Economic Analysis
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This section describes the costs and benefits of our greenhouse designs. For information on how to secure money for greenhouses at Lafayette, see the policy analysis.
Constructing a greenhouse involves costs from several sources. Materials need to be bought from suppliers such as Nolt’s Produce Supplies or Griffin Greenhouse Supplies. Construction can then either be done by volunteer labor for the hoophouse design or needs to be contracted out. Furthermore, there is the cost of the equipment that goes into the greenhouse after the construction, the cost for any additional energy infrastructure at LaFarm needed to power the greenhouses, and the costs of maintenance/repairs down the road.
At the same time, having a greenhouse on-site will mean a lot of cost savings. The cost of plants, greenhouse rent, and potting soil makes up 15% of LaFarm’s Annual budget in 2014, and that number would rise if LaFarm were to mostly purchase transplants. Additionally transport to and from the off-site greenhouse as well as picking up transplants not only costs money but also time, reducing the overall productivity of the farm. The addition of an on-site greenhouse would both increase the amount of produce the farm can make but also decrease the costs we have.
Costs
Materials Costs.
For consistency, the materials costs were all obtained from quotes from Griffin Greenhouse Supplies. Griffin Greenhouse Supply provides all the materials needed to construct a greenhouse in customized packages. The Quotes for these costs are located in the bibliography.
| Hoophouse Materials Cost | |
| Structure | $ 3,472.00 |
| Roof covering | $ 954.52 |
| Endwall Covering | $ 565.78 |
| Total Materials | $ 4,992.30 |
| Gothic Greenhouse Materials Cost | |
| Structure | $ 6,138.00 |
| Roof Vent | $ 2,847.00 |
| Roof Covering | $ 1,586.04 |
| Endwall Covering | $ 565.78 |
| Vent Motors | $ 1,990.00 |
| Roll up Sides | $ 1,164.88 |
| Misc | $ 785.50 |
| Total Materials | $ 15,077.20 |
| A-Frame Greenhouse Materials Cost* | |
| Griffin Quote | $ 90,000.00 |
| Cost of Concrete | $ 5,600.00 |
| Total Materials | $ 95,600.00 |
*When getting the quote for the A-Frame Greenhouse, we were not provided with a breakdown for individual costs (though we have a list of the materials). The overall cost was placed at $90,000.00. The concrete is not supplied by Griffin, but would be purchased by the contractor. Calculating the likely cost of concrete involved finding the average cost of concrete to be ~$80.00 per cubic yard.
Construction Cost.
Griffin Greenhouse Supplies, Nolt’s, etc. do not construct/install the greenhouses, but do recommend contractors who would. At this time, we have contacted the nearby contractors but have been unable to get a quote, and are currently estimating the cost of construction being ~$5,000-$10,000. This construction cost would only be necessary for the Gothic greenhouse or the A-Frame greenhouse designs, the hoophouse is simple enough to be constructed by LaFarm Manager Edmonds and several LaFarm workers.
Additional Equipment.
Beyond normal equipment already on the farm, the hoophouse would not need additional equipment for its operation, but the Gothic A-Frame designs would, because seed starting requires greenhouse benches to keep transplants off the ground and easy to work with. In either of them, to have approximately 24 benches which would give us 2 rows of benches, it would cost ~$2400 for industrial standard greenhouse benches from a supplier such as Griffin. For heating mats as laid out in the technical analysis, it would cost ~$3500.
Cost for additional Energy Infrastructure.
To be able to power the Gothic or A-Frame designs with renewables the amount of potential energy generation at LaFarm would need to be more deeply measured to find the necessary balance of wind, solar, and other methods of generation necessary for the 60-90kWh per day for the designs. Given that, with the data from the 16 panels in the Metzgar Solar Array Dashboard, if we were to assume ~1 250-watt solar panel is able to produce an average of 1kWh of energy per day (a generous estimate, based on data from the dashboard on sunny days in Autumn) and assuming a bulk order of such panels would cost ~$200 per panel, then the cost would easily be approximately $9,000-$14,800, for the panels alone.
For a geothermal system for heating the A-Frame Greenhouse, it could cost ~$4,000 dollars for a heating unit and between $8,000 and $10,000 for installation.
Cost for Operations and Maintenance.
For all the designs, weathering of the structure of the greenhouse means that the materials need to be repaired/replaced after certain intervals. The life of a single polyethylene sheet as in the hoophouse is generally 3 years, the life of a double layer as in the Gothic greenhouse is 5-7 years and the life of polycarbonate as in the A-Frame is a decade or more, and polycarbonate panels can be replaced as needed instead of needing to be replaced all at once. It would cost $1100 to replace the hoophouse cover, $1700 to replace the Gothic covers. For the A-Frame, individual 4’x8′ polycarbonate panels cost around $100. Taking into account the surface area of the greenhouse, this means that it would take a total of $16,000 to replace all of the panels, though these would not likely need to be replaced all at once and are generally warrantied for 10 years. To estimate the yearly cost of repair for each greenhouse, the costs were divided by the average life of each material, assuming for the A-Frame, the cost was estimated to require all of the panels to eventually need to be replaced over 20 years.
| Hoophouse | Gothic Greenhouse | A-Frame Greenhouse | |
| Cost of Frame and Materials | $5,000 | $15,000 | $90,000 |
| Construction Cost | – | $5,000 | $10,000 |
| Equipment cost | – | $6,000 | $6,000 |
| Cost for Extra Energy Infrastructure | – | $12,000 | $25,000 |
| Total Estimated Initial Cost | $5,000 | $38,000 | $131,000 |
| Yearly Repair Cost | $370 | $285 | $800 |
Benefits
Seed Starting.
While the hoophouse cannot be used to start seed, the main function of both the Gothic greenhouse and the A-Frame greenhouse is to start seed which would reduce a number of costs that LaFarm incurs. In 2014, LaFarm spent around $2,300 on plants, rent for the greenhouse, seeds and potting soil to start seed (Edmonds, 2015). Previously to that, LaFarm’s budget did not have enough money for seeds or transplants and LaFarm Manager Edmonds had to donate her own saved seed and transplants. Furthermore, the price of our greenhouse space has been subsidized in the past by $750 because LaFarm Manager Edmonds attended the Seed Farm and volunteers to work there to reduce the price. Without the space we are renting in the greenhouse, which may be lost soon, the cost of plants would significantly increase, because we would have to buy all transplants. But, with an on-site greenhouse, over the course of several years that number could be reduced to potentially zero depending on several choices down the line.
Potting soil can be produced on the farm with combinations of compost and top soil, if the soil is fertile enough. Though LaFarm doesn’t necessarily have that capacity right now, a class or an Excel research project could find a good balance for potting mix that would decrease the cost of soil to nothing. If we start all of our seed ourselves then we will not need to pay for transplants and seed costs fluctuate with the amount of seed that we save v the amount of seed that we buy. Because these costs all depend on future choices, improving the LaFarm system, and doing further research, it is not easy to estimate the amount of savings per year. Still, it can be said that regardless of those choices the costs for seed, soil, transplants and rent will be reduced by having the Gothic or A-Frame designs.
In addition, there is the cost that will be saved from having either the Gothic greenhouse or the High-tech greenhouse in transportation. Since the cost of transportation has been externalized to the Garden Manager, that is hard to measure, but having an hour and a half long car trip multiple times per week uses a good deal of gasoline. Furthermore, that amount of time spent away from the farm decreases the amount of work that can be done, decreasing the productivity as well as the educational potential of the farm.
Other Benefits and Conclusion.
The increase in productivity of the farm is also difficult to calculate in monetary terms for several reasons. Firstly, the productivity of the farm is determined by so many variable factors that it is virtually impossible to determine the exact cause of an increase or decrease in yield. A good example of this is the hail storm that occurred in June of 2015 which did an immeasurable amount of damage to the farm (see this blog post as well as this one). Also, the choice of what to grow always decides something about the yield, but something different about the amount of money that the yield will bring in.
Of course the most important reason why it’s difficult to predict how much money these changes would bring in is because most of the produce is now donated each year ($4,000 worth of donations v $4,450 of income in 2013 and $8,290 worth of donations v $5,590 of income in 2014) and much of the yield is taken home and eaten by the various student researchers, interns, and employees of LaFarm. Further, since LaFarm does both direct sales at retail pricing and wholesale price sales to the dining hall, the worth of even individual units of produce is variable depending on whom it is sold to. Therefore, not only is a yield increase dependent on factors that are beyond any farmer’s direct control, but because of LaFarm’s status as an educational farm that gives food to many sources and also sells to multiple sources, there is no guarantee that yield increase will increase real income.
Still, if all other factors (choice of what to grow, freak weather events, labor hours, management practices, etc.) were held constant, the addition of any of these three greenhouses would increase yield, and extend when most produce would be available for harvest. The hoophouse will do this by allowing earlier plantings in the spring and later plantings in the fall, which would increase the yield of whatever crop is grown there, and make it possible to grow crops that LaFarm otherwise could not, like spinach. Since out of season or hard to grow produce costs more, this does mean there would be an increase in potential income (though, as noted above, that food could be donated, taken home, etc.)
The Gothic greenhouse and the A-Frame will offer that same potential, as well as the indirect yield increase of having extra time saved from transportation. Still, these projects are not likely to actually make money in the short run. These projects are not meant to be a financial investment though, as neither LaFarm nor Lafayette are for-profit institutions. Because we are an educational institution, and these structures will be used first and foremost to educate students and the community about agriculture, these structures should be treated like as an expansion to educational space. The educational opportunities and number of research projects that can be done in these spaces far outweigh the economic costs of these structures. These would be projects like measuring exact gains resulting from certain practices, determining potential yield increase through greenhouse use, or finding the environmental effects of certain practices, which would teach students and add invaluable research to the field.
This last point underlies our suggestions laid out in the Conclusion.
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