MERC (N ET METERING FOR R OOF - TOP S OLAR P HOTO V OLTAIC S YSTEMS ) R EGULATIONS, 2015 Commercial Section

B ACKGROUND MERC has notified regulations of net metering for Roof-top Solar Photo Voltaic Systems,2015 on 10th Sept The objective of the Regulations is to give access to the Grid to the consumers installing rooftop/ground mounted solar system in their premises. There was a demand from the consumers regarding connectivity to the Grid / Distribution network for the Rooftop solar projects. The states such as Gujarat, Karnataka, Andhra Pradesh, Chhattisgarh, Rajasthan, Punjab, Tamilnadu, Kerala etc. has already notified the net metering and connectivity regulations for Rooftop solar.

S ALIENT FEATURES ParametersDescription Eligible consumer who uses or intends to use a Solar Photo Voltaic (‘PV’) generating System having a capacity less than 1 MW, installed on a roof-top or any other mounting structure in his premises, to meet all or part of his own electricity requirement, and includes a Consumer catering to a common load such as a Housing Society Max Allowable CapacityNot more than contract demand Basis of allowing net metering First come first serve basis; 40% of the DT capacity Grid Inter-connectionAs per CEA – Tech Std for connectivity of DG resources; CEA ( Measures relating Safety and Electric supply), Regulations, 2010 and the MERC (State Grid Code) Regulations,2006

C ONTINUED : ParametersDescription Capacity Limits for interconnection Energy Accounting Net billing basis Surplus to carry forward to next billing cycle Any Net injection will be settled at Commission’s approved Average cost of Power Purchase of the Distribution Licensee for respective financial year. TOD Based Settlement Energy to be settled in the ToD block it was generated in and any excess shall be set off against off-peak consumption Metering Bi-directional net meter Voltage levelThreshold limit of Rooftop Solar PV system 230/240 V(1 Ф)Less than 8 kW/40 A 400/415 V (3 Ф) Less than 150kW/187 kVA (in Municipal Corporation areas) Less than 80kW/100 kVA (in other areas) 11kV and above Above 150KW/187 KVA and less than 1000 KVA (in Mumbai Metropolitan Region) Above 80 kW/100 kVA and less than 1000 kVA (in other areas)

S CHEMATIC D IAGRAM

I SSUES RELATED TO MSEDCL Financial Impact – Revenue loss to MSEDCL as subsidizing consumers opt for net metering – Procurement of Net Meters – Purchase of surplus power at the end of Financial year – MSEDCL has to bear fixed cost on account of generation capacity already contracted. – MSEDCL will lose its subsidizing high paying consumers

I SSUES RELATED TO MSEDCL…C ONTINUED DTC wise load survey/Load flow study to be carried out: a. Large No. of DTCs > 4 Lakhs b. The DTC wise spare capacity for connectivity available to be displayed on MSEDCL web-site, which is already displayed. c. The information of DTC wise capacity available and cumulative capacity of Rooftop solar system installed on each DTC have to be updated quarterly. Net metering specifications ( finalized): a.Two meters are to be installed. Existing meters to be replaced by Net Meter and separate meter for recording of Solar generation. b. HT (11 kV and above) Consumers may install and connect Roof-top Solar PV System at their LT Bus Bar System – However in such cases Net Meter shall be installed on HT side of transformer. c. The Distribution Licensee shall be responsible for the supply, installation, testing and maintenance of the metering equipment, and its adherence to the applicable standards and specifications.

I SSUES RELATED TO MSEDCL…C ONTINUED Billing and accounting methodology for such consumers to be discovered: a. Banking to be given to the consumers. The monthly surplus units after own consumption injected into Grid are to be carried forward to next billing month. b. The Surplus units balanced at the end of Financial year are to be purchased by MSEDCL at Average power Purchase cost which shall be accounted for RPO. c. The quantum of electricity consumed by the Eligible Consumer from Roof-top Solar PV System under the Net Metering arrangement shall, if such Consumer is not an Obligated Entity, qualify towards meeting the Solar RPO of MSEDCL Safety precautions and related protections: a. Proper Islanding protection is required to be provided by the consumer for isolation of network in absence of Grid supply. b. The Licensee shall not be responsible for any accident resulting in injury to human beings or animals or damage to property that may occur due to back- feeding from the Roof-top Solar PV System when the grid supply is off.

Thank You