Renewable-energy-based multigeneration systems

TLDR

Multigeneration options improve system performance and reduce environmental impacts. The article develops renewable‑energy‑based multigeneration options that produce multiple outputs—including power, heat, hot water, cooling, hydrogen, and fresh water—and discusses their benefits. The study compares single‑generation and cogeneration systems on energy utilization efficiency, exergy efficiency, GHG mitigation, and payback period. Cogeneration increases GHG mitigation 2–4× and shortens payback time 2.8× versus single generation; exergy efficiency ranges 55–65% depending on cogeneration level, peaking at a 200 °C source temperature; overall multigeneration improves energy and exergy efficiencies, reduces cost and environmental impact, and enhances sustainability. Copyright © 2012 John Wiley & Sons, Ltd.

Abstract

This article develops the concept of renewable-energy-based multigeneration options for producing a number of outputs, such as power, heat, hot water, cooling, hydrogen, fresh water, and so forth; and discusses their benefits. Such multigeneration options obviously lead to improved system performance and reduced environmental impacts. First, single-generation (power generation only) and cogeneration systems are compared with respect to the energy utilization efficiency, exergy efficiency, green house gases (GHG) mitigation, and payback period. It is found that the cogeneration increases GHG mitigation about 2 to 4 times, whereas the payback time decreases about 2.8 times with respect to the single-generation case. Exergy efficiency is found to be between about 55% and 65%, depending on the degree of cogeneration. The exergy efficiency shows the maximum values for certain source temperatures. For the case studied here, the optimum source temperature is taken as 200°C for analysis purposes. The results show that multigeneration of energy systems helps increase both energy and exergy efficiencies, reduce cost and environmental impact, and increase sustainability. Copyright © 2012 John Wiley & Sons, Ltd.