I've always been a bit into Grow Your Own and Self Sufficiency but like many I'm limited by space, time and funds. Also I'm concerned about our climate crisis and that motivated to reduce my CO2 footprint and don't even get me started about single use plastics However my immediate selfish motivation was keeping my Coriander out of the reach of slugs and after three years of trying I ended up with a Tiny Off-Grid Vertical Farm.
The basic structure is a 2 meter cube (photo 1) built from 52 "Grown Up Building Blocks" (photo 12) and double wrapped in insulation and tarpaulin. Each block is like a large Lego brick with racking for 3 seed trays or 8 1.5 litre pots inside and which is just about portable when fully loaded (photos 13 and 14). The whole shed has racking for up to 400 1.5 litre pots or 140 24 cell seed trays - so a maximum of 3400 seedlings.
The wooden Blocks can be stacked vertically or clipped together horizontally so that vertical growers can make any shape structure they wish - such as food walls or vertical farms. The pots are repurposed "single use" plastic milk cartons or water bottles which my family collects from our domestic waste (photo 11). No high embedded CO2 materials were used i.e. no glass, concrete or metal (fixings aside) which you might find in traditional greenhouses or vertical farms.
The covers can be up for maximum ventilation (photo 1), down for maximum warmth retention (photo 3) or out for shade or rainwater harvesting (photo 8). There are two layers of cover - the impermeable outer layer and the inner insulating blackout layer (photos 4 and 6).
The farm is semi-automated with drip feed watering and liquid fertiliser production happening without my intervention. My next build will introduce further automatons.
In March I,ve planted Tomatoes, Peas, Beans and Strawberry's and I'm hoping in April to submit some photos with them cascading down the shed sides - fingers crossed.
What are the Off-Grid Features? It has off-grid rainwater harvesting, grow lighting and hot compost heating:-
1) Rainwater is harvested from the roof, stored and slowly dripped into the top of the plant pots so each rain drop passes through the roots of up to 11 vertically arranged plants before soaking away. (photo 10). In times of drought (or initial water loading) the tarpaulin sides can be turned into awnings for shade and to increase the rain capture area to 20 square meters (photo 8) . My next build is to collect and recirculate this water with a solar powered pump. Overflow water is stored internally in a 100 litre butt which also provides a little thermal mass.
2) Solar powered grow light LED strips boost natural light and provide 250 watts of warming for winter nighttime. (photo 2). To conserve heat, prevent light pollution and so as to not impact insects I have fitted thermal blackout blinds (photo 4 and 6).
3) A cubic meter of leaf and grass Hot Composting sacks continuously provide a tiny bit more winter heat (photo 9 bottom). They also provide compost and liquid fertiliser as they rot down and they give off a high CO2 atmosphere inside the shed which captured by the plants and promotes growth.