Download - ICT and Power (Electricity) Prof. Rahul Tongia School of Computer Science CMU 17-899 Fall 2003
ICT and Power (Electricity)
Prof. Rahul TongiaSchool of Computer Science
CMU17-899 Fall 2003
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Topics for Discussion Electricity and Development Power for ICT ICT for Power
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Fundamentals Electricity is a form of energy (kWh) Does not exist in usable forms
Conversion usually requires prime movers (steam turbines, water turbines, etc.)
Access to fuels (primary energy) is a key issue for developing countries
Electricity is only about 125 years old Widespread use is much more recent
US required special programs Rural Electrification Administration (REA) [now Rural Utilities
Service] TVA
Electricity from the grid can not be easily stored (AC) Most electronics use DC
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What’s Special about LDCs?
Very low levels of Electrification 2 billion+ lack electricity Bad quality, intermittent, and often expensive power if
available Lower Level of Economic Development
Large rural agricultural sector Large quantities of crop residues: primary energy source Special needs for agricultural services (e.g., pumping water ~
1/3 of India’s electricity) Heavily subsidized in many countries
Industrial-Political Organization State-centered economies
State-owned enterprises (SOEs) handle not just power but much of the economy
Weak formal institutions E.g., regulatory institutions, courts, corporate governance
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Energy-Economy Correlation
1
10
100
1000
10000
1 10 100 1000 10000 100000Primary Energy (Trillion BTU)
GD
P (
Bil
lio
n $
)
North America
Developing
W. Europe
FSU/E. Europe
OECD Asia/Pacific
China
USJapan
Turkmenistan
Russia
India
Brazil
Germany
New Zealand
Mexico
South Korea
Australia
Bangladesh
Pakistan
1996
Calculated from EIA Data
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0
100
200
300
400
500
600
700
800
900
1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030
Peo
ple
wit
ho
ut
Ele
ctri
city
Acc
ess
(mill
ion
s)
(Lack of) Access to Electricity
East Asia (China)
Sub-Saharan Africa
South Asia (India)
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Investments in LDC Power Sector
Source: World Bank (2003)
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Where Does Electricity Go? US
~ 1/3 residential, 1/3 industrial, 1/3 commercial Developing Countries
Varies significantly by country Typically higher shares for non-residential (function of large,
centralized design) Grid penetration to rural areas is very low
Kenya used to have more homes served by Decentralized Generation (DG) than the grid (mainly solar)
In reality, a fair amount is lost along the way, or stolen!
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Electricity in LDCs
Source: World Bank (2003)
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How Much Electricity Does ICT Use? Numbers as high as 13% of US
electricity were claimed End users, servers, networking, etc. Later debunked
ICT – Energy (Power) linkages Greater Service Economy, even in
developing countries But, increased globalization
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What Consumes Power (ICT Applications)? Components of an ICT solution
Computing Display
CRT 80 W normal 10 W suspend LCD 15-25 W normal 5-10 W suspend
Storage variable Uplinking 12 W Wifi 40 W VSAT
Role of advanced technologies Chips (processor is largest component)
Pentium 4 uses 50+ watts! LCD screens, OLEDs, etc. Wireless
Cognitive Radios – reduce power to lowest required level But, emitted power is << power drawn from supply
100 mW is legal limit for WiFi Laptops – much less power but less robust (?)
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Details of Desktop Power AGP video card - 20-30W PCI video card - 20W AMD Athlon 900MHz-1.1GHz - 50W AMD Athlon 1.2MHz-1.4GHz - 55-65W Intel Pentium III 800MHz-1.26GHz - 30W Intel Pentium 4 1.4GHz-1.7GHz - 65W Intel Pentium 4 1.8GHz-2.0GHz - 75W Intel Celeron 700MHz-900MHz - 25W Intel Celeron 1.0GHz-1.1GHz - 35W ATX Motherboard - 30W-40W 128MB RAM - 10W 256MB RAM - 20W 12X or higher IDE CD-RW Drive - 25W 32X or higher IDE CD-ROM Drive - 20W 10x or higher IDE DVD-ROM Drive - 20W
SCSI CD-RW Drive - 17W SCSI CD-ROM Drive - 12W 5400RPM IDE Hard Drive - 10W 7200RPM IDE Hard Drive - 13W 7200RPM SCSI Hard Drive - 24W 10000RPM SCSI Hard Drive - 30W Floppy Drive - 5W Network Card - 4W Modem - 5W Sound Card - 5W SCSI Controller Card - 20W Firewire/USB Controller Card - 10W Case Fan - 3W CPU Fan - 3W
Source: FLECOM
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Standalone (DG) Power What are the options if If AC power is unavailable?
Backup or primary supply? Non-Conventional Sources of Power
Issues of Scale For ICT or more (single point or village level)?
Local availability Solar
Only 3-5 hours equivalent per day (1 kW INPUT/m2 of panel; ~10% efficiency) Wind
Windspeeds vary by location; highest efficiency for megawatt class turbines Biomass
Conversion options limited, typically require tens of kW size Microhydel
Location sensitive, and typically 10s of kW Diesel
Expensive to run, typically AC output
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Designing a DG system Battery Life examples
Alkaline (from Duracell)NOMINAL VOLTAGE (volts) RATED CAPACITY (ampere-
hours)D 1.5 15C 1.5 7.8AA 1.5 2.85AAA 1.5 1.15
Gets very expensive, quickly, even if rechargeable Lead-acid batteries give much more power and are standardized
Limits on dischargeability - ~20 kWh total charge Matching supply to demand
AC grid – “infinitely” flexible Power storage is key
Else peak capacities must be matched Intermittency issues for many DG systems
Theft is a major concern for DG design (!)
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Designing a DG system (cont.) Solar Systems
Components PV modules (in series, in panel form) Power Conditioning Equipment (economies of scale) Housing (with or without directionalizing)/mounting Batteries – most expensive operating costs* Inverter – if AC is required
Costs Capex at small scale is ~5/peak watt Gives an operating cost around 20-30 cents/kWh
* cell phone example – Obsolescence of equipment vs. battery
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Designing a DG system (cont.)
Hours per day operational 12Days back-up required 3 (1 current day plus 2 days of no sun)
Power needs 50 Notebook PC20 Communication15 Lighting15 Other*
100 Watts AVERAGE
3,600 W-hrs required to charge up per day
Equivalent peak sunlight 5 hrs per day
System size calculation 720 peak watts5 $/peak watt
3,600 $ Capex
Sizing - 1 meter panel 1,000 W input (peak)10% efficiency (net)100 W electricity out (peak)
Thus need 7.2 sq. m panel
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ICT for Electricity Systems Two main issues
Supply << Demand Requires investments of billions
Ability to pay is limited Often, power companies are loss-making; some of
that is inefficiency Where can ICT contribute?
Components of power sector vertical Generation Transmission Distribution Consumption
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Conventional Wisdom One can not do real-time power flow
management (transactions and billing) for transmission level flows Today, pools operate based on historical or
aggregated information One can not measure demand (usage) from
all consumers in real-time with high granularity
What has changed to make these outdated – the growth of IT technology
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Focus here on Distribution/Consumption IT is already extensively used in
generation/transmission in developed countries
Other Synergies Stringing Optical Fibers along power lines Smart Cards (pre-payment)
Found extensive use in S. Africa in Black Townships (12 years experience)
Can link to other utilities or consumer services (pre-paid cell-phone cards are very popular)
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Using IT to Enable Sustainability
Sustainability has many components Resource utilization
Efficiency and loss reduction are sine-qui-non Economic viability
Theft reduction Management
IT can improve power sector distribution, consumption (utilization), and quality of service Requires a change in mindset, and the
willingness of utilities to innovate
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Case study on IT for power sector improvement in India India today has the world’s largest number
of persons lacking electricity 400 million (equivalent to Africa’s unserved!)
Reforms began in 1991 Vertically integrated government department
monopolies are being broken Initial focus was on generation New realization that distribution is the key to
India’s power sector viability Newer entities should be run as businesses
Many parallels to other developing countries
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India’s Power Sector Overview
5th largest in the world – 107,000+ MW of capacity But, per capita consumption is very low
350 kWh, vs. world average over 2,000 kWh 40% of households (60% of rural HH) lack electricity
In very dire straits Supply << Demand
Blackouts are common, with shortfall estimated between 10-15% Most utilities are heavily loss-making, with an average rate of
return of negative 30% or worse (on asset base) High levels of losses = 25+%
Technical losses – poor design and operation Commercial losses (aka theft) often over 10%
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Reasons for the problems Agricultural sector
Consumes 1/3 of the power, provides <5% of revenues Pumpsets are overwhelmingly unmetered – just pay flat
rate based on pump size Adds to uncertainty in technical losses vs. commercial losses
and usage Utilities lack load duration curves to optimize
generation and utilize Demand Side Management All generation is assumed to be baseload, and priced
accordingly Leads to poor energy supply portfolio
Doesn’t send correct signals to consumers, either Utilities end up using just average costing numbers, not
recognizing the marginal costs
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Idea – use IT for power sector management Posit – If new meters are to be installed,
why not “smart” digital meters, which are also controllable, and communications-enabled? Incremental costs would be low
Instead of just quantity of power, can also improve quality of power
Analysis presented is based on collaborative work with a major utility in India (name withheld for confidentiality reasons)
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Quality of Power India is focusing on quantity of power only
Current “shortfall” numbers are contrived Based only on loadshedding with minor correction for frequency Do no factor in peak clipping fully Do not account for lack of access (e.g., over 60% of rural homes lack
connections) Quality norms are often missed
Voltage – often deviates by 25+% Frequency – often deviates by 5% (!)
Even farmers pay a lot for their bad quality power (around 1 cent/kWh implicit, even higher in some regions)
Use of voltage stabilizing equipment Additional capital costs (in the multiple percent range) Efficiency losses (2-30% lost!)
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Power Quality: ITI CBEMA Curve
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Why the Focus on Distribution? It’s where the consumer (and hence, revenue) is High losses today
Technical losses, 10+ % in rural areas DSM and efficiency measures possible Use of standards required
Use a combination of technology, industrial partnership, and regulations
Learn from experiences elsewhere Bulk of India's consumption is for just several classes of
devices Pumpsets Refrigerators Synchronous motors Heating (?)
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US Refrigerator Efficiency Standards
Similar standards can be established for “smart appliances”
Source: www.standardsasap.org
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Future of Appliances and Home Energy Automation Networks
Incremental cost of putting networking and processors into appliances approaching a few dollars Could allow time of use and full control (utility
benefit/public good/user convenience) Link to a smart distribution system
Micro-monitor and Micro-manage every kWh over the network E.g., refrigerators – don’t operate or defrost during peaks (5% of
Indian electricity usage) 5% peak load management could lead to a 20% cost reduction
Feasible, as most peak loads are consumer-interfaced Bimodal peaks in India, residential driven
Italy is already implementing such a system (ENEL)
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Objectives and design goals for a new IT-enabled Implement a basic infrastructure to…
Micro-measure every unit of power across the network Allow real-time information and operating control Devise mechanisms to control the misuse and theft of
power through soft control
Which would… Reduce losses Improve power quality Allow load management Allow system-level optimization for reduced costs Increase consumer utility, satisfaction, and willingness to
pay
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Additional Benefits A system which will offer
Outage detection and isolation Remote customer connect & disconnect Theft and tamper detection Real time flows
To allow real time pricing Suitability for prepayment schemes Load profiling and forecasting Possible advanced communications and services
Information and Internet access Appliance monitoring and control
Managing such “extra” power (from theft) is enough to give subsistence connectivity to the poor
Requires ICT to determine and manage the margin effectively Telecom is special – very short-run low marginal cost; in electricity it is
much more difficult
Access(440, 220, or 110 V)
Low Voltage
Smart Meter(Can be off-site outside user
Control; Is partly a modem)
Secondary
Distribution
Voltage
House
House
Users
Distribution(~11 kV)
Medium Voltage
Couple
r
Coupler
Coupler
~ 20 km Last Few Hundred Meters
Substation
Data Center
Distribution Transformer
(pole or ground)
Coupler
Sub-Transmission and Transmission
(> 11 kV)
LV Concentrator
Network Schematic
Uplink
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Components of the solution
One segmentation – locational At consumer
Meter/Gateway Meter could be pole-side if required
In home network Needed connect to enabled devices (appliances) Eventually, homes would also have Decentralized
Generation available (?fuel cells, flywheel storage, etc.)
Access (low voltage distribution) From gateway to a concentrator, on user side of
distribution transformers – Using PowerLine Carrier (PLC)
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Solution Components (Cont.)
Concentrator upwards Concentrator – Each Distribution Transformer (aka
Low Voltage Transformer) feeds on the order of 100-200 homes in India (as in Europe). In contrast, US Distribution Transformers feed 5-10 users.
Communications medium Over Medium Voltage PLC to the Sub-station
or Wireless
Limited Coverage in Developing Countries Substation upwards (uplinking)
Usually based on leased lines or optical fiber
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Technologies for various segments In-Home Network
Appliances Emerging Standards are talked about by appliance
companies (Maytag, Samsung, GE, Ariston etc.) Using Simple Control Protocol (or other appropriate “thin”
protocols) Meters
Solid-State meters exist, but not yet the norm in developing countries
Most have communications capabilities for external ports
Lowest cost solution (if feasible) – PLC – target 5$ incremental cost
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Technologies for various segments (cont.) Access
Low Voltage PLC is available today Being explored for Internet access, in fact
(Megabits per second) MV
Crossing through transformers remains a technical challenge
Going long distances an issue Uplinking
Availability of optical fiber or leased lines can be met through planning
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Technologies vs. Capabilities
Accuracy Theft Detection
Communications Control Capabilities
Electro-mechanical Meter
low (has threshold issues for low usage)
poor expensive add-on nil
Digital (solid state)
high Node only external Limited Historical usage reads
only
Next Gen. Meter (proposed)
Arbitrarily high
High (network
level)
Built-in (on-chip)*
*Can do much more than Automated Meter Reading (AMR)
Full (connect/dis-
connect); Extending
signaling to appliances
Real-Time control; DSM
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Design Model and Business Case Only target specific users
All agricultural (almost one-third of the load) All Industrial and larger commercial users Only the larger-size domestic users
Estimated 2/3 of homes only use <50 kWh per month Include every network node that needs
monitoring and/or control Substations Transformers Capacitor banks Relays
etc.
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Design Model and Business Case (cont.) Investment in long run only a few thousand
rupees per targeted user (Target <75$ capex) When amortized, implies requirement of
improvements in system of only a few percent! Savings will come from
Lower losses/theft Increased sales possible Lower operational costs Load management Better consumer experience (and hence, possibility for
higher tariffs) Future interaction with smart appliance and smart home
networks Possibly new services
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Economics of case system
Estimated System (Rural-centric)
62 Consumers (all classes) per Distr. Transformer
98 Distribution Transformers per Sub-Station
Number of Nodes Equipment cost ($) Cost ($)Domestic (applicable) 200,000 75 15,000,000 Commercial 383,000 75 28,725,000 Agricultural 673,000 75 50,475,000 High-TensionDistribution Transformers 70,306 500 35,153,000 Substations 714 5,000 3,570,000
132,923,000 Other IT and infrastructure (capitalized) 10,000,000
142,923,000 15% <-annualized rate incl. Amortization
Needed Savings 21,438,450$ annually
11,625,000,000 kWh sold annually0.06 Electricity Rate ($/kWh) <- Average only;
697,500,000$ Annual CostsExcludes peak
3.1% <- Need improvements worth savings potential
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Economics (cont.) 6-7 year payback on investment
(conservative) possible with just 3% improvement in system
Savings will come from Theft Reduction Time-of-Day and DSM measures (peak
reduction) System Quality, reliability, and uptime Higher Collection
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Challenges Protocols
Use of thin protocols to reduce capex for embedded systems Security – PLC can be a shared medium
PLC How to couple around transformers or other obstacles How to go long runs with low errors (and high enough bandwidth) –
Shannon’s theorem provides a limit Noisy line conditions in many developing countries
Appliances Need for standards to bring down costs and ensure inter-operability
Design – Should the PLC signals pass through the meter/gateway directly to appliances?
How active or passive should consumer behavior modification be?
Costs (as always)
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Challenges – Implementation and Management Utilities are typically risk-averse They face increased regulatory uncertainty
Without some portions of a market, how do they benefit?
Will they (should they) pass all pricing information on to the consumer?
Developing country management issues Utilities were typically State Owned Enterprises (SOEs) Utilities were run with social engineering goals
Increased automation, control, and sophistication (and theft detection) poses risks to the large cadre of current employees
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A New World for Power Systems Includes “smarts” for significant
improvements in efficiency New services can be enabled once the
appropriate infrastructure is in place Segmentation of development allows
independent, modular innovation, e.g., home automation and appliances
Developing countries (esp. Asia) can lead the way through leap-frogging