smart meters

Energy use recommendations

There are a number of systems and projects out there which aim to provide advice on your energy consumption. I don't personally do research on this stuff but it is quite closely related with my core work of disaggregation. So I wanted to start a list of energy use recommendations projects.

THIS LIST IS BY NO MEANS EXHAUSTIVE YET! Please, if you know of an energy recommendation project not currently on this list then please leave a comment and I'll add it! (Makes me think we need a wiki for this type of stuff...)

Smart Meters Equipment Tech Spec Version 2 (SMETS2)

By 2019 2020, all homes in the UK will have a smart meter installed. DECC is working on the spec for these meters at the moment. In the context of my PhD on smart meter disaggregation, I have several questions I need to answer about these specs:

  • exactly which power metrics will UK smart meters expose to the home area network (HAN)? (just active power? And reactive power? Can we distinguish between leading vs lagging? THD?)
  • report rate? (one measurement every 5 seconds? The 2011 "Functional Requirements Catalogue" said "The smart metering system shall support capture of consumption and demand data at 5 second intervals."
  • and how could a disaggregation system read these data?

The Smart Meters Equipment Tech Spec Version 2 (SMETS2) was released in Jan 2013. Some useful paragraphs for those of us interested in disaggregation:

Intel Atom notes

Current preferred spec

Case & PSU

  • Item: Cypher AK-ITX-04BK Mini-ITX from Akasa with 120W PSU VESA Mountable
  • Manufacturer: Akasa
  • Description: Small computer case
  • Supplier: scan
  • Supplier product code: LN45102
  • Web page: http://www.scan.co.uk/products/akasa-cypher-ultra-compact-mini-itx-case-black-with-120w-psu
  • Number required: one
  • Price (ex VAT): £44.98

This case has a "brick" PSU which should work with the 12V power input on the DN2800MT motherboard. Lovely small case. Has a hole for an RP-SMA connector (antenna). Just about enough space to mount a Nanode SMT inside.

The plug on the PSU which comes with the case is too big to fit the mobo. The mobo needs a "8 - 19 VDC external power supply though the DC jack on the back panel. This connector accepts dualbarrel plugs with an inner diameter (ID) of 2.5 mm and an outer diameter (OD) of 5.5 mm, where the inner contact is +8 (±10%) through +19 (±10%) VDC and the shell is GND. The maximum current rating for this connector is 8 A." (from p58 of the mobo manual.) So it's necessary to chop off the HUGE connector on the PSU (which has an outer diameter of about 7mm and an inner diameter of about 5mm) and replace it with:

  • Item: CONN PWR PLUG DC 2.5X5.5 8A MOD
  • Manufacturer: CUI Inc
  • Description: DC plug with 5.5mm OD, 2.5mm ID, 14mm length (and locking groove? TBC)
  • Supplier: Digi-Key
  • Supplier product code: CP3-002BH-ND
  • Web page: http://www.digikey.co.uk/scripts/DKSearch/dksus.dll?Detail&itemSeq=127910444&uq=634992759972123594
  • Number required: 6
  • Price (ex VAT): 1.30

Motherboard

  • Item: Intel DN2800MT Atom motherboard
  • Manufacturer: Intel
  • Description: mini-ITX motherboard with built-in Atom CPU
  • Supplier: Scan
  • Supplier product code: LN43166
  • Web page: http://www.scan.co.uk/products/intel-boxdn2800mt-mini-itx-intel-atom-n2800-motherboard-ddr3-1066-so-dimm
  • Number required:
  • Price (ex VAT): £66.28

(also available from Micom)

The N2800 Atom has enhanced speed step so should be capable of consuming just a few watts. It uses a PowerVR GPU which has virtually no Linux support. But that's not a problem because it'll be a headless data logger..

WiFi

  • Item: U.FL-RPSMA BULKHEAD MOUNT, 200MM
  • Manufacturer: GIGATRONIX
  • Description: Antenna cable
  • Supplier: Farnell
  • Supplier product code: 1706348
  • Web page: http://uk.farnell.com/gigatronix/u-fl-rpsmabulk-200mm/u-fl-rpsma-bulkhead-mount-200mm/dp/1706348
  • Number required: one
  • Price (ex VAT): £6.42

Cheaper cables are available from Amazon but I need to use a college-approved supplier. Farnell 2143312 would also be a cheaper option (£3.50) but wasn't in stock when I ordered.

  • Item: RN-SMA4-RP - ANTENNA, 2.4GHZ, 4INCH W/ RPSMA
  • Manufacturer: MICROCHIP
  • Description: WiFi antenna
  • Supplier: Farnell
  • Supplier product code: 2143322
  • Web page: http://uk.farnell.com/microchip/rn-sma4-rp/antenna-2-4ghz-4inch-w-rpsma/dp/2143322?Ntt=2143322
  • Number required: one
  • Price (ex VAT): £4.08

  • Item: Centrino Wireless-N 2230

  • Manufacturer: Intel
  • Description: mini PCIe wireless network card
  • Supplier: Micom
  • Supplier product code: 2230BN.HMWWB
  • Web page: http://www.micom.co.uk/intel-centrino-wireless-n-2230
  • Number required: 5
  • Price (ex VAT): £11.65

This plugs into the motherboard. It's designed to use two antennae but it seems to work fine with one antenna on my 802.11g network. There are lots of Intel miniPCIe adapters. Some have draft-N support only. Some have Bluetooth (which I don't need). Cheaper adapters can be found on Google but this 6230 adapter is fairly cheap and comes from an approved supplier; plus Intel WiFi adapters should have good support on Linux. Insight also do the WiFi Link 1000 and Wireless-N 1030 (both for £9.99 ex VAT) but these are "order upon request".

Hard drive

  • Item: Seagate Momentus 320GB 5400.5 2.5" Notebook Hard Drive
  • Manufacturer: Seagate
  • Description: Hard disk drive
  • Supplier: Scan
  • Supplier product code: LN26698
  • Web page: http://www.scan.co.uk/products/320gb-seagate-st9320325as-momentus-54005-25-95-mm-sata-3gb-s-5400rpm-8mb-cache-14ms-ncq
  • Number required: one
  • Price (ex VAT): £28.32

The system draws ~14W while logging (but with a power factor of only about 0.35)

Build order:

  • Take top off case
  • Remove HDD bracket
  • Fit back plate
  • Fit motherboard
  • Fit WiFi aerial cable
  • Fit WiFi mini PCIe card & connect to aerial cable
  • Fit cables from case to motherboard
  • Fit HDD to bracket and install in case and fit cables

Additional notes

Electronics

  • Item: HEADER, RIGHT ANGLE, 6WAY
  • Manufacturer: TE CONNECTIVITY / AMP
  • Description:
  • Supplier: Farnell
  • Supplier product code: 1248172
  • Web page: http://uk.farnell.com/te-connectivity-amp/826947-6/header-right-angle-6way/dp/1248172
  • Number required: six
  • Price (ex VAT): £0.199

The header is required because the header supplied on the NanodeRF SMT isn't right-angled, so the FTDI adapter sits at right angles to the Nanode, and this configuration won't fit in the tiny Atom case. So we need to replace the straight header with a right-angled header.

  • Item:
  • Manufacturer:
  • Description:
  • Supplier:
  • Supplier product code:
  • Web page:
  • Number required:
  • Price (ex VAT):

Motherboards

D945GSE

  • Tech specs PDF
  • Min power draw = 12.28 W
  • Max power draw = 42.01 W
  • Audio is ICH7-M with ALC662 audio codec
  • "Front panel audio header with support for Intel High Def Audio"
  • NO LINE IN (see table 4 on p21 of tech spec PDF)
  • N270 (2.5W TDP)

continued...

Group MSc project on "Visualisation and Analysis of Domestic Electrical Energy Consumption"

I'm hoping to organise a Computer Science MSc group project on "Visualisation and Analysis of Domestic Electrical Energy Consumption". One aim of the project is to produce an open-source app tol help people save energy by producing useful and interesting visualisations (pretty graphs) of their energy usage. The ultimate aim is to produce something a bit like Google Powermeter. But better ;)! The full spec of the group project is available here.

I'd be really eager to hear any comments / suggestions at this (very) early stage to try to make the project both lots of fun for the students and also useful to the community. Some specific questions might be:

  • Do you currently use a tool to visualise your energy use? (Such as Current Cost's website or Cosm or open.sen.se or something similar?)
  • Are there any specific statistics / visualisations that you'd be particularly interested in?
  • Would you be interested in being able to share details of your energy use with select friends to compare progress?

(To give a bit of context: Group projects run for the duration of the spring term (11 weeks starting Jan 2013). I'm a PhD student in the computing department so I'll be supervising the project but the detailed design is up to the MSc students. Groups usually consist of 5-6 MSc students. There are no guarantees that a group will actually want to do the project, of course!)

Buying and installing a smart meter

PM1200

I'd like to install a smart meter so I can collect whole-house readings of real and reactive power and voltage once every five seconds for my PhD work on disaggregation. For several months I've been prodding my utility company to replace my "spinning-disk" meter with a smart meter but this isn't going to happen any time soon, even if I offer to pay for the hardware and installation. The existing spinning-disk meter is owned by the utility company so I can't touch it. So my plan is to hire an electrician to install a smart meter downstream of my spinning-disk meter. This blog post is just my notes about smart meters (which to buy? how to communicate with it? etc.)

Domestic power consumption data on github

I've just put all my existing smart meter data on github.

This dataset isn't especially useful for NILM work yet because I don't have a "ground truth" record of each appliance's state change.  This will change when I install my 24 individual appliance monitors.
 

Smart Meter Disaggregation

This blog entry is part of a series of posts introducing the topic of smart meter disaggregation.  In previous posts we've looked at the wider reasons for wanting to reduce energy consumption and we've taken a brief look at smart meters.  In the following blog post, I want to introduce the concept of smart meter disaggregation, also known as "non-intrusive load monitoring" or NILM for short1.  The main aim of smart meter disaggregation is to infer two things from a smart meter signal: 1) which appliances are active in the signal and 2) how much energy has each device consumed.  This blog post will summarise the arguments for disaggregation and we'll look at some of the main challenges.

Why bother to reduce energy consumption

This blog entry is part of a series of posts introducing the topic of smart meter disaggregation.  This specific post looks at the wider reasons for reducing energy consumption.  In other words, this post explains some of the reasons which keep me up at night when I'm not distracted by work! The reasons for reducing energy consumption typically fall into one of two categories: financial and environmental.  We'll focus mostly on the consumption of electricity but the arguments are mostly applicable to the consumption of all sorts of energy.

Financial reasons

There's been a lot of coverage in the press recently about high energy prices.  In January 2012, for example, the Citizens' Advice Bureau stated that 43% of people are worried that they can't afford their next fuel bill.  The following plot shows average annual domestic electricity prices in the UK from 1994 to 2011 (data from DECC, 2011).

Average annual domestic electricity prices in the UK.Average annual domestic electricity prices in the UK.

Electricity prices have risen from 2004 to today; but, when compared to data from the 1990s, today's prices are not quite as earth-shatteringly high as some news papers would have us believe.

What has caused the 35% price rise (in real terms) from 2003 to 2011?  I'm no expert but let's discuss two datasets which shed some light on what's going on.

What is a smart meter?

This blog entry is part of a series of posts introducing the topic of smart meter disaggregation.

Your existing electricity meter probably looks something like this:

Attribution: Kristoferb at en.wikipedia

(image taken by Kristoferb at en.wikipedia)

By 2019, the UK government have mandated every electricity meter in homes and businesses will be replaced by a "smart meter" (that's a grand total of 53 million meters).  A smart meter is simply a digital meter with some basic communications functions.  It will be paid for and installed by the utility company.  It will talk to the utility company over a GPRS data connection; and it will also be able to talk to the "home area network" to provide data to in-house energy displays.

The draft spec for smart meters in the UK was published by the Smart Metering Design Group in August 2011.  The specification states that the meter must be able to supply meter readings to the home area network at a rate of one reading every five seconds.  The meter will measure voltage, real power and reactive power (in both directions).  Some utility companies have already started to install smart meters; British Gas plan to have 2 million smart meters installed by the end of 2012 (Centrica, 2010). 

If you can't wait for a smart meter to be installed then you could buy and install a "home energy monitor". These are available for around £40; although some utility companies give them away for free.  Home energy monitors are user-installable.  I used a Current Cost home energy monitor for my MSc project on disaggregation.  It recorded a sample of apparent power once every six seconds.

This is a reading produced by my Current Cost home energy monitor:

meterPlotmeterPlot

The value of sample at time t is the sum of the power being consumed by every appliance active at time t​.

My MSc project on disaggregation is on the Imperial website

During the academic year 2010-2011, I did a computer science MSc at Imperial (which I thoroughly enjoyed). During the last 3 months of the course, each student does an "individual project". Mine was on "Disaggregating Smart Meter Readings using Device Signatures" and the PDF is now available on the Imperial website (note that my birth name is "Daniel" although I've had the nickname "Jack" since I was 11!)

This MSc project formed the basis for my PhD (I'm doing my PhD with the same excellent supervisor with whome I did my MSc project). 4 months into my PhD, I now recognise that my MSc project was pretty naive but it was lots of fun!

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