Study on the Potential of Reactive Power Compensation Measures to Reduce Transmission and Distribution Losses
The electricity sector in the Sub-Saharan African region is often hampered by a lack of supply capacities in combination with high technical transmission and distribution (T&D) losses. As a result, many countries face an inadequate electricity supply characterized by voltage drops (leading to substantial damage in industrial processes), power cuts and load shedding in order to meet the demand of the remaining consumers.
Parts of these technical losses may be addressed through energy efficiency measures that generate reactive power in situ and thereby reduce the reactive power that has to flow through the transmission and distribution system. Many industrial electricity consumers in Eastern and Southern Africa are typically operating at a low power factor (PF), which defines the relationship between the real power (in kW) consumed by a facility to the apparent power (in kVA) demand from the power utility. A low PF results in substantial energy losses in the power T&D system. As power is generated partially through the combustion of fossil fuels, the improvement of the PF bears the potential to reduce greenhouse gas (GHG) emissions related to power generation.
The proposed study aims to evaluate the energy losses in the power grid caused by industrial electricity consumers due to low PF in Sub-Saharan Africa, as well as to assess potential reduction of energy losses (and related GHG emissions), considering the enhanced uptake of reactive power compensation (RPC) equipment. The envisaged intervention follows the subsequent rationale:
- The RPC equipment generates reactive power on site by employing thyristor controlled capacitor banks (capacitor banks only store energy and thereby do not increase the overall electricity consumption of the facility).
- The stored energy is exchanged as reactive energy with the load in the facility.
- Hence the demand of reactive power is met by on site reactive power generation and does not have to be delivered by the electricity supply system.
- The industrial facility reduces the apparent power demand (S, in kVA) and reactive power (Q, in kVAr) to be supplied by the electricity system to the industrial facility’s consumption of real power (P, in kW) which does not change.
- The PF, which is defined as the ratio of real power (P) to apparent power (S), is increased when appar-ent power demand is reduced for fixed real power consumption.
- Consequently, the RPC equipment will improve the power factor of the industrial electricity consumer whose apparent power demand is reduced.