Stationary battery systems in the main world markets: Part 1: Overview of the state-of-the-art

The role of energy storage systems (ESSs) is becoming more and more important in modern power grids, mainly because of the higher penetration of intermittent renewable energy sources (RESs), such as solar and wind power, spurred by advantageous support policies carried out in several countries. The fluctuation nature of the energy produced by RESs is indeed leading to emerging power quality issues or to renewable curtailments. ESSs can be used to balance generation and demand of electricity over time, allowing a higher penetration of RESs into the power network. The energy storage industry is evolving rapidly, and new electrochemical technologies are entering the market. Besides, most electrochemical technologies have a high cost reduction potential and they will probably attract more and more attention in the scientific, industrial and political context. This paper is the first of a two part series, aiming to provide an overview of stationary battery systems in the major world markets, identifying the ESS technologies most widely used in each storage market. In this first paper, an overview of the state-of-the-art in electrochemical storage systems is provided and the positions of some world markets on the development of ESSs is shown. Furthermore, a description of the main ESS technologies used in stationary applications is carried out and the main trends are also identified, with reference to the main electrochemical technologies currently spread in the main world markets. This has been done analyzing the U.S. Department of Energy (DOE) storage database, containing details about electrochemical projects installed in each country. The analysis carried out in this work could help stakeholders to assess the impact of energy storage policies in different countries, identifying the future trends and the most promising markets around the world

Economic analysis of different supporting policies for the production of electrical energy by solar photovoltaics in eastern European Union countries

Today, photovoltaic (PV) attracts considerable interest in relation to renewable energy technologies, because of its potential to contribute significantly to the future of renewable energy. However, PV market development is related strongly to the support policies introduced by national governments, defined in national laws. The modification or fading out of such incentive schemes can strongly influence the development of the PV market in any given country. In this paper, after a brief review of national support policies in PV technology in eastern European Union (EU) countries, the authors perform an economic analysis of the main support mechanisms that are implemented in these countries. The comparative analysis is based on the calculation of the cash flow, the Net Present Value (NPV) and the Internal Rate of Return (IRR) indices. The analysis shows that in some situations, support policies can be inconvenient for the owner of the PV system and that, in many cases, the differences between the implementation of the same support policy in different countries, can give rise to significantly different results

Stationary battery systems in the main world markets: Part 2: Main trends and prospects

Stationary battery systems are gaining a lot of interest in recent years, mainly because of their ability to balance generation and demand of electricity over time. The intermittent nature of renewable generation connected to the power grid is causing major stability and reliability issues in the power system, that can be solved also using stationary storage systems, able to provide the ancillary services necessary to the proper operation of the power network. Despite the considerable advantages offered by these technologies, the electrochemical storage industry is still in the nascent state and it is important to identify the main trends and prospects in relation to future technical developments, regulatory landscape and future commercial models. This paper is the second of a two-part series, aiming to provide an overview of stationary battery systems in the major world markets, identifying the applications most widely used in each storage market. In this second paper, a country overview is provided for each of the selected markets, in terms of policy regulations, subsidy programs and storage installations. The main trends are also identified, with reference to the viable use cases currently spread in the main world markets. This has been done analyzing the U.S. Department of Energy (DOE) storage database, containing details about electrochemical projects installed in each country. The analysis carried out in this work could help stakeholders to assess the impact of energy storage policies in different countries, identifying the future trends and the most promising markets around the world

ECONOMIC ANALYSIS OF SUPPORT POLICIES IN PHOTOVOLTAIC SYSTEMS: A COMPARISON BETWEEN THE TWO MAIN EUROPEAN MARKETS

The development of the photovoltaic (PV) sector in the last decade was spurred by the implementation of various support strategies aimed at reducing the gap between PV energy cost and the energy price for conventional generation. The deployment of support policies has pushed the reduction of PV energy costs, but despite this PV is still not very competitive and its development still requires adequate support mechanisms, simple grid connection procedures, and so on. This chapter provides a technical-economic analysis of investments in PV systems, evaluating the positioning of the main European markets (Germany and Italy), with the purpose of highlighting the main differences in the implementation of support policies in the two top countries. Several case studies are examined, differentiated in relation to the rated power (from 3 kW to 1 MW) and the type of plant (ground-mounted and rooftop PV systems). The profitability indexes in terms of the payback period (PBP), net present value (NPV) and the internal rate of return (IRR) are evaluated throughout the reference period. The chapter is expected to be very useful for policy makers, energy producing industries and national Governments to estimate the profitability of PV investments in the two selected countries, predicting how the PV sector will evolve in each of the two EU states

Comparative economic analysis of support policies for solar PV in the most representative EU countries

The purpose of this paper is to study the positions of some European Union (EU) countries on the development of PV systems. After a review of the main support policies for PV systems in Europe, the specific situations of five representative countries (France, Germany, Greece, Italy and the U.K.) are examined, with the purpose of describing the main differences in their implementation of support policies adopted for PV systems. In particular, comparisons based on economic indexes such as the net present value (NPV) and the internal rate of return (IRR) are carried out for different sized PV systems, showing that in some situations support policies can be inconvenient for the PV system owner. The paper also shows that the best profitability for a PV system owner is obtained in those countries in which there is an active electricity compensation scheme. The comparative analysis carried out in this work could help: - to assess the impact of PV energy policies in European member states; - to predict how the PV market could evolve in the selected EU member states; - to gain an insight into the future of possible energy policies

Inseguitori solari: diverse tipologie e analisi tecnico-economica

L’utilizzo di strutture di sostegno ad inseguimento, nella realizzazione di impianti fotovoltaici, permette di ottenere un considerevole aumento dell’energia elettrica prodotta dagli stessi impianti. L’incremento di producibilità dipende dalla tipologia di inseguitore considerata (monoassiale o biassiale) ed, in misura minore, dalla località del sito d’installazione dell’impianto fotovoltaico. Nel presente testo, dopo aver preso in rassegna le diverse tipologie di strutture ad inseguimento, descrivendone le configurazioni strutturali, le tipologie di comando ed i meccanismi di movimentazione, viene svolta un’analisi di producibilità in funzione della latitudine del sito d’installazione dell’impianto fotovoltaico. I valori di producibilità vengono infine utilizzati per effettuare una valutazione tecnico-economica delle diverse tipologie di inseguitori, tenendo conto del sistema di incentivazione attualmente vigente nel territorio italiano

Battery storage systems for peak load shaving applications: Part 1: Operating strategy and modification of the power diagram

Battery Energy Storage Systems (BESSs) are gaining more and more attention in the current global energy landscape, thanks to some peculiar characteristics such as the versatility, modularity, scalability, fast response time, etc. BESSs can advantageously be used in the ancillary services market, in order to provide all the services necessary to ensure the stability and the reliability of the power system. Among other applications, BESS can also be used to shift electricity demand from on-peak to off-peak periods, also contributing to relieve peak demand charges, thus ensuring a saving for the customers. The BESS is charged when the electricity prices are the lowest (during the night) and discharged when the prices are the highest (during the daily hours), contemporary achieving a leveling of the daily usage pattern. This paper is the first of a two-part series, aiming to evaluate the economic feasibility of electrochemical storage systems in peak load shaving applications. The sizing and the operating strategy of the BESS are defined, so as to obtain, at the same time, the flattest daily usage pattern and the maximum benefit for the customer. A case study is analyzed, showing the modification of the power diagram when the BESS is added. The simulation results show a customer daily power profile perfectly leveled in shoulder seasons and a peak shaving effect in all other days

Battery storage systems for peak load shaving applications: Part 2: Economic feasibility and sensitivity analysis

This paper is the second of a two-part series, aiming to evaluate the economic feasibility of electrochemical storage systems in peak load shaving applications. The battery energy storage system (BESS) is considered to be added to a private facility, with the aim of reducing the customer electricity bill. The BESS is charged during the night, when the electricity prices are the lowest and discharged during the daily hours, when the prices are the highest, contemporary achieving a leveling of the daily usage pattern. The economical evaluations are carried out considering four different electrochemical technologies: lithium-ion (li-ion), advanced lead-acid, sodium-sulphur (NaS) and flow batteries. First, the total costs and savings are estimated, calculating the net present value (NPV) and the internal rate of return (IRR) for each BESS technology. The economic indexes are calculated referring both to 2015 and to the estimated 2020 BESS prices. Second, a parametric analysis is carried out to investigate the effect of several parameters on the economic feasibility of installing a BESS. The considered parameters are: i) the gap between high and low electricity prices; ii) the peak demand charges; iii) the BESS investment costs. The economic analysis reveals that none of the BESS technologies are cost effective at the current BESS prices, without incentives, but the situation could already change in 2020 thanks to the sharp cost decline expected in the coming years

Effects of electrical and mechanical parameters on the transient voltage stability of a fixed speed wind turbine

In this paper the dynamic behavior of a wind turbine connected to the grid is examined. The model of the fixed speed wind turbine has been developed with the Simulink simulation tool (Matlab Inc.) It is composed of the induction generator, the shaft system, an aerodynamic model of the wind turbine rotor and the pitch control system. Using this model, a three-phase fault is applied close to the wind turbine and cleared by disconnecting the faulty line. The rigorous implementation of the simulink model allowed the authors to evaluate the exact dependence of various electrical parameters for the induction generator on voltage stability. Furthermore, the effects of wind turbine mechanical construction and of grid parameters on voltage stability are also evaluated and discussed. For each parameter, the terminal voltage and the generator rotor speed for different fault-clearing times are drawn. Finally, the terminal voltage and the generator rotor speed obtained for a fifth order model of the induction generator are compared with those obtained for a third order model. The differences between the two models are discussed. The results will help to understand transient stability phenomena in wind farms