Solar Power for All These brothers have set big goals, but that's the only way to make big change.

Lyndon and Peter Rive, 32 and 34, respectively, never tire of meeting new customers. "It's great to see the smiles on their faces when their utility meter starts spinning backward," says Lyndon.

The South Africa-born brothers are the founders of SolarCity, and they've made it their mission to make solar power accessible to everyone. "In the past, solar was typically only available to the wealthy--with a price tag of about $60,000 to install," says Lyndon. "We've designed a system that allows someone to go solar without putting down that money."

The brothers' solution is a leasing program for solar panels: Their Foster City, California, company puts up the capital to install the panels on homes and then rents them to residents. The beauty of the system is that clients' savings on their electricity bills offset the cost of the lease, so residents usually end up spending less per month. Even more money is saved when neighborhoods work together and all residents go solar simultaneously.

Currently, SolarCity boasts about 2,700 customers and has offset approximately 586 million pounds of carbon dioxide. That's the equivalent of taking 63,000 cars off the road for a year or planting more than 500,000 trees, according to the company. Sales reached $23 million in 2007, and in 2008, Peter says, "We did a lot better than that."

They would have grown even faster if they could. "One of the big challenges we face is resistance from building departments, states and communities, which move slower than an entrepreneurial company like ours," explains Lyndon. He says another challenge is lack of consumer awareness. "Many people don't know this is possible. They don't understand you can save money from Day One and use clean power. A lot of people still think of solar as a heating system. They don't understand that it generates electricity."

The Rives admit their goals for the company are ambitious, but they must be in order to achieve the kind of change they seek. "Five thousand homes won't make a difference; we need to build an infrastructure to support tens of thousands and then hundreds of thousands and then millions of homes," says Lyndon. "That's when we'll have a real environmental impact."