The need for electrical energy supply in off-grid or temporarily off-grid areas of the developing world is becoming increasingly significant. Different sizes of applications are implemented, starting at the micro scale level of households and small communities, but also scaling up to more energy intensive applications such as small business, workshops or even small factories. An overall improvement of the living conditions of local communities is achieved by providing energy access and also by strengthening local economies and creating income sources.
The Rural Electrification Research Group is part of Smart RUE (Smart grids Research Unit of the Electrical and Computer Engineering School) of the National Technical University of Athens (NTUA) and a member organisation of the Wind Empowerment association. The main research areas of the group are the following:
Open Source Hardware for renewable energy microgeneration
Concepts of ‘appropriate technology’ have been used in the past decades, mostly in projects that aim to improve living conditions for rural communities in developing countries by involving the users in the design and implementation processes, and thus directly addressing their needs. An evolution of this process of technology transfer is ‘open source hardware’ that follows from the successful history of ‘open source software’. Over the past decade, ‘open source software’ applications have developed new concepts and tools in the field of community research and development with ‘peer to peer’ networks, in the field of intellectual property rights with the ‘creative commons’ licenses, and in the field of business with the ‘open business’ models. Open hardware aims to follow up on these issues and create a new space for the open production of material products, where new concepts of innovation can be explored based on the cooperative nature of these processes. Open hardware focuses on building products that require less initial capital and have less maintenance costs, that are based on open designs which are improved by a community of voluntary users with different technical backgrounds and wishes to face up to challenges such as language limitations, lack of wide spread access to the Internet in isolated areas of the developing world and the need for new design tools to assess this process.
The production of electrical energy from renewable energy sources has not been left untouched by these concepts. Open source hardware applications exist in power electronic components such as maximum power point trackers for PV modules, diversion load controllers, energy management controllers and meteorological and electrical data logging systems for small wind turbines. Apart from the context of electronics, where most of the open hardware applications exist, some small wind turbine (SWT) open designs for residential and rural use have emerged in the past few years.
Locally manufactured Small Wind Turbines
One such SWT has originally been designed by Hugh Piggott in his first design manual in 2006. Since then hundreds of these SWT have been built worldwide proving these turbines to have a robust design. Other groups such as Other Power have developed the design and a wide network of people constructing, using and developing these turbines is emerging, that collaborates through internet forums such as fieldlines.com and networks such as the Wind Empowerment association.
Since the spring of 2009, several final year dissertations in the electrical engineering department of NTUA have focused on locally manufactured small wind turbines, and specifically those described by Hugh Piggott in the ‘Small wind turbine recipe book’. Several students have completed their dissertations since then, completing projects that usually last for almost a year. This work has contributed in the formation of the Rural Electrification Research Group within the Electrical Energy Systems Laboratory of NTUA.
Locally manufactured Pico-Hydro Turbines
Locally manufactured Pico-Hydro Turbines have also been developed in the NTUA using a hybrid design between the locally manufactured axial flux permanent magnet generator described by Hugh Piggott in the ‘Small wind turbine recipe book’ and the locally manufactured pico-hydro casing and runner designs of Joseph Hartvigsen described in his website h-hydro.com
Hardware-in-the-Loop simulation for rural electrification
Hardware-in-the-Loop (HIL) simulation is an advanced tool that can support the higher integration of Distributed Energy Resources (DER) to electricity grids and allow studies focusing on rural electrification applications. HIL simulation allows the connection of physical equipment (e.g. hardware Photovoltaics, Wind Turbine etc.) to a virtual network simulated in a Real-Time Simulator. The simulated system can be changed easily and quickly without the need for hardware adaptations, therefore various experiments can be performed repeatedly and conveniently.
A HIL simulation environment has been developed at NTUA. Applications focusing on rural electrification are studied among others. Rural networks have specific characteristics (e.g. high impedance lines, low generator’s inertia etc..) that rise the need for voltage and frequency support by distributed generation. These phenomena are studied with the developed simulation environment.