Warren Buffett is looking for investment opportunities in renewable energy.

"We have got a big appetite for wind or solar," Buffett said Saturday at Berkshire Hathaway's annual shareholders meeting.

"If someone walks in with a solar project tomorrow and it takes a billion dollars or three billion dollars, we're ready to do it," he said. "The more there is the better."

Buffett said Berkshire is in a good position to compete with electric utilties companies since the conglomerate can take better advantage of tax incentives for alternative energy projects.

Berkshire Hathaway Energy already sells wind-generated electricity in Iowa. In a March presentation, the firm said captial expenditure forecasts for the next two years have increased $4.6 billion from the prior year, primarily due to wind and solar energy projects.

Earlier during Saturday's shareholder meeting, Buffett said he expects coal to decline as a percentage of railroad revenues. "If you're tied to coal, then you've got problems," he said.

Berkshire also owns the Burlington Northern railroad company. Together with Berkshire Hathaway Energy, the two units accounted for a third of Berkshire's after-tax operating earnings in 2016, according to the latest shareholder letter.