Identifying opportunities for developing CSP and PV-CSP hybrid projects under current tender conditions and market perspectives in MENA – benchmarking with PV-CCGT

Concentrating solar power (CSP) is one of the promising renewable energy technologies provided the fact that it is equipped with a cost-efficient storage system, thermal energy storage (TES). This solves the issue of intermittency of other renewable energy technologies and gives the advantage of achieving higher capacity factors and lower levelized costs of electricity (LCOE). This is the main reason why solar tower power plants (STPP) with molten salts and integrated TES are considered one of the most promising CSP technologies in the short term [1]. On the other hand, solar photovoltaic (PV) is a technology whose costs have been decreasing and are expected to continue doing so thus providing competitive LCOE values, but with relatively low capacity factors as electrical storage systems remain not cost-effective. Combining advantages and eliminating drawbacks of both technologies (CSP and PV), Hybridized PV-CSP power plants can be deemed as a competitive economic solution to offer firm output power when CSP is operated smartly so that its load is regulated in response to the PV output. Indeed previous works, have identified that it would allow achieving lower LCOEs than stand-alone CSP plants by means of allowing it to better utilize the solar field for storing energy during the daytime while PV is used [1]. On the fossil-based generation side, the gas turbine combined cycle (CCGT) occupies an outstanding position among power generation technologies. This is due to the fact that it is considered the most efficient fossil fuel-to-electricity converter, in addition to the maturity of such technology, high flexibility, and the generally low LCOE, which is largely dominated by fuel cost and varies depending on the natural gas price at a specific location. Obviously, the main drawback is the generated carbon emissions. In countries rich in natural gas resources and with vast potential for renewable energies implementation, such as the United Arab Emirates (UAE), abandoning a low LCOE technology with competitively low emissions – compared to coal or oil - and heading to costly pure renewable generation, seems like an aggressive plan. Therefore, hybridizing CCGT with renewable generation can be considered an attractive option for reducing emissions at reasonable costs. This is the case of the UAE with vast resources of both natural gas and solar energy. Previous work have shown the advantages of hybrid PV-CCGT and hybrid PV-CSP plants separately [1][2]. In this thesis, CSP and the two hybrid systems are compared on the basis of LCOE and CO2 emissions for a same firm-power capacity factor when considering a location in the UAE. The results are compared against each other to highlight the benefits of each technology from both environmental and economic standpoints and provide recommendations for future work in the field. The techno-economic analysis of CSP (STPP with TES), PV-CSP(STPP with TES) and PV-CCGT power plants have been performed by DYESOPT, an in-house tool developed in KTH, which runs techno-economic performance evaluation of power plants through multi-objective optimization for specific locations[1]. For this thesis, a convenient location in the UAE was chosen for simulating the performance of the plants. The UAE is endowed by the seventh-largest proven natural gas reserves and average to high global horizontal irradiation (GHI) and direct normal irradiation (DNI) values all year round, values considered to be lower than other countries in the MENA region due to its high aerosol concentrations and sand storms. The plants were designed to provide firm power in two cases, first as baseload, and second as intermediate load of 15 hours from 6:00 until 21:00. The hours of production were selected based on a typical average daily load profile. CSP and PV-CSP model previously developed by [3][1] were used. Ideally in the PV-CSP model, during daytime hours the PV generation is used for electricity production, covering the desired load, while CSP is used partly for electricity production and the rest for storing energy in the TES. Energy in the TES system is then used to supply firm power during both periods of low Irradiance and night hours or according to need. A PV-CCGT model has been developed which operates simultaneously, prioritizing the availability of PV while the CCGT fulfils the remaining requirement. There is a minimum loading for the CCGT plant which is determined by the minimum possible partial loading of the gas turbine restricted by the emission constraints. Accordingly, in some cases during operation PV is chosen to be curtailed due to this limitation. The main results of the techno-economic analysis are concluded in the comparative analysis of the 3 proposed power plant configurations, where the PV-CCGT plant is the most economic with minimum LCOE of 86 USD/MWh, yet, the least preferable option in terms of carbon emissions. CSP and PV-CSP provided higher LCOE, while the PV-CSP plant configuration met the same capacity factor with 11% reduction in LCOE, compared to CSP

Peak shaving through battery storage for low-voltage enterprises with peak demand pricing

The renewable energy transition has introduced new electricity tariff structures. With the increased penetration of photovoltaic and wind power systems, users are being charged more for their peak demand. Consequently, peak shaving has gained attention in recent years. In this paper, we investigated the potential of peak shaving through battery storage. The analyzed system comprises a battery, a load and the grid but no renewable energy sources. The study is based on 40 load profiles of low-voltage users, located in Belgium, for the period 1 January 2014, 00:00-31 December 2016, 23:45, at 15 min resolution, with peak demand pricing. For each user, we studied the peak load reduction achievable by batteries of varying energy capacities (kWh), ranging from 0.1 to 10 times the mean power (kW). The results show that for 75% of the users, the peak reduction stays below 44% when the battery capacity is 10 times the mean power. Furthermore, for 75% of the users the battery remains idle for at least 80% of the time; consequently, the battery could possibly provide other services as well if the peak occurrence is sufficiently predictable. From an economic perspective, peak shaving looks interesting for capacity invoiced end users in Belgium, under the current battery capex and electricity prices (without Time-of-Use (ToU) dependency)

Decision-making methodology for managing photovoltaic surplus electricity through Power to Gas: Combined heat and power in urban buildings

Power to Gas technology, which converts surplus electricity into synthetic methane, is a promising alternative to overcome the ¿uctuating behavior of renewable energies. Hybridization with oxy-fuel combustion provides the CO2 ¿ow required in the methanation process and allows supplying both heat and electricity, keeping the CO 2 in a closed loop. The complexity of these facilities makes their management a key factor to be economically viable. This work presents a decision-making methodology to size and manage a cogeneration system that combines solar photovoltaic, chemical storage through Power to Gas, and an oxy-fuel boiler. Up to 35 potential situations have been identi¿ed, depending on the surplus electricity, occupancy of the intermediate storages of hydrogen and synthetic methane, and thermal demand. For illustration purposes, the methodology has been applied to a case study in the building sector. Speci¿cally, a building with 270 kW of solar photovoltaic installed power is analyzed under nine energy scenarios. The calculated capacities of electrolysis vary from 65 kW to 96 kW with operating hours between 2184 and 2475 h. The percentage of methane stored in the gas grid varies from 0.0% (no injection) to 30.9%. The more favorable scenarios are those with the lowest demands, showing temporary displacements beyond the month between injection and utilization

Analysis of the techno-economic viability of a solar wind hybrid power plant

The transition towards an electricity system based on renewable energies leads the battle to mitigate greenhouse gas emissions already reflected in the 2015 Paris Agreement, and it is a key line of action to comply with the international commitment to deal with the social, economic and environmental challenges of globalization, the 2030 horizon. Given the fossil fuels depletion and their polluting effect, renewable energy sources are today a clean, sustainable and inexhaustible generation alternative, where wind and photovoltaic energy, two of the most competitive renewable technologies, play a fundamental role. In Spain, single-resource renewable generation plants, such as a solar field or a wind farm, are fundamental to the modern renewable energy economy, especially in the context of one of the countries in Europe with the most people living in condominium, a housing typology that creates more barriers for the implementation of distributed generation systems in the cities. An important problem as the penetration of wind and photovoltaic energy increases lies in their intermittency, since this energy is conditioned by wind and solar resources, subject to variation in climate and time, which makes it difficult to integrate the electrical production of these sources in the electricity management and distribution system. A tool that is presented as effective to deal with this problem resides in solar wind hybrid power plants, based on the space-time complementarity of wind and solar resources. These facilities seek a less intermittent and more optimized power generation, thus supporting the reliability, profitability and stability of the network system. The design of individual solar and wind power plants involves a large number of design variables, constraints and complex physical factors, so this new paradigm creates an opportunity for the development of new integrated design approaches in which the knowledge of the resources and technologies, as well as the regulatory framework, will be essential.Ingeniería de la Energí

Challenges and prospects of renewable hydrogen-based strategies for full decarbonization of stationary power applications

The exponentially growing contribution of renewable energy sources in the electricity mix requires large systems for energy storage to tackle resources intermittency. In this context, the technologies for hydrogen production offer a clean and versatile alternative to boost renewables penetration and energy security. Hydrogen production as a strategy for the decarbonization of the energy sources mix has been investigated since the beginning of the 1990s. The stationary sector, i.e. all parts of the economy excluding the transportation sector, accounts for almost three-quarters of greenhouse gases (GHG) emissions (mass of CO2-eq) in the world associated with power generation. While several publications focus on the hybridization of renewables with traditional energy storage systems or in different pathways of hydrogen use (mainly power-to-gas), this study provides an insightful analysis of the state of art and evolution of renewable hydrogen-based systems (RHS) to power the stationary sector. The analysis started with a thorough review of RHS deployments for power-to-power stationary applications, such as in power generation, industry, residence, commercial building, and critical infrastructure. Then, a detailed evaluation of relevant techno-economic parameters such as levelized cost of energy (LCOE), hydrogen roundtrip efficiency (HRE), loss of power supply probability (LPSP), self-sufficiency ratio (SSR), or renewable fraction (fRES) is provided. Subsequently, lab-scale plants and pilot projects together with current market trends and commercial uptake of RHS and fuel cell systems are examined. Finally, the future techno-economic barriers and challenges for short and medium-term deployment of RHS are identified and discussed.This research is being supported by the Project ENERGY PUSH SOE3/P3/E0865, which is co-financed by the European Regional Development Fund (ERPF) in the framework of the INTERREG SUDOE Programme and the Spanish Ministry of Science, Innovation, and Universities (Project: RTI2018-093310-B-I00)

Electronic dispatch of energy consumption in a building with its own renewable energy - Smart house

In this study, it has been discussed methodically the control system of energy consumption from the power grid, generating electric energy on a seasonal basis (winter) heat load (thermocouples) and the utility of a set of renewable energy (solar photovoltaic, wind turbines and ground source heat pumps). It has also been taken into account the significant difference of energy network day and night consumption tariffs, seasonal heating load changes, solar insolation, and wind speeds. It has been figured out that the combined system of power supply at home, using the possibilities of the power system for the accumulation of excess renewable energy sources during the summer months, we can substantially simplify and reduce the cost of energy. The ability to use modern energy-saving equipment to simplify and reduce the consumer source system has been demonstrated. As well the new criteria for system optimization based on value analysis, the algorithm of complex consumer source control to implement a minimum cost supply at home, developed implementation flowchart of this algorithm based on modern microprocessor technology have been pointed out. © 2017 WIT Press

Demand side management studies on distributed energy resources: A survey

The number of distributed environmentally friendly energy sources and generators necessitates new operating methods and a power network board to preserve or even increase the efficiency and quality of the power supply. Similarly, the growth of matriculates promotes the formation of new institutional systems, in which power and power exchanges become increasingly essential. Because of how an inactive entity traditionally organizes distribution systems, the DG’s connection inevitably changes the system’s qualifications to which it is connected. As a consequence of the Distributed Generation, this presumption is currently legal and non-existent. This article glides on demand side management and analysis on distributed energy resources. Investigation of DSM along with zonal wise classification has been carried out in this survey. Its merits and applications are also presented.Universidad Tecnológica de Bolíva

Impacts of plasmonic nanoparticles incorporation and interface energy alignment for highly efficient carbon-based perovskite solar cells

This work utilizes a realistic electro-optical coupled simulation to study the (i) impact of mesoporous TiO2 removal; (ii) the embedding of Ag@SiO2 and SiO2@Ag@SiO2 plasmonic nanoparticles; (iii) utilization of solution-processed inorganic p-type copper(I) thiocyanate (CuSCN) layer at the perovskite/carbon interface; and (iv) the increase of the work function of carbon electrodes (via incorporation of suitable additives/binders to the carbon ink) on the performance of carbon-based PSCs. Removal of mesoporous TiO2 increased the power conversion efficiency (PCE) of the device from 14.83 to 16.50% due to the increase in exciton generation rate and charge carriers’ mobility in the vicinity of the perovskite-compact TiO2 interface. Subsequently, variable mass ratios of Ag@SiO2 and SiO2@Ag@SiO2 plasmonic nanoparticles are embedded in the vicinity of the perovskite-compact TiO2 interface. In the optimum cases, the PCE of the devices increased to 19.72% and 18.92%, respectively, due to light trapping, scattering, and strong plasmonic fields produced by the plasmonic nanoparticles. Furthermore, adding the CuSCN layer remarkably increased the PCE of the device with a 0.93% mass ratio of Ag@SiO2 nanoparticles from 19.72 to 26.58% by a significant improvement of Voc and FF, due to the proper interfacial energy band alignment and the reduction of the recombination current density. Similar results were obtained by increasing the carbon work function, and the cell PCE was enhanced up to 26% in the optimal scenario. Our results pave the way to achieve high efficiencies in remarkably stable printable carbon-based PSCs