Reeli Kuhi-Thalfeldt

Assessing demand side flexibility with renewable energy resources

In the perspective of network operators, demand response (DR) is a form of shaping of the overall consumption in the system by peak clipping and shifting. Bearing the necessity and importance and the role of DR in the overall system in focus, the objective of the paper is to extend an analysis on the flexibility of the demand. The potential and the corresponding cost for demand flexibility of different levels in private households is determined from literature. Following that, consumption in a residential house in Nordic Europe climatic conditions was measured. In order to identify the patterns and categorize the consumption, a clustering algorithm is implemented on time-series load demand based on the trend using Wards agglomerative hierarchical clustering to formulate classifications. Using the classifications, a model was simulated in GAMS based Balmorel platform, which chooses optimal operation scheme for categorised loads. Two distinct models were created. One as in grid integrated, where market price acts as an incentive and second as islanded mode, where the resource availability is the motivation. The resulting consumption profiles and the decision making economic stand-point of flexibility offered by means of DR are discussed. The dendogram of the associated individual devices in the consumption pattern confirms that the weekend and weekday pattern of consumption are of different construct. However, same devices provide different flexibility whether operating on workdays or weekends. Modelling results indicate an overall increase in the efficiency of energy consumption with a demand-shifting possibility. In analysis, no attention was paid to type nor price of devices that allow to control individual appliances.

Modelling of solar-wind hybrid renewable energy system architectures

Solar and wind are the most promising among the renewable energy sources. The objective of this paper is to investigate the optimal techno-economically feasible model to mitigate a large scale demand in decentralized scenario. Solar, and wind energy potential in a hybrid scenario is closely assessed with an intermittent support from diesel generator and battery banks. Based on the general usage of appliances in a residential demand for 200 families that comprises of 1000 people a suitable load pattern is developed for this study. Demand in northern Europe predominantly constitutes of heating requirement in the form of water and space heating. The proposed model demonstrates convincing reliability in terms of techno-economical prospective. EnergyPRO, HOMER, and Balmorel software environments were used to simulate the models, results are assessed in the paper.

Progress in development of renewable electricity in Northern Europe in the context of the EU 2020 renewables target

The 20% targets set for Renewables at EU level were translated into national level targets in the 2009 Directive on Renewable Energy Sources (2009/28/EC). In turn, Member States were obliged to provide a detailed plan of their proposed pathway to the targets in the form of “National Renewable Energy Action Plans”, which were due to be submitted by end June 2010 (all plans finally received by early 2011). The plans contain detailed projections for renewable electricity, heating and cooling, and transport up to 2020. This article compares actual progress in the development of renewable electricity against the intentions set out in the plans for the years 2010 and 2011. The focus is upon EU Member States in the Northern European region - Sweden, Finland, Latvia, Lithuania and Estonia. Furthermore, consideration is given to some of the specific national policies and conditions determining the level of progress against the plans to date.