Settlement Calculation for Net Metering/Gross Metering/Net Billing Explained
It is very important for a prosumer (who plans to install Solar Power Plant) to understand the Solar Metering Policy applicable in the state. There are various metering arrangements available like Net-metering, Gross Metering, Net Billing, Behind the meter or Zero Export etc.
A consumer is compensated at a fixed feed-in-tariff for the total units of solar energy generated and exported to the grid (as measured by a unidirectional “gross meter”), you must pay the retail supply tariff to the power distribution company (discom) for the power consumed from the grid. Tariffs for feed-in and retail supply are different and Feed-in-tariff is mostly lower than the retail supply tariff.
Net metering is a system in which power exports are offset by imports, decreasing the electricity bill by deducting electricity generated from total electricity consumed over a set period of time. The adjustments might be made on a monthly, half-yearly, or annual basis. A bidirectional ‘net meter’ typically accounts for both power import and export. If the exported electricity is greater than the imported electricity, the surplus electricity supplied into the grid may or may not be paid depending on the state’s net metering rules.
Consumers can be paid for net access electricity that is generated and exported to the grid under net metering laws.
Here's the calculations explained as per MNRE on the different metering arrangements:-
𝘚𝘰𝘭𝘢𝘳 𝘎𝘦𝘯𝘦𝘳𝘢𝘵𝘪𝘰𝘯 – 𝟧 𝙠𝙒𝙝
𝘓𝘰𝘢𝘥 𝘤𝘰𝘯𝘴𝘶𝘮𝘱𝘵𝘪𝘰𝘯 – 𝟣𝟢 𝙠𝙒𝙝
𝘐𝘮𝘱𝘰𝘳𝘵 𝘧𝘳𝘰𝘮 𝘎𝘳𝘪𝘥 – 𝟩 𝙠𝙒𝙝
𝘚𝘰𝘭𝘢𝘳 𝘱𝘰𝘸𝘦𝘳 𝘦𝘹𝘱𝘰𝘳𝘵𝘦𝘥 𝘵𝘰 𝘎𝘳𝘪𝘥 – 𝟤 𝙠𝙒𝙝
𝘈𝘱𝘱𝘭𝘪𝘤𝘢𝘣𝘭𝘦 𝘵𝘢𝘳𝘪𝘧𝘧 𝘧𝘰𝘳 𝘭𝘰𝘢𝘥 – 𝙍𝙨. 𝟩/𝙠𝙒𝙝
𝘚𝘰𝘭𝘢𝘳 𝘵𝘢𝘳𝘪𝘧𝘧 (𝘧𝘰𝘳 𝘨𝘳𝘰𝘴𝘴/𝘯𝘦𝘵 𝘣𝘪𝘭𝘭𝘪𝘯𝘨) – 𝙍𝙨. 𝟥/𝙠𝙒𝙝
𝘛𝘰𝘵𝘢𝘭 𝘣𝘪𝘭𝘭 𝘢𝘮𝘰𝘶𝘯𝘵 𝘪𝘧 𝘵𝘩𝘦𝘳𝘦 𝘸𝘢𝘴 𝘯𝘰 𝘴𝘰𝘭𝘢𝘳 𝘪𝘯𝘴𝘵𝘢𝘭𝘭𝘦𝘥 = 𝟣𝟢𝙭𝟩 = 𝙍𝙨. 𝟩𝟢/-
𝗖𝗮𝘀𝗲-𝟭 𝗡𝗲𝘁 𝗠𝗲𝘁𝗲𝗿𝗶𝗻𝗴
Billing will be done on net drawl from grid, which is 5 kWh
Bill amount = 5x7 = Rs. 35/-
Saving to consumer = Rs. 70/- minus Rs. 35/- = Rs. 35/-
𝗖𝗮𝘀𝗲-𝟮 𝗚𝗿𝗼𝘀𝘀 𝗠𝗲𝘁𝗲𝗿𝗶𝗻𝗴
Billing will be done on amount on account of total consumption by load (minus) amount on account of total (gross) solar power generated
Bill amount = (10x7) – (5x3) = Rs. 55/-
Saving to consumer = Rs. 70/- minus Rs. 55/- = Rs. 15/-
𝗖𝗮𝘀𝗲-𝟯 𝗡𝗲𝘁 𝗕𝗶𝗹𝗹𝗶𝗻𝗴
Billing will be done on amount on account of total drawl from grid (minus) amount on account of solar power injected into grid
Bill amount = (7x7) – (2x3) = Rs. 43/-
Saving to consumer = Rs. 70/- minus Rs. 43/- = Rs. 27/-