This is set to meet the growing demand.
Kenya suffers from frequent blackouts due to supply shortfalls and an aging grid, forcing most businesses and wealthy people to have stand-by generators. Businesses in East Africa's biggest economy cite frequent localised power blackouts as a barrier to economic growth.
Kenya's sole electricity distribution company serves about 2.8 million customers. Most of its new customers are located in rural areas.
Ben Chumo, Kenya Power's chief executive, said in a statement on Sunday his company had connected 443,000 new customers in its last financial year, which ends in June, up from 307,000 the previous year.
Chumo did not say where the funds to extend the power grid would come from, but the company has in the past year been raising cash through debt and loans from the World Bank, the French Development Agency and the European Union.
Kenya Power's plans are in tandem with the Kenyan government's aim for 70 percent electricity penetration by the year 2020, up from 32 percent, Chumo said.
Kenya plans to add 5,000 megawatts of power generation capacity by 2017 to the existing 1,664 MW to accelerate economic growth, which is expected to push power demand up to 15,000 MW by 2030.
The economy is expected to expand by about 5 percent this year, having expanded by a similar margin last year.
The supplier buys electricity from hydropower stations and geothermal plants, which are run by the Kenya Electricity Generating Company.