State of the art of windthermal turbines: A systematic scoping review of direct wind-to-heat conversion technologies

Abstract

Windthermal turbines convert wind directly into thermal energy. Albeit it is an uncharted field of research, the overall system efficiency and costs of fully developed windthermal turbines are promising; since they can contribute to a sustainable energy transition. We identify the current state of the art of windthermal conversion principles, technology maturity, applications, substitutes, advantages and disadvantages. To scope relevant literature, we follow the Joanna Briggs Institutes selection and screening process resulting in 61 relevant publications from which we identified three main conversion types, namely compression-, friction-, and induction-based windthermal devices. These devices can directly supply thermal energy for space heating or industrial processes, work as a component of wind-powered thermal energy systems, short WTES, or can substitute any conventional or renewable heat device. Although heat is the lowest form of energy, windthermal applications could provide cheap renewable energy that can be stored easily enhancing security of supply. However, these technologies are currently on laboratory-scale, and we suggest scaling up the existing prototypes to engineering-scale. Finally, due to a missing general terminology, we propose to establish one of the terms windthermal energy, ventothermal energy or anemothermal energy to distinguish these specific wind energy conversion technologies.

Study on the Influence of Working-Fluid’s Thermophysical Properties on the Stirring-Heating

“…The manual for the design and selection of mixing equipment points out that the power of the agitator can be calculated by an empirical formula shown as Formula (9).…”

“…However, the heating system requires higher wind speed and quality based on this principle and can only work normally within the rated speed range of the compressor; the system itself is relatively complex and the scope of application is limited as a result. The direct heating mode of wind energy with simple principles and device structure also includes compression heating, friction heating, and induction-based wind heating devices [9]. Zdankus T et al [10] proposed a wind heating device based on a hydraulic system and the heat is produced mainly due to friction losses of this system; the system may reach an overall efficiency of 58.8% under optimal conditions.…”

Direct heat energy harvesting from wind by a permanent magnet eddy currents heater with different magnet arrangements

“…[14][15][16] Neumeier studied different ways of generating heat based on the wind thermal systems and suggested that the PMECH in wind energy storage systems can achieve temperatures up to 560°C or 600°C. 17 Karasu provided a thermodynamic assessment of a wind thermal energy storage system based on the PMECH system incorporated into the nacelle of the wind turbines for heating the molten salt. He showed that the PMECH system is a cost-effective method for converting wind energy into heat.…”

“…While several studies have examined the effects of eddy currents on the power loss of electro‐motors, generators, and induction heating devices, few have investigated ways to capture the thermal energy created by eddy currents in renewable energy systems for heating buildings 14–16 . Neumeier studied different ways of generating heat based on the wind thermal systems and suggested that the PMECH in wind energy storage systems can achieve temperatures up to 560°C or 600°C 17 . Karasu provided a thermodynamic assessment of a wind thermal energy storage system based on the PMECH system incorporated into the nacelle of the wind turbines for heating the molten salt.…”