The problem with Kenya’s clean energy push

Wind and solar have in the recent past become key energy sources for Kenya. [Courtesy] 

The increase in the amount of electricity generated from renewable energy sources is presenting unique challenges to Kenya’s electricity grid. 

While the country’s green energy push has been applauded globally, the high intermittency of renewable energy sources, particularly wind and solar, puts the stability of power grids such as Kenya’s at risk.

They have also proved a challenge for electricity distributor Kenya Power, which in most instances does not end up getting the amount of power stipulated in the power purchase agreements with these companies.

Wind and solar have in the recent past become key energy sources for Kenya, accounting for a combined 15 per cent of the power consumed in the country.

The commissioning of the 310 megawatts (MW) Lake Turkana Wind Power plant in 2018 significantly pushed up power generated through wind.

Last year, the 100MW Kipeto Power in Kajiado County came online, bringing the total installed capacity for wind to 435MW.

Before 2018, the only major wind power plant in the country was KenGen’s plant on Ngong Hills with a capacity of 25.5MW.

On the solar front, the Rural Electrification and Renewable Energy Corporation last year commissioned the largest solar power plant in Garissa with a capacity to generate over 50MW.

Several wind and solar plants are also lined up and should start feeding the national grid in the coming months.

Concerns are, however, mounting about the intermittent nature of these plants, whereby they cannot feed the grid when called upon but can only do it when there is ample wind in the case of wind farms and only during the day for the solar power plants.

There is a push now to have the power plants equipped with storage capabilities. Batteries would enable them to store energy generated whenever there are strong gusts of wind or ample sun, which can then be used whenever demand goes up.

“For underdeveloped power grids, the intermittency of renewables can put the stability of the systems at risk,” said a report by the African Energy Chamber titled The state of African Energy 2022.

“At 15 per cent of installed capacity from solar and wind, Kenya is already suffering from severe voltage instability. The country is at the epicentre of Africa’s energy transition, building momentum in the renewable sector through the 310MW Lake Turkana wind farm and 50MW Garissa solar PV station.

“However, Variable Renewable Energy (VRE) has created unprecedented challenges in power system operations, a problem that will worsen as more VRE sources come online. Better system management and upgraded infrastructure is necessary, but for now, without a long-term power storage technology, complementary fuels (such as) are crucial to satisfy the growing demand for electricity.” The lobby noted that to sustain the integrity and stability of the national power grid, there is a need to invest in energy storage.

“The costs of storage, although high, show promise of falling costs over the coming years,” said the chamber.

Wind power tends to generate higher energy amounts deep in the night. During these hours, there are strong winds but unfortunately, most consumers are switched off.

The result is that without storage and with industries and households switched off, their power does not have much demand, which means they mostly generate well below their potential.

“Two-thirds of Kenya’s electricity is generated from renewable/clean energy sources… the success in the growth of these two energy sources (wind and solar) has inadvertently resulted in excess energy being generated during off-peak hours and increased intermittent capacity in the national grid, thus presenting a good opportunity for introduction of battery storage to balance the demand and supply in the system,” said an August 2021 report by the US International Trade Administration.

The Presidential Task Force on the Review of Power Purchase Agreements (PPAs) also raised concern over the reliability of renewable energy sources.

Following analyses of the performance of wind and solar plants in terms of the power they generate against the requirements of their PPAs with Kenya Power, the task force noted that they have been underperforming. 

In its report presented to President Uhuru Kenyatta last September, the task force recommended that wind and solar power plants compensate Kenya Power whenever they fail to meet minimum generation requirements as stated in their PPAs with the power distributor.

The task force recommended that Kenya Power should “require future IPPs with high intermittency (wind, solar, mini-hydro) to take financial risk for predicting their daily, weekly or monthly dispatch of power.”  

“The penalty for under-producing would be to compensate the grid at the cost of the thermal plants or the highest-peaking plant on the grid as an alternative to the under-generation compared to the forecast. Alternatively, the projects could themselves take on the cost of providing energy storage and presumably adjust the tariff accordingly.”

One of the major IPPs running a plant prone to high intermittency is the Lake Turkana Wind Power plants.

According to the task force, the Marsabit wind farm rarely achieved a continuous power production matching its 310MW installed capacity in 2020.

If anything, it produced 150MW on average per day throughout 2020 – about 50 per cent of the installed capacity. “Over the year ended 2020, the project did not achieve the nameplate 300MW capacity for a sustainable period on any day. The minimum average daily output was 4MW and the maximum 262MW – during only five days of the was output in excess of 250MW,” said the report.

“During 67 days (18 per cent of the year) daily output was less than 100MW. The bulk of the year (225 or 62 per cent) experienced production of between 100MW and 200MW and hence the daily average for the year of 150MW.”

The in-depth look at the LTWP data was on account of the project being in operation for several years and generating adequate data. The task force noted that there is a need to understand the other projects, which are being commissioned and starting to feed the grid.

The Rural Electrification and Renewable Energy Corporation’s 50MW Garissa Solar, the task force noted, has also been experiencing high intermittency.

“An additional four plants – Malindi Solar (40MW), Alten Kenya (40MW), Selenkei (40MW) and Eldosol (40MW) – are under construction,” said the task force report. The power plants currently being developed are expected to add another 160MW of capacity to the national grid. President Uhuru directed the Energy Ministry to fully implement the recommendations of the task force.

He also appointed a committee to oversee the implementation of the recommendations.