BiogasPermaculture Design Magazine: The Unexplored Promise of Biogas Image December 1, 2017 Bob Hamburg Leave a commentPlease click the link below to read my article published in the Permaculture Design Magazine in May 2017.Permaculture Design #104 May 2017Share this:Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Pinterest (Opens in new window)Click to email this to a friend (Opens in new window)