Correlation Filters for Load Classification @ IEEE SmartGridComm

We are happy to announce that our paper "On the Applicability of Correlation Filters for Appliance Detection in Smart Meter Readings" was accepted and presented at this year's SmartGridComm conference in Dresden.

With our load classification approach based on correlation filters, we aim to provide a low-cost non-Intrusive Load Monitoring (NILM) method for measurement equipment with limited computational capabilities such as networked sensors or smart plugs. One of these small devices to run such an algorithm on would be our YoMo metering board.

Abstract:

"Communication systems utilise correlation filters to detect waveforms. In a broader sense, these filters examine the amount of resemblance between a template pattern and the input pattern. In the domain of smart grids, many applications require the detection of active electrical appliances, their condition as well as their current state of operation. Furthermore, the identification of power eaters, the recognition of ageing effects, and the forecast of required maintenance represent important challenges in (home) energy management systems.

In this paper, we examine the applicability of correlation filters as a possible solution to meet such challenges. First, we introduce the concept of predictability to power consumption patterns of electrical appliances. Second, we present our concept and the implementation of correlation filters for this kind of application. The correlation filters utilise a particular consumption pattern of an electrical appliance to detect the respective appliance in energy readings from smart meters and smart plugs.

Lastly, we assess the performance of the correlation filters on the real-world energy consumption dataset GREEND, which provides readings from smart meter data as well as appliance-level measurement equipment. As the results approve, the correlation filters show a good performance for appliances with predictable consumption patterns such as refrigerators, dishwashers, or washing machines. Thus, we propose that future work should evaluate the applicability of correlation filters in appliance diagnosis systems."

Christoph Klemenjak presenting at the load classification session

C. Klemenjak and W. Elmenreich. On the Applicability of Correlation Filters for Appliance Detection in Smart Meter Readings. In Proceedings of the 2017 IEEE International Conference on Smart Grid Communications (SmartGridComm), Dresden, Germany, October 2017.


The Correlation Filters were evaluated on real-world energy consumption data provided by the GREEND dataset, which is available at Sourceforge:

A. Monacchi, D. Egarter, W. Elmenreich, S. D'Alessandro, and A. M. Tonello. GREEND: An energy consumption dataset of households in italy and austria. In Proc. IEEE International Conference on Smart Grid Communications (SmartGridComm'14), Venice, Italy, 2014.

Should I drive with my car to turn off forgotten lights?

I forgot to turn off the lights in my office today. True story. And it's Friday, so unless the cleaning personel turns them off, the lights there will burn unnecessarily for 60 hours until Monday morning. This is a bit embarassing when you are doing research[1] and teaching[2] in sustainability and energy management.
So the question is, should I go there immediately and turn them off? Normally I would use my bike, but it's dark and cold outside so I consider using the car.

Let's crunch the numbers first. My car consumes about 5,5l Diesel per 100 km, so using it for a single person trip is far from contributing to a sustainable future. But the trip will save the energy that would be consumed by the office lights. The trip there and back is 11km, so this would use 0.6 l of Diesel. 1 liter of diesel contains chemical energy worth 9.85 kWh, weighs 835 g, and contains 86% carbon. This 720 g carbon would be mostly burned to CO₂, resulting in 2640 g of CO₂ [3].

Burning 0,6 l Diesel would thus generate about 1,5 kg of CO₂ and waste 5,9 kWh of energy.

What if I let the lights burn? Unfortunately the office lights are not LED-based, but they are fluorescent tubes. I would guess all together the lighting has a power consumption of 100 W. Letting them burn for 60 h would thus waste 6 kWh, basically the same value that we calculated for the used fuel.

About 3/4 of Austria's "Strom-Mix" come from hydropower, wind, waste and solar sources, the remaining part from fossil fuels like gas, oil and coal. I'm lucky that Austria has no nuclear power, first because it is a dangerous technology and second because the effective CO₂ emissions of nuclear power are hard to estimate :-).

Coal is the worst source, it comes with 882 g CO₂ per kWh[4]. All together Austria's electric energy comes with emissions of 181 g/kWh[5]. So the 6 kWh of electrical energy from the "let's the lights burn" scenario are a bit more than 1kg - less than the scenario where I drive with the car to turn the lights off.

So I should feel bad about the environment, but at least I have my lazyness supported. I might go there by bike tomorrow :-)

How do you use your electrictiy?

MONERGY

The MONERGY project aims to develop innovations that contribute to a more efficient energy consumption in households. We look specifically at the situation in the regions of Carinthia and Friuli-Venezia Giulia.

To guide our research efforts, we need your help in the form of a short survey (approximately 10 minutes) on the use of electrical appliances at home:

• Survey: Energieverbrauch (in German language)
• Survey: Consumo di energia (in Italian language)

Since we especially aim at the situation in Carinthia and Friuli-Venezia Giulia, the survey is only available in Italian and German. If you don't live in that region, your contribution is still helpful and appreciated, but there is no English version, sorry.

The results and conclusions will be published later on via the MONERGY website (in German/Italian) and in this blog (in English language).

Looking forward to your participation in the survey!

Evolving Non-Intrusive Load Monitoring

Our paper Evolving Non-Intrusive Load Monitoring by Dominik Egarter, Anita Sobe and Wilfried Elmenreich has been accepted for the conference track EvoEnergy (Evolutionary Algorithms in Energy Applications) of the EvoApplication (16th European Conference on the Applications of Evolutionary Computation) 2013, taking place in Vienna form 3rd to 5th of April.

Basic principle of the ON/OFF time genome appliance
detection. Given is the total power consumption over
time. The goal is to deduce the on/off times of devices
(colored blocks) that add up to the measured power profile.

Non-intrusive load monitoring (NILM) identifies used appliances in a total power load according to their individual load characteristics. In this paper we propose an evolutionary optimization algorithm to identify appliances, which are modeled as on/off appliances. We evaluate our proposed evolutionary optimization by simulation with Matlab, where we use a random total load and randomly generated power profiles to make a statement of the applicability of the evolutionary algorithm as optimization technique for NILM. Our results shows that the evolutionary approach is feasible to be used in NILM systems and can reach satisfying detection probabilities.



Dominik Egarter, Anita Sobe, Wilfried Elmenreich,   Evolving Non-Intrusive Load Monitoring,   EvoApplication 2013,   16th European Conference on the Applications of Evolutionary Computation, April, 2013

Workshop on Modeling and Simulation of Cyber-Physical Energy Systems 2013

Workshop on Modeling and Simulation of Cyber-Physical Energy Systems 2013

May 20 2013, Berkeley CA

http://www.palensky.org/mscpes/

Modern energy systems combine information technology, electrical and thermal infrastructure, autonomous roles and interact with other systems like markets and regulations. Existing modeling and simulation tools are not capable to cover such systems in all of their aspects, new languages, methods and tools are necessary. A combination of universal modeling languages like Modelica and established, specialized tools like grid simulators and telecommunication simulators is necessary. This leads to modeling and co-simulating hybrid systems where for instance a multi-agent framework and an electric grid simulator are combined to investigate smart electric vehicle charging algorithms. It is especially the potential size of such systems that constitute a challenge for modeling and simulation. Implementing these future CPS are another substantial challenge. The designed algorithms need to be compact, computationally inexpensive, potentially self-organizing and intrinsically stable if applied to real energy systems. New methods and alternative ways are necessary to overcome these challenges.

This workshop is a platform for researchers and developers to exchange ideas to the following (not exhaustive) list of topics:

-    Hybrid modeling and simulation

-    Co-Simulation

-    High-performance computing

-    Analytics of system data

-    Ontologies for energy systems

-    Applications of cyber-physical energy systems

-    Distributed algorithms and control

-    Standards in interfacing components

-    Numerics for hybrid and co-simulation

-    Formal languages for energy systems

-    Smart Grid modeling

-    Demand response and power quality

-    Information and communication technology for intelligent energy systems

Submitted papers are peer-reviewed by at least 3 reviewers. Workshop language is English. Proceedings will be published by Springer.

Full paper submission: January 31, 2013

Notification of acceptance: February 20, 2013

Your workshop chairs,

Peter Palensky (Austrian Institute of Technology)

Edward A.Lee (University of California Berkeley)

National Energy Production in Comparison

Guest Post by Lizzie Dawes

Of the individual countries looked at (Austria, UK, Germany, USA), Austria produces the most renewable energy, in terms of proportion. Unsurprisingly, given its area, the USA produces the most renewable energy. The USA was second only to China in its investment in renewables, spending $51 billion (around 41 billion Euros) in 2011. 

  

As can be seen from the graphs, Austria produces more hydroelectric power than any other type of power – including conventional thermal power. Why is this? Is it because Austria has ample opportunity for hydroelectric power stations? Is it because Austria’s waterways are not vital for commerce, with Austria being landlocked? Is it because Austrians are more receptive to the idea of renewable energy and are prepared for hydroelectric power stations to be built? 

Perhaps the answer lies in Austria’s geography – Austria is mountainous, to a degree that Britain and Germany are not – 68% of Austria’s land is above 500m. The majority of its hydroelectric power stations are in mountainous regions. Similarly, most of Britain’s hydroelectric power plants lie in mountainous regions – in Scotland and Wales, largely.

It is not as if other countries lack opportunity for hydroelectric power –Britain has mooted the idea of a barrage on the River Severn for decades, for example. Recently, there have been plans for more plants along the Mississippi River (USA), some of which have been abandoned as the price of natural gas has fallen.

Is hydroelectric the answer, though? Germany has invested heavily in renewable energy – 200 billion Euros have been pledged to build offshore wind farms. Indeed, Germany’s investments appear to have been successful – it now produces nigh on four times the energy from renewable sources as the UK and well over twice as much as Austria. 

It should also be noted that even Austria has not run away with itself building hydroelectric power plants – a protest at the Hainburger Au in 1984 stopped the construction of a hydroelectricity power station there, due to the impact the power station would have had on the environment. 

Austria, as can be seen from the graphs, has never produced any nuclear power, after a referendum in 1978, deciding that the Zwentendorf Nuclear Power Plant was never to be used and since then, Austria has never operated a nuclear power plant. An interesting twist in Zwentendorf’s tale is that it has become, at least for the present, Austria’s largest solar power station.

Another factor to take into consideration is that most renewables (wind, solar, hydroelectric, for example) cannot be used constantly - they depend on the time of day, weather, etc. 

It is obvious that there are still issues to be solved, with regard to providing energy, even through renewable sources – careful consideration will still be needed on how to provide power when renewable sources currently cannot – either new ways of generating energy need to be found, or further investment is needed in geothermal, biomass, or nuclear energy.

All graphs based on data from US Energy Information Administration. 

Should we convert our electrical energy to methane?

At night between 11 PM and 4 AM there is an overcapacity of electrical energy. With the installation of wind energy, this overcapacity will even increase, since the is no merit in not using the wind to produce energy. In a smart grid, we will have time-of-use pricing for electrical energy and smart appliances being able to pick an economically good time to use energy. However, most appliances will still need to run during daytime or evening. Since electrical energy cannot be easily stored, we are in need for profound ideas to solve this issue.

Synthetic methane production

One possibilty could be the use of electrical energy to create methane, which can then be stored and used later for heating, cooking, or driving. In this process, first an electrolysis is performed to split water (HO2) into its components hydrogen(H) and oxygene(O). The hydrogen is then used to create methane or other gaseous fuels. Therefore, CO2 is added to produce methane (CH4). The produced methane is greenhouse-neutral since the amount of CO2 creation when being burned is exactly balanced by the amount of CO2 used in the production.
The biggest disadvantage of the approach is the limited efficiency of the method (about 50% of the energy is lost in the creation process, in total the efficiency is around 20-30%) and the comparably low price of natural methane sources. However, as soon as Russia is going to rise the gas prices, I'm gonna start my electrolyzer.

Home appliance energy usage

The Smart Grid will help to balance energy production and consumption.
While we are waiting for the Smart Grid to come, there is something we can do meanwhile - optimizing the energy usage of our local network of electrical appliances. Because one thing is for sure: energy does not come for free now and won't come for free in the future either.
When doing optimization, the important thing is to identify the parts of a system, where an optimization significantly affects the overall outcome. In the blog of the General Electric Company, you can find a nice interactive visualization of the power consumption for a selectable set of typical appliances.

A zero-Watt cloth dryer
(source:Wikimedia commons)

The website application tries to guess power consumption and cost of your set of appliances. While the values are just rough estimates, the numbers still give you a feeling for appliances which are expensive in terms of energy consuming and appliances which are more frugal.

I personally was quite surprised by the high power consumption of an electrical cloth dryer. Luckily, I have the zero-Watt edition at home :-)

e-Energy 2012: where energy, computing and communication meet

Call for Papers

Third International Conference on Future Energy Systems

May 9-11, 2012 -- Madrid, Spain

http://e-energy2012.networks.imdea.org/

e-Energy is the conference on future energy systems, where energy, computing and communication meet. The first e-Energy conference was held in April 2010, in Passau (Germany), and the second took place in May/June 2011 at Columbia University, in New York City (USA).

e-Energy 2012 invites submission of two categories of paper: full papers and discussion papers. Full papers should be no longer than 10 pages and discussion papers should be no longer than 4 pages. All papers must present original theoretical and/or experimental research that has not been previously published, accepted for publication, or is not currently under review by another conference or journal. Submissions must be in PDF-format using the double-column ACM format given at http://www.acm.org/sigs/publications/proceedings-templates Further submission information can be accessed via http://events.networks.imdea.org/content/e-energy-2012/paper-submission Proceedings will be published by ACM and appear in the ACM library and IEEE Xplore (subject to agreement by ACM and the IEEE).

Full papers should include a detailed description of research either in progress or completed. A discussion paper describes innovative and novel ideas that have not yet been fully explored, but have the potential to influence the research community. A discussion paper could, for example, expose a new problem, advocate a new approach, re-frame or debunk existing work, report unexpected results from a deployment, or propose new evaluation methodologies. We especially encourage submissions of early-stage work and enticing but unproven ideas.

Papers are to be submitted via EDAS: http://edas.info/N11357

Topics of interest include, but are not limited to:

Energy-efficient networking and protocols:
------------------------------------------
-energy-efficient network architectures
-high-capacity optical transport
-access networks (wired and wireless)
-energy-efficient network components (switches, routers, transceivers, amplifiers, etc.)
-peer-to-peer networking and overlays
-energy, performance, quality of experience trade offs
-sensing techniques and sensor networks for energy efficiency
-energy-efficient data transmission
-security challenges in energy-efficient networking
-instrumentation and measurement of energy-efficient networking

Energy-efficient computing:
---------------------------
-cloud computing and virtualization
-energy-efficient data centers
-energy-efficient application design
-energy-efficient terminal design
-security challenges in energy-efficient computing
-energy and performance trade offs
-design methodologies and tools for energy-efficient services
-instrumentation and measurement of energy-efficient computing

ICT for energy efficiency:
--------------------------
-energy-demand reduction techniques
-demand management in industrial applications
-demand management in domestic applications
-energy monitoring and management
-smart metering and dynamic pricing
-energy-efficient transport and logistics
-energy-efficient buildings

Smart Grids:
------------
-network architecture for future power networks
-networking and computing issues in smart grids
-reliability and power management
-service design and management
-electric vehicles and smart grids
-virtual power plants, distributed generation, microgrids, renewables and storage
-field trials

Important Dates
---------------
Full paper due: January 10, 2012
Notification of acceptance: March 25, 2012
Final version due: April 13, 2012

The smart grid challenge

The transformation of our energy system from fossil fuel resources to sustainable resources is one of the great challenges of our time, but opens also a great chance for establishing a more efficient and robust distribution of energy to the benefit of all its users. A way to do this is the intelligent integration of the behavior of all users (generators and consumers) of an electricity grid to optimize the operation of the system, e.g., by balancing energy consumption based on availability and demand.

In order to achieve this goal, we need to define innovative products and services together with intelligent monitoring, control, communication, and self-healing technologies: Electrical devices, generators, and energy storages will be integrated with local intelligence and a network interface. These smart meters will form a network that dynamically adapts pricing and distribution based on demand, supply, and network load. The emerging network will be a self-organizing smart grid which efficiently maintains existing services, allows for prediction of future energy and network requirements.

However, the challenge is not a mere technical one. A main characteristic of the smart grid is that it will allow consumers and suppliers to play an active role in optimizing the system. While this is a very positive aspect, it leads to new challenges such as social aspects like fairness and acceptance, economic aspects such as market stability and resilience against speculation attacks, and legal issues such as warranty, data security and privacy. Last but not least, the smart grid forms a complex system of interacting agents, which will require new models similar to those from physics, biology or economics.

The goals of the smart grid are ambitious. But considering the importance of energy to our society, there is no other chance than to work on it in a global cooperative effort. There is no time to wait.