In this paper, various ambient energy-harvesting technologies (solar, thermal, wireless, and piezoelectric) are reviewed in detail and their applicability in the development of self-sustaining wireless platforms is discussed. Specifically, far-field low-power-density energy-harvesting technology is thoroughly investigated and a benchmarking prototype of an embedded microcontroller-enabled sensor platform has been successfully powered by an ambient ultrahigh-frequency (UHF) digital TV signal (512-566 MHz) where a broadcasting antenna is 6.3 km away from the proposed wireless energy-harvesting device. A high-efficiency dual-band ambient energy harvester at 915 MHz and 2.45 GHz and an energy harvester for on-body application at 460 MHz are also presented to verify the capabilities of ambient UHF/RF energy harvesting as an enabling technology for Internet of Things and smart skins applications.

http://users.ece.gatech.edu/etentze/Procs14_Sangkil.pdf

Ambient RF Energy-Harvesting Technologies for Self-Sustainable Standalone Wireless Sensor Platforms

In this paper, various ambient energy-harvesting technologies (solar, thermal, wireless, and piezoelectric) are reviewed in detail and their applicability in the development of self-sustaining wireless platforms is discussed. Specifically, far- field low-power-density energy-harvesting technology is thor- oughly investigated and a benchmarking prototype of an embedded microcontroller-enabled sensor platform has been successfully powered by an ambient ultrahigh-frequency (UHF) digital TV signal (512-566 MHz) where a broadcasting antenna is 6.3 km away from the proposed wireless energy-harvesting device. A high-efficiency dual-band ambient energy harvester at 915 MHz and 2.45 GHz and an energy harvester for on-body application at 460 MHz are also presented to verify the capa- bilities of ambient UHF/RF energy harvesting as an enabling technology for Internet of Things and smart skins applications.

Ambient RF Energy-Harvesting Technologies for Self-Sustainable Standalone Wireless Sensor Platforms This paper presents various ambient energy-harvesting technologies and investigates their applicability in the development of self-sustaining wireless platforms.

Radiative wireless power transfer (WPT) is a promising technology to provide cost-effective and real-time power supplies to wireless devices. Although radiative WPT shares many similar characteristics with the extensively studied wireless information transfer or communication, they also differ significantly in terms of design objectives, transmitter/receiver architectures and hardware constraints, and so on. In this paper, we first give an overview on the various WPT technologies, the historical development of the radiative WPT technology and the main challenges in designing contemporary radiative WPT systems. Then, we focus on the state-of-the-art communication and signal processing techniques that can be applied to tackle these challenges. Topics discussed include energy harvester modeling, energy beamforming for WPT, channel acquisition, power region characterization in multi-user WPT, waveform design with linear and non-linear energy receiver model, safety and health issues of WPT, massive multiple-input multiple-output and millimeter wave enabled WPT, wireless charging control, and wireless power and communication systems co-design. We also point out directions that are promising for future research.

Communications and Signals Design for Wireless Power Transmission

Radiative wireless power transfer (WPT) is a promising technology to provide cost-effective and real-time power supplies to wireless devices. Although radiative WPT shares many similar characteristics with the extensively studied wireless information transfer or communication, they also differ significantly in terms of design objectives, transmitter/receiver architectures and hardware constraints, etc. In this article, we first give an overview on the various WPT technologies, the historical development of the radiative WPT technology and the main challenges in designing contemporary radiative WPT systems. Then, we focus on discussing the new communication and signal processing techniques that can be applied to tackle these challenges. Topics discussed include energy harvester modeling, energy beamforming for WPT, channel acquisition, power region characterization in multi-user WPT, waveform design with linear and non-linear energy receiver model, safety and health issues of WPT, massive MIMO (multiple-input multiple-output) and millimeter wave (mmWave) enabled WPT, wireless charging control, and wireless power and communication systems co-design. We also point out directions that are promising for future research.

This communication presents a comprehensive review on the solar photovoltaic (SPV) systems for recent advances and their emerging applications in the present and future scenario. Besides, the performance study of off grid and grid connected SPV power plant has been discussed and presented in detail. From the literature, it is found that the efficiency of photovoltaic (PV) systems varies from 10% to 23%. Thus, the efficiency is the important factor which needs to be explored further for the best implementation and utilization of this emerging and useful technology around the globe. However, among all the applications discussed here, Building integrated photovoltaics (BIPV), Concentrated photovoltaics (CPV) and photovoltaic thermal (PV/T) are found to be the most technically sound and exhibit that SPV may be a feasible solution for the future energy challenges. Again, the building integrated PV system not only reduces the area requirement, but also cuts the material and infrastructure costs of the building and hence, fulfills the technical thrust for smart building requirements. Recently developed CPV cells are found to be feasible, most promising and cost effective technology having higher efficiency and lesser material requirements than those of the other solar cells. On the other hand, as the PV/T systems produce not only the electricity but also the heat energy are found to be more useful, suitable, and promising for most of the real life applications especially, where both forms of energy are required simultaneously.

Recent advances in solar photovoltaic systems for emerging trends and advanced applications

This paper begins with an introduction to the concept of space solar power (SSP) and summarizes selected prior studies of proposed solar power satellite (SPS) systems. The functional components of a generic SPS are delineated, and various approaches and promising concepts from prior and current development efforts are elucidated. The fundamentals of wireless power transfer for the SPS application are reviewed, including a discussion of retrodirective beam control approaches. A survey of related technology research and development campaigns for energy conversion and transmission modules for recently proposed modular architectures is outlined. Advances in solid state amplifier technology with relevance to SSP are reviewed, with areas of particular criticality highlighted. Performance metrics for proposed SPS systems and their components are enumerated, and efforts to design, fabricate, and test a prototype conversion module operating at 2.45 GHz in a space-like environment are described.

J. McSpadden

Papers

Energy Conversion and Transmission Modules for Space Solar Power