Renewable Energy Sources Penetration in Greece: Characteristics and Seasonal Variation of the Electricity Demand Share Covering

Abstract

The significant penetration of renewables, in the Hellenic electricity system, during the last 12 years, was based on feed-in tariff-supporting schemes, according to the compliance to European Directives. The characteristics of this penetration are presented and analyzed in this paper based on real data. Photovoltaics, wind parks, hydroelectric plants, biomass-driven plants, and cogeneration systems are examined. The cost of the feed-in tariff incentives is qualified and analyzed. Simple but effective models are proposed to describe renewable seasonal variation: (a) A simple cosine model adequately describes the seasonal performance of various renewable technologies in terms of capacity factor; (b) a smart seasonal model based on the separation between winter and summer consumption activities (both following normal distributions) adequately describes the electricity consumption profile. The predicted values of renewable shares using the proposed models were also validated with historical data. Thus, the applied models can be used to forecast renewable shares under different penetration scenarios.

An Ex-Post Assessment of RES-E Support in Greece by Investigating the Monetary Flows and the Causal Relationships in the Electricity Market

“…Figures 4 and 5 depict the daily electricity demand and actual wind RES-E generation during the period under study. Note that seasonal variation of the time series data for both electricity demand and wind RES-E generation is in line with previous findings from the scientific literature [57]. Since identifying the correlation of two non-stationary variables is not useful, because of an either deterministic or stochastic trend, the load time series used were detrended and wind capacity factor data were selected instead of the actual wind RES-E electricity generation.…”

“…Figure 6 depicts the daily wind capacity factor for Greece, for the period under study. Note that there is not any long-term variation since the evolution of penetration does not affect capacity factors [57]. The variation that appears in Figure 6 is statistical due to weather conditions that differ among years.…”

Merit Order Effect Modeling: The Case of the Hellenic Electricity Market

“…The seasonal variation of the electricity demand appears as two peaks, one during the winter and one during the summer. Loumakis et al [31] considered the following three additive kinds of demand with different variation each: (a) A constant demand independently of the season, (b) a winter activities demand, and (c) a summer activities demand. A normal distribution was proposed to describe both the winter and summer activities with different characteristics.…”

“…A normal distribution was proposed to describe both the winter and summer activities with different characteristics. The resulting equation is [31]:…”

“…The renewable electricity production appears also to have both seasonal and daily variations. Loumakis et al [31] proved that all types of renewables follow a cosine seasonal variation with different amplitude and peak time. Thus, the resulting total renewable also appears cosine variation with characteristics depended on renewable mixture.…”