Shares of Plug Power (PLUG 9.41%), one of the highest-profile companies involved in the hydrogen power revolution, enjoyed a solid rise this morning as its shares rocketed 8.1% through 10:10 a.m. ET.

The reason for the rise is no mystery: This morning, Susquehanna analyst Biju Perincheril raised his price target on Plug stock by an astounding 80% -- from $1 a share to $1.80. The bigger question is whether Plug Power stock deserved to jump even 8.1% on this change in one analyst's opinion.

And whether investors should buy Plug Power stock.

Image source: Getty Images.

Is Plug Power's pop justified?

The first question is tricky. On the one hand, an 80% price target hike seems unusually generous, and hints at some important underlying change in the company affected. On the other hand, a price target change of only $0.80 doesn't.

It's also worth pointing out that after Plug's share price jump today, the stock already costs more than Perincheril says it's worth -- more than $1.90 per share.

And Perincheril is only "neutral" on the stock. He doesn't say you should buy it.

Is Plug Power stock a buy?

Neither do I. Perincheril argues, in a note on The Fly, that renewable energy stocks that deserve buy ratings are those with a strong U.S. manufacturing presence and "robust backlogs" such as GE Vernova and First Solar. Most of Plug's manufacturing assets are located in the U.S., true, but the company makes no mention of strong backlog in its latest 10-K filing. To the contrary, sales dropped nearly 30% last year, which suggests backlog may actually be shrinking.

With a long history of losing money and burning cash, I suspect Plug stock is still a sell.