China
Africa
Explore chapters and articles related to this topic
Energy and Environment
Published in T.M. Aggarwal, Environmental Control in Thermal Power Plants, 2021
Geothermal power requires no fuel; it is therefore immune to fuel cost fluctuations. However, capital costs tend to be high. Drilling accounts for over half the costs, and exploration of deep resources entails significant risks. A typical well doublet in Nevada can support 4.5 megawatts (MW) of electricity generation and costs about $10 million to drill, with a 20% failure rate. In total, electrical station construction and well drilling costs about 2–5 million € per MW of electrical capacity, while the levelised energy cost is 0.04–0.10 € per kW/h. Enhanced geothermal systems tend to be on the high side of these ranges, with capital costs above $4 million per MW and levelised costs above $0.054 per kW/h in 2007.
Energy and Environmental Markets
Published in Anco S. Blazev, Power Generation and the Environment, 2021
As a result of “the development of what were once thought to be non-viable resources, more and more public and private entities are looking into geothermal power as part of their strategy to mitigate global warming while still meeting growing energy demands.
Environmental literacy for the sustainable designer
Published in Rob Fleming, Saglinda H Roberts, Sustainable Design for the Built Environment, 2019
Rob Fleming, Saglinda H Roberts
Geothermal power refers to using heat energy from deep within the earth which emerges as rising steam, and is used to rotate turbines and generate electrical energy. There are several environmental impacts associated with geothermal electricity. It produces 95% less CO2 than coal-generated electricity. Geothermal electricity can only be produced in specific sites where lava exists in abundance. Iceland is the most well-known user of geothermal power. Wildlife and ecosystems are disturbed by the process of accessing and developing these sites, as well as by the massive drilling that takes place. Drilling is also a water-intensive process, and the waste “drilling fluid” is often deposited into nearby waterways with harmful effects. Although geothermal is considered a “flow,” locally, the heat energy and hot water that’s being converted to steam can be depleted through mass extraction, leading to changes in pressure and levels of underground water reservoirs, as well as changes in ground temperature and ground levels surrounding a site.
Feasibility study for size optimisation of a geothermal/PV/wind/diesel hybrid power plant using the harmony search algorithm
Published in International Journal of Sustainable Energy, 2021
Majid Reza Naseh, Emad Behdani
Geothermal unit: Two main factors determine the installed capacity of a geothermal power plant: (a) the share of the electrical demand of the system that can be provided from the power plant, and (b) the potential of the geothermal reservoir. Most geothermal power plants in the world generate more than 5 MW of electricity. Small-scale geothermal power plants have the potential for widespread applications, but achieving cost-effectiveness in small power plant sizes presents several challenges.
Opportunity and challenges in large-scale geothermal energy exploitation in China
Published in Critical Reviews in Environmental Science and Technology, 2022
Yuanan Hu, Hefa Cheng, Shu Tao
The applications of geothermal energy can be grouped into two major categories: power generation and direct use. In geothermal power generation, the thermal energy of geothermal fluid, which can be steam, hot water, or their mixture, extracted from the reservoir is converted into mechanical energy and subsequently into electricity by rotating the turbines that drive electrical generators. The process is similar to electricity generation using steam turbines, and the engineering design is straightforward and well-established. Depending on the reservoir depth, and the temperature and pressure of the geothermal fluid, as well as the nature of geothermal resource, three main types of geothermal power plants have been developed: flash steam, dry steam, and binary plants (DiPippo, 2015). Flash steam plants are most common for the utilization of high temperature resources, where the geothermal fluids are made of steam and hot water (Figure S1a). The hot water boils or flashes to produce steam with drops in pressure, and the steam is subsequently separated to drive turbines for power generation. Dry steam plants, which operate directly with the dry steam extracted from the reservoirs for power generation (Figure S1b), are less common than flash steam plants. In binary plants, the thermal energy of the extracted geothermal fluids is transferred to an organic liquid (the ORC cycle) or a mixture of ammonia-water (the Kalina cycle) through heat exchangers to generate vapor, which is subsequently used to drive turbines for power generation (Figure S1c). Being able to generate electricity with low to medium temperature geothermal resources, binary plants have gained increasing popularity worldwide (El Haj Assad et al., 2017; Moya et al., 2018). Geothermal power generation is sustainable, and unlike solar and wind power, it does not bear the limitations of weather dependence and intermittency (Bilgili et al., 2015; Hu & Cheng, 2013a). Geothermal power is arguably the only baseload source that is renewable, clean, and safe, and is expected to replace a large portion of fossil-fuel-fired generation at competitive prices in the United States in the future (Matek, 2016; Michaelides, 2016; Tester et al., 2006). With the stepped-up global investment on renewable energy, interests in geothermal energy as a renewable source of power generation have been growing quickly (Brimmo et al., 2017; Colmenar-Santos et al., 2016; Pambudi, 2018).