_{Source: dsisolar.com}

As the world races to decarbonise its energy systems, solar power has emerged as a leading force in the renewable revolution. Yet, its intermittent nature poses a challenge to reliability. This review explores how photovoltaic (PV) systems, when integrated with wind turbines, diesel generators, and energy storage, can form robust hybrid solutions. Drawing on over a hundred academic studies, the authors examine the most effective ways to size and combine these technologies for both grid-connected and off-grid scenarios.

The paper highlights a wide range of mathematical models and optimisation techniques used to determine the ideal mix of energy sources. From traditional linear programming to advanced heuristic algorithms like Particle Swarm Optimisation and Genetic Algorithms, the review maps out the tools researchers use to balance cost, reliability, and environmental impact. Software such as HOMER also features prominently, offering practical solutions for real-world applications.

A key strength of the study lies in its comprehensive approach. It not only categorises the types of systems and objectives—economic, technical, environmental, and social—but also considers real-world constraints such as export limits, energy pricing models, and equipment degradation. The authors stress the importance of tailoring solutions to local conditions, noting that what works for a rural microgrid may not suit an urban rooftop installation.

In conclusion, the review offers a valuable roadmap for policymakers, engineers, and researchers seeking to design smarter, more resilient energy systems. It calls for future work to address overlooked areas such as demand uncertainty, export timing, and the social impact of renewables. As solar adoption accelerates, such insights will be vital in ensuring that clean energy is not only sustainable but also dependable.