Energy-efficient vertical farm to fight food poverty
Vertical farming has been suggested as a way to bring fresher food to urban dwellers while reducing the carbon footprint needed to grow and transport them, but a group of Carnegie Mellon University (CMU) students sees it as a way to improve basic nutrition in impoverished areas. Using simple equipment and LED lights, the students are developing an inexpensive way to allow almost anyone to grow fresh, nourishing food for their families and community.
There are many kinds of poverty, but one of the most intractable is food poverty. This is because the concept is one of access as much as affordability. In other words, some people may suffer from food poverty because they don't have enough money to buy enough nutritious food, but others, even in very wealthy countries, may live in areas known as nutritional islands. That is, areas where anything beyond poor quality, prepackaged foods is rare and expensive, which results in malnutrition and generally poor health.
To address this, a group of students from the CMU chapter of Engineers Without Borders (EWB), led by Engineering and Public Policy (EPP)/Chemical Engineering (ChemE) undergraduate student Jack Ronayne, has turned to vertical farming as a way for people to grow food in their own homes.
"Something we identified was this idea of nutritional islands in urban communities: places with limited access to fresh food either by distance, freshness, or cost," says Kelvin Gregory, a professor in civil and environmental engineering and faculty advisor for EWB."We asked ourselves: could you simply grow fresh fruits and vegetables in your house? Obviously the footprint needs to be small, so you have to go vertical. And you'll need to use artificial lighting. These are the problems we decided to solve for."
Whereas some vertical farming systems look like something out of a science fiction film, the CMU system looks a lot more low tech. Instead of a bespoke cabinet with all sorts of designer bells and whistles, the system is a set of metal shelves about the size of a bookshelf of the sort that can be bought from any storage shop. This is covered with a black plastic tarp and wired with lights.
In fact, it looks like the sort of indoor greenhouse that a gardener might knock together for starting seedlings, but there is a special twist to it. The LED lights used in the system can be set to flash rapidly at different speeds as a way to figure out how much light is needed to best grow plants with the least amount of energy.
"What we wanted to study was energy efficiency," says Gregory. "LEDs are already more energy-efficient than old-school halogen bulbs, but they also have the added benefit of being able to be turned on and off very quickly. So by rapidly flickering these lights at different speeds, we have been able to measure how much light is necessary to grow the biggest plant, using the least amount of energy."
The present setup uses 40 tomato plants, though smaller plants like lettuce would allow 100 to be packed in with a very small footprint. In addition, the home version is relatively easy to scale up to hold more plants for community vertical farms. The hope of the group is that this research will one day allow everyone to have access to fresh, healthy foods whatever their location or socioeconomic status.
"The students will take it from here," says Gregory. "In a few years, we see this being implemented in different spaces around the Pittsburgh area. It'll be about finding resources, going out to local foundations, and setting up something that both serves the community and still allows for a research component."