Significance of large-scale renewable energy integration
Generating electricity using renewable energy resources (such as solar, wind, geothermal, and hydroelectric energy) rather than fossil fuels (coal, oil, and natural gas) reduces greenhouse gas emissions from the power sector and helps address climate change crisis.
Renewable energy sources are clean, plentiful, widely distributed, inexhaustible and increasingly becoming economically competitive relative to fossil options. Renewable resources exhibit notably different characteristics from their fossil-fuel-burning counterparts principally in their diversity, abundance and potential for use anywhere in the country.
Furthermore, their costs are steadily plummeting at a sustainable rate, whereas fossil fuel prices skyrocket and are coupled with unpredictable volatility. The renewability qualities and favorable economics of renewable energy sources make them attractive for the country’s electrical power generation and ultimately integration into the grid
The development and use of renewable energy resources have been a major endeavor since 2004 to Tanesco by introducing research works in renewable energy resources such as wind and solar for investment. The optimal balance of electricity supply and demand on the power grid is important by knowing how much renewable energy is being generated at any given moment and how much renewable energy generation is expected in order to improve the generation mix in the grid. All of this information was important to Tanesco to know due to the intermittent nature of renewable power and the wide variety in the size and locations of renewable energy resources across the National grid.
The Ministry of Energy (MoE) in collaboration with Tanzania Electric Supply Company Limited (Tanesco) and Rural Energy Agency (REA) under the support from DANIDA and SIDA conducted wind energy resource assessments.
The assessed ares incude Mkumbara (Tanga Region), Karatu (Manyara Region), Gomvu (Dar es Salaam Region), Timbe (Mtwara Region), Makambako (Njombe Region), Mgagao (Kilimanjaro Region), Kititimo (Singida Region), Usevya (Katavi Region) and Mafia Island (Pwani Region). The assessment indicates areas such as Makambako and Singida have sufficient wind speed for grid-scale electricity generation with an average wind speed of 8.9 m/s to 9.9 m/s.
While the assessment of potential solar energy resources are found in the central (Dodoma and Singida) and part of the Lake Zone (Shinyanga) of the country. High solar energy levels are ranging from 2,800 to 3,500 hours of sunshine per year and global horizontal radiation of 4–7 kWh/m2/day.
According to the World Bank, Tanzania has a solar energy potential greater than that of Spain and wind energy potential greater than that of the US State of California. With such great potential for solar and wind energy resources, Tanzania is naturally appropriate for producing solar and wind energy as a feasible alternative source for modern energy supply from the national grid.
The utilisation of renewable energy sources would provide clean power and support a sustainable generation mix.
Integrating large shares of intermittent renewable plants based on wind and solar power sometimes poses certain challenges to the power supply system.
There are a number of technical challenges, which may arise, but cost impacts should also be considered which might also in the end have a significant impact on the optimal share of intermittent renewable energy sources that can be integrated on the system.
In 2015. Tanesco through the Ministry of Energy, got support from the Norwegian Embassy for conducting an assessment of the optimal share of the intermittent renewable energy generation to the national grid. The Norwegian Embassy engaged Norconsult of Norway to carry out the assessment. The assessment considered short term, medium-term and long term plans for investment in generation and transmission of which gas and coal power projects were among them.
Therefore, the assessment revealed that in the short term the capacity of 385MW of renewable energy generation can be integrated into the grid, when the peak load will reach 1,250MW and for the medium to long term, the capacity of 710MW of renewable energy generation can be integrated at the maximum peak load of 2,500MW which estimated to be in the year 2025.
The above capacity of renewable energy integration to the grid will reduce the dependency in hydro during daylight hours and would allow conservation of energy. By so doing, the spare capacity can be used during peak demand periods as well as during the extended dry season.
This addition of renewable energy generation to the national grid will significantly enhance power supply capacity to the mines in the Central and Lake zones as well as stabilise the grid and strengthen power supply capacity.
By Gwalusako Mwaipopo
