Utility-scale photovoltaics and storage: Decarbonizing and reducing greenhouse gases abatement costs

•PV + storage can reduce CO2 emissions while lowering cost of abatement.•Storage optimal power rating seems to be lower than 25% of PV capacity.•Storage with low energy-to-power ratio is cost effective with lower PV shares.•PV + storage systems would achieve breakeven point with expected costs projections.•Optimal configurations can reduce carbon emissions in the DEC/DEP system up to ~57%. This study explores the performance of the Duke Energy Carolinas/Progress (DEC/DEP) electric power system under one hundred forty-one configurations combining different capacities of utility-scale photovoltaics (PV) and battery energy storage (lithium-ion batteries or BES). The different configurations include PV installations capable of providing 5–25% of the systems energy and batteries with varying duration (energy-to-power ratio) of 2, 4, and 6 h. A production cost model comprised of a day-ahead unit commitment and a real-time economic dispatch simulates the optimal operation of all the generation resources necessary to supply hourly demand and reserve requirements during the year 2016. The model represents in detail the generation fleet of the system, including 221 nuclear, natural gas, coal and hydro power generators with a combined installed capacity of 37.8 GW. Results indicate that: 1) adding BES to a power system that includes PV further reduces carbon dioxide emissions while also lowering the cost of carbon abatement. 2) The optimal power rating of a BES system that supports PV seems to be lower than 25% of the capacity of the PV. 3) BES of short duration (2-h) are more cost-effective (i.e., result in a lower cost of abatement) when the level of PV penetration is low (lower than ~12.5%), while BES of longer duration (6-h) are more cost-effective when there are larger shares of PV. 4) The installation of optimal configurations of PV + BES to reduce carbon emissions in the DEC/DEP system by ~14–57% would increase the levelized cost of electricity (LCOE) ~8–65%. 5) If projections of declining costs for the next decade materialize, the installation of up to 15 GW of PV + 1.88 GW / 3.76 GWh of BES would reduce the LCOE while achieving up to 33% reduction in carbon emissions.