ES electricity and the grid

current

rate at which electrons flow

voltage

push of energy (gets the charge to flow)

resistance

tendency of material to resist electron flow

frequency

speed at which current alternates

AC

alternated current → current flows back and forth ie alternates (frequency is measured in HZ) normally 60

DC

direct current → steady rate in one direction only

inversions

some things like batteries and solar panels have to transform DC to AC to be used on the grid (lost energy associated with inversions)

AC vs DC

AC: easier to step up and down voltage, lower transmission losses

DC: smaller regional girds, different scale

DC gaining favor

increased in electric appliances, increase consumer electrics, increase batteries for storage, increase solar, data centers, and efficiency in conversions

steps for electicity

PP (step up) for transmission → transmission center (step down) for power lines → power lines (step down for house)

og characteristics of the grid

1 way centralized communication

instantaneous: no storage

load following

natural monopoly

load following

producers generate electricity at rate of consumer demand - generally longer periods of time than peaking - hourly demands per day (hydro and NG)

why was grid central

base to different types of users (1890s-1900s)

– Set different rates for high/low-demand times

– Exclusive franchise to City of Chicago

• regulated monopolies

peakers

short period of time that need energy → costly, valuable power = NG combustions and hydro

baseload

operate at constant power (nuclear and coal)

minimum level of demand over 24 hours

grid parts

grid is divided into E, W and texas = texas is diff and has own regulations that it doesn’t have to abide by the national grids policies → why the winter storm was so bad

grid needs to be

reliable: provide electricity 100% of the time

resiliency: needs to be able to recover from adverse events

grid challenges

no storage, demand varies, severe weather

balancing supply and demand

needs to stop and start in seconds, energy forcast, opperaters work everyday, reserves that can turn on fast within 10 -30 mins, As demand increases during day, turn on next cheapest power plant,

independent system operating Challenge

have to maintain 60hz in both supply and demand

duck curve

a graph representing the difference between peak electricity demand and the 24-hour supply of solar energy.

daily demand variation

steep ramp up power sources that can output quickly

coal: few hours

nuclear day - few days

other things to consider when balencing the grid

planning,location, social cost, predictability, dispatchability, price risk

black out

all consumers loose power → weather, unexpected

hour - days

rolling blackout

power cut to a group of consumers = when demand is greater than supply, can be planned

mins to hours

brown out

decrease demand by decreasing voltage consumers

causes of blackouts

weather, trees, imbalance, failed equipment, climate change

blackout ex

2003: could see blackout from space

increase temp → a/c → load → increase heat in transmission lines which made them sag → a tree feel and the alarm never went off

power surge and pp shut down

pr hurricanes: power lost for millions

both hurricanes ran straight through pr and 80% generations destroyed, took 9 months to recover = across island

wildfires

wildfires destroy power lines

disruption to the power lines

fix: underground power lines, sensors, insulate wires, trim the trees, sensor to turn off power lines, replace wood poles

winter storm in tx

lost 50% if generation capacity, natural gas not require to weatherize bc not considered critical infrastructure

fail bc not associated with real grid

froze and explode

monopolies

regulated by the government

PUCs - public utility commission

state regulated, Approves/rejects investments in new facilities, sets rates

Public Service Commission

- Siting of gas & electricity transmission facilities

– Safety of natural gas & petroleum pipelines

Public Utility Regulatory Policies Act of 1978 (PURPA)

– Encourage cogeneration + renewables

– Promote generation competition

– Encourage energy conservation

• Requires utilities to purchase from Independent Power Producers (IPPs)

Led to more renewable and NG generation

regulated vs deregulation

regulation: utilities operate everything

• stable prices, long term certainty BUT no choice

Deregulation: different companies generate and distribute

• compare rates, different price structure, can have total green electricity BUT lots of choice, price variability

more facts abt demand and supply

solar and battery storage = 81% of new and electric generating capacity, increase demand in A/C, need more electricity and pay more if have EV at home, increase data centers with efficiency and use lots of electricity

Challenges: supply

variable solar and wind,

flexible dispatchable power

energy storage

Challenges: demand

Distributed generation reduces net load
• Storage reduces net load
• (EVs & electrification increase load)

Challenges: infrastructure

Transmission and distribution system

• Market (pricing) design

• Two-way communication

traditional v future system

traditional: rigid and centralized power plants, 1 way flow

future: flexible system, diverse distributed power sources, 2 way flow

distributed generation

demand follows generation, onsite, storage, demand adjust to supply

net metering

feed electricity to grid when overflow amount generated (gets money if go to grid)

integrated energy storage

absorb power during periods of low demand in order to provide during peak times

global storage

lots of batteries batteries BUT pumped hydro has the largest current storage capacity worldwide.

other storage options

ev → vehicles charged at night by grid power during off-peak hours or during day if solar generation is high

manage duck → charge evs during peak hours

micro grid

bunch of difference places that generate and load shedding

smart grids

integrate users

• better with blackouts

• 2 way communication with consumers and ultilities

• sensors and controllers

• integrate renewables, evs, and distribute

time differented pricing, demand response, faster response to blackouts

flexible loads

dispatch to match renewable generation

Heating/cooling

– Smart thermostats: pre-cool or pre-heat

– Thermal mass: store energy in a thermal mass (eg., concrete floor or wall); good for one day,

difficult for multiple days

– Ice: freeze water when electricity price is low – off-peak used to be at night, may become

middle of day

• EV charging: middle of day if sunny, at night if windy

• Water heating: super-heat during peak generation

• Appliances: washers/dryers, dishwashers, refrigerators can run at right time or

be grid-connected to get signaled about when to run

how do utilities respond to advancements in the grid

sell less electricity→ increase prices because need to make money

consumer: look elsewhere for electricity

*good for environment not utilities*

preserve status quo: oppose distributed generation, support policies that decrease benefits, highlight cons of distributed generation

Adapt and profit: decouple profits from electricity sales: expand business model to accomidate, self sufficent tech

flexible load

Dispatch to match renewable generation

time of use rates

vary depending on load

volumetric

linear

pros: simple, fair, good incentives for efficiency of solar

cons: poorly aligned with utility costs, cannot insentivize flexible loads, create cost shifts

tired

pros: good at insentivizing efficenct and solar, wealthier pay more

cons: poorly aligned with utility costs, cannot insentivize flexible loads, cost shifts

time differentiated

pros: more aligned wth utility costs, can insentivize flexible loads, fair allocation of costs

cons: complex, can remove incentives for efficiency and solar

fixed demand charge and real time pricing

pors: most economically efficent, allocation of costs are fair, best incentive flex loads

cons: complicated, can remove incentives for efficiency and solar

load shifting

delay to times with lower demand (often through pricing)

load shedding

reduce total demand (often through pricing)

ramp rate

how fast a power plant can increase or decrease output

negawatt

the energy not consumed because of efficiency