With Europe scrambling to close a gap between gas consumption and constrained supply, Galamba said speeding up installation of 1.2 gigawatts of solar photovoltaic capacity would "make a very important contribution, as it will allow electricity generators to consume less gas."
"It is the most effective measure Portugal can take without applying heavier measures in the electricity or industrial sectors, which are the main consumers," he told public television RTP late on Wednesday.
But Portugal and Spain, which have weak energy interconnections with the rest of Europe, may reduce consumption by only 7% if they send as much gas as possible to EU neighbours. The two countries import liquefied gas from producers other than Russia and can re-export some.
The 1.2-gigawatt capacity equals that of a now closed coal-burning power station at Sines, Galamba said. Solar generation is far more intermittent than thermal generation, however.
The accelerated capacity is in solar parks already approved or under construction. As part of the plan, "300 megawatts to 400 megawatts of new solar capacity from small, medium and large-scale photovoltaic solar parks will come into operation by October," the secretary said.
Portugal currently has installed solar capacity of over 2 gigawatts, double what it had at the end of 2020.
It consumes around 5 million cubic meters of natural gas annually. Electricity producers use 45%, industry 45% and households 10%.
"We are working to minimize or even eliminate risk of negative impacts on industry," Galamba said. The government would take measures to reduce use of gas in buildings and encourage the public also to use less.