What happened 

Shares of SunPower (SPWR -1.15%) plunged as much as 19.1% on Thursday following the company's fourth-quarter 2019 report. Shares are still down 18.4% at 3:30 p.m. EST, so there's not any recovery happening in the stock. This comes just one day after shares jumped 10.6%, so the stock is now going backward over the last two trading sessions. 

So what

Fourth-quarter revenue of $603.8 million was up 32.2% from a year ago but fell shy of the $627.7 million that analysts were expecting. Adjusted earnings of $0.23 per share were a penny short of expectations. 

Large solar installation in a field.

Image source: SunPower.

Revenue guidance of $2.1 billion to $2.3 billion in 2020 was on the low end of the $2.26 billion that analysts were expecting. That's not a huge disappointment, but investors were clearly hoping for a higher range. 

The solar industry has generally been reporting very strong earnings the last few quarters as solar panel sale prices rise and volume increases. So the fact that SunPower didn't beat expectations by a wide margin may be why the stock is pulling back today. 

Now what

2020 is a transition year for SunPower as it splits off its manufacturing business and focuses on deploying residential and commercial solar projects. The company shouldn't be judged on just one quarter. But investors should be looking for signs that a clearer focus and simpler balance sheet leads to better earnings in 2020. Unfortunately, it may be a while before we learn how this strategy shift in renewable energy ultimately plays out.