Fabrizio Fattori

Implications of the photovoltaic generation on the non-photovoltaic generation in the Lombardy region

Photovoltaic generation has reached high penetration levels in many countries. Photovoltaic like other variable renewables can have significant implications for the adequacy and operation of the power system and in general these implications can be location specific. This work focuses on the Lombardy region, in Italy, to study the implications that different penetrations of photovoltaic would have on the need for firm generation capacity and on the variability that this firm capacity would have to face. This is done by analyzing a the combination of real historical irradiance and demand data for the year 2012. Results show that even high penetrations of photovoltaic in the region would not reduce the need for firm generation. Moreover, high levels of generation from PVwould lead to higher and more frequent changes in generation. These considerations must be properly taken into account when encouraging the penetration of photovoltaic and when modeling power systems for planning purposes.

The impact of electric vehicles on the grid for local energy models

The paper investigates the role, thus the impact, that Electric drive train Vehicles (EVs) can play on a local level and it proposes a new way of taking into account events that drive the building and, eventually, the results from a scenario. This is done by means of a MarkAl local model coupled with a static transportation model. Results show the important role of Plug in Hybrid Electric Vehicles (PHEVs) in achieving emission reductions and highlight the need for longer-lasting batteries or distributed recharging facilities for an effective penetration of Battery Electric Vehicles (BEVs). Moreover, they show that the additional power load, brought into the grid by EVs penetration, would lightly affect the local grid.

An instrumental contribution to include the impact of PV on capacity adequacy in long-term energy models

Long-term energy system models can be used to plan the expansion of generation capacity within a holistic view of the energy system. Some of them are based on linear optimization problems that make use of heuristics to reduce the calculation effort. Nonetheless, most of the existing frameworks lack of heuristics describing the impact of solar photovoltaic (PV) penetration on capacity adequacy. Within this work we propose an important step to include such feature into long-term energy systems models. We based our work on a prior study, which is needed, dealing with the impact of PV penetration on the area under focus. For the considered case study, the (i) peak reduction, the (ii) increase of ramp rates and the (iii) increase of excess energy are not linear and change behavior with PV penetration. We thus define the best piecewise linear functions that linearize such dynamics, by fixing an acceptable error and then choosing those with the lowest number of segments. We finally propose an approach to include such equations into models like OSeMOSYS.

New proposal for the assessment of the impact of EVs, smart charging and V2G on the grid

The substitution of the conventional fleet with plug-in Electric Vehicles (EVs) is one possible path towards the decarbonisation and more sustainability of private transportation. However, benefits related to a high number of vehicles, and the measures that could mitigate negative effects on the electric grid have to be assessed. In this paper a new model is presented for investigating the effect of a high-medium penetration of EVs on a local grid and their role on the emissions reduction. Besides it allows analyzing how the smart charging and the Vehicle-to-Grid (V2G) options can reduce the additional load or even support the power grid stability. Pro and cons are presented and a case study is proposed.

Review on the stochastic nature of photovoltaic generation and its impact on the energy systems: Why it matters

As the share of photovoltaic (PV) generation is growing worldwide, so is the concerns about its stochastic nature that can complicate the operation and planning of energy systems. With this paper we give an overview on the topic, analyzing and quantifying the stochasticity of PV and its impact on energy systems, with a main focus on the generation sector. The impact is analyzed in terms of ability to replace conventional generation, required operating reserves, and requirements of related storage systems. The work is a literature review detecting concerning matters, interesting methods to quantify the problem, interesting results and open matters. The paper may be interesting for system operators, policy makers, researchers and producers.

Including smart charging and vehicle-to-grid strategies in long term energy models

The long term benefits and costs of many technologies and control applications of the next future will depend on short time span dynamics. The resolution of most available economic energy system models is not able to detect their impact on the long time horizon. By adding equations to the code of OSeMOSYS, the open source energy system model, we enabled electric vehicles and related smart control strategies to be taken into account in a long term perspective. An application to a local case study explores the effect of the penetration of the electric vehicles on the power load and the role of the smart control strategies in shaving the additional peaks and pursuing environmental targets.

Modeling the energy features of a vehicle-to-home system to provide user-specific technical requirements

The combined management of vehicle-to-home and distributed generation can provide several benefits. Costs and benefits would differ depending on the technical requirements and the utilization profiles. In this study we use the EVLS model to simulate and analyze the dynamics that would occur in a hypothetical household provided with a vehicle-to-home system and a rooftop photovoltaic plant. The aim is to understand how different surrounding conditions can impact on specific technical requirements. The model shows to be instrumental for the purpose and the results indicates that, depending on the case, no additional benefits might exist when increasing the capacity of the battery and the vehicle-home connection over certain values.