The solar sector has been rocky terrain under cloudy skies for investors this year. JA Solar (Nasdaq: JASO) has been no exception, with shares falling more than 40% from their January highs. If other solar players can mirror the kind of growth JA Solar revealed Wednesday morning, however, the entire sector may just start catching some rays.

The company's full-year revenue rose 286% to $369 million, and operating income rose 240% to $61.2 million. Revenue growth outpaced operating income growth, partially because of leaner gross margins. The company continues to ramp up production capacity at an impressive clip, from 75 megawatts in 2006 to 175 mw in 2007. And management expects capacity to rise at an even faster clip in 2008 to 500 mw, well above the previous target of 425 mw.

As fellow Fool contributor Toby Shute explained last month, the solar sector is a highly competitive space where innovation will mean as much as production cost in dictating which companies do the best for investors. JA Solar makes photovoltaic cells and, like most solar players, puts great emphasis on reducing costs to the consumer in hopes of achieving parity with the cost of coal-based electricity. Boston firm Photon Consulting believes producers could reach this parity, known as grid parity, by as early as 2010, so the race is clearly on. The field is crowded, though, with small competitors like Ascent Solar (Nasdaq: ASTI) and big dogs like First Solar (Nasdaq: FSLR) and investing heavily in furthering their own innovations and production methods.

In my opinion, meaningful growth in the solar sector is a foregone conclusion, given the rising global demand for energy and the prevalent indications that cheap oil is now a thing of the past. Furthermore, even though speculative buying had propelled the sector to lofty multiples, the punishment that solar shares have taken lately creates some compelling values.

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Fool contributor Christopher Barker captains yachts and writes about stocks. He can also be found acting foolishly within the CAPS community under the username Sinchiruna. He owns no shares in the companies mentioned. The Motley Fool has a sunny disclosure policy.