Toine Van Megen and Martin Scherfler
Feeder segregation, the installation of dedicated electricity supply lines for agriculture, is often celebrated as the solution to the electricity utilities pain point of free or highly subsidized electricity supply for agriculture. But does it address the root cause of the issue?
Feeder segregation requires double the number of rural feeders with substation bays, circuit breakers, right-of-way width, poles, cross arms, insulators, air-break switches, distribution transformers and LT distribution networks to serve the same number of consumers. In fact, it implies a duplication of the whole rural electricity distribution system. This comes not only with a high capital cost, but also with a significant increase in operating costs.
Imagine a consumer, who needs an electrical connection for a workshop, shop or residence and who is located very close to an agricultural feeder. For this consumer a separate non-agricultural HT feeder, transformer and LT line will have to be drawn to maintain ‘feeder segregation’. Eventually ‘exceptions’ to the feeder segregation will be made under pressure from consumers. Electrical agricultural service connections that are located close to non-agricultural lines will be connected to these lines and non-agricultural consumer will be connected to nearby agricultural feeders. Back to square one but with double the rural electrical distribution infrastructure to maintain!
For the solarisation of agriculture there is no need of feeder segregation . Solar PV systems can, and should as much as possible, be connected to mixed-use rural feeders (agriculture and non-agriculture). This will result in the same electricity supply cost reductions than what can be achieved with dedicated agricultural feeders, but without the additional capital and maintenance costs. In fact, it will be more effective as there will be less distribution losses. The probability of locally produced solar energy getting consumed close to the solar PV system is much higher with a mixed load feeder.
A feeder which is used exclusively for agriculture will be idle during many hours in the day, especially during night time hours, and many days in the year. When it rains, the feeder will not have any load as the farmer does not need to pump water for irrigation. In this case the solar energy generated at the agricultural feeder will flow all the way to the substation and find its way to the loads of other outgoing feeders or to the incoming EHT substation feeder (e.g. 110KV).
The idea of introducing separate agricultural feeders seems to be driven by the following concerns and issues:
- The absence of electricity meters at most agricultural service connections, resulting in a lack of reliable electricity consumption data for agriculture. With a dedicated agricultural feeder you can do feeder-wise energy metering;
- Load shedding of agricultural loads without affecting other rural consumers;
- Reduction of commercial losses to the utilities on account of free electricity supply to agricultural consumers.
There at certainly more cost effective and appropriate solutions to address these issues instead of capital-intensive feeder separation. These alternative solutions may include energy metering at distribution transformer level and the running of demand response program for agriculture to reduce the need for load shedding.
The root cause, free power supply to agriculture and its impact on Discoms, is not addressed. This then justifies load shedding; load shedding justifies separate feeders and separate feeders justify even more load shedding. Agricultural consumers deserve a better deal. The root cause can be addressed by ensuring that Discoms are compensated by State Governments for the actual cost of electrical energy that they deliver to agricultural consumers and by incentivising farmers to minimise electricity (and water) consumption. The KUSUM A and C programs also contribute to addressing these issues, but for these programs to work no feeder segregation is required.
The following article was published in PV Magazine on 28th December 2020.