Networked ElectricityPresented By –

Bruce Nordman, ScientistLawrence Berkeley National Laboratorybnordman@lbl.gov – nordman.lbl.gov

1st IEEE Energy Efficiency Tutorial:

Wednesday, September 19, 2018

• Disclaimer• Energy and Communications• Energy and 5G• Power and 5G• Local Power Distribution (LPD)• LPD and 5G

2

OVERVIEW

• Electronic devices (data for 2010)§ Electronics about 14% of buildings electricity* (10% of all)

o Data centers only about 10% of electronics energy

§ Annual U.S. electricity (TWh) – at $0.10/kWh, 1 TWh = $100 million

o All electronics ~400 (all electricity: ~3,600)

o Network equipment ~20 (only switches and routers)

o Set-top boxes ~25

o PCs/monitors ~140

§ Since 2010, data centers ↑, rest ↓ - but generally similar

*includes data center electronics; data centers are technically industrial buildingsSource: M. Malinowski, B. Nordman, K. Kaplan, J. Clinger, R. Unger, Light at the End of the Tunnel for Electronics Energy Use?, ACEEE Summer Study on Energy Efficiency in Buildings, August 2014.

3

Energy and Communications

• Edge vs. Core§ Most E in non-network equipment

• Being networked changes device operation

• Edge network holds greatest opportunities / challenges§ New consumption§ Efficiency gains

• Dimensions§ System architecture / topology§ Efficiency§ Operation

4

Energy and 5G

• Contexts for powering§ Data centers and large base stations

o Easy grid connections; on-site backup§ Smaller sites

o Grid connection may be difficult and/or expensiveo May be on top, on side, or inside of buildingso May be remote from grid connectiono May be new and/or temporaryo May be installed, owned, or operated by others

=> alternative powering may be advantageous

5

Power and 5G

6

LPD - OriginsImage from Eric Brewer talk“Energy in the Developing World”January 14, 2010(LoCal Retreat)

Photo: Matthew Kam, TIERSchool near Lucknow, India

• “Local” – within a building (or campus)§ Internal to single utility grid customer

• “Power Distribution”§ “Technology / infrastructure that moves electrons

from devices and times where they are available to devices and times where they are wanted”

Local Power Distribution is a network model of power

7

“Local Power Distribution”

• Microgrid Capability“… a group of interconnected loads and distributed energy resources …that acts as a single controllable entity with respect to the grid. A microgrid can connect and disconnect from the grid to enable it to operate in both grid-connected or island-mode.” (DOE Microgrid Exchange Group)

Implies must connect to utility grid; CIGRE C6-22 defn. similar

• Nanogrid Simplicity“A single domain of power; single voltage, frequency (if AC), reliability, quality, capacity (power), price, and administration. Storage is internal to a nanogrid.” Generation forms its own nanogrid. (Nordman, 2010)

• Picogrid SingularityAn individual device with its own internal battery for operation when external sources are not available or not preferred, and managed use of the battery. (S. Ghai et al. in e-energy 2013; paraphrased)

8

Grid terminology

9

136 … 87 years later

Generation End use Distribution

“Unitary grid” - single undifferentiated “pool” of power

Traditional power distribution

Buildings and all devices part of the pool

• Phone system and utility grid invented about same time§ Synchronous – highly coupled§ Unitary – to end points – centrally managed§ Organizations conservative - regulated§ Technology advances slowly§ Local variations in technology§ One mode of operation

11

Communications and Power

12

Paradigms

Old phone systemUtility grid19th centuryCentralizedAnalogNo storageTightly coupledEntangled technologyCustom / Expensive …..

InternetNetwork model of power20th/21st centuryDistributedDigitalStorage widespreadLoosely coupledIsolated technologiesCommodity / Cheap…..

Unitary Networked

Need paradigm shift

“Technology / infrastructure that moves data / electrons from devices and times where they are available to

devices and times where they are wanted”

All bits/packets different; all electrons same

Need a fundamental mechanism for a network model• Communications: understand system topology (addressing)

and move data accordingly§ Data routing is how bits know where to go

• Power: balance supply and demand§ Price is how electrons know where to go

o Routing power makes no sense

Location, quantity, timing13

Power & information distribution

14

Example local grid network

Utility Grid Meter

NanogridController

Loads

All connections peer-to-peer and can be changed dynamicallyPrice is how devices know which way power should flow

Microgrid Controller

PV

15

Paradigm changes

• Narrow waist in layering isolates complexity – facilitates interoperability§ Buildings need three layered models

• Conventional network communication§ Application and physical layers

• Electricity / utility meter§ Utility grid from building§ Use only Price, Quantity§ Only need 1-way communication

• Device internal Network Power Integration

16

Layered models – (e.g. OSI Model)

Fig. 3. Layered model for device operation for LPD

Application

Transport

Network

Data Link

Physical

5. Functional coordination

4. Device discovery and events

3. Internal integration

2. Exchange within/between grids

1. Transport of electrons

Network layers NPI layers

UtilityGrid

Building

Layered model for device operation for Local Power Distribution

17

Network Power Integration

Fig. 3. Layered model for device operation for LPD

Application

Transport

Network

Data Link

Physical

5. Functional coordination

4. Device discovery and events

3. Internal integration

2. Exchange within/between grids

1. Transport of electrons

Network layers NPI layers

[

[QuantityPrice [

18

Communication about power“Standard DC”

A method for transmitting DC power defined by a well-known technology standard, enabling plug-and-play interoperability

“Managed DC”Standard DC technologies that include communications for managing power distribution within the power cable & connector§ Over the power wires or over adjacent wires§ Examples: USB and PoE (and UPAMD and HDBaseT)

Cable

Comm. about Power

Power

General Comm.

Network/PowerInterface

Device A Device BNetwork/PowerInterface

• Smallest unit of power distribution• Single physical layer (voltage; usually DC)• Single domain: administration, reliability, capacity, and price• Can interoperate with other local grids through gateways

§ Generation forms own nanogrid§ Only two device types: grid controller and load

• Wide range in technology,capability, capacity

19

What is a Nanogrid?

20

Example local grid network

Utility Grid Meter

NanogridController

Loads

All connections peer-to-peer and can be changed dynamicallyPrice is how devices know which way power should flow

Microgrid Controller

PV

21

Example local grid network

Utility Grid Meter

NanogridController

Loads

All connections peer-to-peer and can be changed dynamicallyPrice is how devices know which way power should flow

Microgrid Controller

PV

Simplicity

• Only two device types• load, grid controller

• Only two interface types• controller ßàload• controller ßàcontroller

• “Plug-and-play” operation§ End-use devices§ Local generation§ Local storage

• Improved safety• Arbitrary power topologies – inter-building links• Fine-grained management of constrained supply

§ Optimal use of distributed storage• Greater reliability – and lesser• Universal technologies• Enabling optimal operation with a local price• Security / privacy• Greater efficiency with Direct DC

§ Powering DC end-use devices from DC local generation, possibly via DC storage

22

Features we should demand for Power Distribution

LPD provides these features

• Electricity is not equally available across space and time§ Has long been true within utility grid

o “Locational Marginal Price”§ Increasingly true within buildings

o Local storage and/or generation, islanded grids, capacity constraints, combined heat-and-power, vehicles/mobile

• Technology we have today presumes uniform availability – hence constant price• Dynamic pricing at meter a needed starting point

§ Grid can express preferences to customer

23

Myth of uniform power availability

• Differential buy/sell prices from utility• Local valuation of carbon• Losses from AC/DC or voltage conversion, battery losses, wiring

losses• Capacity constraints• Off-grid operation – incl. mobile• Battery management goals• Local generation conditions (dispatch; co-gen)

Price always current price and non-binding forecast of future prices

24

Reasons for differing local prices

25

Communications DetailsNo fixed time-steps; No central clock; No central entity

Any message can be sent any timePrice• Price: GC sends a price (incl. forecast) any time it changes ($/kWh)

GC <--> EUD (1-way power flow)Power Allocation• Request: EUD requests authority to consume up to XX W• Allocate*: GC grants the EUD

§ full power request or partial grant or no power at all§ EUD may then consume any amount of power between zero and the granted amount

GC <--> GC (2-way power flow)Prices establish direction of any power flow (low to high)Power Allocation• Allocate: Each GC announces to the other how much power is available

§ The lower power level is set for the exchange quantity§ Power flows across the link

EUD: End-Use DeviceGC: Grid Controller

GC

EUD

• Reduce costs§ Capital, installation, operation, maintenance, …

• Increase reliability• Reduce distractions (clutter, noise, …)• Reduce environmental damage• Increase flexibility

§ Mobility, eqt. change, powering change§ Not rely on utility grid coordination§ Not rely on customer/premise coordination§ Rely on customer/premise power

26

LPD and 5G – Powering considerations

• Mains connectivity§ Always/easy§ Possible/expensive§ Not possible§ Grid unreliable

• Local generation§ PV§ …

• Customer/premises power§ Unreliable§ Reliable

27

LPD and 5G - Powering contexts

28

Conclusions• Need standard digitally-managed power links

• LPD may be highly useful in 5G network deployment• Opens up new options for powering• Can reduce costs and increase reliability• Can apply beyond 5G

Thanks a lot for your time and attention!

Any questions and/or comments?

29

Q & A