How are the BESS and GEP connected to the grid? Are they DC-connected and share one grid connection point and metering point connected? If not, do the BESS and GEP have separate grid connections and metering points?
According to the CRESS Guidelines, Clause 8.14, Renewable Energy Developer (RED) shall install BESS with direct connection to fulfill the firming requirement. The size of BESS is at least 50% of the GEP registered capacity or the tested capacity during commissioning, whichever is lower.
a. Direct connection here means the GEP and BESS are directly connected to the 132kV busbar at the RED facility via either 132/33kV or 132/11kV step-up transformer individually. These transformers shall be appropriately sized (in MVA) to allow maximum delivery from GEP and BESS without overloading their individual transformers while doing this.
b. The minimum GEP size under the CRESS program is 30MW; therefore, based on the required firming, BESS shall be at least 15MW, 4hours. As such, the BESS and GEP connection is required to be AC-coupled.
c. In the CRESS Guideline, a meter MRED is required and will be installed at the Interconnection Facility by the EUC (electricity utility company, in this case TNB) for energy billing purposes. However, RED is encouraged to install an individual meter at its GEP and BESS, especially if the GEP and BESS are at different locations, to be ready for future use.