The world is currently suffering from the careless usage of fossil fuels, which is primarily responsible for global warming and pollution. As a result, researchers have looked into alternate techniques to alleviate this issue and limit the dependence on fossil fuels. Renewable energy, particularly solar energy, offers a promising and sustainable future for energy markets. Over time, researchers have discovered various novel techniques to harness solar energy, including solar water heaters (SWHs), which are made up of absorber surfaces, pipelines, storage, and other mechanical components such as pumps. Recently, there has been a significant increase in interest in SWH as a means to save expenses and enhance thermal efficiency by canceling the connecting pipes. Pipe cancellation was the result of merging the absorber and storage into a single unit. This cancellation led to the creation of a new type of solar collector called integrated collector storage (ICS). These collectors are geometric shapes filled with water and painted black to optimize solar radiation absorption. This article examines the approaches for improving storage solar collectors, specifically integrated solar water heaters (ISWHs). The study focuses on structural design improvements, PV cells, evacuated pipelines, and phase change materials (PCMs). Furthermore, the study examines the performance of ICSSWH. These improvements demonstrated that the integrated solar heater provides good and promising efficiency at a reasonable cost, in addition to meeting the desired goal of lowering polluting emissions.