Question 5.1.5 Data Field (8/b) Accepted Measurement units

Consumption unit, injection and offtake capacity of gas storage facilities has thermal capacity in MW. How can it be measured in other units?

Answer: If the time element of the event is considered, the thermal capacity can be converted into units of energy. For a consumption unit, the unavailable capacity is the total technical capacity which cannot be used in the period of the outage, even if under normal circumstances it is not utilised at full capacity.

The time element of an event allows for the conversion from units of power into units of energy. Further, storage withdrawal and injection capacity availabilities can be expressed in MWh/d.

Using GWh/d or MWh/d is the general practice for measuring outages in the gas market.

Example on how to convert MW into MWh/d for a loss in the gas consumption: Assuming we have a gas power plant with a technical capacity of 200 MW and a net efficiency of 46%. If this unit would be completely unavailable it would result in an unavailable capacity of 200MW*24h/0.46 ≈ 10435 MWh/d.

However, for a five minute partial outage in which the average unavailability will be a rough estimate the extrapolation for the whole day may be somehow less accurate. Nevertheless, according to the samples collected by ACER the number of outages which lasted less than half an hour were extremely low in recent years. Therefore, based on the evidence currently available, ACER does not see a need to expand the list of available units of measurement with MW for gas related UMMs.