Over the last decade, the global energy mix for electricity generation has undergone several changes. Even though fossil fuels continue to serve as the dominant source of electricity generation, there are greater ongoing efforts to introduce cleaner renewable energy sources (RES) in the power grids. Solar and wind are the two most widely used and abundant RESs, and both of them are inherently intermittent. In this context, some RES intermittency in microgrid (MG) may be mitigated through careful planning and investments in deployment of RESs that exhibit complementary behaviour. Complementarity between RESs provides good prospects for integrating several local energy sources and reducing the costs of MG setup and operations. However, the share of complementary RESs (termed as, RES mix) in the combined energy mix and the location of MG deployment has a direct impact on the power generated.

To address this problem, we propose two steps in which the optimized RES mix can be determined. The first step is to establish the relation between possible RES deployment locations, RES mix, and the solar-wind complementarity through an assessment of the statistical characteristics of solar and wind energies. In the second step, the initial assessment of solar-wind complementarity, RES mix, and optimal location is then used to evaluate the economic gains of grid-tied MG. This process requires computation of energy production costs, and some additional costs that are incurred due to bi-directional energy exchange with the main grid. Particularly, these costs include system power loss (SPL) cost, energy export cost (from MG to grid), and energy import cost (from grid to MG). For a given solar-wind complementarity value, these costs are determined for a range of values of RES mix.

In this work, different sites are analyzed for solar-wind energy based grid-tied MG deployment. The application of the proposed framework for a grid-tied MG is demonstrated by modelling MG as a balanced IEEE 33-bus system, at four different locations in Ireland, each with a different solar-wind complementarity value. All factors that may influence the MG operator's choice of RES mix are determined and then analyzed for providing suitable recommendations for deployment of energy sources in different regions. The proposed framework can be used for designing hybrid solar-wind farms or augmenting existing solar-only/wind-only farms according to solar-wind complementarity and the objectives of the MG operator.