RESEARCHMICROGENERATION
25 years and this should be the target of every new system. Therefore O&M&M have to be carefully integrated in the project business planning right from the inception in order to foresee a cash flow sufficient to cover these costs.
Microgenerated electricity can transform rural possibilities
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Bus bars and local distribution network are the last key elements within a hybrid mini-grid. The choice of AC or DC current in particular has an impact on the system, its capacities and its price, as well as on the devices that can be powered. However, the choice of AC or DC mostly depends on the technologies to be coupled in the system as well as whether batteries will be used in the system. Single-phase distribution grids are cheaper than three-phase ones, but the later allow greater opportunity to obtain power and the possibility of future inter-connection to the national grid.
Field studies and exhaustive demand analysis are a basic pre-requisite for any mini-grid project, regardless of the technology selected. Over-sizing some components, such as wiring and the converters, can be a good idea to anticipate a future growth and facilitate expansion.
Financial/Sustainability Issues Financial and operation issues are critical to the long-term sustainability of mini-grids. Questions such as operations and maintenance, role of the private sector, tariffs and subsidies, and capacity building and training are essential to consider when developing rural electrification programs. This is particularly true with the use of hybrid mini- grids. Key issues to consider follow.
1) Sustainable financial and technical solutions for operations, maintenance and management (O&M&M) are key to overall system success. A well maintained and managed system can run over
There should be always some kind of automatic management measures built into the system to protect critical components from severe damage, such as total depletion of the battery charge. Training of local operators and users is essential to ensure that the components are used correctly and will last throughout the whole projected lifetime.
If long-term O&M&M is the key indicator of a successful project/program, many external factors will also play a role. Availability (of products, trainings, reliable actors willing to assume responsibility for O&M, spare parts) for instance is of the biggest importance as is access to finance at all project levels. Therefore, successful rural electrification programs have to rely on functioning networks of local companies and financial intermediaries, which should be looked at and supported in parallel with or as part of the program. This can be addressed in different ways: for example, through technology transfer and company agreements, well-designed call for tenders, technical and business trainings and support to business organizations. The financial sector especially is central and its absence is often critical in rural areas. Therefore, targeted capacity building actions as well as financial instruments such as guarantees and financial risk mitigation instruments are very important.
2) In general, access to information and to training is fundamental to ensure long-term program success. Many stakeholders involved in the rural electrification project chain do not know how to deal with renewable energies, or may not be used to obtaining and paying for electricity. Hence, education, trainings and information about the benefits of access to energy and of renewables are necessary prior to any project. Strong and targeted publicity campaigns explaining rural electrification programs will also increase positive impacts.
3)The private sector must in the future play a bigger role in investing, implementing and operating hybrid systems all over the world if investment is to be scaled up and the challenges to system sustainability are to be overcome. Several factors can be influenced to attract companies and investors over the long term:
The first option to increase the economic attractiveness of rural electrification is to act on the size of the market. To become more interesting economically, projects should be built around existing applications or public institutions in order to increase their critical mass, potential profits, and local involvement (i.e., interest in maintaining a system).
Another option is to support directly income generating activities as part of the rural
www.solar-pv-management.com Issue V 2011
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