Going Geothermal

Going Geothermal

Mark Elzinga held nothing back when he built his four-acre organic greenhouse at Elzinga & Hoeksema in Portage, Mich.

He spent money, took risks and entrusted a lot of people with the future of his operation–people like Stephen Hamstra, executive vice president at GMB, who helped design the solar-geothermal energy system that should provide 80 percent of Elzinga’s heating needs. The GMB-designed system should cut down on Elzinga’s energy costs, as well, and significantly reduce the greenhouse’s carbon footprint.

“The geothermal hybrid is a new thing,” Hamstra says. “I’m not aware of a greenhouse that’s done it like this. We presented the concept in 2006 in a white paper at the International Ground Source Heat Pump Association (IGSHPA) annual meeting in Albany, N.Y., and there was a lot of favorable response.” 

One Of A Kind

Elzinga was among the first to take notice, and he now has an impressive solar-geothermal system that includes 200 solar energy collectors, a 60,000-gallon insulated water tank and a heat exchanger that includes 26 miles of polypropylene tubing sunk in 200 wells that are each 300 feet deep.

The system uses Michigan’s year-round ground temperature to create hot water that’s stored in an above-ground tank and available for most of the greenhouse’s heating needs. In the summer, only a handful of heat is obviously needed in the building, yet available heat from the sun and air is abundant. So that excess heat is pumped into the ground and available to Elzinga the following winter.

Another part of the GMB design involves two air-handling units that sit outside the greenhouse.

“They’re basically fans and big radiator coils,” Hamstra says. “Each one moves 100,000 cubic feet of air per minute. If the air temperature (outside) is warmer than the soil temperature (underground) in the earth heat exchanger, we’ll turn on a pump and circulate cool water through those coils and blow warm air across the coils to also try to capture free solar energy and warm the soil.”

As reliable as Elzinga’s geothermal system is, the greenhouse can’t exclusively depend on heat from it year-round. Once cold temperatures arrive, high-efficiency boilers kick in to make up the difference that the heat pump cannot fill. And, if for some reason the geothermal system needs to be turned off, the boilers are capable of handling the heating load for the entire greenhouse. 

Greenhouse Rookies

Surprisingly, Elzinga is the first greenhouse GMB has ever served. The architectural and engineering company based in Holland, Mich., has mainly worked with the healthcare, corporate and education sectors. And, according to Hamstra, few of his peers have even thought much of having greenhouse growers as clients.

“It’s a huge market with a huge need, and the response is typically that the greenhouse market has been characterized by low-cost heating systems and that growers will put in the minimum to get by,” Hamstra says.

Elzinga’s vertical closed-loop system certainly bucks that trend, but the idea behind it is that the long-term benefits will eventually offset the costs upfront. Still, there’s more to geothermal heat systems in greenhouses than growers simply being open to invest in their futures now. Each greenhouse structure is unique, Hamstra says, and any system GMB installs is custom made.

At Elzinga, GMB was called on midway through the building process. But the earlier it could have been involved, the better, Hamstra says, because geothermal applications are functions of the greenhouse site.

If, for instance, GMB was involved with the Elzinga project at the start, it might have been able to put the bore field underneath the greenhouse itself. And that, among other applications, probably could have reduced the amount of area taken up by various parts of the system, too.

“We need some real estate to do this,” Hamstra says. “Talking to one grower who has a huge aquifer available and a big irrigation system with greenhouses and large open fields, a ground-water heat pump system is certainly a possibility. If you’ve got a good source of ground water, a good place to get rid of it after you’ve just pulled some heat out of it and no bacteria that will cause problems over time, it can work well.” 

Thinking Ahead

A geothermal system can also work well for a greenhouse, Hamstra says, if it collaborates with another building, particularly one that’s refrigerated. In a study conducted last year on a Meijer store in Michigan, GMB found that the store rejects nine times more heat each year than it needs.

Following the study, Hamstra did a computer simulation that gave the Meijer store a geothermal heat pump system, and he put the store side-by-side with Elzinga’s greenhouse. He then found that if Meijer’s waste heat was moved to the greenhouse, the size of Elzinga’s geothermal heat exchanger would drop in half in a virtual building simulation. He also concluded that the greenhouse could use that waste heat to significantly reduce the cost of operation while Meijer had a less-expensive way to lose its heat. “If you’ve got greenhouses that are next to some industrial process–plastic injection molding, even power plants–the waste stream from one industry could become the feedstock for the other industry,” Hamstra says.

As good as that scenario sounds, few growers are positioned right next door to buildings that can accommodate that amount of heat. But if growers are considering geothermal heat pumps for their greenhouses, Hamstra recommends that they consult engineers who’ve gone through the rigors of Certified GeoExchange Designer (CGD) training administered by IGSHPA. The investment is simply too much, he says, to rely on some run-of-the-mill heating company that’s conveniently located.

“I’ve heard reports, even in our area of West Michigan, of people who have applied geothermal pumps in greenhouses and the heat exchanger was way undersized,” Hamstra says. “They pulled the soil temperature down very quickly, and partway through the season it ceased to function.” If applied correctly, growers could see financial benefits for years to come. The benefits of such systems on the environment are big, too.

“Reducing our footprint by only moving energy instead of burning a fossil fuel to create heat is a significant one,” Hamstra says. “I think as an industry, growers have been looking for something to relieve them from these huge fuel bills.”

Leave a Reply

9 comments on “Going Geothermal

  1. i am in the business of building geothermal systems currently i have done one small green house system and works quite well my customer is very happy with it but i have mostly done residential i have the potential for much larger projects i would like to go after. there are many large growers in our area so maybe looking at partnering up with someone who has done larger project and expand our business

  2. I am new to greenhouses but I want a geothermal heating/cooling system for 4 greenhouses. Just wondering how much space is really needed only have about a half acre to spare, is it enough?

  3. I have a good thermal greenhouse question I have been pondering about. When constructing my first portable cold frame I only wanted the cold frame to be as tall as it needed to be for the plant heighth. I thought that the extra room would somehow be all the more space for cold air to hang out. Then I thought maybe it would also be a space where the heat collected during the day to be stored.
    So, my question is that is it advantageous to have extra unused room in a greenhouse to store heat captured during the day? The reason I ask is that I really want to make my next greenhouse a walk-in greenhouse but it doesn’t really “have” to be.

    Thanks,

    Jon

  4. I want to know your experience using underground geothermal water for city building.can you help me? if you help me, i am very thankful. And I wish you happy & health in the new year.

  5. i am in the business of building geothermal systems currently i have done one small green house system and works quite well my customer is very happy with it but i have mostly done residential i have the potential for much larger projects i would like to go after. there are many large growers in our area so maybe looking at partnering up with someone who has done larger project and expand our business

  6. I am new to greenhouses but I want a geothermal heating/cooling system for 4 greenhouses. Just wondering how much space is really needed only have about a half acre to spare, is it enough?

  7. I have a good thermal greenhouse question I have been pondering about. When constructing my first portable cold frame I only wanted the cold frame to be as tall as it needed to be for the plant heighth. I thought that the extra room would somehow be all the more space for cold air to hang out. Then I thought maybe it would also be a space where the heat collected during the day to be stored.
    So, my question is that is it advantageous to have extra unused room in a greenhouse to store heat captured during the day? The reason I ask is that I really want to make my next greenhouse a walk-in greenhouse but it doesn’t really “have” to be.

    Thanks,

    Jon

  8. I want to know your experience using underground geothermal water for city building.can you help me? if you help me, i am very thankful. And I wish you happy & health in the new year.

More From Technology...
mcconkey-plastic-shelves-feature

December 1, 2016

How Color Point Is Stopping Cart Theft With Plastic Shelves

Plastic shelving on carts acts as a deterrent to theft, and employees enjoy the benefits of being able to handle the racks without difficulty or injuries.

Read More
oasis-water-valve-feature

November 30, 2016

How You Can Water Plants Based On Basket Weight

The Oasis from Control Dekk is designed to reduce water use by giving baskets the exact amount of water they need.

Read More
Silver Bullet Heaters (Heat Star By Enerco) Feature

November 28, 2016

The Latest In Greenhouse Heating And Cooling Products

New developments in heating, cooling, ventilation, and humidity control technology are designed to help you manage your greenhouse environment more efficiently. Check out some of the latest offerings from leading manufacturers.

Read More
Latest Stories
mcconkey-plastic-shelves-feature

December 1, 2016

How Color Point Is Stopping Cart Theft With Plastic She…

Plastic shelving on carts acts as a deterrent to theft, and employees enjoy the benefits of being able to handle the racks without difficulty or injuries.

Read More
oasis-water-valve-feature

November 30, 2016

How You Can Water Plants Based On Basket Weight

The Oasis from Control Dekk is designed to reduce water use by giving baskets the exact amount of water they need.

Read More
Silver Bullet Heaters (Heat Star By Enerco) Feature

November 28, 2016

The Latest In Greenhouse Heating And Cooling Products

New developments in heating, cooling, ventilation, and humidity control technology are designed to help you manage your greenhouse environment more efficiently. Check out some of the latest offerings from leading manufacturers.

Read More
north-creek-nurseries-gutter-connected-greenhouse-feature

November 23, 2016

How Greenhouse Technology At North Creek Nurseries Expe…

The new structure is the latest step in a lean flow efficiency process designed to help the company cut waste, drive down shrink, and increase profits.

Read More
Sensaphone alarms system

November 21, 2016

Five Things To Consider Before Purchasing A Greenhouse …

A greenhouse alarm can be the difference between you and a major catastrophe that results in crop losses. Before you make a purchase, take these factors into account.

Read More
bell-nursery nc-planting-lines

November 15, 2016

Thoughts For Greenhouse Growers To Consider When Automa…

With labor getting scarce and minimum wages on the rise, Cole Mangum of Bell Nursery says it’s time to take a closer look at automating your operation.

Read More
LED lights used in greenhouse

November 4, 2016

Evaluating Greenhouse Supplemental Lighting For Young A…

Researchers at Purdue and Michigan State University compare young and finished plant production under LED toplighting and HPS lamps to determine which source is most effective.

Read More
light-deprivation-system

October 27, 2016

5 Things Cannabis Growers Should Look For In A Light De…

From automation to installation, here are five things you need to know when adding a light deprivation system to your cannabis greenhouse.

Read More
cannabis-under-led-lighting

October 24, 2016

Study Shows Effectiveness Of Growing Cannabis Under LED…

The study, conducted by the Wageningen University & Research Centre in The Netherlands, shows some varieties of cannabis plants grown under LED lighting may produce more medicinally active substances than if they had been grown under other intensive lighting systems.

Read More
greenpower-led-production-module-philips-lighting

October 18, 2016

Lighting Research Center Is Surveying Growers On Supple…

The Center, part of the Rensselaer Polytechnic Institute, is looking for commercial growers to participate in an online survey regarding supplemental greenhouse lighting.

Read More
ag-robotics-forum

October 17, 2016

International Forum Of Agricultural Robotics Will Highl…

The inaugural event, organized by two France-based companies, is designed to bring together ag robotics stakeholders to discuss, debate, and exchange ideas on the future of agriculture.

Read More
Dual Atrium Greenhouse (Nexus)

October 12, 2016

Gibraltar Industries Acquires Nexus Corporation

The building manufacturer and distributor strengthens its position in the U.S. greenhouse market, complementing its RBI greenhouse company with the aquisition of Nexus Corp.

Read More
Chemical hopper

October 3, 2016

New Soil Mix Technology Generates High-Precision Greenh…

Advancements in soil mixers help growers achieve the highest level of automation and efficiency to create the ideal growing media for every type of crop.

Read More
nc-state-solar-cell-greenhouse

October 3, 2016

North Carolina Researchers Studying Solar Cells For Gre…

Researchers from North Carolina State University and University of North Carolina-Chapel Hill are launching a project to develop next-generation greenhouses with built-in solar cells that make use of the entire spectrum of solar light.

Read More
hoffman-new-greenhouse-feature

September 30, 2016

How Hoffman Nursery Invests In Technology In Response T…

The North Carolina-based ornamental and native grasses producer recently invested in greenhouse structures and advanced automation to help increase efficiency.

Read More
totalgrow-night-and-day-management-boom-lighting-venntis-feature

September 27, 2016

Check Out The Latest In Lighting Technology For Greenho…

Manufacturers are developing several innovative lighting systems that can help growers save on energy efficiency, while improving plant quality. Here’s a look at some of their newest offerings.

Read More
sbi-software-triumph

September 25, 2016

Greenhouse Software Suppliers Offering A Range Of New S…

Want to know what some of the leading software suppliers are doing to address the ever-evolving needs of their greenhouse customers? Here’s a brief update.

Read More
cannabis-lighting

September 24, 2016

4 Tips On Picking The Best Lighting System For Cannabis…

From energy use to maintenance, here are some suggestions from one expert on how to ID the best lighting system for your greenhouse.

Read More
[gravityform id="35" title="false" description="false"]