When you think of a turbine, you probably image something massive.

Turbines are rotary mechanical devices that extract energy from a fluid flow (like wind, water, steam or gas) to convert into electricity or mechanical power for things like vehicles and industrial machinery. They’re critical devices in power plants, aircraft, ships and more. You probably haven’t thought about using one in your greenhouse.

One company that presented at this year’s Cultivate conference is trying to shift that mindset. Vergent, partnering with Capstone Green Energy, brought Director of Projects Jessie Gillis onstage to discuss how onsite energy can power greenhouse profitability through microturbines.

Gillis acknowledged the issues greenhouse growers are dealing with: high energy demands, volatile and rising utility costs and power grid limitations. “Growers need energy resiliency and crop protection,” he said. “And with data centers coming in, using huge amounts of power, it’s raising costs for everyone. We’re seeing more often and longer-term outages.”

So, the race for accessible, affordable and reliable power is on. New and different options are needed. Adding grid infrastructure isn’t always an option – and increasing the electrical capacity of existing facilities can be expensive.

“When adding electrical capacity, there’s no payback on the investment of upgrading infrastructure,” Gillis said. “With onsite generation using CHP, there is a payback.”

Combined Heat & Power

Also known as cogeneration, combined heat and power (CHP) is “the simultaneous production of electricity and usable thermal energy from a single fuel.” It’s where microturbines come into play.

Capstone’s microturbine technology has only one moving part, according to Gillis. “It’s not a complicated installation, and there’s not a lot that can break or go wrong,” he added.

It’s also not new; it’s actually 30-year-old technology that features low emissions, low noise and no vibration. It offers a high power density and clean waste heat. Users can take advantage of remote monitoring that measures temperature, pressure and power output of the microturbine in real time, alerting users to any issues, and it communicates with other devices and systems such as power electronics, grid connection and heat recovery and exchanging data or commands.

It’s a scalable technology to match energy demands. There are two capacities of microturbine currently offered by Capstone, a 65 kW and a 200 kW. The former is the size of a double-door fridge; the latter is six feet by six feet larger.

CHP technology can be paired with a hot water heat recovery system, a steam generator or an absorption chiller. This form of onsite generation can provide up to 90% total system efficiency, according to Gillis, capable of producing electricity that’s cleaner and less carbon-intensive than the grid in most of North America.

CHP microturbines offer three modes of action – grid connected, dual mode (acting as a back-up generator) and standalone. In this way, they can integrate well with existing facilities or as part of brand-new ones.

These devices run on conventional natural gas today but are also developed to operate on (or blend with) lower-carbon fuels like biogas (which is readily available from ag waste), renewable natural gas and hydrogen.

The circular system continues since the exhaust heat produced from generating electricity has multiple uses. It can be directly used for space heating, domestic hot water or even CO2 enrichment (as the exhaust gases, after treatment, are often rich in CO2, which is beneficial for plant growth).

Even better, though, are the extremely low emissions produced. Gillis said the Capstone emissions are one-tenth of that from best-in-class reciprocating engines such as CAT.

Those looking to be more green (environmentally) and save more green (financially) in their greenhouses may want to consider investigating microturbine tech. Their self-sufficiency, along with their potential to integrate with other onsite renewables (like solar) and storage, “positions greenhouses to thrive in a decarbonizing energy future where reliable, localized power generation will be increasingly valued,” Gillis concluded.

Want to learn more? Check out capstonegreenenergy.com.

by Courtney Llewellyn