Research
Research
Abstract
The literature highlights ambiguity in the effect of storage from hydroelectric power production over the levels of carbon emissions. This paper examines the external benefit related to charge and discharge operations of hydroelectric storage power plants, applied to the case of the Northern area of the Italian wholesale electricity market. The OLS estimations based on data for year 2018 indicate that storage generation reduces carbon emissions in aggregate terms, being the estimated storage marginal emission factor (MEF) equal to 0.13 tCO2/MWh. This finding is largely explained by the value of the MEF during off-peak hours (0.17 tCO2/MWh), thus showing effectiveness of storage in the displacement of the carbon-intensive baseload generation acting on the margin during night-hours. However, the calculation of the MEF for peak-demand hours indicates that storage generation, individually taken, is not able to affect the structure of marginal generation in the considered area. Finally, the use of a simulation approach indicates that pumped hydroelectric storage (PHS) contributed to reduce carbon emissions into the atmosphere by 471ktCO2. The obtained result is consistent with the typical coefficient of round-trip efficiency of PHS documented in the literature, which amounts to 74%.
Abstract
In this paper we investigate the role of Renewable Energy Sources (RES) on the Italian power exchange. The purpose of this analysis is to assess the impact of electricity generation from RES on the reduction of CO2 emissions and on the value of the power supply. The study is based on hourly zonal micro-data for 2018 from the Italian power market and identifies the amount of avoided carbon emissions related both to crowded-out thermal units and to potential "load-shedding" situations. Finally, the investigation leads to the assessment of both the economic value of RES penetration and to the economic value of the CO2 emissions avoided by renewable power generation. The results show that annual savings of carbon emissions nationwide amount to nearly 22 Mt CO2 whereas the value of CO2 reduction is estimated at €348 million. The economic savings from large and small-scale wind and solar generation in 2018 account for nearly €19 billion and welfare is increased by 44%, thus confirming the net positive effect arising from RES promotion.
Link at: https://doi.org/10.1007/s10640-021-00567-9.
Abstract
This paper estimates the seasonal and zonal CO2 marginal emissions factors (MEFs) from electricity production in the Italian electricity system. The inclusion of the zonal configuration of the Italian wholesale power market leads to a complete measurement of marginal emission factors which takes into account the heterogeneous distribution of RES power plants, their penetration rate and their variability within the zonal power generation mix. This article relies on a flexible econometric approach that includes the fractional cointegration methodology to incorporate the typical features of long-memory processes into the estimation of MEFs. We find high variability in annual MEFs estimated at the zonal level. Sardinia reports the highest MEF (0.7189 tCO2/MWh), followed by the Center South (0.7022 tCO2/MWh), the Center North (0.4236 tCO2/MWh), the North (0.2018 tCO2/MWh) and Sicily (0.146 tCO2/MWh). The seasonal analysis also shows a large variability of MEFs in each zone across time. The heterogeneity of results leads us to recommend that policymakers consider the zonal configuration of the power market and the large seasonal variability related to carbon emissions and electricity generation when designing incentives for renewable energy sources expansion and for achieving emission reduction targets.
Link at: https://doi.org/10.1016/j.eneco.2020.104905.
Abstract
This paper offers a novel contribution to the literature on Marginal Emission Factors (MEF) by proposing a robust empirical methodology for their estimation across both time and space. Our Autoregressive Integrated Moving Average models with time-effects not only outperforms the established models in the economics literature but it also proves more reliable than variations adopted in the field of engineering. Utilising half-hourly data on carbon emissions and generation in Great Britain, the results allow us to identify a more stable path of MEFs than obtained with existing methodologies. We also estimate marginal emission effects over subsequent time periods (intra-day), rather than focussing only on individual settlement periods (inter-day). This allows us to evaluate the annual cycle of emissions as a result of changes in the economic and social activity which drives demand. Moreover, the reliability of our approach is further confirmed upon exploring the cross-country context. Indeed, our methodology proves reliable when applied to the case of Italy, which is characterised by a different data generation process. Crucially, we provide a more robust basis for valuing actual carbon emission reductions, especially in electricity systems with high penetration of intermittent renewable technologies.