Development of stock exchange prices - consequences for innovative electricity tariffs in the German residential market

This paper deals with the analysis of the spot and future market from 2003 to 2012 of the European Energy Exchange (EEX) regarding the option of innovative electricity tariffs for residential customers in Germany. The first step was to evaluate the Phelix day-ahead spot market in respect of hourly positive and negative prices, a comparison of the price levels of the indices Base and Peak as well as the general development of the spot market. The Phelix future market was also analysed in a general way in order to find out the price levels of the procurement years in front of the corresponding delivery year. The investigation of the positive spot market price showed a maximum in 2006 because of the influences of the economic crises as well as the temperature characteristics in that year. Since 2007 the number of high positive electricity prices has almost been at the same low level as in 2004 and 2005, because of the price reducing effect of renewable energies. The development of negative prices is closely linked with the feed-in of wind power plants. Negative prices have been permitted on the day-ahead auction on the EEX since 2008. These prices occur primarily at times when a lot of wind power generation meets low demand. That is typically during the morning hours from midnight to 8 a.m. and on Sundays and holidays. Furthermore, the comparison of the indices Base and Peak of the Phelix day-ahead market showed a higher Base price level than the Peak price level in several days. This took place in 2012 on 46 days, mainly from April to September as well as on Sundays and holidays. This effect could be attributed to the influence of solar power generation during the midday hours (Merit-Order-Effect). The general development of the average Phelix spot market showed a harmonised price effect over the trading hours of a day. The main reasons are a price increase during the night hours, which is based on expensive peak load power plants as compensation of the volatile wind power generation and a price reducing effect during the midday hours because of the feed-in of solar power plants. The future markets showed price advantages for the long term procurement within the delivery years 2003 to 2009. Since 2010 the short term purchasing has been, against the current procurement strategies for retail customers, much more economical. Finally, the meaningfulness of time of use tariffs for retail customers has to be considered as very questionable because of the harmonised effect of the spot market.