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Use of commingling to avoid propane addition at biomethane injection points. Objective of the measurement regime for CV Protect downstream customers Comply with Gas (Calculation of Thermal Energy) Regulations
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Use of commingling to avoid propane addition at biomethane injection points • Objective of the measurement regime for CV • Protect downstream customers • Comply with Gas (Calculation of Thermal Energy) Regulations • At suitable locations where sufficient gas grid flow exists, commingling may be sufficient to produce a blended CV that does not trigger CV “cap” • CV of “pure” biomethane flow measured and used to establish energy content of gas input (and for RHI purposes) but not for testing against the local network CV re triggering CV cap • CV of commingled flow measured downstream of blending point and tested against network CV for purposes of CV cap
Example of how this works in practice – based on Adnams • Biomethane flow CV = 36.6 MJ/m3 (120 m3/h max) • Network FWACV = 39.6 MJ/m3 • Minimum flow to blending point = 5 * BM flow • Worst case blended CV = 39.1 MJ/m3 • This is 0.5 MJ/m3 less than Network FWACV; does not trigger cap • If biomethane flow were included in area FWACV calculation, it would have negligible effect on FWACV • No consumers supplied with gas prior to blending
Conclusions • Blending and remote CV monitoring can in some cases avoid the need for propane addition • In other cases blending can limit the period for which propane addition is required (and/or the volume of propane to be input) to periods of low network flow • Financial benefit to biomethane producer • Environmental benefit from mitigating fossil fuel addition • GDNs should be incentivised to identify and implement commingling opportunities