Pumped hydro dams are prominently used as energy storage in East Africa, but that is changing with the increase in renewable energy and battery energy storage systems.
East Africa countries have announced a total of more than 2,000MW in new solar PV and wind power projects over the next three years. Battery systems in both Front Of The Meter (FOTM) and Behind The Meter (BTM) applications provide for energy access leading to rural electrification, diesel generator replacement, and support grid systems.
Countries such as Libya, Egypt, Sudan, and the Democratic Republic of Congo (DRC), Ethiopia, Kenya, Rwanda, Tanzania, and Uganda are in Eastern Africa Power Pool (EAPP). In this region, pumped hydro dams are usually the main source of energy storage. In essence, a scan across most countries in the region show that reliance on hydroelectricity is significant.
Lately, other sources of generation, namely wind and solar, are starting to be built at utility-scale, and that has driven the conversation towards deployment of battery energy storage. This storage interest is particularly strong in Kenya, where variable renewable energy generation now accounts for 14% of installed generation capacity.
The Eastern Africa countries have announced more than 2,000MW in new solar PV and wind power projects. These new projects are estimated to start online over the next three years. On the commercial and industrial front, Battery Energy Storage System (BESS) technologies have made headway, especially in both Front Of The Meter (FOTM) and Behind The Meter (BTM) applications.
The use cases lend themselves to three broad categories:
- Energy Access Projects / Rural Electrification
- Diesel Abatement / Replacement
- Weak Grid Mitigation
Various rural electrification programmes and private sector-led investments across Kenya, Uganda, Tanzania, Rwanda, Ethiopia, South Sudan have deployed dozens of hybrid micro-grids (solar plus BESS plus generator). These represent the most common and only FOTM BESS applications in the region. Lead-acid batteries have dominated the market space due to lower capital expenditures (Capex), but Lithium BESS installations are making their mark.
Energy access projects are designed to provide towns and villages with reliable and cost-effective renewable energy, often displacing diesel generators and the darkness.
Some projects include:
- A 2.3MWh BESS coupled with a 450KWp solar PV site in Eritrea
- A 1.9MWh BESS coupled with a 400KWp solar PV at another site in Eritrea
- A 2MWh BESS coupled with a 1.5MWp solar PV site in DRC
- Ethiopian Government pilot programme with 6.5MWh of BESS spread across 12 rural electrification sites
- Kenyan Government pilot programme with 11.2MWh of BESS spread across seven rural electrification sites
This market segment has seen several hybrid mini-grids deployed to supplant thermal generation as the primary power source in commercial facilities that are situated away from the reach of the main grid. With the prices of the primary fuel source, diesel in the region of $1.00/liter, which translates into a Levelised Cost of Energy (LCOE) of $0.35/kWh, a combined solar + BESS LCOE in the region of $0.18-$0.25 has proven very competitive.
Adoption has, however, been slowed down by the high initial Capex associated with switching. More is needed to provide well-matched financing to spur uptake.
Notable diesel abatement projects include:
- A 1.3MWh BESS paired with a 660KWp at a game lodge in Kenya
- A 500kWh BESS at an off-grid lodge in Tanzania
- A 700kWh BESS at an office complex in South Sudan
Weak grid mitigation
In industrial hubs, most activity in East Africa is concentrated, which is well supplied by the national grid. However, you do come across agricultural-processing facilities that are located relatively far from these industrial parks. Often, they happen to be situated at the end of a long distribution line with brownouts.
Brownouts are voltage and frequency fluctuations leading to equipment at the factory sites being damaged or rendered unusable. By combining on-site generation (Solar PV) and BESS, grid-interactive mini-grids solve the brownouts problem. The advanced BESS controls enable these sites to monitor grid conditions and island the site when there is a grid outage or severe deterioration on power quality.
A notable weak grid mitigation project is a 4MWh BESS co-located with a 1.5MW Solar PV + grid at a Tea Plantation and factory in Kenya.
Authors: Anthony Mburu and Rao Konidena