This article presents the results of the first large-scale mail survey of non-residential green power customers in the United States. The survey explored the motivations, attitudes, and experiences of 464 business, non-profit, and public-sector customers that have voluntarily opted to purchase-and frequently pay a premium for-renewable electricity. Particular attention in this article is paid to the motivations of these organizations in purchasing renewable electricity, and our findings are compared to the extant literature on the motivations of firms to voluntarily exceed environmental regulations. Perhaps the most interesting contribution of this research comes in its demonstration of the importance of "altruism" as a motivator in non-residential green power purchases among early adopters. This finding, and the further discovery that the principal non-altruistic motivation for purchasing green power is employee morale, differs substantially from the predictions of the extant literature. Results of this study should be of value to marketers trying to meet the needs of non-residential customers, to policymakers interested in fostering and understanding nonresidential demand for green power, and to academics pondering the motivations for firms to engage in such voluntary environmental initiatives.