develop solutions for conversion of a significant share of European fixed rotating speed pumped hydro storage units into variable speed units Organization : EDF : Hydro and research & development divisions. ALSTOM Grenoble (turbine), ALSTOM Birr (DFIM) 28/10/2013 eStorage ambition : « Deploy flexible PSPs across the EU and enhance grid management systems to support the integration of renewable energy »

3. Upgrade of le Cheylas PSP Presentation of le Cheylas PSP, located in the Alps, close to Grenoble Commissioned in 1979 2 identical 240 MW reversible units A plant with two purposes : Electricity generation (Arc river inflows) Electricity storage, on a daily cycle Benefits from conversion ofunit 2 to variable speed, Increased efficiency in both turbine and pump mode +/- 35 MW regulation in pumping mode 28/10/2013

4. Upgrade of le Cheylas PSP Details of operation Main components to be replaced, modified or added : Runner and wicket gates (replaced) Motor / generator and its refrigeration system (replaced) Main transformer (replaced) Overhead travelling crane (modified) Additional electrical equipment (VSI) (added) Main challenges : Optimisation of hydraulic design to both gain efficiency and extend range of operation in pump mode Minimise impact on existing structures and handling equipment of increased weight of the new motor generator Minimise downtime of unit 2 for conversion 28/10/2013

5. WP1 Actions (1) Results Task 1.1 : performance and service target A comparison between the operational performance of le Cheylas in 2010, 2011 & 2012 inits existing configuration and of its probable operational performance over the same years with a variable speed unit The increased turbine efficiency procures additional peak generation both from the Arc river inflows and from the volumes from the lower reservoir, and should therefore procure - under likely future values of peak energy – additional revenues that justify the expenditure incurred by improving the efficiency of the pump-turbine, Concerning the ancillary services in pump mode, under the current French grid code compensation for ancillary services, the additional revenues are unlikely to justify the corresponding expenditures. However, compensation to operators for providing ancillary services may need to be increased in the coming years to take into account the development of wind and solar projects 28/10/2013

6. WP1 Actions (2) Results Task 1.2 : Unit Design and Model Test, AHF The Basic design of the motor generator has begun, including the first mechanical computations , and the main characteristics have been determined : weight, size etc.. Based upon the new runner design, the flow transient computer simulations have been performed : the overspeed and overpressure values during these transients are acceptable, The model tests of the modified pump-turbine are underway : the first results indicate that the performance targets (efficiencies and extended operating range in pump mode) should be reached, Simulations conducted by ABB (the VSI manufacturer) to verify compliance with the French grid code : harmonic studies, short circuit studies, response to a voltage drop, amperage variation during machine start-up &shutdown are well underway (ABB final report is due at the end of November). No difficulty has been identified so far. 28/10/2013

7. WP1 Actions (3) Results Task 1.2 : Unit Design and Model Test, EDF, re engineering of the whole unit electrical equipment The basic design of the circuit breaker used for the DFIM, for the launching in motor mode and for the regenerative braking sequence (based upon ABB simulations) has been performed, The basic design of the GCB (Generator Circuit Breaker), using the results of the ABB simulation has also been performed, A verification that no change in design of the new main transformer for unit 2 is necessary due to the different harmonics of the new unit, DFIM rotor feeding : studies have started for the isolated phase bus ducts, The existing structures can take the load and torque applied by the stator ; the best way to apply the additional weight of the new rotor to the unit fixed parts and civil structures is being worked out , The cooling system modifications required for unit 2 are now defined, Handling of the heaviest component (the new rotor) : The existing metallic supports of the overhead travelling cranes and their foundations can take the additional weight. The extent of the modifications to the travelling cranes is still being studied. 28/10/2013

8. WP1 : next year actions Get ready to start the demonstration phase Final results of Model tests are expected in early December 2013, The objective is to complete all design & tests necessary and to identify, quantify and to reduce to an acceptable level all major project risks by the end of 2013, Starting then procurement in early 2014 should be adequate for achieving unit 2 conversion to variable speed in the selected 2016 window to limit the loss of revenue induced by unit 2 shutdown. 28/10/2013

9. WP1 : critical success factors PROGRESS Reach target Performances of modified pump-turbine 90% Re arrange equipment in the powerhouse 90% Compliance with grid code 80% Duration of Outage period : looks realistic but is still an important risk to control during demonstration phase Modify Overhead Travelling crane : two options appear satisfactory ; best one to be selected Take new rotor weight : one preferred option identified – feasibility being confirmed Adapt interfaces with cooling system, SCADA, Bus bar, GCB.. 80% 28/10/2013

10. eStorage project Summary of deliverables 28/10/2013

11. 28/10/2013