It’s difficult to walk through a neighborhood in America without hearing the constant hum of HVAC units.
89% of households in America have an HVAC (heating, ventilation, and air conditioning) system, and most residential homes use a split system, with both outdoor and indoor components.
The indoor component has evaporator coils, air filters, and a blower to pump air throughout the house, while the outdoor component condenses refrigerant and dissipates heat with a constant, running fan.
For decades, in millions of homes, the wind energy coming off of those outdoor fans has been languishing in backyards as wasted potential — but now scientists have figured out a way to harness it.
This year, Spanish researchers at the Distance University of Madrid explored transforming “artificially generated wind gusts” into clean electricity “through small wind turbines.” In early October, they published their findings in the scientific journal Nature.
To test their theory about HVAC systems, the team — Isabel Gil-García, Ana Fernández-Guillamón, and Álvaro H. Montes-Torres — applied small vertical turbines to “chillers” at a data center in Colombia.
The data center had three units — one which rotated weekly and two which were constantly running — in order to pump cold air into the facility to cool the facility’s computer equipment.
According to the study, the 16 fans of the chillers consumed a total of 336.39 MWh (megawatt-hours) annually, but generated a net electricity of 467.6 MWh. These metrics accounted for a 9% loss due to unplanned downtime and maintenance.
Overall, this led to a 131.2 MWh surplus of energy — but those small vertical turbines could harness that surplus, feeding renewable energy sources into the electrical grid or fulfilling other electrical needs at the facility.
They posited that this redirection and implementation of power could be easily applicable to residential and commercial HVAC units around the globe, potentially using that “leftover” clean energy to power itself — and the same household it was heating and cooling.
The scientists urged that solutions like this are more critical than ever.
“The need to reduce global emissions leads us to look for various sources of clean energy,” Gil-García and her colleagues wrote in their study, praising the “large-scale” advancements of wind technology in recent years in “both marine and terrestrial environments.”
It has indeed been a record decade for wind technology, with constantly evolving conversations on the creation and efficiency of wind farms, floating wind turbines, and wind-powered electric charging stations.
“However,” Gil-García and her colleagues wrote, “we often underestimate the capacity of certain human activities and production processes to generate clean energy, wasting their true potential.”
Powered by this desire to study the “overlooked” potential of man-made devices, the Distance University of Madrid scientists realized that common HVAC units could be the answer scientists have been looking for.
“This work estimates an annual clean energy production of approximately 468 MWh, avoiding about 300 metric tons of CO2 emissions,” the team wrote, suggesting that the data center in Colombia was just a starting point.
At first, clamping attachments to HVAC systems on a global scale would be expensive — the initial cost of nine micro wind turbines, installation, and equipment comes to $1,23,101. With an estimated lifespan of 20 years, and an annual maintenance cost of $1,109, the price was projected to increase by 12 percent.
But the scientists stated that the price would take a turn three years in, creating a positive return on investment “and an attractive internal rate of return of 50.69% over a 20-year period,” ultimately making their solution an economically viable one, too.
Concluding their research, the scientists wrote: “By adopting proactive policies and encouraging innovation, we can significantly reduce our environmental impact, save energy, and move towards a more sustainable world for future generations.”
Header image via Free Malaysia Today (CC BY 4.0)