The U.S. Industrial and Building

lettucestewΗλεκτρονική - Συσκευές

21 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

67 εμφανίσεις

The U.S. Industrial and Building
Sectors


Industrial energy usage = 35 quads; building energy
usage = 40 quads(total = 100 quads)


Building energy consumption split roughly 50:50
between commercial and residential buildings


These two sectors account for about 70% of total U.S.
GHG emissions


By 2030, 16% growth in U.S. energy consumption,
which will require additional 200 GW of electrical
capacity (EIA)


Energy efficiency goals of 25% reduction in energy use
by 2030(McKinsey and National Academies Press
reports)


1

Impacts of proposed US GHG
legislation if enacted in 2007

http://www.wri.org/climate/topic_content.cfm?cid=4265

2

Cap


Sets a firm limit of CO
2

emissions


Government sets initial cap


Cap steadily decreases over time


Only effects large emitters

Trade


Emission permits distributed


-

Auctioned


-

Given away


Excess permits traded/sold


Creates market for emission permits


3

Future GHG Legislation

Other Alternatives


Carbon Tax


-

Price Predictability


-

Could be Revenue Neutral


-

Apply to all Carbon Sources


Regulated CO
2


-

Recent EPA Announcement


4


CO
2

Absorption/Stripping of
Power Plant Flue Gas

Flue Gas

With 90% CO
2

Removal

Stripper

Flue

Gas In

Rich

Solvent

CO2 for

Transport

& Storage

LP Steam

Absorber

Lean
Solvent

Use
30%

of

power plant output

5

IGCC PROCESS

6

7

Theoretical Limit

Ceramic Vanes

and Blades

Ceramic Vanes

Precooled Air

Conventional

Cooling

Increased Generation Efficiency


Conventional efficiency: 40
-
55%


Cogeneration efficiencies: 75
-
85%



8

9

What is a Smart Grid?


Delivery of electric power using two
-
way digital
technology and automation with a goal to save
energy, reduce cost, and increase reliability.


Power will be generated and distributed optimally for
a wide range of conditions either centrally or at the
customer site, with variable energy pricing based on
time of day and power supply/demand.


Permits increased use of intermittent renewable
power sources such as solar or wind energy and
increases need for energy storage.


10

Utility of the

Future Vision

Bio fuels

Plug
-
in

H2

Zero Energy Home

Distributed Utility

Fossil Fuels

Solar

Nuclear

Wind

i

11

Electricity Demand Varies

throughout the Day

Source: ERCOT Reliability/Resource Update 2006

12

Wind and ERCOT daily load

0
0.2
0.4
0.6
0.8
1
1.2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Normalized
Hour Ending
Normalized
wind
Normailized
load
Source: Dispatchable Hybrid Wind/Solar Power Plant, Mark Kapner, P.E

13

14

Today’s Grid

Smart
Grid 1.0

15

Smart
Grid 2.0

Tomorrow’s Grid

16

Three Types of Utility Pricing


Time
-
of
-
use (TOU)


fixed pricing for set periods of
time, such as peak period, off peak, and shoulder


Critical peak pricing (CPP)


TOU amended to
include especially high rates during peak hours on a
small number of critical days; alternatively, peak time
rebates (PTR) give customers rebates for reducing
peak usage on critical days


Real time pricing (RTP)


retail energy price tied to
the wholesale rate, varying throughout the day

17

18

Smart Grid Challenges/Unknowns


Design of the grid


Power storage


Redundancy and reliability for peak/base loads


Power flow management


Power stability


Cybersecurity


Automation/decentralized control


Distributed power generation (
renewables
)


Power electronics


AC vs. DC


19

Electrical Energy Storage (EES)
Research Needs


Increase energy/power densities, reduce system
cost, and improve battery durability and reliability


Solve materials challenges and model complex
systems


Obtain fundamental understanding of atomic and
molecular processes that govern performance and
durability


Reduce the gap between identification, synthesis
and characterization of new EES materials vs.
manufacturing and design specs for devices

20

Thermal Energy Storage


Thermal energy storage (TES) systems heat or cool a
storage medium and then use that hot or cold medium for
heat transfer at a later point in time.


Using thermal storage can reduce the size and initial cost of
heating/cooling systems, lower energy costs, and reduce
maintenance costs. If electricity costs more during the day
than at night, thermal storage systems can reduce utility
bills further.


Two forms of TES systems are currently used. The first
system used a material that changes phase, most commonly
steam, water or ice. The second type just changes the
temperature of a material, most commonly water.

21

TES Economics Are Attractive for


High utility demand costs


Utility time
-
of
-
use rates (some utilities charge
more for energy use during peak periods of
day and less during off
-
peak periods)


High daily load variations


Short duration loads


Infrequent or cyclical loads

22

Methods of Thermal Energy Storage


TES for Space Cooling: produce ice or chilled water at night
for air conditioning during the day


Shifts cooling demands to off
-
peak times (less expensive in areas with
real
-
time energy pricing)


May be used take advantage of “free” energy produced at night (like
wind energy)


TES with Concentrated Solar Power: store energy in thermal
fluid to use when sunlight is not available


Gives solar concentrating power plants more control over when
electricity is produced


Seasonal TES


Long term energy storage


Store heat during the summer for use in the winter


Many other methods

23

UT’s Thermal Storage System


Acts as chilling station, but with 1/3 of the cost


4 million gallon capacity


30,000 ton
-
hours of cooling (~105 MWh)


Enough to run A/C for 1500 Austin homes (2500 sq ft) each day

24

TES for Space Cooling:
Calmac’s

IceBank
®
Technology

Charge Cycle: At night, a chiller is
used to cool a water/glycol solution.
This runs to the Ice Bank, where
water inside the tank is frozen.

Discharge Cycle: During the day, the
glycol solution is cooled by the ice in
the tank and then used to cool the
air for the building’s AC needs.

http://www.calmac.com/products/icebank.asp

25

An Inside View of the IceBank®


Coolant runs through
tubes


Water in the tank gets
frozen by the coolant at
night


The ice is then used to
cool the solution during
the day for air
conditioning

http://www.calmac.com/products/icebank.asp

26

Why Use TES for Space Cooling?


Shifts electricity demands to the night to take advantage of
lower rates at night



Can also be a way to take advantage of wind power, which is
more abundant at night

http://www.calmac.com/benefits/

27

TES with Concentrated Solar Power (CSP)


CSP technologies
concentrate sunlight to heat
a fluid and run a generator


By coupling
CSP with TES,
we can better
control when
the electricity
is produced

28

TES with Concentrated Solar Power (CSP)


Two
-
tank direct method


Two tanks, hot and cold


Heat transfer fluid flows from
the cold tank and is heated by
the solar collectors.


This hot fluid travels to the hot
tank, where it is stored.


As needed, the hot fluid passes
through a heat exchanger to
make steam for electricity
generation.


Other methods include two
-
tank indirect (where the heat
transfer fluid is different than
the storage fluid) and single
-
tank thermocline (storing heat
in a solid material)


http://www1.eere.energy.gov/solar/thermal_storage.html

The two
-
tank direct method


29

Seasonal Thermal Energy Storage

Drake Landing Solar Community (
Okotoks
, Alberta, Canada)

http://www.dlsc.ca/how.htm

30

Annual Energy Savings at Drake Landing

http://www.dlsc.ca/brochure.htm

31