Randal Charlton’s efforts at Detroit’s business incubator TechTown, where he was the executive director from 2007 until the end of October – and the turnaround in his personal life ­­– landed him one of five $100,000 Purpose Prizes, which honor Americans over 60 who are developing new ways to tackle social problems. In this article, Charlton shares crucial lessons that can help people who want to start their own businesses.

The folks at the Southwest Initiative Foundation in Minnesota had a hunch. The population it served was aging, and those older than 55 were hardest hit by the recession. So the foundation, which makes microloans and counsels new business owners, began to target encore entrepreneurs. One such entrepreneur is 2011 Purpose Prize fellow Andy Wells, who helps Native Americans and their neighbors train for factory jobs. The prize honors social entrepreneurs 60 and older.

Edward Mazria, architect, founder and CEO of Architecture 2030 was awarded this year’s Purpose Prize. His work over the past eight years, after founding Architecture 2030, has set numerous environmental goals for the building industry. It has also brought many issues of sustainable design to the forefront of conversations and policies about buildings and their construction.

Purpose Prize winner Judith Broder's second act – providing free counseling to Iraq and Afghanistan war veterans – took her all the way to the White House, where she was honored this year by President Obama. "It was absolutely thrilling," says the soft-spoken, 71-year-old psychiatrist. She was one of 13 recipients of the Presidential Citizens Medal, chosen from among 6,000 nominees.

Purpose Prize fellow Andy Harris is finding fulfillment in his encore career. He developed a college course designed to give U.S. medical professionals a chance to provide care in poor countries overseas. It also enables them to provide care locally – in free medical clinics for the uninsured where course participants volunteer one evening per week.

A serial entrepreneur, Randal Charlton needed a new challenge. He got it by taking over Detroit's ambitious TechTown, a business incubator that was teetering on the brink of insolvency. In four years, Charlton re-energized TechTown, putting more than 2,200 entrepreneurs through training programs and helping more than 250 fledgling companies raise $14 million. For his work, he won a $100,000 Purpose Prize.

Randal Charlton's efforts promoting entrepreneurship in the depressed city of Detroit led him to a $100,000 Purpose Prize. The prize honors Americans over 60 who are creating new ways to solve tough social problems. "It's as much a prize for Detroit and the (budding entrepreneurs) as anything else," Charlton says.

Our sputtering economy needs workers with more of that entrepreneurial spirit. Think tank Civic Ventures suggests they might come from an unexpected demographic: workers who are approaching middle age or their retirement years. The group found that one in four Americans between 44 and 70 want to build an enterprise, and nearly half of them want it to be a business with a strong social impact. (This article also appeared in Good.)