ANNEX IU.K. GENERAL PRINCIPLES FOR THE CALCULATION OF ELECTRICITY FROM COGENERATION
Part I U.K. General principles
Values used for calculation of electricity from cogeneration shall be determined on the basis of the expected or actual operation of the unit under normal conditions of use. For micro- cogeneration units the calculation may be based on certified values.
Electricity production from cogeneration shall be considered equal to total annual electricity production of the unit measured at the outlet of the main generators;
in cogeneration units of types (b), (d), (e), (f), (g) and (h) referred to in Part II with an annual overall efficiency set by Member States at a level of at least 75 %, and
in cogeneration units of types (a) and (c) referred to in Part II with an annual overall efficiency set by Member States at a level of at least 80 %.
In cogeneration units with an annual overall efficiency below the value referred to in point (i) of point (a) (cogeneration units of types (b), (d), (e), (f), (g), and (h) referred to in Part II) or with an annual overall efficiency below the value referred to in point (ii) of point (a) (cogeneration units of types (a) and (c) referred to in Part II) cogeneration is calculated according to the following formula:
ECHP=HCHP*C
where:
ECHP is the amount of electricity from cogeneration;
C is the power-to-heat ratio;
HCHP is the amount of useful heat from cogeneration (calculated for this purpose as total heat production minus any heat produced in separate boilers or by live steam extraction from the steam generator before the turbine).
The calculation of electricity from cogeneration must be based on the actual power-to-heat ratio. If the actual power-to-heat ratio of a cogeneration unit is not known, the following default values may be used, in particular for statistical purposes, for units of types (a), (b), (c), (d) and (e) referred to in Part II provided that the calculated cogeneration electricity is less or equal to total electricity production of the unit:
| Type of the unit | Default power to heat ratio, C |
|---|---|
| Combined cycle gas turbine with heat recovery | 0,95 |
| Steam back pressure turbine | 0,45 |
| Steam condensing extraction turbine | 0,45 |
| Gas turbine with heat recovery | 0,55 |
| Internal combustion engine | 0,75 |
If Member States introduce default values for power-to-heat ratios for units of types (f), (g), (h), (i), (j) and (k) referred to in Part II, such default values shall be published and shall be notified to the Commission.
If a share of the energy content of the fuel input to the cogeneration process is recovered in chemicals and recycled this share can be subtracted from the fuel input before calculating the overall efficiency used in points (a) and (b).
Member States may determine the power-to-heat ratio as the ratio of electricity to useful heat when operating in cogeneration mode at a lower capacity using operational data of the specific unit.
Member States may use other reporting periods than one year for the purpose of the calculations according to points (a) and (b).
Part II U.K. Cogeneration technologies covered by this Directive
(a)Combined cycle gas turbine with heat recoveryU.K.
(b)Steam back pressure turbineU.K.
(c)Steam condensing extraction turbineU.K.
(d)Gas turbine with heat recoveryU.K.
(e)Internal combustion engineU.K.
(f)MicroturbinesU.K.
(g)Stirling enginesU.K.
(h)Fuel cellsU.K.
(i)Steam enginesU.K.
(j)Organic Rankine cyclesU.K.
(k)Any other type of technology or combination thereof falling under the definition laid down in Article 2(30).U.K.
When implementing and applying the general principles for the calculation of electricity from cogeneration, Member States shall use the detailed Guidelines established by Commission Decision 2008/952/EC of 19 November 2008 establishing detailed guidelines for the implementation and application of Annex II to Directive 2004/8/EC of the European Parliament and of the Council(1).