The principles of sustainable development and of Integrated Product Policy are applied in new voluntary regulations, which have been internationally agree. The aim is to grant transparency of environmental information and to promote the diffusion of environmentally friendly products. A new tool under study is the Environmental Product Declaration (EPD), a technical paper annexed to products that synthesises their energy and environmental performances. This paper points out the reasons for developing EPD for the energy sector, and puts special focus upon renewable energy systems, products whose environmental performances are often not clearly defined. We describe how results of a LCA upon a solar thermal collector can be included in an EPD-document, summarising its ecological profile and making information comparable. EPD could be employed for a correct decisional strategy, making a balance between the benefits and the impacts of this technology, and could represent a way to diffuse scientific results to customers.