Why you are likely to be hit by a blackout every Wednesday

In 2025, Kenyans were most likely to experience an outage on Wednesday evenings, according to data from electricity sector agencies. 

Data by the Energy and Petroleum Regulatory Authority (Epra) shows that electricity demand in the country peaks during the middle of the week, with consumption being at its highest on any given Wednesday.

This points to the day when productivity in industries is at its highest during the week.

Demand reaches 41,000 megawatt hours (MWh) on Wednesday, which puts the grid under the most strain.

Electricity demand is lowest on Sunday, when the average demand stands at 34,959MWh and starts going up on Monday and reaches the highest levels on Wednesday.

Demand then starts to slow down and drops to 38,000MWh on Saturday. 

This is even as it emerged that Kenya Power has been rationing electricity for regions during peak hours as demand outstripped capacity.

President William Ruto, in early November, confirmed that: “Between 5pm and 10pm, we have to do load shedding. We have to shut off some areas to be able to power others because our energy is not enough.” 

Noting how dire the situation is, the President announced plans to increase installed power-generating capacity by an additional 10,000MW by 2032, up from the current 3,192MW.

Going by the President’s statement and the Epra data, it means that industries and households were most likely to experience what can be termed as demand-driven outages on Wednesday evenings. 

Critical to note, however, is that not all outages are due to demand exceeding the installed generating capacity. 

There are also instances when the power agencies schedule outages to undertake maintenance work on infrastructure such as the transmission and distribution lines.

There are also numerous instances where there are incidents, such as trees or tree branches falling on transmission lines or cars hitting electricity poles, that end up causing blackouts.

Kenya Power, in its annual report to June 2025, noted that there have also been increased instances of outages due to transmission constraints.

The electricity retailer said its own analysis of its power system data “links the widespread power outages to system disturbances driven by transmission constraints, which created major imbalances on the grid and triggered service disruptions.”

While demand has been steadily growing, investments in power generation capacity have not kept pace. 

Thus, while peak demand, which is the maximum power required by the system at a specific time, has increased from 1,993.53MW in 2021 and grown to 2439.06MW this December, installed capacity has, over the last two years, been on the decline to stand at 3,235.5 MW compared to 3,321.3MW in 2023.

Slowdown in investments in power generation has been due to a 2018 freeze on signing of new power purchase agreements, put in place to give the state time to put in place safeguards to protect consumers from inflated power purchase agreement (PPA) costs that had been blamed for the high cost of electricity in the country.

The moratorium was lifted in November. 

In the absence of new power plants coming on board, Kenya has relied on imports, mostly from Ethiopia, as well as increased output from costly thermal power plants.

Kenya has an installed power generation capacity of 3,192MW as of June 2025, according to the latest data from Epra.

This is theoretically enough to meet the current peak demand of 2,439.06MW recorded in early December. 

However, the system’s effective capacity – what can realistically be dispatched to the grid – is 3,082MW.

Of the effective capacity, about 645MW is from variable renewable energy sources, such as wind and solar.

The solar plants cannot always be relied on during evening peak hours after sunset. The wind plants cannot also be heavily relied on during the evening peak, as reports indicate that production starts going up after 9pm and only produces optimally and consistently between 3am and 9am.

This would mean that the power generating capacity that can be relied on at all times - also referred to as firm capacity – is at 2,547MW. This capacity includes the 200MW imported from Ethiopia.

“The intermittent nature of solar and wind may hinder the system’s ability to meet peak demand, necessitating load management,” said Kenya Power in a past report