Identifying the Conditions of Maximum Electricity Demand Coverage in a Direct Mode, by Wind and Photovoltaic sources

To reach the objectives of energy security and updated NDC targets, 100% RES scenario is considered for the R. Moldova. The specific goal of this study is to identify the conditions under which a maximum coverage of the annual electricity demand can be obtained directly from WF+PV sources. Two approaches are used to reach the goal: WF and PV cover energy demand in a direct mode without considering the balancing power - Technical Weight, and second, WF and PV cover the demand in a direct mode together with a source of balancing power - Gas turbine (GT) - Economic Weight. The results obtained: When the capacities of WF and PV are determined in a way to produce electricity equal to annual power demand, Technical Weight is equal to a maximum of 71-72%. If WF and PV electricity produced is higher than demand by 50%, WF+PV tandem may cover the energy demand in a direct mode at maximum level of 80.5%. Five variants of WF, PV and GT economic parameters variation were considered when these sources are operating together. The calculations done and analysis performed showed that: The minimum price of electricity produced by WF+PV+GT in V1 (basic variant, current data) takes place at a PV integration level of 18% (Zopt). At WF specific investment of $750/kW (V2), compared to $1445/kW in V1, Zopt is equal to zero. That is, at such WF specific investment, PV implementation is not feasible. Price for electricity is lower than in V1 by 25.4%. Even at a specific investment of about $1000/kW for WF, the minimum energy price is obtained in the absence of PV. Decreasing PV specific investment by up to 50% (V3) compared to the level established in V1 has little influence on the maximum Technical Weight. The electricity price is lower than in V1 by circa 8%. A 25% decline in TG specific investments (V4), or a 17% drop in the price for natural gas (V5) compared to V1, have no material effect on the maximum Technical Weight.