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• Pioneer Spain: first country to include in grid code the synthetic inertia capability. • Synthetic inertial response of a PV inverter studied based on the Spanish grid code. • Analyzed the role of power plant controller in the dynamic response of the facility. • PV system able to contribute to frequency control providing an inertial response. As the large-scale integration of renewable energy grows, inertia in power systems is reduced, which causes the rate of change of frequency to increase and worsens the frequency nadir during disturbances. There is, therefore, an urgent need to accelerate the development of international standards and regulations that require solar PV systems and other renewable installations to also contribute to stability in the network by emulating inertia. Spain is a pioneer in this field: it is currently the only country that includes the synthetic inertia technical requirement in its grid code. In this context, the present paper analyzes the synthetic inertial response of a PV system model that forms part of an actual PV power plant in Spain under two scenarios, according to its grid code: i) when measurements are conducted at the power conversion PV system level and hence only its control algorithms are executed; and ii) when measurements are conducted at the power plant level and the power plant controller also influences the response of the entire installation. Among its aims, this paper seeks to thoroughly assess the response of an actual PV power conversion system that has the capability of actively contributing to frequency regulation in a network and to critically analyze the suitability of having a power plant controller when the PV facility contributes to power-frequency control by means of an inertial response. The results reveal, at the power conversion PV system level, that the inertia emulation module significantly reduces the response times of the installation to changes in frequency -by more than 68% in the worst case under frequency increases, and by 73% under frequency decreases, thus contributing to more rapid power-frequency regulation in the network. However, at the power plant level, the power plant controller disturbs the PV power conversion system's behavior and causes the opposite effect: response times increase -up to more than 7% in the most unfavorable case when the inertia module is enabled. [ABSTRACT FROM AUTHOR]

This paper proposes the first application of a split-range control technique on a concentrating solar collector to improve an absorption plant production. Solar absorption plants have solar power availability in phase with cooling demand under design conditions. Thus, it is a powerful cooling technology in the context of renewable energy and energy efficiency. These plants need control systems to cope with solar irradiance intermittency, reject irradiation disturbances, manage fossil fuels backup systems and dump closed-loop thermal-hydraulic oscillations. In this work, control techniques are proposed and simulated in an absorption plant in Spain. The plant consists of a concentrating Fresnel solar collector connected to an absorption chiller. The objectives are to operate with 100% renewable solar energy and avoid safety defocus events while reducing temperature oscillations and control actuators effort. Firstly, the current available plant controllers are defined, then two modifications are proposed. The first modification is a split-range controller capable of manipulating both flow and defocus of the Fresnel collector, the second modification is a PI controller to substitute the original chiller on-off controller. The results compare, through validated models, the different control systems and indicate that using both proposed controllers reduces 94% of the sum of actuators effort and 43% of the integral of absolute set-point tracking error compared to the plant's factory pre-set controllers. The suggested controllers increase 66% of energy production and 63% of exergy production. Besides, the split-range technique can be extended to any concentrating solar collector control. [Display omitted] [ABSTRACT FROM AUTHOR]

The European Commission and EU Member States have recently promoted legislation (under the REPower EU Plan) to accelerate renewable energy projects by allowing the elimination or reduction of environmental assessment and public participation in the approval procedure. To avoid adverse effects on the environment, these regulations propose the exclusion of certain areas (identified through available information on protected and/or environmentally sensitive areas) from the procedure. This paper aims to evaluate whether such measures are effective to avoid damage to biodiversity from the implementation of photovoltaic energy. To this end, we studied the distribution and abundance of a threatened bird species, the Black-bellied Sandgrouse, at two geographic scales: i) regional: Andalusia (southern Spain); ii) local: Campo de Tabernas (an excellent example of the semi-arid ecosystems of southeastern Spain) and evaluated the quality of the information that Administrations have on the species by comparing it with own censuses. We also assessed the effectiveness of the environmental impact procedure for photovoltaic plants planned in Campo de Tabernas. Data from the regional Administration reveal that Andalusian protected areas cover a minimal part (17.7%) of the species' range. Moreover, neither the regional nor the national Administration have reliable and updated information on the distribution of the species in Campo de Tabernas (only 17% of the current distribution area is known). The wrong choices made by developers about where to locate the photovoltaic plants together with wrong decisions of the regional Administration (with land-use planning competences, including the planning of power plant locations) have led to the loss of 630 ha of the species' range in Campo de Tabernas. Public participation of experts prevents, through allegations to the projects, an important part of the impact on the species. Policy implications: the information that the Administrations have on this species does not allow them to make proper decisions on where to apply renewable acceleration. Obtaining complete and updated information on the distribution of endangered species to elaborate detailed wildlife sensitivity areas is essential and urgent before implementing measures to accelerate renewables. • The new EU renewable acceleration directives are analysed here for the first time. • A threatened species becomes locally extinct due to solar power plants' poor planning. • Involving experts in EIA procedure greatly reduces the impact on a threatened species. • The design of renewable go-to areas demands specific research on threatened species. • Current EU legislation to accelerate renewables will negatively affect biodiversity. [ABSTRACT FROM AUTHOR]

• Evaluation of the most recent Spanish grid code requirements. • A new tool to speed up the commissioning of new solar PV power plants is presented. • The accuracy of the aggregated PV power plant dynamic model proposed is demonstrated. • The aggregated model is shown to be ten times faster than the detailed equivalent. • The aggregated solar PV power plant simulation model approved by the Spanish TSO. Renewable energy and, in particular, solar PV power, will play a crucial role in achieving net-zero emissions scenarios over the coming decades. Increasing the share of renewables in countries' energy mixes is therefore a major challenge that must be urgently addressed. Within this context, the present work proposes an innovative tool that may accelerate the commissioning process of new solar PV power plants, in the form of an aggregated simulation model to assess a power plant's responses under the technical requirements established in the Spanish grid code. Our analyses, based on the comparison of the proposed model with a detailed model -both representing the same installation, show, from a quantitative and qualitative viewpoint, the accuracy and usefulness of the dynamic simulation model proposed. The aggregated model is shown to be ten times faster than the detailed equivalent, while the errors encountered in the simulation responses of both models are below 0.1% in all cases. It must also be noted that the present paper has allowed for the introduction, in the most recent version of the Spanish grid code and following approval of the Spanish Transmission System Operator (TSO), Red Eléctrica de España (REE), of this new and advantageous PV power plant model. Finally, it is worth mentioning that this study could form the basis for encouraging other countries to also adopt this model in their grid codes as a new tool to help integrate PV power into power grids. [Display omitted] [ABSTRACT FROM AUTHOR]