From the early days of experimental windmills and inter-seasonal solar heat stores to today's water-balanced cliff railway, wood chip burner and award-winning rammed earth construction, the Centre for Alternative Technology's (CAT) knowledge-sharing ethos has always helped to push sustainable technologies towards the mainstream. This paper covers three decades of engineering innovations at the CAT and looks toward future methods for renewably meeting our energy demands or, rather, making our energy demands meet the renewable solutions.