are matched to end-use needs in terms of scale, and (5) are matched to end-use needs in terms of quality. Residential solar energy technologies are prime examples of soft energy technologies and rapid deployment of simple, energy conserving, residential solar energy technologies is fundamental to a soft energy strategy. Active residential solar technologies use special devices to collect and convert the sun's rays to useful energy and are located near the users they supply. Passive residential solar technologies involve the natural transfer (by radiation, convection and conduction) of solar energy without the use of mechanical devices. Lovins argued that besides environmental benefits, global political stresses might be reduced by Western nations committing to the soft energy path. In general, soft path impacts are seen to be more "gentle, pleasant and manageable" than hard path impacts. These impacts range from the individual and household level to those affecting the very fabric of society at the national and international level. Implementation Lovins recognised that major energy decisions are always implemented gradually and incrementally, and that major shifts take decades. A chief element of the soft path strategy is to avoid major commitments to inflexible infrastructure that locks us into particular supply patterns for decades. The following transitional strategy to a soft energy path has been proposed: Double the efficiency of oil utilization, mainly through improved vehicle design (the development of improved hybrid cars, ultralight designs, and streamlined large transport vehicles). Apply creative business models which focus on certain advanced technologies and lightweight materials. Substitute 25% of U.S. oil needs via a major domestic biofuels industry, which could result in an economic boost for the rural regions that would supply the plant material for biofuels. Make natural gas again abundant and affordable through wider utilization of well-established efficiency techniques. Lovins argues that the barriers to soft energy paths are not technical, nor in any fundamental sense economic. He suggests that barriers are mainly institutional, and relate to obsolete building codes, an innovation-resistant building industry, promotional utility rate structures, inappropriate tax and mortgage policies, imperfect access to capital markets and fragmentation of government responsibilities. Lovins wrote in 1977 that "a largely or wholly solar economy can be constructed in the United States with straightforward soft technologies that are now demonstrated and now economic or nearly economic". Film Lovins on the Soft Path is a documentary film made by Amory and Hunter Lovins. It received