30 years ago, Warren Buffett's Berkshire Hathaway (BRK.B 0.11%) (BRK.A -0.36%) was mainly a holding company that invested in public stocks. Fast forward to today, and Berkshire now owns and controls multiple companies that are extremely important to the infrastructure of the United States. One of the largest companies in this mix is Berkshire Hathaway Energy (formerly MidAmerican). Through acquistions, Berkshire Hathaway Energy has been able to expand its electric-utility footprint, as well as expand into areas like wind energy.

In the following video, Motley Fool Associate Advisor Alex Scherer visits the exhibition floor at the annual Berkshire Hathaway shareholder meeting in Omaha, Nebraska. This year, over 40 of Berkshire Hathaway's operating subsidiaries set up exhibits and allowed investors to see their latest products and innovations. During the meeting, Warren Buffett and his business partner, Charlie Munger, took questions from shareholders for nearly six hours and provide their thoughts on everything from investing, corporate governance, and personal success. Touring the floor, Alex stops by the Berkshire Hathaway Energy exhibit to discuss the company's latest purchase.