Editor's note: Krista Van Tassel will be conducting a workshop on “Using Strategic Philanthropy to Promote Employee Engagement” at the San Francisco GreenBiz Forum.

One hot Saturday in April 2012, in California’s Central Valley farm country, I found myself on a rooftop installing a solar electric system for a family of agricultural workers. My fellow installers were bankers from two Wells Fargo branches in the Fresno area.

Farm country? Solar? Bankers?

That same month, Wells Fargo released a set of environmental commitments — to be achieved by 2020 — that include reducing the company’s environmental impact, financing the transition to a greener economy and encouraging stronger and more sustainable communities. One of the beneficiaries of our community and philanthropy commitment was GRID Alternatives, a California-based nonprofit that installs solar electric systems for low-income families. This was one of its clients, the Martinez family, and we had come to pitch in.

Many large companies spend a lot of time finding and organizing appropriate corporate volunteer activities. The most effective engagement programs are ones that both inspire large numbers of team members and demonstrate the company’s values and priorities to a broader audience.

With more than 265,000 team members serving one in three households in the United States, Wells Fargo is focused on leading positive change through an integrated approach to sustainability that starts with its team members. Through our Green Team Program, our employees take the lead in finding projects that speak to them. A Wells Fargo Green Team member first introduced us to GRID Alternatives in 2005 and in a similar fashion our Green Team in Milwaukee, Wis., has forged a partnership with Growing Power, a local nonprofit focused on sustainable urban agriculture and youth education. Our Puget Sound Green Team works with Seattle University on its community farming and food bank initiative.

Wells Fargo employees have been volunteering with GRID Alternatives since 2005, getting on the roof to learn new skills, build stronger working relationships with their teammates, and be involved in their communities. Volunteers over the years have included Chief Administrative Officer and Senior Executive Vice President Pat Callahan and Executive Vice President David Weber. Wells Fargo also provided GRID with an initial $600,000 in grants to support both its solar installation program and its workforce development efforts. In September 2012, Wells Fargo announced a five-year, $2 million commitment to help the organization take its model national.

The expansion was kicked off with installations for 12 low-income families in a Habitat for Humanity development outside of Denver with help from more than 30 local Wells Fargo employee volunteers. Abdelati and Malika Moumen were one of the families that received a solar electric system. Immigrants from Morocco, they have made huge personal sacrifices to help their three children succeed in the United States. Their daughter, Fatimah, a business student at University of Colorado, Denver, spoke during the launch event about the value of opportunity and the impact the modest savings from their system will have on their lives and their community. For the Wells Fargo volunteers, who got to work on the roof with Fatimah and her brother, Zackaria, the experience was tremendously rewarding.

Often, as with GRID Alternatives, the most popular and effective employee-initiated projects become integrated into our wider employee engagement program. With GRID Alternatives, we were easily able to plug into the nonprofit's existing volunteer model to expand both our Green Teams and environmental volunteer opportunities across California. GRID projects are some of the most popular volunteer events that our teams host, and we leverage the organization’s annual Solarthon blitz-build events throughout California to launch new Green Teams, or use them as an opportunity to help existing Green Teams with recruitment.

What makes this model successful is that GRID hosts a predictable program for our volunteers. It is not easy to manage large-scale volunteer opportunities, but GRID does this quite well by offering a standard schedule for the day and pre-event training so that everyone arrives ready to start work and the work ends on time and as expected. As a corporate volunteer partner, we appreciate that approach as it makes it easy for us to promote this work to our busy Green Team leaders.

But good volunteer opportunities are also about what the employees take away from a day of volunteering. I have been on seven GRID Alternatives installations now, and what makes the experience stand out for me is always the people.

On that sweltering day in Fresno, we got to meet and work alongside Floricel Martinez and her partner, Arturo. Floricel came to the U.S. from Oaxaca, Mexico, nine years ago. She and Arturo, both seasonal farmworkers, are raising two sons, ages 5 and 9, on wages from cherry and grape picking. In between jobs it was often hard to pay their electricity bills, which averaged $210 a month. They had built their home together from the ground up through a self-help housing organization, and when it came time to put on solar, they were ready to roll up their sleeves.

Watching the family turn on the system for the first time at the end of the day was a thrill for the whole team. We could see on their faces what our own sweat and our company’s investment was doing for them. We also got to work that day with a young man whose experience volunteering with GRID had recently landed him a steady job with Real Goods Solar. This was community and environmental sustainability in action. We do a lot of cleanup-type events as well, but when you have that direct contact with the people you are helping, those are always the kinds of projects that keep people engaged.

“Communities rely on the involvement and support of those who live and work within them,” said Melanie Tillotson, a Wells Fargo team member (Sacramento Green Team leader) who recently volunteered on a GRID Alternatives project in Chico, Calif. “What GRID is doing in our communities transcends sustainability and cost savings for low-income families. They are providing an opportunity for individuals to make connections, learn new skills and contribute to the legacy we leave behind for our children.”

The GRID model really helps bring the concept of green energy and its benefits to lower-income communities to life for our team members, while our investment in and work with GRID demonstrates in real time Wells Fargo’s corporate values. In 2012 GRID Alternatives trained more than 3,000 volunteers and job seekers in solar installation, and installed solar for more than 1,200 low-income families in California and Colorado, saving them an estimated $36 million over 30 years — money that helps them live more affordably in their homes and provide for their children.

Large companies have many opportunities to share their resources by investing in employee engagement. Where they succeed on a large scale is where they follow the lead of their employees in finding projects that have meaning, both for the employees and for the company’s strategic priorities.