China-based Suntech Power Holdings Co. (NYSE: STP) is one of China's top stocks. The country's largest solar panel maker recently took steps to increase its hold on the Chinese solar market when it reached an agreement with a unit of China Huadian Corp. to develop 500MW of solar projects in China.

The collaboration between Suntech and China Huadian New Energy Development Co. could include some of the 1.8 gigawatts of Chinese projects Suntech recently announced. According to the company, the projects resulting from those agreements could be installed between 2010 and 2012. This deal means a solid pipeline of earnings for the solar maker, and that could translate into solid earnings going forward.

On July 24, Northern California-based SunPower Corp. (NASDAQ: SPWRA) stunned the Street with a red-hot earnings beat. For Q2, SunPower reported earnings of 24 cents per share, beating consensus by 10 cents. Revenues rose 39% year-over-year to $298 million versus the $263 million consensus. The company also issued upside guidance for fiscal year 2009, seeing EPS of $1.15 to $1.60, compared to the consensus of 96 cents.

In a really bullish sign for SunPower going forward, the company also reiterated its 2009 capex guidance of $250 million to $300 million.

Also reporting after the close on July 30 was Arizona-based First Solar Inc. (NASDAQ: FSLR). Now these guys had a blowout quarter!

The company reported net income more than doubled in the second quarter, easily beating consensus Street estimates. In Q2, net income was $180.6 million, or $2.11 per share, compared with $69.7 million, or 85 cents per share, a year ago. The word on the Street was for earnings of just $1.65 per share.

After the closing bell on July 30, Massachusetts-based Evergreen Solar Inc. (NASDAQ: ESLR) reported second-quarter revenues of $63.8 million, compared to $55.8 million for the first quarter of 2009. The company's gross margin for the second quarter of 2009 was 1.9%, compared to 1.2% for the first quarter of 2009.

Unfortunately, these gross margins are way off the 34.7% we saw in the second quarter of 2008.

Before the opening bell on July 30, Northern California-based Akeena Solar Inc. (NASDAQ: AKNS) reported a 17% decline in second-quarter revenue year over year. However, like we've seen so often this earnings season, the company's cost-savings efforts resulted in a better-than-expected bottom-line earnings numbers.

Akeena reported a net loss of 9 cents per share in the quarter, a number well above the 11-cent loss expected by Wall Street.

Several high-profile solar companies recently reported earnings, and although these companies posted mixed results for the most recent quarter, there's no denying that Wall Street has been turning its face toward the sun and bidding up the shares of solar stocks.

So, what's the latest earnings front from stocks in the solar space, and why do the shares of some of the hottest solar stocks continue to shine? More importantly, should you own solar stocks right now, and if so, which ones should you make room for in your portfolio?