Discoms in almost all the states serve the Net Metering amenity by which the consumers can stock the excess energy produced from the roof top solar plant with the Discom Grid and can use it in future hours.
During the Sun hours, while the load (in KW) of the factory or the commercial edifice is less than the roof top solar production for any 15-minute block interim, the surplus solar energy goes back to the Grid. In the evening hours, when the load is added and there is barely any solar production, then the deposited solar energy is used back by the user from the Grid.
The accounting of the roof top solar energy is done on a monthly basis.
- At the end of each month, the solar energy is set off against the energy consumed by the factory or the Plant through a bi-directional meter installed by the Discom at the Consumer premises.
- If there is any excess solar energy which is not used during the month, it is taken forward to the next month in which the consumer can use the same.
- However, if there is unused solar energy left in March (end of Financial Year), then it will lapse as per the policy in Haryana while it will be paid at Rs 2.0 /kWh in Uttar Pradesh. Similar policies exist in other states also including Delhi, Rajasthan, and Punjab.
So, there is excess solar generation in the months of April and March. However, the excess generation of April month is utilized in future months during the settlement year. But the excess solar generation in month of March will lapse in spite of Net Metering facility.
Especially for seasonal industries that have a lean period during winter months, the coincidence of the settlement year with the financial year is a problem. For example, the potato cold storages (aloo godowns) have this typical problem as they hit an off-season from October to February when their load dips significantly.