Shares of fuel cell producer Plug Power  (PLUG)  gave back some of Wednesday's huge gain from an announced deal with Amazon in Thursday trading, but rivals FuelCell Technology (FCEL) and Ballard Power (BLDP) rose sharply as the deal signaled a renewed confidence in the technology.

Fuel cells combine hydrogen and oxygen to produce electricity, producing only water as a byproduct. The technology has been competing with solar and wind energy in the market for electricity generation, and with electric vehicle applications with Tesla.

Ballard Power and Fuelcell Technology are Plug's leading competitors. Both shares rose more than 6% in Thursday trading.

Ballard unveiled its own deal on April 5 but Plug's Amazon news drew all the attention.

The Vancouver-based Ballard said it has an equipment supply agreement with Zhongshan Broad-Ocean Motor to supply and deliver 200 FCveloCity fuel cell engines to be used in demonstrations of clean energy buses and commercial vehicles in key Chinese cities.

Ballard will make the engines in Vancouver and said it expects to $11 million of the goods in 2017.

"We are working to close the strategic technology transfer, licensing and supply deal with Broad-Ocean that we announced in February, said Randy MacEwen, Ballard President, and CEO.

"Once closed, we will work to execute terms of the deal this year. In parallel, Broad-Ocean plans to seize early market demand for fuel cell buses and commercial vehicles in strategic demonstration projects in key Chinese cities," Ballard said in a press release.

On a March 2 earning conference call the company's CEO told listeners that, "We believe we have a very strong setup as we start 2017. We have a record $87 million of committed orders expected for delivery in 2017, already exceeding last year's revenue."

Ballard has an agreement with Zhongshan to supply 200 fuel cell engines to be used in demonstrations of clean energy buses and commercial vehicles in key Chinese cities.

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