APEC 2014: Transforming Energy Management

Editor’s note: This is the second in a series of guest blogs by Jeff Nilles from Texas Instruments. Jeff will be giving us his observations of APEC 2014 as he tours the conference this week.

When I entered college I supported the ecology movement. Not that I was much of a hippie, being an engineering student, but I did take a field biology class which strongly influenced me. Somehow, I became an ecologist of sorts due to this class. I saw the movement as a way to save the planet by using fewer resources. As the years went on, I connected the idea of saving resources to the save the world with improving efficiencies in power supplies and equipment so the world could use less electric power.

In Monday’s opening plenary session at APEC, Dave Freeman, CTO of power for TI, reminded us about resource savings again with a great example — something that kept us on the hook waiting for the real answer. His speech, “Transforming Energy Management,” covered the vast territory of power in automotive to powering the cloud.

Dave started the case study with a customer needing an ultra-low-power sensor for a room. This sensor needed to figure out if there were four people in a room, and it also needed to be ultra-low-power so it could harvest enough energy to run. From there, the sensor needed to send the information it gathered to the master system via WiFi. As I was listening, I speculated that this was some sort of security system sensor, or something to predict the need for more air conditioning due to these four people heating up the room.

Then the customer tells him they really need it to be a CO2 sensor. Is that really how they will figure out if there are four people in the room? Unless one person can hold his or her breath for a long time, this might work. Or is it for a security or heating/cooling (HVAC) system?

As it turns out, the goal was to make sure there is not too much CO2 in the room due to the occupants' breathing. In order to keep these four people alert, and keep them from making mistakes due to a high level of CO2 , the system would increase the level of outside air coming in from the HVAC system. It seems so simple now. If the room is empty, then there is no reason to bring cold or hot air in from outside or to expend the energy it takes to move or cool the air.

This ultra-low-power sensor would allow the system to adjust the blower speed and outside air mix as people moved into the room, allowing the CO2 to maintain a safe level. Since HVAC systems are a major electrical grid load, this simple device could be a major resource saver, making those who use it ecologists. As a side benefit, no one will fall asleep in conference rooms anymore. I’ll talk with you again soon.

9 comments on “APEC 2014: Transforming Energy Management

  1. Davidled
    March 21, 2014

    There are so many sensors in the house with wireless connectivity. Air pollution sensor detects the air purity level. But who check the sensor pollution in the house in the future. Some people go back to house built by lumberjack. In the future, the number of sensor could be optimized in home automation industry with the lowest power management.

  2. Netcrawl
    March 22, 2014

    @Steve thanks for a great article! @Daej there's a lot of development and buzz in home automation and sensors, its getting more attention these days. In the future sensors can sense not only the presence of person but know who that person is and perhaps set the appropriate lighting or temperature. And a much more sophisticated sensor system, able to track and maintain an inventory of products, record their usage using RFID or even order a replacement. This is home automation at its extreme point.   

  3. eafpres
    March 23, 2014

    @Steve & Jeff–monitoring CO2 to adjust HVAC initially seemed overkill to me.  So off to the web I went.  Doing a Google search for “CO2 levels in large buildings” the 2nd item was:


    This study, funded by California, was impressive in scope “Accordingly, this study evaluated: (a) the accuracy of 208 CO2 single-location sensors located in 34 commercial buildings, b) the accuracy of four multi-location CO2 measurement systems that utilize tubing, valves, and pumps to measure at multiple locations with single CO2 sensors, and c) the spatial variability of CO2 concentrations within meeting rooms.”

    A quick scan showed a lot of tests using various calibrated concentrations of CO2 and the resulting errors or biases from the sensors.  Initially, seeing that most were within 10s of PPM I thought that was pretty good (from my experience with chemical measurements).  

    The conclusion however was different:  “The accuracy of single-location CO2 sensors, as they are applied and maintained for demand controlled ventilation in commercial buildings, is frequently less than specified in the Title 24 standard and frequently less than needed to meet the design goals of saving energy while assuring that ventilation rates meet code requirements.”

    So, thanks for the post; I've learned at least a couple things: 1)Measuring CO2 for HVAC control is a reality, and 2) there are needs for better sensors.

    As I've noted, all these sensors are inherently analog, so the future of analog looks pretty good.  I also think more analog front ends (AFEs) and more integrated sensors + conditioning + power + communications are likely directions.  TI has been aggressive in AFEs and most of the other areas, good for them!

  4. Sachin
    March 31, 2014

    @DaeJ, I believe the point that you are trying to put across is the presence of too many sensors in a single room could prove to be counterproductive in the sense that each of these sensors also consumes energy and when they are very many then they might just end up consuming more energy than they are helping you save. This problem is addressed by only using ultra-low-power sensors inside the room.

  5. Sachin
    March 31, 2014

    If these systems are to work effectively and efficiently (not to say that they cannot work at all) a lot of thought should also be given to the response time; the difference from the time the sensors detect the presence of individuals in the room, however they do that, and the time the necessary measures such as letting in more air are implemented.

  6. SunitaT
    March 31, 2014

    Its a great idea to automate our homes, unless we also think about its cons as well. We must also agree upon  “sensor pollution”, besides having too many wireless sensor connectivity. One should also keep in mind to deal with these in future.



  7. yalanand
    April 30, 2014

    With everything being digitized, home automation has become a subject of great debate; I am yet to be convinced on effectiveness of sensors because I believe that just like other electronic devices they can fail. The question then will be how does one know that all the sensors are working? It good to automate but we should have a clear understanding of both the cons and pros, it is great though to learn that, there is another way to reduce energy consumption through use of ultra low power sensors.

  8. yalanand
    April 30, 2014

    The response time of these systems can help to a great extent in the reduction of the cons of the systems. The difference between the time that the sensors detect the presence of an individual in the room and the time of the required action by the sensors should be reasonably small to enhance efficiency. The sensors will therefore work at specific times and reduced amount of time thereby reducing sensor pollution and saving on the amount of energy used.

  9. yalanand
    April 30, 2014

    @Netcrawl, that is very true, the future of home automation is very promising given the intensification of researches by many scientists currently on the topic of “Artificial intelligence”. I also see a time when the sensors in your house will even be able to set to motion following a unique command from your preset biometrics code. However, these sensors prove to be a draw back if they are too much concentrated to a single room. The main purpose of the sensors is to help save on energy, but if they are too many, this will also mean that they will consume a lot of power, rather than save on energy. 

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