Imagine a grocery store in Wisconsin that doesn't get its produce from warmer states hundreds of miles away.

Instead, fruits and vegetables are grown right on the supermarket's rooftop, making the produce as fresh as possible for consumers.

This is the idea behind Sky Vegetables, a business venture being created by UW-Madison senior Keith Agoada and MBA student Troy Vosseller. Their concept won first place and a $10,000 prize in the G. Steven Burrill Business Plan Competition at the UW-Madison School of Business in April.

For the past year, Agoada worked as a manager's assistant in the UW-Madison botany greenhouses. His rooftop idea came to him after watching a program about community gardens in Chicago, where people can rent inexpensive garden plots and grow their own vegetables.

Agoada realized this practice could be expanded to other urban areas as well, and he did research on rooftop agriculture as part of an independent study project.

"Rooftops made sense to me," Agoada said, adding that supermarket rooftops were ideal because they eliminate the cost of delivery.

UW-Madison horticulture professor Brent McCown advised Agoada and Vosseller as they wrote their plan. McCown said the idea has a lot of potential, but admitted he laughed when they first proposed it.

"Since they aren't agricultural students themselves, this was all new to them," he said. "I had to do a lot of teaching."

Agoada found that a good strategy to pursue was hydroponic farming, or growing plants without soil in an insulated greenhouse.

Instead of soil, nutrients are directly injected into the water the plants are rooted in, and provide the exact chemical mix of organic substances that the plants need to grow.

As a result, the yield is greater and the system is lighter.

"By taking out soil, you eliminate a huge risk of pesticides and lower the weight of the system," he said. The weight becomes one-fourth of what it would be with soil, and one-tenth of the amount of water is used, which would otherwise be absorbed by the soil.

Hydroponics, a technique that has been around for 30 years, is widely practiced in countries such as Australia, New Zealand and Holland. Agoada said the U.S. has been slower to adapt to the trend.

Agoada teamed up in February with Vosseller, a co-founder of the Madison apparel company Sconnie Nation. Vosseller said the idea of growing produce locally was what attracted him to the project.

"In the current agricultural system," he said, "if you want a tomato, you can go to any grocery store you want, but they're all coming from California, Arizona, Mexico and very far away."

With fuel prices going up, Agoada's research indicated eating locally grown food is becoming more popular. McCown said the popularity of hydroponics is increasing as well.

"People know exactly where it's from," Agoada said about Sky Vegetables. "They can feel safe about it."

He added the development of more efficient solar-energy technology will alleviate the inability to get fresh produce year-round, even as more people move to cities.

Their win in the Burrill competition automatically enters Agoada and Vosseller into the Governor's Business Plan Contest. Winners will be announced at the Wisconsin Entrepreneurs' Conference in Milwaukee in June. They will compete against 20 other groups for a $200,000 top prize of startup money and services for their potential business.

The next step, Vosseller said, is assembling a team of construction and hydroponics experts as well as hydroponics equipment suppliers. He said this will be followed by fundraising and making the sale to chain supermarkets.

Vosseller said the experience he has acquired with Sconnie Nation has helped him learn about the balance between customers and supplies, and he hopes to continue learning new things with a business that is "very different from selling T-shirts."

Vosseller and Agoada agreed that excitement about their venture continues to grow but emphasized the importance of taking it one step at a time.

According to Agoada, "There's always a possibility it doesn't work, but we do know that there's definitely a need for this and that people want this very much."