Low-Temperature Geothermal Power Generation ; Organic Rankine Cycle (ORC) : A Review

Abstract

In the present scenario of growing population and their increase in the consumption of energy, it is wise to explore and establish alternatives and clean sources of energy. Crude petroleum is a primary resource that fulfils the need of the ever growing population, but its exploration cannot be in same rate with the increasing consumption and volatile prices. The geothermal power industry has been experiencing steady growth and support around the world with governments keen to find a cheap and sustainable source of abundant energy. This support could see the geothermal industry take off during the upcoming decade in the same way as the wind and solar industries boomed in the last decade. Geothermal power emits virtually no CO2 or pollutants which catches the eye of the world. Therefore it is considered as an ideal alternative energy source. Such a source of geothermal energy can be best harnessed using Organic Rankine Cycle (ORC). ORC is the standard process for low temperature energy conversion .India is lacking experience in the design and manufacturing of low temperature geothermal ORC plants. One proposed method to develop this experience is to understand the design process of existing low temperature geothermal ORCs. A qualitative and a thematic analysis of ORC projects around the world can highlight the common steps involved in their development and patterns in data, which could help to identify the common processes involved in these projects. The research material available from CEGE and the various companies which are providing service in parts to ORC will be organized into: prospecting, conceptual design and plant feasibility, detailed design, and construction. These steps are the important stages in ORC development, based on the research till now. The outcome of this analysis will help to establish a guideline for developing ORCs. The number of case studies required to develop robust guidelines is unknown; however, once clear patterns and similar steps emerge from a number of case studies that should be sufficient to finalise the proposed guidelines. The focus of the present article is to develop an ORC in Indian Climatic Condition. The goal of the project is to provide electricity in rural areas and developing countries with this system. This system can be manufactured locally Centre of Excellence for Geothermal Energy (CEGE) at the Gujarat-based Pandit Deendayal Petroleum University (PDPU) has found success by drilling the state's first geothermal bore well in Dholera Hot water up to 50 degrees Celsius to 55 degrees Celsius temperature gushing out from 272m deep drilled well at an unexpected flow rate of five liters a second, which can be used to harness electricity using ORC. So, the final objective is to generate possible electricity and develop a guideline that industries will adopt for their own ORC projects and eventually encourage development of the low temperature geothermal design standard.