Hammar_Modern Energy Review 25/02/2010 13:40 Page 72
Electrification Based on Small Electricity Grids in Africa
Vandalism Generation Reliability
High generation reliability in systems based on weather-dependent Rural implementation of solar and other energy technologies has
renewable sources requires a combination of energy sources. Tidal shown that theft and vandalism pose serious threats to
energy is predictable but stops delivering energy several times per day implementation in poor settings.
11
Technical appliances with valuable
(during turning tides), and generation is much lower during neap components can be exposed to theft even if the technology is
compared with spring tides. Consequently, the load factor of tidal accepted and socially protected by the local community.
12
Expensive
energy is low.
9
However, even a small portion of constant or at least batteries are typically at risk, but as energy systems are expensive any
predictable power, such as tidal energy, is very valuable for a small piece may be regarded as valuable to steal. Vandalism is a serious
grid based on several sources,
10
especially if the load is scheduled to fit threat to rural energy projects, perhaps more related to issues of
the availability. For example, industrial activities can be given different social acceptance. In Tanzania, the problem of energy system
priorities where the highest priority will always be electrified while the vandalism has drawn attention and certain measures have been
lowest will be dependent on availability. In such systems, critical loads, taken by the government. Technological adaptation towards reduced
and those paying for it, can always be supplied. The importance of risk of theft and vandalism may include special tools and
keeping certain key customers such as industries or hospitals supplied robust design.
cannot be over-emphasised since they are often the cornerstone of
remote area electrification projects. Since neither tides nor waves are Marine Environment
constantly flowing or easily regulated energy sources, they must be Rural communities in developing countries often rely heavily on
utilised in combination with other energy sources. Of note, specific neighbouring ecosystems. The local ecosystem services often
technical solutions such as tidal impoundments with compartments constitute the main source of income. In tropical coastal communities,
provide the possibility to store energy over short periods. fisheries are fundamentally dependent on coastal mangrove, seagrass
and coral reef ecosystems. As they are particularly vulnerable to
Maintenance and Transports changes of ecosystem services, rural communities may become
Technical maintenance is a common and serious obstacle for rural severely affected even by local environmental impacts. Considering
electrification, irrespective of the power source.
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Local future employment of ocean energy in Africa, it is mandatory to avoid
understanding of technical systems is often poor, and this becomes conflicts with local coastal communities.
especially problematic for energy systems that are too small to
economically support the continuous presence of technical Large applications of tidal energy, such as tidal barrages damming a
personnel. This is a certain setback for energy technologies with river mouth or a bay, must be avoided and even smaller
complicated maintenance, such as most ocean energy applications. impoundments should be thoroughly investigated since changes in
Hence, it is unlikely that converters, which require underwater tidal regimes may cause unexpected ecosystem damage. However,
maintenance work, will be suitable for rural small-scale applications. most ocean energy concepts utilising waves and tidal currents are
In this context, suitable adaptations require keeping the most likely to interfere very little with the natural environment. The
sensitive equipment above water, or at least allowing easy access, construction phase of some converters includes harmful pile-driving,
and above all promoting low-maintenance machinery. Among the but it is not yet known whether the moving turbine blades pose any
ocean energy prototypes available today there are both wave power danger to marine animals. Site planning and risk assessments are
and tidal power concepts with few moving parts and land-based or important measures to avoid impacts, but of equal importance may be
dry machinery. A relatively straightforward example is artificial tidal convincing fishermen and other stakeholders that the technology does
impoundments that rely entirely on mature technology since they not harm the local environment. Further prospective studies of
are based on conventional low-head generators. However, all environmental risks associated with ocean energy installations are
machinery needs maintenance, not least those in a saltwater-stained needed before a massive launch can be recommended.
environment. Examples of successful logistics for securing
maintenance competence at an adequate level can be drawn from Powering African Coasts
the implementation of solar photovoltaic systems in Africa. Regional Rural Africa is sparsely populated and local grids in remote areas are
organisation of trained personnel, with many village caretakers and an important step towards creating a national grid. With technical
few engineers, can provide the right level of assistance at reasonable solutions meeting the issues discussed above, small/medium-scale
costs. Such systems presume a common use of similar technologies ocean energy may contribute to a leapfrogging of the African
in the same area. In remote rural areas most roads have a very energy system that can support rural development. The importance
low standard, making transport of equipment and personnel with of socioeconomic prerequisites, such as acceptance, prevailing
trucks slow and costly. Hence, energy systems that require fuel energy demand and efficient institutions, is still fundamental to any
import and transport create both financial dependence and electrification project. Our research in that area is still in an early
transport vulnerability. Here, many ocean energy sources benefit stage, but we have found that niche markets exist where the
from eased transports by boat at installation and independence from price–performance balance is in favour of smaller, robust and reliable
fuel transports during operation. generators based on renewable energy sources. n
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Technical Assessment Guide-TAG-RE 1010489, 2005. 5. Nhnyete IK, Mahongo SB, Tanzania Ports Authority, 2007. 10. Ehnberg E, Chalmers University of Technology, Göteborg,
2. Barnes DKA, Afr J Ecol, 1999;37:424–34. 6. Foley G, Energy Policy, 1992;20(2):145–52. Sweden, 2007.
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MODERN ENERGY REVIEW VOLUME 2 ISSUE 1
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