Regional Electricity Interconnections for the Clean Energy Transitions in East Africa: Evidence from an Open-Source Energy System Model

Regional electricity interconnections are increasingly recognised as enablers of cost-effective power system expansion and deep decarbonisation in emerging economies. In East Africa, Kenya and neighbouring countries — Tanzania, Ethiopia, and Uganda — operate relatively low-carbon electricity systems; however, rapidly growing electricity de-mand and expanding thermal generation are placing upward pressure on grid emissions intensity, particularly in Kenya. This study examines whether planned cross-border in-terconnections can mitigate this trajectory using OSeMOSYS Global, an open-source least-cost capacity expansion model, comparing stand-alone national power systems against an interconnected regional grid over 2022–2050. Results show that interconnec-tion enables access to low-cost renewable electricity and facilitates surplus generation ex-ports, maintaining system-wide carbon intensity within climate-finance eligibility thresh-olds of 100 gCO2/kWh. Outcomes are heterogeneous: Ethiopia and Kenya incur cost in-creases (+USD 481 million and +USD 568 million respectively) attributable to transmis-sion capital expenditure, whereas Tanzania and Uganda achieve net cost savings (−USD 590 million and −USD 891 million) alongside substantial emissions intensity reductions of 141.9 and 280.5 gCO2/kWh respectively. Regional emissions equity is preserved, with modest intensity increases in Ethiopia and Kenya offset by large reductions elsewhere. These findings strengthen the case for climate-financed regional transmission as a scala-ble and equitable mitigation strategy in East Africa.