He also said that profits generated from the power firms will fund social programmes for "marginalised" indigenous communities in the country.
Shortly after taking office in 2006, Morales nationalised Bolivia's natural gas industry and has since taken control of several other utility companies.
Morales said on Saturday that the state now controls 80 per cent of electricity generation in Bolivia and he was aiming for complete government control over the sector.
"This is essentially what Morales, the Bolivian president, was elected on," Alex Van Schaick, a Bolivia analyst, told Al Jazeera.
"This is essentially what Morales, the Bolivian president, was elected on"
Alex Van Schaick,
"It was for the recuperation of basic public services putting oil, natural gas and other strategic public utilities back in the hand of the public sector."
The companies involved in the nationalisation process include Bolivia's largest power producer, Empresa Electrica Guaracachi SA, controlled by Rurelec PLC of Britain, as well as Empresa Corani SA, a hydroelectric company operated by France's GDF Suez.
Rurelec said it was "very disappointed" Morales had decided to nationalise its assets in Bolivia.
"We're disappointed because Rurelec is third largest British investor in Bolivia. And since 2006, when Evo became president, we have invested more than $110 million in new power plant capacity," Peter Earl, Rurelec CEO, said.
A GDF Suez spokesperson said the company "always respects the legislation of the country where it is active while defending its interests as a company".
Also nationalised were the Valle Hermoso company, and the Empresa de Luz y Fuerza de Cochabamba, which was owned by its workers and local citizens.
Morales said the Bolivian government had tried, but failed, to convince investors to sell the shares the state needed to take a controlling stake in the companies.
"It is the state's obligation to compensate investors for their assets, we made an effort to reach an agreement with the private, multinational companies, but they were unwilling to reach an accord," he said.
Several companies have launched legal action over the compensation they were offered as part of the nationalisation.
Bolivia's state-run National Electricity Company (ENDE) was privatised in 1994 and broken up into a number of generation, transmission and distribution companies.
Roberto Peredo, the president of the current state power company, said in a speech at the Corani power plant on Saturday that the renationalisation"one of the biggest achievements of the cultural revolution".
He said that privatisation had seen ENDE solde to "neoliberal capitalists for the price of a dead chicken".