What happened 

Shares of solar manufacturer SunPower Corporation (NASDAQ:SPWR) fell 10.6% in February, according to data provided by S&P Global Market Intelligence, after a few disappointing trends emerged in the company's fourth-quarter earnings report. 

So what 

SunPower's core operation of manufacturing and selling solar panels has performed reasonably well over the past year, despite the recent tariff impact. But what investors are seeing today is the value of projects on the balance sheet being lower than they expected. 

Utility solar installation being cleaned by a robot.

Image source: SunPower.

In 2018, SunPower has announced the sale of 8point3 Energy Partners (NASDAQ:CAFD) for a disappointing price and also said it was selling 45,000 solar leases for $200 million in cash. The lease sale triggered a $474 million writedown last quarter and investors were seeing that as a loss for the company, even if it reduces financial risk going forward. What's clear right now is that rising interest rates is pushing project values down and that's having a negative impact on project values and the stock today. 

Now what 

SunPower is trying to transition to a model of mostly solar component sales, but as it does that, there are wild swings in financial results as it offloads projects. Right now, the impact on the income statement is very negative and is hurting the stock, although the strategy over the long term will stabilize earnings. I don't think there was a huge change in the long-term outlook for SunPower, but short-term earnings are down and that's what investors were focused on last month. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.