The average yield on Feb. 16 for BBB rated debt maturing in more than 15 years was 5.54 percent and has declined to 5.38 percent as of Feb. 28, the lowest in data going back to June 1998, according to Bank of America Merrill Lynch index data.
Two Solar Purchases
MidAmerican agreed in December to buy the Topaz project from Tempe, Ariz.-based First Solar Inc., which is supplying the solar panels. Later that month the Des Moines, Iowa-based utility holding company agreed to take a 49 percent stake in NRG Energy Inc.'s $1.8 billion Agua Caliente solar project in Arizona.
MidAmerican has become the largest generator of wind energy among regulated U.S. utilities by investing or committing $6 billion to the renewable power source.
"We can make this sort of investment because MidAmerican retains all of its earnings, unlike other utilities that generally pay out most of what they earn," Buffett said in his annual letter to Berkshire shareholders, posted on the company's website Feb. 25. "Many more wind and solar projects will almost certainly follow."
MidAmerican sells electricity to about 2.5 million customers in the U.S. and is the largest supplier in Iowa, Utah and Wyoming, according to the letter. The Berkshire unit also transports about 8 percent of the country's natural gas through its network of pipelines.