Does Indoor Farming Make Green Sense?

In a previous blog I discussed why energy use is a pervasive challenge to the indoor farming industry. Increased automation in the indoor farming market is taking away the hand of labor, making it all the more difficult to justify additional energy demands the industry places on city grids. In terms of carbon footprint, critics of urban farming argue that the convenience of high quality, locally sourced food does not compensate for the negative environmental effect of these facilities.

Determining whether it makes ecological sense to produce food in a greenhouse instead of in an open field requires an analysis of two considerations fundamental to indoor agriculture: crop type and facility type. Applying an ecofriendly lens to a traditional, cost-benefit analysis may help energy managers weigh in on the sustainability debate and decide what grow method makes more sense from an environmental perspective.

You Reap What You Sow

As more of the world’s populations move to urban areas, the ability to meet the steadily rising demands of year-round, locally produced food is increasingly important. Some of the most common crops grown indoors include leafy greens like spinach and lettuce and vine crops such as tomatoes, cucumbers, and peppers. Consumer demand ultimately determines what is grown indoors, and the type of crop grown indoors determines what inputs cultivators must apply. In other words, if the market wants leafy greens, then growers will use whatever inputs are necessary to grow leafy greens.

This is important for energy managers and growers to understand as not all crops are created equal. The indoor grow process for each crop varies by energy intensity. Lettuce, for example, requires less lighting compared to tomatoes. Like most vine crops, tomatoes require interlighting to ensure that each part of the plant receives adequate photon capture. Thus, in terms of lighting cultivating tomatoes indoors tends to be a more energy intensive process compared to leafy greens. Yet, when it comes to greenhouses, there’s more than one way to light a plant.

If You Build It, They Will Grow

Proper building design is critical to operational efficiency and biosecurity for the plant, and enables cultivators to make the most out of the facility’s square footage. Building design is especially crucial for greenhouses as these facilities are purposed to take advantage of natural light, so from an energy perspective, greenhouse cultivation tends to be more efficient and less demanding on city grids.

Vertical farms (where small plants are stacked along vertical shelving from floor to ceiling) rely entirely on artificial lighting and are an energy-intensive operation for municipalities to support. Thus, the environmental cost of indoor farming systems cannot be based off production type alone. Considerations for the building envelope must also be factored into the energy equation when determining the ecological effect of these systems. There are combinations of crops and building types that can result in a sustainable indoor farm. These solutions require understanding the local environment and constructing well-designed facilities that rely on as few artificial inputs as possible—this will help reduce the energy demands of the indoor farming market. For more information on energy and indoor agriculture, check out Guidehouse Insights’ recent report, Energy Efficient Solutions for Indoor Farming.