by George Looby
On March 29, 2018 a group of officials and interested individuals gathered at the Collins Powder Hill Farm in Enfield, CT, to review the progress that had been made on a new energy installation on the farm. This project was the result of a study initiated by the Connecticut Resource Conservation and Development Organization (CTRC&D), a non-profit, non-governmental group dedicated to the conservation of energy on Connecticut farms.
This is just one of its many goals in the support of Connecticut agriculture. Its membership includes regional councils of government, regional planning boards, conservation districts and others. It was decided that the initial project would be competitive and letters of application were distributed to farms on a selected list. The Collins Powder Hill Farm was selected as the winner. The project was funded in part by the Connecticut Department of Energy and Environmental Protection and the U.S. Department of Energy. The farm assumed the responsibility for site work and other activity. What made the project unique was that it represented the first such installation in the state.
The Collins farm is a dairy operation, a wholesale and retail compost producer and a seasonal dairy bar. The plan was to use heat generated from composting as a source of energy to heat water used in the dairy operation and also make the composting more efficient. The unit making this possible, the Hot Skid 250R, was manufactured by Agrilab Technologies in Enosburg Falls, VT. It has been installed at other sites in New England. Funding for the unit itself was provided by CTRC&D. The Collins Farm has been in the composting business for a number of years and the expectation was that the upgrade would make the present system more efficient.
Two perforated pipes were laid along the length of the basic storage units resembling bunker silos already in place. The pipes were attached to the Hot Skid unit, housed in a small shed nearby. Once the bunker is filled with compost the process begins. Each bunker has a capacity of 110 cubic yards of compost. The heat generated by composting processes can reach a peak of up to 160 degrees F. The heat is the drawn by negative pressure through the pipes into the Hot Skid and into a specialized heat exchanger which heats a water/ethylene glycol loop. This heated mix comes in contact with the water to be heated. The heated water is then moved by a circulating pump into the milk house where hot water for washing is used. On a seasonal basis, the same mix may be used to operate a space heater. The cooled water is returned to the Hot Skid for reheating. Meanwhile, fresh air is being drawn into the pipes which aids in speeding up the decomposition process. Vapor flow can run 50 to 500 cubic feet per minute and is affected by compost pile density and fan power. The farm estimates the new system has cut the time it takes to create a new batch of compost significantly – from two years to six months – especially when a lot of wood shavings make up the compost.
Cost savings constitute one of the most important aspects of this transition. The installation of the Hot Skid unit accounted for a savings of $300 to $350 for electricity per year. The cost savings generated by reduced loader hours amounted to 400 hours, which at $2.40/gallon for diesel fuel amounted to $3,600. Prior to the installation of the new system loader, operations were tracked at about 1,500 hours per year, which included all the time spent turning the material to achieve thorough mixing. The 400 hours represent a 27 percent reduction in loader operating hours. Using a conservative $50/hour operating cost (excluding the cost of diesel fuel) the farm saved $20,000 the first year of operation, with total savings of $23,000. Savings are realized when considering the turnaround time necessary, especially with wood chips in the mixture. What had taken about two years to achieve was now possible in three to six months, which allowed a lot more product to be sold. Using an average price under the new system, an additional $21,600 in farm income was generated in the first year of operation. Using the five-year warrantee period of the Hot Skid 250R, the expected annual increase in sales will total approximately $4,320 per year.
In January 2018 a hydronic heating unit was installed in the milk room, replacing a temporary propane one. It connects to the glycol loop from the Hot Skid, adding one more fuel saving device to the milk room. Precise figures are not available but the Collins family reports the total fuel consumption in this section dropped from an average of 3.1 to 1.9 gallons per day for an annual savings of $3,360.
Additional changes are in the planning stage and will be put in motion when the market price of milk shows signs of rebounding. One project will be an improved mixing pad area; another will be a hoop cover over the processing area. A hoop cover will do much to make the finished product delivered to the customer more uniform. A bit further down the road will be the extension of the hydronic heating loop to a nearby equipment shed to make winter repair work a bit more comfortable.
It is likely that other operators around the state will study the Collins plan carefully and make changes on their own farms using that plan as a model. Support resources are available through the office of Armanda Fargo-Johnson, CT Farm Energy Program Director, P.O. Box 70, 10666 Saybrook Rd., Haddam, CT 06438 (call 860.345.3977 ext. 100).