"Unfortunately, the CEA industry, including both indoor cultivation and greenhouse farming, is highly energy intensive. Cultivators rely heavily on climate control systems, especially cooling systems, to maintain optimal growing conditions. With energy costs rising and the risk of grid instability increasing, managing electricity expenses and safeguarding operations during power disruptions are top priorities for growers," says Dalton Allaben, Sales engineer at Tecogen Inc..
One particularly effective strategy is energy arbitrage with engine-driven chillers. These systems can help growers mitigate expensive demand charges, avoid reliance on grid electricity during peak hours, and protect their operations from costly brownouts and blackouts. In this article, we will explore how engine-driven chillers provide an ideal solution for energy management in greenhouse and indoor cultivation.
Indoor cooling
Dalton continues explaining that maintaining the right climate is crucial for the success of any cultivation operation. Whether in a high-tech greenhouse or an indoor grow facility, cooling systems are used to regulate temperature and humidity ensuring an optimal environment for plant growth. "However, conventional electric chillers can drive up electricity consumption, leading to high utility bills that include both energy usage and demand charges. Demand charges are a cost associated with peak electricity consumption during high-demand periods," he points out. Often, these times peak when the ambient temperature is at its hottest and there is a greater need for cooling.
"Engine-driven chillers, powered by pipeline gas or other fuel sources, offer an alternative that enables cultivators to lower their electrical use during these periods more reliably than by producing electricity on-site."
Shifting cooling load to avoid peak demand
Energy arbitrage refers to shifting energy consumption from peak hours (when electricity prices and demand charges are high) to off-peak hours (when prices are lower). There's a few ways how engine-driven chillers can help cultivators implement this strategy, Dalton points out.
Tecogen's hybrid-air cooled chiller
Reducing peak electricity consumption
"By using engine-driven chillers powered by pipeline gas or renewable fuels, growers can avoid relying on grid electricity for cooling during peak periods. Since demand charges are typically based on the highest 15-minute interval of power use within a billing period, switching to non-electric cooling systems during peak times can significantly reduce these costs," Dalton affirms. Producing electricity on-site can result in similar demand savings, however, if your power generators go offline for 15 minutes or 0.035% of time in a given month you still risk getting charged a high demand rate.
Time-of-use pricing optimization
In regions where electricity pricing fluctuates based on time of use, engine-driven chillers allow cultivators to manage cooling needs more efficiently. Dalton explains that running the chiller during off-peak hours helps reduce the impact of expensive daytime electricity rates, enabling greater control over energy costs.
Protecting against brownouts and blackouts
"We see that power reliability is a critical concern for indoor and greenhouse growers. Brownouts (voltage reductions) and blackouts (complete power loss) can cause equipment failure, disrupt critical growing conditions, and lead to crop losses. Engine-driven chillers provide a solution by offering energy independence and resilience from the grid," Dalton reassures.
Continuous operation during power disruptions
"The great thing about engine-driven chillers, is that they do not rely on electricity from the grid, powered by fuels like natural gas, biogas, or propane." During a blackout, these chillers can continue to operate with only 2kW, ensuring that climate control systems in the greenhouse or grow facility remain functional. This protects crops from sudden temperature fluctuations, which can lead to reduced yields or even crop failure.
Avoiding equipment damage during brownouts
"When it comes to brownouts, these can be rather damaging to the chillers. When the voltage fluctuates, it strains motors and compressors. Engine-driven chillers avoid this issue entirely, since they don't rely on electric power from the grid," Dalton remarks. "This makes them more reliable during unstable grid conditions, ensuring that cooling systems remain operational without the risk of damage."
Integrating with backup power systems
For growers using CHP (Combined Heat and Power) systems, engine-driven chillers can complement this setup. As Dalton explains, a CHP or backup generator system can easily be scaled down because of the reduced need to produce electricity for the cooling system. "Additionally, the engine-driven chillers produce high-grade hot water as a 'mechanical' CHP system. This integrated approach adds another layer of resilience and boosts the overall system efficiency by skipping the step of power generation."
For more information:
Tecogen
Dalton Allaben, Sales engineer
[email protected]
www.tecogen.com