Increased Penetration Of Renewable Energy Sources Research Articles

Increasing RES penetration through H2 technologies on Flores island, Azores: A techno-economic analysis

On Flores island (Azores, Portugal), energy production depends up to 47% on fossil fuels, namely Diesel. To minimize CO2 emissions, the dependency on fuel prices, and to mitigate the consequences of variability and intermittency of renewable energy sources, a new energy system, based on H2 storage was analysed. To achieve the optimal size of the system, a computer model was developed and a multi-objective genetic algorithm function was used to minimize three objectives: the difference of levelised cost of energy (△LCOE), CO2 emissions and the percentage of renewable energy dumped (RRES, dump). From the set of solutions obtained, one that meets RRES, dump ≤ 1%, lowest CO2 emissions and lowest △LCOE is chosen and an economical and energetic analysis is performed. The newly proposed system reduces Diesel consumption by 68,7% (1057487 L/year) and CO2 emissions by 65,9% (2455,1 CO2 tons/year) achieving a renewable energy sources (RES) penetration of 89% (36% increase), but fails to decrease the levelised cost of energy (56,62 €/MWh increase). However, a way to make the project viable through financial support is presented and an alternative to reduce the levelised cost of energy by commercialising the products of electrolysis, hydrogen and oxygen, is proposed. Finally, it is expected that with further research and development of H2 technologies, economic and energetic results will get more advantageous, opening up new perspectives for the future.

Impact of Societal Events on Frequency Stability Considering LED TVs in Low Inertia Trending Power Systems

Due to environmental concerns, renewable energy sources (RESs) gradually replace conventional power generations. Over the past decade, wind and solar electricity generation have increased from 55 to 275 million MW·h and from 2 to 96 million MW·h, respectively, in the U.S. Recently, FERC order 2222 allows distributed energy resources, including distributed renewable generation and energy storage, to participate in the electricity wholesale market through aggregations. Limited rotating inertia of renewable generation resources results in reduced system inertia, which will increase the rate of change of frequency due to sudden mismatches of generation and demand. During the high visibility national social event, the brightness of LED TV display put simultaneous demand change in power systems. With the development of slim, tightly packaged, and yearly update features of smart TV, the penetration of different LED displays climbed rapidly from 9% to 60% in the U.S. during 2012–2019. In this article, the impact of societal events on frequency stability caused by large viewership on LED TVs are discussed. Increasing RESs penetration and FERC order 2222 are considered in this study. The power demand data of a 55-inch LED TV are collected and analyzed to address the problem. This article discusses the frequency stability issue caused by LED TVs in a low inertia power system. It can help system operators to develop frequency control practices accordingly.

Optimising energy flows and synergies between energy networks

The increased use of fluctuating renewable energy sources (RES) that is expected in the near future will lead to challenges concerning their full integration in the distribution grid, the reduction of RES curtailments and the mitigation of electric unbalances on the grid. Besides electric batteries (EB), other technologies, such as Power-to-Gas (P2G), Power-to-Heat (P2H) and Combined Heat and Power (CHP), make it possible to exploit synergies between various energy networks, thus alleviating problems of RES integration. In fact, when these technologies work simultaneously in a single energy system, their installed power mix, along with their optimised management and control, play a fundamental role in the energy optimisation of the whole system.The aim of this paper is to offer a methodological approach for the analysis of the synergies between the different energy networks in order to cope with the increasing RES penetration. The proposed model has been used to perform a sensitivity analysis on the installed capacity of the various technologies; moreover, different simplified system management logics have been analysed by changing the priority order of the renewable energy surplus usage. The obtained results have been compared from an energetic, economic and environmental point of view.