PNNL NILM User Group

The Pacific Northwest National Laboratory (PNNL) has set up on online NILM user group via the Conduit platform. The user group consists of a monthly call, followed by an online summary and discussion. The group aims include:

• vetting NILM metrics and test protocols
• exploring utility use cases –mapping NILM characteristics and performance levels to each use case
• better understanding non-US products and use cases;
• maintaining a list of NILM products, including overviews on new products
• sharing field test results
• informing future NILM projects, including surveys to provide feedback on projects

The first call was on 6th November 2015, and gave an overview of PNNL's recent analysis of the performance of a number of NILM vendors in the Northwest Energy Efficiency Alliance's NILM field study. Challenges with evaluating the performance were also highlighted along with planned next steps to overcome these challenges and potentially accelerate the development of NILM technologies. EPRI also gave an overview of the NILM segment of their EE Symposium. The full webinar is available to watch on demand.

The user group welcomes any researchers who wish to join and contribute to the discussion. See you on the next call!

EPRI's 2015 NILM workshop

The Electric Power Research Institute (EPRI) has been a long term research player in the field of NILM since beginning development of NIALM systems in the 1980s. In conjunction with its efforts of laboratory and field trials, EPRI has been attempting to facilitate an industry effort to develop “consensus based” performance metrics, create protocols to test metric impacts and demonstrate the need for product labels. To this end, EPRI hosted a NILM workshop on 13 November 2015 in Orlando, FL, to follow on from the previous 2013 EPRI NILM workshop in Palo Alto, CA. The event was attended by disaggregation vendors, utilities, universities, a U.S. Department of Energy National Lab and research organisations and covered topics such as current EPRI research, use cases, utility and consultant experiences with NILM and product labelling (see full slide deck). One of the key outcomes of workshop was the recognition of gaps related to NILM metrics and how to address them as an industry through collaborative efforts. Specifically the need to define an analytical framework to understand metric characterisation, their impact on the representation of NILM device performance and ways to assess these impacts.

The meeting was conducted for the following two-fold objectives:

• Facilitate a collaborative dialogue between product manufacturers, utilities and other stakeholders such as national labs and researchers for identifying gaps and new opportunities that enable adoption of NILM technologies.
• Propose a set of “straw man” metrics to stimulate discussion and focus efforts to create working groups and follow-on activities to address identified gaps.

The discussions covered four key areas:

• Value of end use load data to utilities and new use cases
• Current research
• Practitioner experiences
• Quest for metrics and product labels

The collaborative industry group arrived at the following conclusions and expressed interest in the following activities for the future:

• Non-intrusiveness is a significant attribute of the technology that makes it appealing for both utilities and customers.
• Customer interfaces such as mobile apps and web dashboards play a decisive role in persuading customers to use the technology and benefit from the information reported
• Metrics and product labels can improve the credibility, visibility and confidence for use of these products both in utility and customer applications.
• Automatic load labelling is a must for high-value utility applications, and this characteristic may well be the “deal breaker” for some utilities.
• Metrics need to be simple and articulate so that utility customers can derive tangible benefit. EPRI’s set of metrics is a good start and lays the ground work for future work to assess metric characteristics and impacts on performance representation
• Other industry stakeholders such as PNNL’s NILM user group effort should coordinate their efforts to represent industry interest and requirements. (more on this soon!)

The following next steps are proposed:

• Identify use cases that can lend themselves well to the use of AMI data and demonstrate customer integration case studies.
• Start engaging with NILM vendors and interested utilities for pilots targeting the commercial sector by building type.
• AMI meter manufacturers are interested to develop embedded NILM solutions which can be included as part of the meter hardware and software. Partner with AMI meter manufacturers to define requirements for such apps for various use cases.
• Continue to track the NILM market space and understand product performance and features.
• Engage utilities and vendors through laboratory trials and field assessments as newer technologies become available 
• Continue to assess NILM metrics and test protocols. By virtue of the metrics proposed at the meeting, EPRI should work to create analytical frameworks to assess impact of metrics on performance representation.
• Exploring utility use cases, map NILM characteristics and performance levels to each use case
• Informing of future utility and research projects and release the data to vendors for algorithm development and refinement.

Many thanks to Chris Holmes and Krish Gomatom for contributing most of the material for this post!

REFIT analysis using NILMTK converter

I recently wrote a NILMTK converter for the REFIT data set, which allowed me to do a quick piece of analysis over the data set which I wanted to share. See my post on the release of the data set for further details about REFIT.

Below is a plot showing the duration of data recorded from each of the 20 houses. We can see that the installations took place between September 2013 and March 2014, and data continued to be collected until July 2015. The data set is pretty complete, apart from a gap of one or two months during early 2014, and a few small gaps mid 2015.



Below is a bar graph showing the number of instances of each appliance category across the data set. It can be seen that the television is monitored in all 20 houses (while the washing machine is monitored once in 18 houses, and twice in one house), while other common kitchen appliances, such as the microwave, dish washer and fridge freezer, were monitored in most houses. However, no lighting or oven/hobs were monitored in the data set, since only plug monitors were used.



Below is a histogram showing the proportion of the total electricity that was also sub-metered by the plug-level monitors. It can be seen that only 30-50% of the electricity was sub-metered in 16 out of the 20 houses, while no houses managed to sub-meter greater than 65% of the electricity consumption. This is likely due to a range of appliances which hardwired into the ring main consuming a large amount of energy, which could not be measured using plug-level monitors.



Below is a scatter plot showing the average daily energy consumption of each appliance instance in the data set. It can be seen that white goods often consume the most energy, with the dish washer, fridge freezer, tumble dryer and washing machine all consuming large amounts of energy. However, it should be noted that I've limited the y-axis to 2.5 kWh/day, despite one fridge freezer consuming nearly 6 kWh/day and one dishwasher consuming more than 3 kWh/day.

From Southampton to London

This week I finally said goodbye to Southampton as I started my new full-time role as a Data Scientist at British Gas Connected Homes. I'm definitely a little sad to be leaving my academic life behind me, but I'm also excited about the new challenges that lie ahead. The Connected Homes team are a fantastic group of people, and are the ones responsible for products such as the Hive thermostat and the My Energy dashboard. I'm still hoping to continue writing this blog and to stay in contact with the NILM community, though I doubt I'll be writing as many papers. Fingers crossed I'll still make it to Vancouver though for NILM 2016!

Below is a photo I shared this time last year of the Connected Homes' London office, which is probably not what you might expect from the UK's largest gas and electricity supplier!

3rd Int’l Workshop on NILM — SAVE THE DATE!

The 3rd International Workshop on Non-Intrusive Load Monitoring (NILM) will be held in Vancouver, Canada from May 14 to 15, 2016. The venue for the workshop is still under consideration. Last workshop was held June/2014 at the University of Texas, Austin, in Austin, TX.

The agenda for the NILM2016 is still being defined, but the current proposal is to have two full-days of activities. There will be working groups, paper presentations and a poster session. We have two confirmed invited speakers George W. Hart and Robert Sonderegger (Itron). Website will go live first week of January 2016 (http://nilmworkshop.org/2016/).

WORKSHOP MISSION AND OBJECTIVES

The mission of this workshop is to create a forum that can unite all the researchers, practitioners, and students that are working on the topic of energy disaggregation. The main objective of this event is to review the main types of approaches that have been explored to date to solve the problem of electricity disaggregation, and to then discuss possible paths forward knowing what has been tried and what has yet to be experimented. We also intend to have a group discussion about possible solutions to the growing need for standardized datasets and performance metrics that can allow the field to move forward, as well as possible areas of collaboration among different research groups.

PAPER SUBMISSION AND AUTHOR INFORMATION

We invite all researchers working on NILM-related topics to submit 4-page papers to the conference for oral presentation or presentation during a poster session. All submissions must use IEEE style files for LaTeX or Word. We encourage authors to submit papers on research that is ongoing or contains recent results: as the workshop will only include online proceedings, submission to the workshop will not prevent any material from being submitted later to a journal or conference.

IMPORTANT DATES

Paper Submission Deadline: March 15
Notification of Acceptance: April 10
Final Paper Submission Due: April 24
Registration Deadline: April 24

Registration Fee: FREE

Keynote Speaker: George W. Hart
Invited Speaker: Robert Sonderegger, Itron

We are looking forward to welcoming you to NILM 2016 in Vancouver!

Stephen Makonin
Workshop General Chair
3rd International Workshop on Non-Intrusive Load Monitoring (NILM)

Update 04.01.2016: deadlines have been pushed back.
Update 18.02.2016: updated CFP available on conference website

REFIT Electrical Load Measurements dataset released

The REFIT Electrical Load Measurements dataset is an output of the REFIT: Personalised Retrofit Decision Support Tools for UK Homes using Smart Home Technology project, which is a consortium of three universities - Loughborough, Strathclyde and East Anglia. The whole team contributed to the data acquisition and dataset design. The data set contains active power measurements of the aggregate and 9 individual appliances from 20 homes in the Loughborough area of the UK, at a resolution of 1 sample every 8 seconds. This makes the REFIT the largest UK data set (in number of houses) which contains appliance level data at a sample rate great than once per minute. In addition, aggregate gas consumption data was also recorded at 30 minute intervals, although no sub-metered data was also collected. It should be noted that the data has been compressed by removing samples for which the power demand had not changed since the last reading. Further details can be found in a presentation from the EEDAL 2015 conference, a detailed technical report, and the dataset readme file.

I've updated my list of Public Data Sets to include the REFIT data set, and I'm also hoping that a NILMTK converter will follow shortly!

Edit 04.01.2016: The REFIT is not the only UK dataset to contain appliance level data at a sample rate greater than 1 minute as initially claimed! The UK-DALE data set also meets that criteria.

Kien Trung's PhD defence

Last week I had the pleasure of being an examiner for Nguyen Kien Trung's PhD thesis at the Université Nice Sophia Antipolis. Kien's thesis focused on a an efficient electricity disaggregation algorithm which he deployed using a low-cost system-on-chip. Kien successfully defended his thesis against the panel's questions, which sometimes came in a mixture of English and French, which I found particularly very impressive!

I also managed a brief visit to Qualisteo's office, who demonstrated some the disaggregation algorithms they're applying across a range of built environments, including the Eiffel Tower, a motorway tunnel and a sports stadium. I had a great time, but hopefully my next trip to Nice will last a little longer than 24 hours!