Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of SolarCity Corp. (NASDAQ:SCTY.DL) jumped 19% today after the company reported another outstanding quarter.

So what: First-quarter installations were 82 MW, at the high end of its guidance, and revenue more than doubled to $63.5 million. SolarCity's model defers revenue for as much as 20 years so actual loss attributable to shareholders was $24.1 million, or $0.26 per share.  

The biggest news was that 2013 guidance was increased 25 MW to 500-550 MW and 2015 installed guidance was set at 900 MW to 1 GW.  

Now what: SolarCity continues to grow at breakneck speed in residential solar and it's impressive to book 136 MW of installations in the quarter, of 80% of which were residential systems. The one flaw I see is a 139% increase in operating expenses to $81.8 million. SolarCity needs to keep operating expenses in check and keep retained value per watt, which fell about $0.05 to $1.83, high to generate value long term. But in a high-growth mode, it's expected to see operating expenses rise.

Long term, the guidance is extremely encouraging and even though I have questions about SolarCity from a valuation perspective, I can't deny that they're knocking it out of the park operationally.

Travis Hoium has no position in any stocks mentioned. The Motley Fool recommends and owns shares of SolarCity. Try any of our Foolish newsletter services free for 30 days. We Fools may not 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.