**9. Distribution generation**

68 Renewable Energy – Trends and Applications

 Establish a programme or mechanism to solve the problem of already installed systems. The programme should include some mechanism for informing the user about the

Setting up coordinating committee for planning and implementing the action plan to

 Strengthening the cooperation between the concern ministry, authorities, institutions and organisations involving them in the national action on renewable energy

Setting rules and legislation for quality assurance, standardisation and certification for

 Development of effective public awareness and promotion programmes such as demonstrating systems, some printed materials (leaflets, brochures etc) training courses, seminars, presentations and workshops for targeted users, small-scale

Renewable energy resources and technologies can serve as one of the key drivers for rural

Enhancing local micro-economic development in agriculture, manufacturing, and small

 Providing vital economic generating activities in the rural areas such as water pumping, battery charging, lighting schools, ICT development, crop drying, milk refrigeration,

Improving human development such as accessibility to modern education, internet, and

Helping to lower the pace of migration of young people to overcrowded municipalities

Renewable energy technologies for rural and semi-urban electrification is more sustainable; suitable for supplying geographically dispersed villages by means of distributed energy often without relying on a national grid. Grid connection to remote and dispersed villages is expensive and technically difficult; therefore, local mini-grids developed from renewable energy sources can be established and serve the purpose of rural electrification either as stand lone power generating unit for a particular village or interconnected with other village

 Biomass. The majority of the rural population in Tanzania relies on traditional biomass to meet their cooking and heating needs. The challenge is to ensure more efficient and sustainable use of biomass for heat extraction, cooking and generation of electricity

Solar PV systems can be widely used in poverty alleviation projects for electrification of

Establish credit mechanism to finance prospective technologies.

all renewable energy technologies components and systems.

laboratories in schools, technical colleges and universities.

drug refrigeration, and ice making in semi-urban areas.

Preventing social unrest in particular to young people

development in the country in a number of ways in:

improve health services, etc.

**8. Social impact of renewable energy technologies in sustainable** 

systems and their regular duties.

acceptable technologies.

technologies.

**development** 

industries

and cities.

Poverty alleviation

generating unit. In this way:

instead of using raw biomass.

remote underdeveloped areas.

Dondi *et al* (2002) defined distributed generation as a small source of electrical power generation or storage ranging from less than a kW to tens of MW that is not a part of large central power system and is located close to the consumer (load). Chambers (2001) also defined distributed generation as a relatively small generation units of 80 MW or less. According to Chambers, these units are sited at or near customer sites to meet specific customer needs, to support economic operation of the distribution grid or both. The two definitions assume that distributed generation units are connected to the distribution network. It is clear that the two definitions give or allow a wide range of possible generation schemes. So, the definitions allow the inclusion of larger scale generation units or large wind farms, landfills, etc connected to the transmission grid, others put the focus on small-scale generation units connected to the distribution grid. Nevertheless, all the definitions suggest that at least the small scale generation units connected to the distribution grid are to be considered as part of distribution generation. Moreover, generation units installed close to the customer (load) or at the customer side of the meter are also commonly identified as distributed generation.

Ackerman *et al* (2001) precisely defined distributed generation in terms of connection and location rather than in terms of generation capacity. They defined a distributed generation source as an electrical power generation source connected directly to the distribution network or on the customer side of the meter. The definition is adopted in this chapter even though it is rather broader. The definition does not put limit or technology or capacity of the potential distributed generation application. It suits the Tanzanian condition when referring to renewable resources the country has.

Distribution generation is a latest trend in the generation of electrical power. The distributed energy resource concept allows consumers who are generating electricity for their own needs to send surplus electrical power back into the power grid or share excess electricity via a distributed grid. Distributed generation system can be divided in two segments, as shown in Figure 10. The segments include:


Combined heat and power (CHP) is the use of a power generator to simultaneously generate both heat and electricity. The method is new in the country, but can be applied at Mufindi Paper Mills (MPM) where the paper machines generate enough back pressure which is useful in electricity generation.

Renewable energy resources (RER) capture their existing flow of energy, from on-going natural processes such as solar, wind, small hydro and biological processes. The two segments are the main component in implementation of distributed generation in the country and can accelerate rural electrification, hence improving accessibility of Tanzanian to modern energy and spur sustainable development.

Distributed generation could serve as a substitute for investment in transmission and distribution capacity or as a bypass for transmission and distribution costs. Distributed generation could result in cost savings in transmission and distribution of about 30% of electricity cost compared to the cost incurred by TANESCO in electrifying rural areas. Distributed generation can substitute for investments in transmission and distribution capacity. It can be used as an alternative to connecting a customer to the grid in a stand alone application. Furthermore, well selected distributed generation from the resources the country has can contribute in reducing national grid losses.

Distributed generation can contribute in the provision of ancillary services. These include services necessary to maintain a sustained and stable operation of the national grid. For instance to stabilize a dropping frequency due to a sudden under capacity such as power plant switching off due to technical problems or excess demand.

Installing distributed generation schemes will allow the exploitation of cheap fuel resources available in the country. For example in the proximity of landfills resources, distributed generated units could burn landfill gases. Also, biomass resources may be envisaged.

Fig. 10. Split up of Distributed Energy Sources

Increased environmental concern induces an increase interest in distributed generation application worldwide, also in innovations in the appropriate technologies. Nevertheless, the economic as well as technical challenge will be to optimally integrate the distributed generation units in the electricity system available in the country that up to now has been very centralized. The challenges emanating from application of distributed generation in the country is a blessing as more opportunities to engineers and researcher in investigating new and affordable means of integrating distribution generation in the national grid.
