Solar

COOLING TOWER: An EVAPCO solar-powered SUN cooling tower. (Courtesy EVAPCO)

ECMS: SUN cooling tower fans are powered by ECMs. (Courtesy of EVAPCO)

TRACKIING: The control package includes a subscription to a web-based interface to track real time solar production. (Courtesy of EVAPCO)

SUNLIGHT: EVAPCO's SUN cooling tower is energized by sunlight. (Courtesy of EVAPCO)

Renewable energy enthusiasts now have reason to celebrate: EVAPCO offers a solar-powered evaporative cooling tower. The SUN cooling tower, available in two sizes — 241 and 383 nominal tons — is paired with PV panels to dramatically reduce energy consumption.

The SUN cooling tower is capable of achieving net-zero operation because its 9 or 12 photovoltaic (PV) solar panels power the unit fully at 50% capacity. Its net-zero capability stems from an annual average of energy usage (most of the year, evaporative cooling towers operate at less than 50% of their capability).

Cooling towers are among the large mechanical systems that are most scrutinized during energy audits performed at commercial, municipal, and industrial buildings.

PV Panels, ECMs, and Proper Control

The stainless steel-constructed evaporative tower's controller gives priority to electrical power coming from its array of 250 watt PV panels. If the system needs more than 50% of power for the fans, or if solar energy is insufficient for operation at the time, the control shifts to grid or backup power to assure continuous, evaporative cooling.

The cooling tower is independently certified to be IBC (International Building Code) compliant to withstand seismic and wind load forces in North America. Its performance and ratings are certified by CTI, the Cooling Technology Institute.

Electrical savings are sure to boost a customer's ROI. Given that the SUN tower can operate at 50% of specified load on solar energy alone, a customer's energy savings are improved. The better ROI improves the likelihood of an approved proposal and the likelihood that — once approved or commissioned — the customer may seek to fund other energy saving, carbon-reducing projects.

Why a Solar Cooling Tower?

According to Becker: Because it can be done!

How they did it: The first step was to change the characteristics the cooling tower's most energy-consuming function — the fan. For the SUN, EVAPCO designers "broke one fan into many." Rather than using a single, large fan — as most evaporative cooling towers do — they opted to use four to six EC (electrically commuted) fan motors, otherwise known as ECMs. They’re also direct-drive, as opposed to the typically fan-belt-driven larger fan. The direct-drive fans are controlled using speed controlled 0-10 volt or Modbus signal.

The system also comes with a proprietary SUN control panel. It provides continuous, real-time display of powered generated from the panels and electrical draw of the motors, and offers the flexibility of multiple control configurations.

Stay on Top of Maintenance (Leads to Business Opportunity!)

In order to ensure that the system is operating properly and at its highest efficiency, the cooling tower — like all mechanical equipment — will require routine inspection and occasional maintenance — such as monitoring water quality, the cleaning or replacing of tower media, and occasional cleaning of the solar PV panels.

Rain does not wash all dirt and debris from PV panels. Though a good rainfall eliminates most dust, pollen, bird droppings, and other debris isn't so easily washed away. Washing the panels is easy, so why not make a habit of it?

What of the idea that this could be a new service offering for your firm? After all, solar PV arrays are spreading quickly across all of North America, many of them attached to the operation of commercial, institutional, or industrial mechanical systems (and that's your sweet spot, right?). So, tell me: Why shouldn't your services include the spit-shining of solar panels to enhance a customer's energy production? After all, most solar installation companies are focused on installing the panels, then moving on.

Add solar panel maintenance to your repertoire for increased revenue and profit. Your competitors won't know what hit ‘em.

Goldstein is an author and HVAC expert who's spent decades working with commercial, institutional, and industrial mechanical systems, including solar PV and thermal, and IAQ.