Heike Wetzel

The Costs of Power Interruptions in Germany: A Regional and Sectoral Analysis

Abstract A high standard of security of electricity supply comes at serious electricity system costs. However, these system costs have to be balanced with the economic costs induced by an insecure supply of electricity. Following a macroeconomic approach, we analyze the economic costs imposed by potential power interruptions in Germany. Using an extensive dataset on industries and households, we estimate both Values of Lost Load and the associated hourly costs of power interruptions for different German regions and sectors. We find that interruption costs vary significantly over time, between sectors and regions. Peaking at midday on a Monday in December at 750 Mio € per hour, the average total national outage costs amount to approximately 430 Mio € per hour. A missing gigawatt hour creates average outage costs of about 7.6 Mio €.

Efficiency Effects of Quality of Service and Environmental Factors: Experience from Norwegian Electricity Distribution

Since the 1990s, efficiency and benchmarking analysis has increasingly been used in network utilities research and regulation. A recurrent concern is the effect of environmental factors that are beyond the influence of firms (observable heterogeneity) and factors that are not identifiable (unobserved heterogeneity) on measured cost and quality performance of firms. This paper analyses the effect of geographic and weather factors and unobserved heterogeneity on a set of 128 Norwegian electricity distribution utilities for the 2001-2004 period. We utilize data on almost 100 geographic and weather variables to identify real economic inefficiency while controlling for observable and unobserved heterogeneity. We use the factor analysis technique to reduce the number of environmental factors into few composite variables and to avoid the problem of multi-collinearity. We then estimate the established stochastic frontier models of Battese and Coelli (1992; 1995) and the recent true fixed effects models of Greene (2004; 2005) without and with environmental variables. In the former models some composite environmental variables have a significant effect on the performance of utilities. These effects vanish in the true fixed effects models. However, the latter models capture the entire unobserved heterogeneity and therefore show significantly higher average efficiency scores.

Investigating the Influence of Firm Characteristics on the Ability to Exercise Market Power – A Stochastic Frontier Analysis Approach with an Application to the Iron Ore Market

This paper empirically analyzes the existence of market power in the global iron ore market during the period 1993-2012 using an innovative Stochastic Frontier Analysis approach introduced by Kumbhakar et al. (2012). In contrast to traditional econometric procedures, this approach allows for the estimation of firm- and time-specific Lerner indices and, therefore, the assessment of the influence of individual firm characteristics on the ability to generate markups. We find that markups on average amount to 20%. Moreover, location and experience are identified to be the most important determinants of the magnitude of firm-specific markups.

The impact of ownership unbundling on cost efficiency

Several countries around the world have introduced reforms to the electric power sector. One important element of these reforms is the introduction of an unbundling process, i.e., the separation of the competitive activities of supply and production from the monopole activity of transmission and distribution of electricity. There are several forms of unbundling: functional, legal and ownership. New Zealand, for instance, adopted an ownership unbundling in 1998. As discussed in the literature, ownership unbundling produces benefits and costs. One of the benefits may be an improvement in the level of the productive efficiency of the companies due to the use of the inputs in just one activity and a greater level of transparency for the regulator. This paper analyzes the cost efficiency of 28 electricity distribution companies in New Zealand for the period between 1996 and 2011. Using a stochastic frontier panel data model, a total cost function and a variable cost function are estimated in order to evaluate the impact of ownership unbundling on the level of cost efficiency. The results indicate that ownership separation of electricity generation and retail operations from the distribution network has a positive effect on the cost efficiency of distribution companies in New Zealand. The estimated effect of ownership separation suggests a positive average one-off shift in the level of cost efficiency by 0.242 in the short-run and 0.144 in the long-run.