It was a busy week in the solar industry, and we haven't even reached earnings season. SolarCity (NASDAQ:SCTY) was the rock star of the week after announcing an acquisition and upping its own guidance estimate.

In China, Suntech Power (NASDAQOTH:STPFQ) may have gotten a little hope for life, although it's unknown what that means for U.S. shareholders. Here's more on those two stories and what else happened in solar this week.

SolarCity going big or going home
It was a busy week for SolarCity. On Wednesday, it announced the $158 million acquisition of racking maker Zep Solar, which has become something of an industry standard for solar racking.  

Manufacturers such as Trina Solar and Yingli Green Energy are making Zep Compatible products, so this could be an opportunity to actually create a standard and make money off licensing Zep's design to competitors. But I think this is much more simple than that.

CEO Lyndon Rive has said that Zep helped double throughput by making it faster to install rooftop solar systems. Even if that lowers cost per watt installed by $0.05, SolarCity would only be paying an effective price of about 6 times earnings, based on next year's installation projections. That's not a bad price even if Zep becomes an internal standard and not an industry standard.

Speaking of guidance, this is what really blew investors away this week. SolarCity said it installed 78 MW of solar in the third quarter and will install 178 MW this year. For next year, it expects to deploy between 475 MW and 525 MW, a growth rate of between 71% and 89%.  

SolarCity has two levers to increase long-term profits: installation growth and retained value per watt. This week's guidance means the company is pulling the growth lever about as hard as it can, which is great news for investors.

Suntech is for sale
The Suntech Power saga continued this week. Shunfeng Photovoltaic is interested in buying the company's Suntech Wuxi subsidiary and put a deposit of $82 million down to show how serious it is. Suntech Wuxi is the main subsidiary of Suntech Power and it owns most of the manufacturing and intellectual property assets of the company. A sale would be a way to keep Suntech in business, although it comes with consequences.

Suntech Wuxi is actually in bankruptcy, and it owes $1.75 billion to creditors, mainly Chinese state-run banks. For U.S. investors to come out with anything from a sale the price would have to be above the current debt load, something that's not happening.

U.S. Suntech debt holders may end up with something as bankruptcy wears on but stockholders will likely be wiped out. I wouldn't touch this stock with a 10-foot pole, because a company that can't pay debt holders certainly won't be kind to stockholders.

News and notes
Here are some of this week's important developments from around the industry.

Canadian Solar (NASDAQ:CSIQ) is attempting to get into the U.S. residential market with a program called Canadian Solar Residential Financing Program. This is in conjunction with Admirals Bank and will begin in Boston. Unlike solar leases, homeowners will take out the solar loan for up to $40,000 and work with installers to build the system. The other benefit is that homeowners will be able to monetize solar tax credits themselves and reamortize the loan if they choose.  

This may not be a terribly popular model today, but as tax subsidies drop and system costs fall, I think solar loans will grow in popularity.

First Solar (NASDAQ:FSLR) took another step to cut costs and rationalize its capacity this week by selling its Mesa, Ariz., operations and maintenance facility. The vision was once to make a 250 MW manufacturing plant at the facility but now the company has sold the building for somewhere over $100 million.  

Management said it expects to incur a loss of $55 million to $60 million on the sale and another $5 million to $10 million to relocate employees so look for that in the next earnings report.

Fool contributor Travis Hoium has no position in any stocks mentioned. The Motley Fool owns shares of SolarCity. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.