Reactive Power Compensation in East African Power Systems: Technical Innovations and Grid Stability Solutions
East Africa’s power sector is rapidly expanding, with increasing reliance on renewable energy sources and growing regional electricity trade. The region’s transmission infrastructure is expanding to allow for robust power trade and eventually, to achieve the Africa Single Electricity Market (AfSEM), so managing reactive power becomes crucial. However, inadequate reactive power management poses significant challenges to grid stability. Voltage instability limits efficient power transfer, increases congestion, and necessitates costly grid expansion projects. Mitigating power quality issues such as flickering, harmonics, and load imbalances, ensures a more resilient and reliable grid.
This article explores East Africa's electrical infrastructure, the difficulties in managing reactive power in emerging power grids, and the vital role that reactive power compensation plays in guaranteeing a reliable, effective, and sustainable power system in East Africa.
Theoretical Foundations of Reactive Power
Reactive power is the portion of what is made available by the network power, which results from the interaction between voltage and current in an alternating current system and cannot be actively used by consumers. It is generated or consumed in many electrical devices such as capacitors, electric motors and generators.
Below is the mathematical representation and relationship between different types of power:
· Active Power (A): The power that performs actual work, measured in watts (W).
· Reactive Power (Q): The power that oscillates between the source and load, measured in volt-amperes reactive (VAR).
· Apparent Power (S): The vector sum of active and reactive power, measured in volt-amperes (VA).
In power systems, reactive power has a major impact on power factor, harmonic performance, transmission losses, and voltage stability. Grid dependability will be increased, losses will be decreased, and power quality will be improved by putting advanced compensatory techniques into practice.
Current Reactive Power Challenges in East African Grids
Key findings by the Energy and Environment Partnership (EEP) highlight grid inefficiencies, limited rural access, ageing infrastructure, and limited grid capacities for renewable energy integration that impact regional integration. Regional energy planning must consider risks to mitigate offsetting regional interconnection prospects and misaligned policies that may potentially hinder energy access and security efforts.
National grids such as the Adama-I Wind farm, Ethiopia were not initially designed to support large-scale reactive power compensation, leading to inefficiencies in power transmission and voltage regulation. The growing reliance on solar and wind energy introduces voltage instability, requiring advanced reactive power control to maintain grid reliability.
Further, the development of the energy market is constrained by a lack of market information and technical capacity, and in specific countries, poor tariff policy (Tanzania), the cost of doing business (Ethiopia), and lack of funding (Uganda). Moreover, off-grid technology faces an additional challenge in being largely private sector driven, in a domain where electricity service has typically been provided through public utilities, most of which deliver power well below the cost of production. Even if the off-grid sector is growing in the region, many policy and regulatory obstacles remain, and these will continue to challenge achievement of SDG7: Sustainable, modern energy for all.
Reactive Power Compensation Technologies
Flexible AC Transmission Systems (FACTS) have revolutionized grid management by enhancing voltage stability, reducing transmission losses, and improving power flow control. These technologies are essential for East African power systems where aging infrastructure challenges reactive power management. In this article three types of technologies are investigated.
Static Var Compensators (SVCs) provide rapid voltage control by adjusting reactive power in real time. Kenya is set to install SVCs to manage power flows effectively and avoid grid imbalances, especially in distributed generation. Most common topologies for SVCs are Thyristor Controlled Reactor (TCR), Thyristor Switched Capacitor (TSC), and Harmonic Filter (FC). The main advantage of using a topology with TSC branches is to reduce the losses by reducing the filter size.
Figure 2. Basic scheme of SVC. Source
Static Synchronous Compensators (STATCOMs) provide real-time reactive power support using voltage source converters (VSCs). They offer faster response times than SVCs, making them ideal for high-voltage transmission networks and renewable energy integration. STATCOMs enhance voltage control in weak grids, which is crucial for East Africa’s expanding power infrastructure.
Synchronous Condensers generate or absorb reactive power to stabilize voltage. While historically used in large power systems, they are less common today due to high installation and maintenance costs. While implementation is still limited, their inclusion in hybrid grid stabilization strategies offers a forward-looking opportunity for East African utilities to address growing reactive power challenges.
Emerging technologies like Silicon Carbide (SiC) and Gallium Nitride (GaN) power devices improve efficiency and reduce system losses. Additionally, machine learning-based predictive compensation enhances grid resilience by detecting and mitigating voltage instability before failures occur.
These innovations are crucial for East African grids, ensuring a reliable, resilient, and economically viable power supply while supporting long-term sustainability goals.
Regional Implementation in Tanzania
Energy demand is growing in Tanzania and driven by increasing population and economic activity. Biomass today accounts for 80-85% of all energy demand in Tanzania. Even with the current supply, accessibility, affordability, and connectivity continue to be critical issues in Tanzania. For instance, current electricity tariffs in Tanzania are ranked among the highest in the region. On the other hand, there are several initiatives aimed at enhancing the country's electrical infrastructure that may encompass aspects of reactive power management.
The Tanzania Rural Electrification Expansion Program (TREEP) supports electrification through both grid and off-grid approaches, including support to small private power producers (SPPs) and other distributed renewable energy sources. NRECA International implemented two rural electrification pilot projects in the Kilombero and Mbozi districts. These projects demonstrated newly developed and low-cost rural electrification design standards.
Currently, the national utility company TANESCO is upgrading the infrastructure to Advanced Metering Infrastructure (AMI) that automates reading and the billing of power consumption. By adopting a holistic, technology-driven approach like Tanzania’s, other East African nations can improve energy access, integrate renewables effectively, and enhance overall grid stability. For instance, Tanzania’s Electricity and Water Utilities Regulatory Authority (EWURA) introduced a specific regulatory framework for small power producers (SPPs) that saw the implementation of standardized power purchase agreements (SPPA) and standardized power purchase tariffs (SPPT). East African countries can learn from Tanzania and similarly benefit from streamlined licensing and tariff-setting procedures that address the power sector's challenges and encourage further investments in renewable energy-based mini-grid systems in the region.
Economic and Technical Feasibility Analysis
Reactive power compensation in East Africa demands substantial capital but yields long-term benefits. Investments in infrastructure upgrades, FACTS devices, and capacitor banks reduce transmission losses, improve voltage stability, and enhance grid efficiency. A technology selection matrix ensures cost-effective deployment, with STATCOMs and synchronous condensers providing strategic advantages. A technical study conducted in Kenya recommended the installation of fast-acting reactive power and voltage control devices at strategic locations across the network that lead to greater utilization of renewable energy resources and overall cost savings in the power system.
Technically, improved voltage stability prevents disruptions, while transmission efficiency minimizes congestion. Reliability enhancements reduce outages and boost grid resilience. Environmentally, reducing reliance on fossil-fuel backup systems and supporting renewable energy integration promotes sustainability. These advancements strengthen East Africa’s energy security, foster economic growth, and align with SDG 7. Thus, combining technology adoption, regulatory reforms, and regional cooperation will be key to achieving a resilient, efficient, and sustainable power grid for the region.
Outlook and recommendations
With the goal of preserving the quality of the electrical system, East Africa needs regional standards governing reactive power compensation. In addition, to enhance grid efficiency and reliability, the region must adopt a forward-looking strategy integrating advanced compensation technologies, grid modernization, and supportive policies. As part of the strategies, harmonizing voltage control and reactive power management protocols among East African countries facilitates effective regional power exchange, as outlined in the East African Power Master Plan.
To facilitate this, funding and technical assistance for grid modernization projects can be obtained through partnerships with international energy organizations, such as the World Bank and the African Development Bank.
By creating certification programs in reactive power management, specialized training programs for engineers can improve local engineers' skill sets and guarantee the successful deployment of compensation technologies.
Conclusion
Effective reactive power compensation is key to East Africa’s grid stability, reducing losses, and enhancing power quality. As renewable energy integration grows, technologies like FACTS help manage voltage fluctuations and improve reliability. However, progress not only depends on technology but also requires strong policies, regional collaboration, and investment in infrastructure and workforce development. By implementing subsidy schemes and ROI-based planning like Tanzania, other East African nations can improve energy access and integrate renewables effectively. Therefore, extensive research in predictive compensation and distributed architectures is required to further optimize performance. Prioritizing these efforts will ensure sustainable energy access, drive economic growth, and advance towards SDG 7.
