Tariffs

Approach to tariff determination (based on the case of the Himachal Pradesh Electricity Regulatory Commission, India)

The Commission while determining the tariff, in the past has kept numerous factors and principles in view, which has already been outlined in the Tariff Regulations. Some of the important measures it has undertaken in the past tariff orders are mentioned below:

• introduction of kWh and time of use tariffs for various categories of consumers
• slab rationalisation across categories of consumers
• cost-to-serve approach in determination of tariff for various consumer categories
• rationalise the Peak Load Exemption Charge (PLEC) and the Peak Load Violation Charge (PLVC)
• introduction of a night time concessional tariff for industrial consumers

The Commission believes that there is further scope for tariff rationalisation across various consumer categories, which will make the industry more competitive, drive growth in the state and attract investments into the sector. The NEP states that consumers below poverty line, who consume below a specified level, say 30 units per month, may receive special support in terms of tariff, which is cross-subsidized. In Himachal Pradesh, such support is currently available to consumers below poverty line consuming 45 units per month. Commission may rationalise the existing slabs for domestic consumers further. The Commission may align the qualification criteria for support in terms of tariff in line with what has been suggested by the National Electricity Policy. The Policy also states that tariffs for such designated group of consumers will be at least 50 % of the average (overall) cost to serve. The Commission will also consider this guideline when determining the tariff for such consumers. It also believes that the future tariff determination exercise will be based on Cost to Serve and under a Multi Year Tariff framework.

Cost to Serve (CoS)

The Classical CoS approach is based on estimating the voltage-wise cost, losses and coincident demand factor, i.e. the extent to which each consumer category contributes to the peak demand. Broadly, there are two approaches to determining the cost of supply: The Embedded Cost Approach and the Marginal Cost Pricing Approach.

• The Embedded Cost Approach seeks to identify and assign the historical, or accounting costs that make up a utility’s revenue requirement.
• Marginal cost approach seeks to determine the incremental (marginal) change in total costs imposed on the system by a change in output (whether measured by kWh, customer, customer group or other relevant cost driver).

While being a forward-looking approach, marginal cost studies are data intensive and are, therefore, contingent upon the accuracy of data. Embedded Cost Model can be easily implemented and understood and data is readily available and verifiable.

Methodology adopted by the Commission

The Commission adopted the CoS approach for the first time in the tariff order of 2004-05 based broadly on the embedded cost approach. In absence of data on daily load curves of various consumer categories the Commission had slightly deviated from this approach. However, the Commission had then observed that the current analysis would not be affected much, because of absence of essential information required to implement the classical model, since in case of Himachal Pradesh, the state is in surplus during the summer, when most of the country faces peak demand and cost of power purchase is high. Conversely, in Himachal Pradesh the peak occurs in winters when the country does not face any deficit, power purchase price is lower than average and therefore coincident demand would not have any perceptible impact on CoS. The Commission designed and developed a Cost to Serve model on the ‘basic assumption’ that power in Himachal Pradesh electricity network flows through each voltage level to reach Low-Tension (LT) consumer. The Commission also made certain assumptions to arrive at the losses at various voltage levels and network cost at various voltage levels. The CoS for various voltage levels was determined and thereafter COS to various consumer categories falling in those voltage categories was assigned.

Though the Commission had given directions to the HPSEB in 2004-05 to submit relevant data to enable computation of the voltage level cost of supply in a more scientific and robust manner, the HPSEB had not submitted any additional data at the time of filing the tariff petition for 2005-06 and had proposed tariffs in relation to the average cost of supply. Accordingly, the Commission again had to apply its own basis and assumptions to determine the voltage level cost of supply. Considering that there is no additional data to either prove or disprove the assumptions considered by the Commission in the previous tariff order, the Commission has by and large retained the same assumptions, apart from some changes to the loss levels in line with the target loss levels for FY2005-06 in the tariff order issued for 2005-06.

The Commission proposes to continue with the same methodology while designing tariffs for the ensuing year 2006-07 since the Board has again neither filed the present petition on the COS basis and nor has it submitted any additional data to either prove or disprove the assumptions considered by the Commission in the previous tariff orders.

The existing tariff structure in the State indicates that the tariffs are below the cost to serve (determined as per methodology explained above) for some consumer categories and higher than the cost to serve for other categories. The Commission recognises this distortion and has been taking suitable steps from its first Tariff Order to remove this cross subsidisation in a phased manner keeping the interests of both the licensee and the consumers into consideration. In the Tariff Order for FY 2005-06, the Commission moved a step further towards the reduction of cross-subsidy and attempted to align the tariffs with the cost to serve. The Commission finds no reason to deviate from this path in the forthcoming tariff order.

The Commission recognises that the cost to serve for various consumer categories would require extensive, reliable and credible data and information which is a separate detailed exercise on its own. Therefore the Commission would like the utility to take adequate steps in this regard and make the tariff filing for FY 07-08 on the basis of Cost to Serve instead of Average cost to serve.