"extend the power" is a correct and usable phrase in written English.
You could use it when you want to express the idea of increasing the strength or force of something. For example: "We must extend the power of our army if we wish to achieve victory."
"It's a total fraud that will extend the power of monopolists rather than promote competition," he said.
To extend the power of microinjection experiments, mouse embryo fibroblasts (MEFs) have been used with a variety of genetic modifications.
"What the Government is doing is the Deregulation Bill, which is currently before the House, will extend the power to set term dates to all schools by 2015.
Americans extend the power of the Sovet Union to include industry and economy when, in fact, they are only a threat to us militarily.
Its principal change would extend the power to order the departure of foreign troops to the interim government coming into office on June 30.
The path out is a steady, patient advance of the faltering Geneva negotiations to extend the power and authority of a reformed Syrian state and military.
The power converter is based on Multilevel Converters technology which allows to extend the power-handling capability of the electronic switches, reaching the medium voltage operation without step-up transformers.
On Monday the government could seek to extend the powers for several months.
The two-day Commons report stage of the investigatory powers bill, which will extend the powers of the security services, is scheduled for Monday and Tuesday next week.
The bill would put an end to extortionate fees, and would extend the powers of the housing ombudsman to all landlords.
In addition, TechDirt warns that the bill may extend the powers of law enforcement agencies in general and the police in particular.
