The cost of energy is rising at an alarming rate. Natural gas prices, in particular, have greenhouse growers nervous about their operational costs and questioning their business viability. This trend should act as an incentive for cultivators to look towards gas-free and energy-efficient greenhouse solutions in order to thrive. Luckily, these alternative energy solutions are more attainable than one might think and are already proving to be successful for many growers. In this blog we will discuss electric greenhouses and their equipment, and how they produce the same end result (if not higher yields and better quality) as a traditional gas-powered greenhouse.
(Markets Insider graph of natural gas prices (Henry Hub) in the US over the last 6 months (snapshot taken 6/23/22) https://markets.businessinsider.com/commodities/natural-gas-price)
The Greenhouse Envelope
While we will focus on electricity-based environmental control options, it’s important to think about the thermal envelope of the greenhouse as a first step. Traditional greenhouses are poorly insulated (or not insulated at all), which means they require more heat, and more gas, to keep them operating in colder temperatures. Highly insulated greenhouses, on the other hand, can reduce heating loads by as much as 70% based on their design and materials used, reducing heating needs significantly.
From gas-powered greenhouses to electric greenhouses
Traditionally, commercial greenhouses use central gas boilers to heat water or steam that is distributed through the greenhouse via a piping system. This method of heating is similar to a radiant heating system you may have in your home. While tried and true by many commercial greenhouse operators, this method of heating is becoming less sustainable with natural gas prices reaching an all time high across the globe.
Natural gas powered boilers in a commercial greenhouse. Image from shutterstock.com
So what’s the alternative? Well, just as many people are turning to electric vehicles to skip out on gasoline prices and lessen their impact on the environment, growers are turning to electric greenhouses to grow crops. You may be thinking, “well, isn’t the price of electricity rising too?”. This is true, but at Ceres, we have developed energy-efficient heating, cooling, and dehumidification systems that use less electricity because they rely on heat pump technologies to condition the greenhouse environment. These energy-efficient HVACD systems are called EcoLoop™ and EcoPack™, and they enable our growers to cut their ties to natural gas and propane.
How the “Eco” HVACD series saves you money
The EcoLoop™ is a hybrid ground coupled heat pump system. This means it includes a ground loop component that lies underneath the footprint of the greenhouse that constantly circulates water through the underground system. The circulating water either absorbs heat from the earth surrounding the mats or dissipates heat back into the earth – depending on whether the system is in heating or cooling mode. The ground loop component transfers thermal energy to and from the heat pump component of the HVACD system which sits above ground on the exterior of the north wall of the greenhouse. Through this process, the system utilizes free geothermal energy to regulate the temperature of the greenhouse space. This energy-efficient technology is saving growers on operational costs at a time when natural gas prices are sky-rocketing.
A SunChamber™ integrated with the EcoLoop geothermal HVACD system
The EcoPack™ is a very similar system to the EcoLoop™ in that they are both use heat pumps and they combine heating, cooling and dehumidification into one system. The main difference is the EcoPack™ doesn’t utilize the geothermal ground coupling, nor does it use external evaporation as part of its cooling methodology. While the EcoPack™ is slightly less efficient than the EcoLoop™, the system is simpler and cheaper to install. While it can utilize natural gas for heating, it can also be used as an electric only unit. Either way, it is significantly more efficient than traditional gas powered boiler systems.
A SunChamber integrated with the EcoPack™ HVACD system
To learn more about how HVAC systems and the EcoLoop™ works, watch this informational video.
What other greenhouse systems are gas-powered?
Desiccant dehumidification systems. When plants transpire into the greenhouse space, this extra moisture in the air needs to be dealt with, either through ventilation or dehumidification. Dehumidification systems are an important aspect of a commercial greenhouse, and depending on what kind of system is used, it may use gas to function. If you are unfamiliar with how dehumidification systems work, visit our blog, “Greenhouse Dehumidification Strategies for Vented and Sealed Commercial Greenhouses”.
With the EcoLoop™ and the EcoPack™, dehumidification is built into the system. The heat pump component uses a refrigerant to cool the incoming moist air to dew point, and then after condensation happens, waste heat from the heat pump reheats the dehumidified air back to a comfortable temperature suitable for plant growth before it’s exhausted back into the greenhouse. By combining dehumidification with heating and cooling, we ensure that our growers can reach specified vapor pressure deficit (VPD) levels. And like we mentioned above, the Eco HVACD Series runs entirely on electricity – eliminating your reliance on gas.
Other benefits of geothermal and electric greenhouses
The Ceres EcoLoop™ and EcoPack™ are just one component of Ceres’ holistic greenhouse solution called the SunChamber™ – a sealed design with full system integration. The SunChamber™ uses the power of the sun along with innovative climate control technology to create a highly productive growing environment. With this holistic solution, you can grow higher quality crops and reduce the risk of crop failure by taking advantage of the SunChamber™’s biosecure and highly controlled environment. Combine the growing capabilities of a SunChamber™ with the lower cost it takes to operate it, and you have a growing capabilities/ abilities that will allow your business to thrive even with rising energy prices and unstable fuel markets.
