Innovative Building Technologies for the Smart Grid

In 1931, Thomas Edison mentioned during a conversation with Henry Ford and Harvey Firestone one of the key issues of modern society lies in facing the depletion of conventional energy sources: “We are like tenant farmers chopping down the fence around our house for fuel when we should be using Nature’s inexhaustible sources of energy — sun, wind and tide. I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that.”

 

Renewables capacity worldwide

Despite Edison’s visionary and inspiring statement and the increasing societal concern with reducing our dependency on coal and gas, the total renewables capacity worldwide reported by the U.S. Energy Information Administration (EIA) was less than 30 percent in 2012, with more than half of that coming from hydroelectric power.

Solar, tide, wave and wind represented just seven percent of the energy mix at that time, and the further increase of these renewable – but highly unpredictable and uncontrollable energy sources – still requires innovative thinking and technology breakthroughs to support the design, operation and metering of the electrical power grid of the future.

The 30 percent renewables limit has been recognized as the threshold at which grid operators can assure system stability, even in the presence of the unpredictable nature of wind and sun energy sources. Beyond this limit, meeting the real-time balance between energy generation and consumption is challenging, and often requires significant capital expenditures to offer enough system flexibility to cope with sudden power generation shortfalls or excesses… at least if the conventional generation-follow-demand concept is applied. However, in order to increase the penetration of renewables in the energy grid without losing controllability, grid operators might find it easier to control electricity demand while moving toward a demand-follow generation approach.

 

Smart Grid is intended to facilitate the transition

The Smart Grid is intended to facilitate the transition to this new paradigm through the extensive use of communications and ubiquitous real-time acquisition and control signals in the electrical power system.

As the largest energy demand-side actor, buildings play a key role as one of the basic building blocks in this complex puzzle. In addition, energy directives related to nearly zero-energy and even net zero-energy buildings require buildings to reduce energy consumption, increase self-sufficiency,  improve intelligence (i.e. interacting with the ecosystem), and increase flexibility. 

In this scenario, building operators would be required to equip building infrastructure with the technology to communicate automatically and securely with utility suppliers in order to reduce energy demand during critical periods – and offer tenants voluntary and automated reductions and re-scheduling options through time-of-day-pricing or event dispatching.  

 

Provider of integrated and intelligent building technologies

As the world’s largest provider of integrated and intelligent building technologies, United Technologies Corp. offers such technologies today through our elevator, escalator, fire safety, security, building automation, heating, ventilating, air-conditioning and refrigeration systems and services – all designed to promote integrated, high-performance buildings that are safer, smarter and sustainable.

These technologies provide innovative building-management solutions for increased building energy demand flexibility.

For example, Automated Logic Corp., a UTC brand specializing in innovative building management solutions, provides an open automated demand response (ADR) add-on for the provision of ADR services for increased flexibility in building energy demand.

This application provides a standard way for utility suppliers to automatically and securely communicate with customers’ building automation systems to reduce energy demand during critical periods.

 

Energy is dissipated as heat in a set of resistors

Further, new generations of Otis elevators, manufactured by Otis Elevator Company,  another UTC company, use regenerative drives in place of conventional non-regenerative drives. In a typical non-regenerative drive, energy is dissipated as heat in a set of resistors when braking occurs, resulting in reduced efficiency and creating additional waste-heat loads in the building.

The Otis ReGen™ drive feeds this energy back into the building’s internal electrical utility where it can be used by other loads or users connected to the same network. Electrical power is generated when the elevator travels up with a light load, travels down with a heavy load and during the elevator system’s deceleration. In this way, building owners can save up to 75 percent of energy consumption compared to conventional systems. 

Now, what if those same elevators easily connected to building-based solar power — like the Otis Gen2® Switch elevator released in Europe recently? The result would be 100 percent savings in electricity costs. That technology is also currently available from UTC.

 

Summary

The radical revolution in electricity generation, transmission, distribution and consumption is significantly increasing the demand for innovative intelligent buildings technologies able to integrate buildings into the smart grid. With a final goal of transitioning toward a more sustainable energy model, buildings are expected to play a key role by offering the required flexibility, while providing new business opportunities for technology providers and energy consumers.

 

About the Author

Dr. Francisco Gonzalez-Espin received his PhD in Power Electronics at Polytechnic University of Valencia, Spain. He is a multidisciplinary and versatile PhD electronics engineer with experience in research, industry and academic fields. Self-motivated and self-started, he is part of creative and cooperative R&D teams. He has also experience in design of control algorithms for power electronics converters and its implementation in real time embedded systems. Other areas of expertise include design and development of power electronics converters for space systems, renewable energies and audio applications. He participated in private and public funded projects both as principal investigator and technical contributor. He has specialties power electronics, digital control of single and multi-phase power electronics converters, real time embedded systems, power conditioning and distribution units for satellite applications, and smart grids and microgrids.

 

This article originally appeared in the Bodo’s Power Systems magazine.