Wireless automation systems play a key role in reducing energy consumption. They can help to improve the carbon footprint of plants with a quick return on investment. World energy consumption will increase 56% by 2040, using 820 quadrillion Btu, but will already reach 639 quadrillion Btu by 2020, six years from now, according to U.S. Energy Information Administration, World energy demand and economic outlook, July 2013. This development is closely linked to CO2 emissions and global warming. In the past few years, areas in the United States have experienced high temperatures, wildfires, and droughts. These weather events could become more prevalent with the threat of climate change. As temperatures increase and as population grows, the drain on power capacity will lead to more brownouts and rolling blackouts.
Fossil fuels have fallen out of favor, nuclear power is viewed as risky, and renewable energy is nowhere near the point at which it can take the place of coal. Energy efficiency, in the minds of many, is a vital component to mitigating energy-related demand and curbing the impact that the rising cost of electricity has on a business’ bottom line.
Energy harvesting wireless systems could become more popular in monitoring and controlling energy-efficient facilities.
Hot demand for cooling
An important statistic to consider when discussing the future of energy demand is that nearly all of the world’s booming cities are located in the tropics, according to the 10th edition of Demographia World Urban Areas, published in May 2014 and written by Wendell Cox. These hot and humid areas will be home to nearly 1 billion new power-consuming individuals by 2025, according to the McKinsey Global Institute report, “Urban world: Cities and the rise of the consuming class, published in June 2012 and written by Richard Dobbs, Jaana Remes, James Manyika, Charles Roxburgh, Sven Smit and Fabian Schaer. As population grows and as temperatures rise, demand for air conditioning will grow. China, as a matter of comparison, is expected to surpass the United States as the world’s biggest user of electricity for air conditioning by 2020, according to Stan Cox in his July 2012 article, “Cooling a Warming Planet: A Global Air Conditioning Surge,” published on environment360. Air conditioning not only consumes considerable energy but also releases planet-warming emissions. But air conditioning is not all bad; it does offer thermal comfort.
The aim of an efficient HVAC system is to minimize energy consumption while providing healthy and productive indoor environments. Conversely, poor air quality or a lack of thermal comfort can have adverse impacts. The American Council for an Energy-Efficient Economy states, “In commercial office spaces, Sick Building Syndrome is a real concern, and can be a result of HVAC systems that don’t adequately distribute air to occupants. Efficient HVAC systems should ensure that occupants get adequate, filtered, fresh air. Typically, inefficient systems are not only energy-inefficient, but also ineffective at doing their intended function.”
Scientific studies show, for example, that health and productivity rise significantly if indoor temperature is cooled in hot weather, according to Lea Sabbag in “Temperature Impacts on Health, Productivity, and Infrastructure in the Urban Setting, and Options for Adaptation,” a paper published in 2013 by the Institute for Social and Environmental Transition-International. “It is true that air conditioning made the economy happen for Singapore and is doing so for other emerging economies,” states Pawel Wargocki, associate professor at the International Center for Indoor Environment and Energy at the Technical University of Denmark and president of the International Society of Indoor Air Quality and Climate. The demand for cooling is all the rage in India, where air conditioning has become a cultural priority, forcing scientists to scramble to invent more efficient air conditioners and better coolant gases to minimize use and emissions. This demonstrates the beneficial relationship that HVAC systems can have with economic development. Without air conditioning, no one could effectively and efficiently do business in Singapore.
The cost of electricity
In addition to the warming trends in the more northern climates, southern states, as well as tropical environments, are forced to cool their spaces, sometimes year-round. In places such as Hawaii and around the Caribbean, electricity is typically generated with petroleum-based products. In Hawaii, transportation consumes 63% of the state’s imported oil, while electricity generation uses about 30%. The issue here is that the cost of electricity fluctuates due to variations in the price of fuel used in power plants.
In some regions of the Caribbean, the use of petroleum products for power generation is around 75%. While manufacturers in the United States pay somewhere between $0.04 and $0.06 per kWh for electricity, manufacturers in the Caribbean pay around $0.38.
Significant effects with automation
Contributing factors like warmer temperatures and the inevitable rise in electricity prices make the need for energy management even more critical. Energy management, by definition, is the process of monitoring, controlling, and conserving energy in a facility. Energy management systems that utilize energy harvesting wireless building automation and control technology hold the key to saving energy. These wireless technologies can be used for retrofitting existing spaces, and, with no batteries, there is virtually no maintenance. Such a solution controlling HVAC and lighting can be expected to save anywhere from 20% to 50% on energy.
|Graham Martin is chairman and CEO for the EnOcean Alliance. He is a veteran of the electronics industry with more than 25 years of experience in analog and RF solutions. Before joining EnOcean, Martin was responsible for business development at wireless sensor networks specialist Chipcon. At the same time he was president of Figure8Wireless and vice chairman of ZigBee Alliance. Martin studied in the United States and Britain, and he graduated in physics at Edinburgh University in Scotland. Contact him at (925) 275-6601 or email@example.com.|
For example, if a sensor detects that a room or area is no longer occupied, lights can be automatically switched off and the HVAC systems automatically controlled. Alternatively, if enough natural sunlight is entering a room, then lights can be automatically programmed to dim or switch off completely.
The intelligent control of energy requires sensors to collect the relevant data from several points of measurement and receivers to process the information. A larger system can be composed of hundreds to thousands of these sensory nodes.
There are established technologies already, primarily in the field of automation, which can be a driver for an intelligent energy management. In an automation system, for example, thousands of sensors measure data from many different points, recording data on temperature, CO2, light, or room occupancy to enable a central control to manage all technical areas of a facility in an optimized way, meeting individual requirements.
A major challenge is how to network an increasingly large number of individual wireless nodes or sensors that can communicate with long-range wireless networks. Different wireless standards, for example GSM, Bluetooth, or IP, can be used for this purpose. These standards support applications in which large volumes of data must be transmitted quickly.
For smaller devices, such as sensors for detecting data, these technologies are suitable to a limit. This is particularly true when measured data from many different points must be available to an intelligent controller. Energy harvesting wireless technology can connect a large number of self-powered and maintenance-free sensors into existing Wi-Fi or mobile networks that process data for intelligent energy control.
The technology powers wireless communications by collecting energy from the surroundings, such as motion, indoor light and temperature differentials. The radio protocol is efficient enough to support self-powered devices that require no batteries and no wires. The products achieve this by delivering very short data packets and by utilizing frequency bands that have excellent signal propagation and minimal interference. The range of wireless sensors is about 900 ft in open spaces, such as warehouses, and up to 90 ft inside buildings. Repeaters can also be used to extend the signals.
These wireless devices can be integrated with other communication protocols such as Ethernet/IP, KNX, BACnet, or LON via gateway controllers incorporating the standardized energy harvesting wireless technology into an automation system.
Based on batteryless technology, an intelligent system can be realized by interconnecting automated thermostats, window contacts, humidity sensors, occupancy sensors, or CO2 sensors. These are just a few examples of the products in place to regulate climate control automatically. In an intelligent automation system, for example, a room controller receives information related to temperature, humidity, window position, or CO2 from the respective sensors and controls the heating or cooling accordingly. At the same time, the room controller sends information to an energy controller. This automation calculates the demand as a function of outdoor temperature and flow temperature to control energy generation.
The more complex a cooling or heating installation is, the more information it takes to control it. This is where the self-powered technology demonstrates its advantages. Single room controllers with energy harvesting wireless technology and the integration of self-powered wireless sensors to capture values can significantly reduce and optimize the energy needs of an HVAC system. Additionally, information can be transmitted wirelessly to an HVAC regulator or programmer, without batteries and with no need for maintenance or servicing.
Industry accounts for about one-third of all the energy consumed in the United States, according to the U.S. Energy Information Administration, Annual Energy Outlook 2013, Early Release Overview. This is about 24 quadrillion Btu. There is a fast-growing need for more efficient use of energy in industrial facilities. Newly constructed plants typically incorporate energy-efficient buildings and equipment; however, existing facilities are often less efficient and face greater retrofit challenges.
These retrofit projects call for technologies that can be installed at relatively low cost.
Wireless control for cardboard factory
In Montreal, Canada, the Norampac 427,000 sq-ft cardboard factory realized a retrofit project integrating energy harvesting wireless solutions and benefit from cost as well as from energy savings. The factory had 25 gas-fired unit heaters originally controlled by mechanical thermostats. The challenge was to integrate the heaters within the existing BACnet IP system of the factory. Because installing miles of conduits and wires throughout would be costly and cause downtime, the self-powered wireless option was the only one offering a short payback period.
Using relays communicating in the energy harvesting wireless standard, controlled wirelessly by wired and wireless controllers, themselves equipped with embedded BACnet IP gateways, the mandated contractor was able to install the link between the heaters and a BACnet management system without extensive wiring costs or significant downtime.
In the factory, 16 heaters are now controlled by energy harvesting wireless sensors communicating with the controllers. One controller is connected to the LAN, sending the end-devices data as BACnet objects to the third-party BACnet IP system. The contractor estimated spending 40% less time on the job than if it had been a completely wired retrofit. 4,000 ft of conduit and wires were saved.
Building codes are a means to achieve higher levels of energy efficiency. The move toward energy-wise code modification began in California through the adoption of Title 24, a set of high-efficiency standards dictating energy-saving requirements for walls, roofs, windows, insulation, heating, lighting, and HVAC systems. The introduction of Title 24 has saved Californians billions in electrical and natural gas expenses, according to the California Energy Commission. Although per-capita electricity use in the United States has increased by nearly 50% since the mid-1970s, California has essentially maintained its per-capita electricity use.
Retrofitting of existing buildings with energy-efficient lighting, HVAC, or upgrades to the building envelope to save money on energy costs needs funding for those improvements. Fortunately, there are alternative strategies that can be put into place to pay for energy-efficiency projects by significantly lowering tax burden.
One such tax benefit that can be applied to energy-efficient construction or improvements is found in section 179D of the Energy Policy Act of 2005. Also known as the Commercial Buildings Tax Deduction, 179D includes full and partial tax deductions for investments in energy-efficient commercial buildings that are designed to increase the efficiency of energy-consuming functions. The deduction available is up to $0.60/sq ft for lighting, HVAC, and building envelope. These deductions are applicable to buildings that were either built or retrofitted after Dec. 31, 2005. To qualify for the deduction, the taxpayer must receive a third party energy-efficiency certification.