Floriculture Greenhouse Update

We came across this short video (15 minutes long) that might interest some growers. A Minnesota farmer, Steven Schwen explains how his thermal-storage greenhouse works. He uses diagrams and talks a little about costs. This project was funded in part by SARE.

http://cookingupastory.com/sustainable-energy-thermal-banking-greenhouse-design 

Paul Lopes and Tina Smith University of Massachusetts

Occasionally growers want to use an unvented heater as a back up heat source. The following was taken from an article that John Bartok, Agricultural Engineer wrote on using unvented heaters. Tina Smith, UMass

An unvented heater is one that is designed without a flue connection so that the heat and products of combustion are exhausted into the greenhouse. Dumping these flue gases into the greenhouse may improve the overall efficiency rating as compared to a conventional heater but the pollutants and added moisture from combustion may put your plants in jeopardy. Unvented heaters can be fired with natural gas, propane or kerosene. These fuels are advertised as clean-burning. This is generally true if the burner is clean and has been adjusted to top efficiency. A heater that has been serviced in the fall will probably not be at peak efficiency as spring approaches. Inefficient combustion can emit unwanted and harmful pollutants into the greenhouse that can affect the plants and the people working with them. All fuels contain traces of sulfur, some more than others depending on its source. During combustion sulfur in the fuel is combined with oxygen to form sulfur dioxide. Levels as low a ½ part per million (ppm) can cause injury on some plants. Once the sulfur dioxide enters the plant through the stomates, it reacts with water to produce sulfuric acid that will cause leaf burn, flecking and general chlorosis. Tomatoes and white petunias are very sensitive to this and will show signs in as little as one hour. They therefore make good indicator plants. Ethylene gas is another pollutant formed during combustion. It can also be formed from ripening or rotting plant materials. Levels as low as 0.01 ppm can create symptoms such as malformed leaves and flowers, stunted growth, bud abcission, epinasty and flower senescence. Levels are usually highest near the heater and can be diluted by air circulation. Care should taken if you install unvented heaters. Be sure to have an adequate makeup air supply and provide frequent maintenance. Use indicator plants near heaters or commercially available indicator tubes to warn of excess levels of pollutants.

For the complete article see: Problems With Using Unvented Heaters

Several greenhouse businesses received financial incentives for energy conservation and renewable energy systems this year. More funding is available and now is a good time to find out if you qualify and how to apply.

www.dsireusa.org is a comprehensive source of information on federal, state, local and utility incentive programs. The following are some incentives for CT and MA that apply to greenhouse and nursery operations.

Connecticut To help sort out what is available for Connecticut growers, John Bartok, UConn compiled a good fact sheet on Federal and Connecticut Incentives for Greenhouse Energy Conservation and Renewable Energy. It includes contacts for the USDA Rural Development Section 9006 Loan and Grant Programs for Energy Efficiency and Energy Generation, Energy Programs as part of the Connecticut Energy Efficiency fund, and many others. For details see: http://www.umass.edu/umext/floriculture/fact_sheets/UConn/08energy_resources.pdf

Massachusetts Phase 2 of the Mass Farm Energy Program (MFEP) will provide energy audits, renewable energy assessments, and/or provide incentives for implementation of audit recommendations, including those recommended by public utility programs. MFEP audits, assessments, and consultations will be paid at 75% with the applicant responsible for the remaining 25%. Incentives for implementation will be based on energy savings. Although the emphasis of Phase 2 is energy conservation and efficiency, there will be some funding opportunities for renewable energy projects, especially those projects that are not eligible for other programs. Some fundable energy saving technologies for greenhouses include: electronic temperature controls, thermal blankets, automatic or manual, sidewall/foundation wall insulation, energy efficient ventilation fans & associated tight sealing louvers, lighting, higher efficiency heating systems, higher efficiency refrigeration systems including heat recovery and IR layer of polyethylene.

See the Berkshire-Pioneer RC&D website to learn more about the MFEP Energy Audits & Incentives: http://www.berkshirepioneerrcd.org/mfep/energy.php

Berkshire-Pioneer RC&D will also offer technical assistance and grant writing assistance to at least 25 farmers interested in the 2009 funding for USDA-Rural Development's Section 9007: Rural Energy for America Program (formerly called the Renewable Energy Systems and Energy Efficiency Improvements Program).  This program pays 25% of the cost of energy projects through grants and can also provide guaranteed loans.

Contact information: Berkshire-Pioneer RC&D (grant writing, energy audits and financial incentives): Ann Gibson at 413-256-1607, agibson@berkshirepioneerrcd.org Darlene Monds, 413-256-1607, Darlene.monds@ma.usda.gov

USDA-Rural Development's Section 9007: Rural Energy for America Program (grants and loan programs for energy generation and energy efficiency) Rural Development Area Office

Tina Smith, University of Massachusetts Leanne Pundt, University of Connecticut Paul Lopes, University of Massachusetts

The payback on energy conservation is only 6 months to 2 years according to John Bartok at a recent Connecticut Greenhouse Growers Program.

Energy conservation is an important first step even if you are considering changing to alternative fuels. So, take some time to do a walk thru energy audit of your greenhouse operation and see web sites below for links to more information on energy conservation and renewable energy to assist in your decision making and planning for the future.

For more information:

Connecticut Greenhouse Growers Program: Dealing with Energy

Fact Sheet: Greenhouse Energy Conservation ChecklistGreenhouse Energy Website

University of Massachusetts:Energy Choices for Farms and Greenhouses

North Carolina State University Database: State Incentives for Renewables and Efficiency

Leanne Pundt, University of Connecticut

It is a tough time of year for greenhouse businesses to apply for energy grants, however, it may be something to think about for future opportunities if you don't have time now.

Grants and loans are available for greenhouse growers and other agricultural industries to support investments in energy-efficiency improvements and renewable energy. The USDA Rural Development Office recently announced that $220.9 million is available to agricultural producers and rural small businesses. Application deadlines are April 15 and June 16.

The Renewable Energy and Energy Efficiency loan and grant program was established to encourage agricultural businesses located in rural areas to create or install renewable energy systems and energy efficiency improvements. Grant requests must not exceed 25% of the eligible project costs. Renewable energy grants can range from $2,500 to $500,000. Energy efficiency grants can range from $1,500 to $250,000.

Eligible projects include, but are not limited to, investments in anaerobic digesters, biomass boilers and burners, solar collectors, wind energy, and energy efficiency improvements. Examples of energy efficiency projects might include the installation of more energy-efficient motors, pumps, fans, ventilation systems, insulation, curtains and heating and lighting systems.

Two separate grant competitions are available. For the first competitive window, grant-only applications must be submitted no later than April 15. For the second competitive window, grant-only applications must be submitted between April 16 and June 16. Applications for loan guarantees and loan/grant combinations must be submitted by June 16.

To qualify, you must be in a rural area and you must be either an agricultural business producing at least 50% of your gross income from the farm or a small business. For details to determine eligibility see: Eligibility Requirements

In Massachusetts, for information on applying, contact your Rural Development Area Office  Link for other states to find their USDA Service Center.

Tina Smith, University of Massachusetts

A frequently asked question (FAQ) is "Can I use unvented heaters in the greenhouse, either for back-up or as a primary heat source?

An unvented heater is one that is designed without a flue connection so that the heat and products of combustion are exhausted into the greenhouse. Dumping these flue gases into the greenhouse may improve the overall efficiency rating as compared to a conventional heater but the pollutants and added moisture from combustion may put your plants in jeopardy.

Unvented heaters can be fired with natural gas, propane or kerosene. These fuels are advertised as clean-burning. This is generally true if the burner is clean and has been adjusted to top efficiency. A heater that has been serviced in the fall will probably not be at peak efficiency as spring approaches. Inefficient combustion can emit unwanted and harmful pollutants into the greenhouse that can affect the plants and the people working with them.

Care should taken if you install unvented heaters. Be sure to have an adequate makeup air supply and provide frequent maintenance. Use indicator plants near heaters or commercially available indicator tubes to warn of excess levels of pollutants.

For more information about the fuels, the combustion process and their pollutants see the fact sheet:

Problems With Using Unvented Greenhouse Heaters

John Bartok, Extension Professor Emeritus, UConn

Bare heating system pipes waste a considerable amount of fuel each year in areas such as boiler rooms and headhouses where heat is not needed. This heat loss continues every day the system is operating. Adding 1" thick fiberglass or foam insulation to a ¾" pipe will save about $2.25/linear foot and on a 2" pipe about $5/linear foot over the heating season in northern climates. The payback usually takes less than two years. Installation is simple and can be done by unskilled workers in slack time.

John Bartok

Mechanical thermostats tend to loose accuracy over time. You can easily check the accuracy of a thermostat. Start by checking the accuracy of a good thermometer by inserting it into an ice bath. The reading should be 32°F. After allowing it to come back up to room temperature, place it next to the thermostat you want to check.. Slowly move the dial until the heater turns on. The reading should be the same as the thermometer reading. If not, mark the thermostat accordingly. Next time the heating system is serviced, have the service person recalibrate it. If the thermostat setpoint is 1°F too high, a 30' x 100' double poly covered hoophouse will use an additional $300 of fuel for the heating season. This is based on maintaining 60°F inside where the average winter temperature is 25°F outside with fuel oil at $2.00/gallon, natural gas at $1.37/therm or propane at $1.17/gallon.

John Bartok

Energy prices are one every one's mind today as spiking prices of heating fuels cut into profits and consumers budgets. Prices have been moving up for the past two years culminating in the recent devastation caused by hurricanes Katrina and Rita. More than a month after the storms 66% of US gulf oil production and 55% of natural gas production are still shut in. In mid October 1.65 million barrels per day of refinery capacity, almost ten% of all US capacity is still out of service. Repairs have been slow due to difficult working conditions and displaced workers and prices are expected to stay high for the winter.

Purchasing heating fuels used in a commercial application requires an analysis of costs and revenues. The goal of purchasing fuel in advance is to guarantee supply and to lock in costs against revenue streams. The nursery industry in New England needs heating fuel in the winter and should be contracting for fuel in the late spring and early summer prior. Depending on the amount of fuel consumed, it should be purchased in blocks, possibly 25% at each time spread over a period of a couple of months. In the event you think prices will fall in the following winter, downside protection can be purchased from your supplier. For a fee your supplier can cap your price but in the event the market price falls, your contract price will fall also.

A money saving option would be for a few growers to pool their volumes and offer the contract to a number of companies to get the best terms and price. Aggregation will allow the supplier to offer hedging opportunities to companies who may be too small to get attention from their supplier.

High energy prices for the future offers incentive to make an investment in other ways to make heat. Waste oil or wood refuse burners are cheaper than oil or propane and are worth making the investment.

This article was written by Lew DeRosa, Petrohedge, East Hampstead, NH.

Lew DeRosa presented the subject of Purchasing Oil in a Tight Market at the MFGA/UMass Fall meeting on October 5, 2005.

Paul Lopes

One factor that influences heat loss from a greenhouse is the amount of glazed area. In a 30° wide hoophouse, the glazed area from the ground to bench height is about 15% of the total surface area. Insulating this area with an inch or two of polyurethane or polystyrene can reduce total heat loss over 10%. Use a closed cell insulation board and not beadboard as this absorbs moisture reducing its insulating value.

For more energy saving tips see: Greenhouse Energy Conservation Checklist

John Bartok

In some greenhouses, cold air infiltration adds considerable to the cost of heating. Cracks around doors, vents and shutters that don't close tight, broken glass and tears in the plastic are typical examples. For example, a 4 foot square shutter that fails to close fully and leaves 1/2 inch gaps will allow about 12,000 cubic feet of cold air to enter each hour. To heat this amount of air over a 24 hour period to 60°F when the outside temperature is 0°F require almost 4 gallons of fuel oil. Most infiltration leaks can be corrected with minimal cost. Weatherstripping and foam insulation work well on small gaps. Shutters not needed for cooling should be covered with a sheet of film plastic or one inch of polystyrene or polyurethane insulation board. A few hours spent in tightening your greenhouses is well worth the effort.

Fact Sheet: Greenhouse Energy Conservation Checklist

John Bartok