Bringing electricity to remote and sparsely populated communities, often beyond the reach of national power grids, remains a global challenge. According to a report by the International Energy Agency (IEA) in 2019, 15% of the world's rural population faced significant difficulties in accessing electricity. To address this issue, two primary strategies are being pursued: reliance on fossil fuels or transitioning to a blend of renewable energies. However, the drawbacks of fossil fuel use, such as environmental degradation and finite resources, have led some countries to consider the more attractive option of hybridizing various renewable energy sources. A hybrid renewable energy system typically integrates renewable and conventional energy sources alongside energy storage devices. Given the intermittent nature of renewable resources, incorporating conventional energy systems and storage devices as support enhances reliability and mitigates surplus electricity in hybrid renewable energy systems.
Another fundamental challenge is the access to freshwater for drinking and other essential needs, particularly amid rapid global population growth. Only 1% of the world's total water resources are usable freshwater, with the majority in the form of saline water (97%) and frozen water (2%). Desalination emerges as a promising solution to this water scarcity issue. Desalination is the process of separating salt from saline water to produce freshwater for various purposes, including drinking and agriculture. While there are various methods for salt separation, Reverse Osmosis (RO) holds wide acceptance, constituting 65% of the installed capacity.
The Combined Heat and Power (CHP) system presents an advantageous framework for simultaneously producing heat and power from a single fuel source, with the recovered waste heat generating additional energy. The notable features of the CHP system include higher efficiency, lower fuel consumption, and reduced greenhouse gas emissions. As we navigate the complex landscape of energy access and freshwater scarcity, the integration of hybrid renewable energy systems, desalination technologies, and CHP systems emerges as a promising approach to address these critical global challenges.
Illustrating the concept of simultaneous power generation and seawater purification, this system incorporates a simple cycle gas turbine unit, a Heat Recovery Steam Generator (HRSG), and a Multi-Stage Flash (MSF) unit. The HRSG operates as a single-pressure radial tube boiler, where water boils within the pipes. The ensuing steam is separated and directed into the upper drum. Heat exchange occurs through convection, conduction, and radiation between the hot gases traversing the channel and the water inside the pipes. The steam, generated through this process, undergoes initial pressure reduction before entering the MSF brine heater, contributing to the overall efficiency of the system.