Are solar stocks finally cheap enough?

Adding to the malaise, a slide in oil prices in recent weeks has further dampened investor enthusiasm in shares of renewable energy companies.

Given this year's sell-off, are solar stocks cheap enough to buy now? Two opinions:

Matthew Zuck, manager of the $53 million AHA Socially Responsible Equity Fund:

"We prefer to pay a relatively low price-to-sales ratio for a company. And so if you look at something like a First Solar Inc, the market cap of the company is about $20 billion right now and sales for the last 12 months are less than $1 billion. There is still a tremendous amount of optimism built into that stock price for things that haven't happened yet.

"We tend to shy away from stories which are more speculative or are premised on future growth. (Equipment maker) Applied Materials (Inc.) is a little bit different because they are in the process of evolving their business.... They have strong current cash flows from their historical semiconductor business while they are also allocating capital toward the emerging solar business. So it's a way for us to have some exposure to the developing solar industry while using their existing business as a way of minimizing the financial risk of doing that.

"Right now, we have a very cautious involvement and exposure to (solar) and we're simply trying to be careful observers of a developing industry."

Kevin Landis, Chief Investment Officer of Firsthand Capital Management:

"The subsidies are material to how the companies are going to do this quarter and next quarter, but they are not really that important in terms of the industry driving toward grid parity (where production costs reach those of traditional plants), which is the big deal.Â… Our focus is on the technology and what people are working on that hasn't been introduced to the market yet, but is likely to be soon. And what people are doing to change the cost equation.

"We have a pretty big position in Suntech Power (Holdings Co. Ltd.).... We did use the weakness to build a bit of a position there. There is a lot of management depth there and there is a lot of technology edge there.

"We own Corning (Inc.), which is a way to own Hemlock (Semiconductor Corp.), a big polysilicon provider. We also own (polysilicon makers) Wacker (Chemie AG) and Renewable Energy Corp.... The industry is constrained as to supplies of good quality polysilicon - people have not been able to get enough. If you look forward toward this industry growing by leaps and bounds, they are going to need a lot of polysilicon.

"Another company is Motech (Industries Inc). You don't hear a lot about them. For some reason Taiwanese stocks tend to trade at a bit of a discount, but Motech has been around for some time and they are a very real player in the industry."