Electric car company Tesla may require as much as $10 billion in additional capital by 2020 to fund the company's operations, according to Goldman Sachs.

"We believe this level of capital transactions may be funded through multiple avenues, including new bond issuance, convertible notes, and equity," analyst David Tamberrino said in a note to clients Thursday. "We see several options available to the company to refinance maturing debt and raise incremental funds, which should allow Tesla to fund its growth targets."

While Tamberrino was confident CEO Elon Musk won't have trouble acquiring the extra cash, the infusion will likely present its own costs. Issuing additional debt could weigh on the company's credit profile, while supplying more stock or convertible bonds would dilute current shareholders.

Tesla declined to comment for this story.

Despite the forecast for additional capital requirements and a sell rating from Goldman, Musk insisted as recently as May 2 he has no intention of raising new money.

Asked earlier this month if he's mulling a capital raise, Musk simply said "no."

"I specifically don't want to," he said on a conference call after Tesla posted first-quarter earnings that beat expectations.