Preamble:

Storengy’s existing Storage Facilities were not designed to operate to cover within-day flexibility requirements.

This kind of operation would require profound modifications, entailing significant investment, that would not be possible on all sites.

However, in order to meet its Customers’ needs, Storengy has identified elasticities which make it possible to respond to the new within-day flexibility requirements.

In a first stage, these needs will be met on an interruptible basis, using existing but unused day-to-day capacity.

For the future, Storengy is ready to enter into the necessary discussions with all the stakeholders involved to make all or part of this offer firm capacity, should the market show interest in such changes. In this case, Storengy will make sure that the seasonal modulation requirements of residential Customers and of those subject to obligations under their public interest roles continue to be met. In the event of a sustained market demand, Storengy will also institute the measures needed to adapt its sites as far as possible within a medium-term timeframe, and provided that these changes are economically relevant.

SERVICE OFFERED

The within-day flexibility offer enables the Customer to respond to gas supply needs involving heavy within-day modulation, which means where there are sizeable variations in the quantities delivered throughout the same day.

The service on offer matches the possibility of varying within the same day the hourly quantities injected into or withdrawn from Storage groups, in order to balance the hourly exit quantities delivered on the transmission system with a heavy within-day modulation. This service is equivalent to an offer of injection (downward within-day flexibility) and withdrawal (upward within-day flexibility) capacities for use on an hourly basis.

TERMS OF USE

The within-day flexibility offer is independent of other Storengy offers and does not require prior subscription to one of these.

The within-day flexibility offer is on an interruptible basis as it is based on Storengy customers leaving unused injection and withdrawal capacities available on a day-to-day basis by way of other offers.

This offer relies on flexibility sources in the form of storage site groups, in order to benefit from resource pooling while maintaining a simple structure.

Requests to use the within-day flexibility service are made each day for the following day. If the sum total of requests exceeds available capacity for the service, requests will be dealt with on a “first-come, first-served” basis.

The sum total of injected and withdrawn quantities in the same day under the within-day flexibility offer is zero. This offer can be used in association with other Storengy offers, the latter specifically helping ensure customers’ daily balancing.

Fluctuations in quantities injected and withdrawn under the offer are limited, for each and all of the customers, to one single upward movement and one single downward movement on any single day, and within two predefined time windows during that day.

PRICE

The price of the within-day flexibility service for a within-day flexibility need of 0,9 GWh/h (need of a 400 MWe combined cycle gas power plant) is broken down into :

• a fixed yearly subscription fee : k€400
• a charge rate proportional to the actual use of the within-day flexibility service :
  • in injection / downward flexibility : k€8,16 per day per GWh/h,
  • in withdrawal / upward flexibility : k€2,88 per day per GWh/h.

PRICING EXAMPLE

The within-day flexibility need of a 400 MWe combined cycle gas power plant is 0,9 GWh/h, and corresponds in the case of a 16h functioning profile to downward and upward within-day flexibility needs of 0,3 GWh/h and 0,6 GWh/h respectively.

The price of the within-day flexibility service is thus broken down into :

• a fixed yearly subscription fee : k€400
• charge rates proportional to the actual use of the within-day flexibility service :
  • downward flexibility : 0,6 GWh/h x k€8,16 per day per GWh/h = k€4,90 per day,
  • upward flexibility : 0,3 GWh/h x k€2,88 per day per GWh/h = k€0,86 per day.

In the case of a 16h functioning profile during 310 days, the price of the within-day flexibility service is : k€400 + k€(4,90+0,86) per day x 310 days = M€2,2.