Valeria Cocina | Politecnico di Torino (original) (raw)

Papers by Valeria Cocina

A new concept of PV grid-parity is presented for three typical case studies in Germany and Italy ... more A new concept of PV grid-parity is presented for three typical case studies in Germany and Italy by including the fixed costs of the electricity bills. The electricity bills have been analysed for residential and tertiarysector users: in Germany the fixed costs are negligible, whereas in Italy the common loads of apartment blocks are heavily charged by the cost of the available power. The grid-parity problem is analysed as an investment in which the net present value provides the convenience or not of the installation of a PV plant. The main results take into account the different economic situation in the Countries by the interest rates of 3-5 % in Germany and 4-9 % in Italy. The grid-parity for dwelling houses is close to be reached in South of Germany/Italy; the grid parity is achieved in Munich for the users in apartment-blocks, while it is unrealistic to be reached in Italy with the current tariff situation; the grid-parity is reached in South of Germany/Italy for the tertiary-...

Operations, Planning, and Economics of Insular Electricity Grids, 2015

2014 International Symposium on Power Electronics, Electrical Drives, Automation and Motion, 2014

ABSTRACT Considering the distributed generation from solar energy, the topics of this paper are m... more ABSTRACT Considering the distributed generation from solar energy, the topics of this paper are multiple: firstly, to analyze accurate measurements of solar irradiance from pyranometer and to compare them with 1-3 day weather forecasts by the suitable statistical error parameters. Then, to describe a detailed PhotoVoltaic (PV) conversion model, from the solar irradiance to the AC power profile delivered to the utility grid, and to compare the simulation results with the 15-min mean power measured by the energy-meter of a real grid-connected PV system with megawatt size. The results show that an adequate accuracy can be obtained and that useful information can be provided for fault diagnosis of a portion of a PV array.

2012 IEEE International Energy Conference and Exhibition (ENERGYCON), 2012

The measurement, as accurate as possible, of solar irradiance is the starting point for the evalu... more The measurement, as accurate as possible, of solar irradiance is the starting point for the evaluation of photovoltaic (PV) power profiles in an electricity market in which many gigawatts of PV power are connected to the national network. This paper discusses the setup of five meteorological stations in South of Italy and the yearly experimental results of short-term global irradiance on the horizontal plane and on the best tilted plane. The “broken clouds” phenomenon causes noticeable peaks in the irradiance and thus in the PV power. Its knowledge and prediction can be very useful to the Transmission System Operator for the management of peak generation. The evolution of relative humidity can give important information if the direct measurement of irradiance is missing. Finally, simple models for the irradiance in clear/cloudy sky situations can be used as a first approximation tool to predict the PV power profiles for the electricity market.

2014 IEEE International Energy Conference (ENERGYCON), 2014

ABSTRACT The different representations of the input data for energy system studies need to be con... more ABSTRACT The different representations of the input data for energy system studies need to be conducted to the same time step for the purpose of carrying out power system calculations. Availability of data with different time steps, or even provided with irregular timing, needs a pre-processing phase to unify the representation within the same time step. This paper describes a dedicated pre-processing tool that accepts input data with different characteristics and provides a regular representation of the output. A specific application in which the differences between the time steps are relevant is analysed by considering a grid-interfaced system with local generation and local load, carrying out the input/output energy calculations and the assessment of the energy-related economics in net metering conditions.

Solar Energy

A new concept of Photovoltaic (PV) grid-parity is presented for three typical case studies in Eur... more A new concept of Photovoltaic (PV) grid-parity is presented for three typical case studies in Europe by including the distribution-network limits and the fixed costs of the electricity bills. Real cases are described for residential/tertiary sector loads: the PV penetration results, achieved without investments in the distribution upgrading, are presented through the ratio of the admissible PV energy ratio which can be close to 30% of the total consumption for residential users and 45% for tertiary-users. The future approach of distribution limits certainly will increase the electricity bills which have been analysed here in the current situation: in Germany the fixed costs are negligible, whereas in Italy the common loads of apartment-blocks are charged by the cost of the available power. The grid-parity problem is analysed by the net present value which provides the cost effectiveness or not of the PV installation. The results are obtained by the interest rates of 3–6% in Germany ...