What happened Shares of renewable energy companies Plug Power (NASDAQ: PLUG), Nikola (NASDAQ: NKLA), and JinkoSolar Holding (NYSE: JKS) jumped in early morning trading Thursday, rising 4% (Plug), 9% (Nikola), and 11% (Jinko). Around noon EDT, all three were giving back some of their gains, but remained in positive territory -- Plug just barely, while Nikola's 3.4% and Jinko's 4.5% gains remain more respectable. But what was it, precisely, that sparked these gains in the first place? Image source: Getty Images. So what In the case of Plug Power, the answer is easy: An upgrade -- or more precisely, a new buy rating, from Seaport Global Securities, which initiated coverage of the $26 stock today with a price target of $36. Calling Plug the "best-positioned technology provider for [the] emergence" of the hydrogen economy, Seaport predicted that Plug, which is showing negative revenue over the last 12 months, will in fact end 2021 with positive revenue of $465 million, and then grow that revenue 57% to $730 million in 2022, reports StreetInsider.com. In fact, Seaport sees Plug doubling its revenue again by 2024, to $1.7 billion, as it: expands its materials handling (i.e., fuel cell-powered forklifts) business, begins producing increasing amounts of "liquid green hydrogen," and enters brand new markets building fuel cells for electric commercial vehicles and data center back-up power. Nikola's surging on good news, too, specifically, a press release out this morning announcing the addition of five new dealers for its Class 8 electric trucks, operating 51 dealership locations across nine states. Granted, Nikola is still in the process of validating and testing its prototype trucks, and has yet to sell even one, but investors today seem happy that it's at least laying the groundwork to do so. Now what What about JinkoSolar, today's third gainer in the renewable energy business -- and indeed, the strongest gainer of the three? There's no specific news about Jinko to explain today's rise, but we do have some general positive news on renewable energy that appears likely to benefit this stock (and the other two, too). Yesterday, the European Commission unveiled a plan to reduce its carbon emissions by 55% (in comparison to 1990 levels) by 2030. The "Fit for 55" legislation under consideration comprises about a dozen separate proposals, including, for example, a ban on the sale of new internal combustion engine cars and trucks (great news for Plug and Nikola), and also a requirement that 40% of energy produced in Europe be renewable. That's great news for Jinko in particular, which as a solar module manufacturer counts Europe among its most important markets, accounting for more than 13% of total sales last year -- and perhaps even more than that over the 10 years still to come. 10 stocks we like better than Plug PowerWhen our award-winning analyst team has a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* They just revealed what they believe are the ten best stocks for investors to buy right now... and Plug Power wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of June 7, 2021 Rich Smith has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source