We’re excited to say we’ve made some good progress in the last two weeks! When we last left off we had set up our workspace and finished building the wooden base for our NuTree. You can find that post here. Our next steps were to build the pipe network for the vertical farming attachment in our system and continue work on our Microbial Fuel Cells (MFCs) that will power the NuTree.
The first step to building the pipe system was to bend our PVC pipes into the helix shape we need for the NuTree design. This created some logistical challenges for us. In order to bend the PVC pipe we had to heat it up and when we bent the hot pvc pipe in a circle uneven heating caused the pipe to kink excessively and be unusable. Our solution was to both get better insulating covers for the pipe, but to also construct the circular brick structure (pictured below) to serve as a support system for the PVC as it was being molded.
The PVC pipe needed even more support when we were bending it, so we created a wood frame around the brick structure. We also fixed a set of large hooks to the brick structure to support the pipes while they were cooling. Viola! Our PVC was bent into shape and ready to be attached to the metal pole which will serve as the “trunk” of our NuTree! We still have a few kinks, but we’re looking forward to welding the support from the trunk to our spiral!
After bringing our MFCs online, our next task was to get a usable amount of energy out of them. To this end we constructed a joule thief (picture below) which is a circuit that allows the fuel cells, which have relatively low voltage and electrical current, to generate rapid bursts of usable higher voltage.
We then connected the MFCs together in “stacks” that even further increased voltage and power output. Eventually the stacks will be able to charge a battery so we can do (almost) whatever we want with that clean bio-energy! The first thing we want is for it to power the pump that sucks the water from our NuTree basin up to the top of the central pipe. From here, gravity will allow the water to fall down the spiral and feed microgreens.
That’s all for now, our next steps will be to polish our MFC stacks and finish our work attaching our pipe/trunk system to the NuTree basin. We will of course continue sharing our progress and posting updates whenever relevant. We’re incredibly excited to be so close to finishing our first NuTree and thank you all deeply for your interest and support!