Abstract
Achieving the European Union renewable energy source penetration 2030 targetsrequires an increase inflexible resources to compensate for the variability/inter-mittency of solar and wind generation to ensure system safety and balancing.Herein, two readily deployableflexibility solutions to balance demand/supply as analternative to building additional thermoelectric reserves are proposed. How thetransmission system OPERATOR can use the ancillary services provided by aflexiblephotovoltaic (PV)fleet (solar regulation) or PV/windfleet (variable renewable energy(VRE) regulation) together with a suitableunderforecast and proactive curtailment ofvariable renewable generation (aka, implicit storage) to reduce current and futureItalian imbalances is shown. How theseflexibility solutions can become even moreeffective when combined with a strengthening of the transmission grid is shown.The imbalance reduction achievable by 2030through solar/VRE regulation strategieswouldbeoftheorderof20–50% with zonal balancing and 27–80% with nationwidebalancing is found. Imbalance costs wouldremain comparable with the business-as-usual (thermal generation) costs. A proactive curtailment of 5–17% of the total VREgeneration is the environmental cost of stabilizing the system using VRE plants,avoiding the construction of thermoelectric reserves