ECE 333
Renewable Energy Systems
Lecture 22: Water Pumping, Hydro
Prof. Tom Overbye
Dept. of Electrical and Computer Engineering
University of Illinois at Urbana-Champaign
overbye@illinois.edu
Announcements
•
•
Read Chapter 8
HW 9 is 6.18, 6.19, 8.8, 8.10; it will be covered during
an in-class quiz on April 30
1
In the News: Tesla to Announce
Home Battery Systems
• Tesla plans to announce a "home battery" and a
"very large utility scale battery" on April 30
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–
•
CEO Elon Musk thinks rivals' batteries "suck," according
to the note from Jeff Evanson, Tesla's investor relations
director (as reported by CNN)
Tesla shares rose 5% on
the news of the announcement
Currently they have a 10 kWh
battery; cost is not clear (one
source says $1500 upfront
plus $15/month for 10 years)
Pictures from last year
Source: money.cnn.com/2015/04/22/technology/tesla-home-battery/index.html
2
Permanent Magnet DC Motor
Example
• A dc motor has va= 300 V, a rated armature current if =
60 A, Ra = 0.2 , and a constant k of 3 V/rad/sec. What
is the speed, and what is the torque at this speed? What
is the starting torque?
va  60  Ra  3m
300  60  0.2
m 
 96 rad/sec = 917 rpm
3
300  60  0.2   60

Tm 
 180 N-m
96
300
Tstart  k ia  3 
 4500 N-m
0.2
You cannot
calculate the
starting torque
by first calculating
Pm and then
diving by m since
both are zero at
starting. Starting
losses can be
very high!
3
PV Powered Water Pumping
http://www.rajkuntwar.com/html/Solar.html
http://www.oksolar.com/pumps/
http://solar-investment.us/solar-pv-surface-and-bore-waterpumping/
4
Example: Energy to Pump Water
from Shallow Well
• How many kWh/day are required to pump 250
gallons/day with a 66 ft head + 230 ft pressure head
assuming 35% efficiency?
With efficiency given, the below equation works for any rate, so
calculate power required if the 250 gallons is pumped in one hour
0.1885  H ( ft )  Q ( gal / min)
Pelec (W ) 
Efficiency
250gal / day
Q( gal / min) 
 4.167 gal / min
60 min/ day
0.1885  296  4.167
Pelec (W ) 
 664 W (for one hour)
0.35
Cost is about $0.05 or
Answer  0.664 kWh
$0.02 per 100 gallons
5
Water Costs
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•
Average person in US uses about 80 gallons per day
In CU water is provided by Illinois American Water
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•
For Springfield, IL water provided by the city (CWLP)
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•
Monthly fee is $39.10 for 1 inch supply, and $0.51 per 100
gallons (flat rate)
Monthly fee is $26.94 for 1 inch supply, and $2.67 per unit
(which is 100 cubic feet or 748 gallons); cost per 100 gallons
is $0.357 (flat rate)
For Los Angles (also municipal)
–
No monthly fee, Tier 1 rate is $0.646 per 100 gallons, rising to
$0.823 for Tier 2 (Tier 1 allotment is based in part on lot size)
http://www.amwater.com/files/IL-pdf-Champaign%202015%20February%201.pdf
http://www.cwlp.com/customer/rates/water.html
6
Electricity Associated with
Water Usage
• Various numbers have been associated with how much
•
•
electricity is associated with water uses
Depends on location, with Illinois being lower because
of more water drawn from wells and less irrigation
A California Energy Commission report put the value
at 19% for California (see below reference)
–
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Water is often transported long distances, with 6138
kWh/MG for Colorado River Water (about 10 times greater
than an Illinois well!); desalination is about 13000 kWh/MG
(MG is million gallons)
Wastewater treatment is about 2500 kWh/MG
gov/2005publications/CEC-700-2005-011/CEC-700-2005-011-SF.PDF
7
Electricity Associated with
Water Usage
Total electricity
during 2001
was
250,494 GWh
gov/2005publications/CEC-700-2005-011/CEC-700-2005-011-SF.PDF
8
In the News:
•
Because of the drought, California is increasingly
turning to desalinating sea water
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Largest plant in the Western Hemisphere is coming online in
Carlsbad, CA later in 2015 to provide water for 300,000
people in San Diego at a cost of $1 billion
Will produce 54 million gallons per day using a reverse
osmosis process
Energy usage is estimated to be between 10 and 14 MWh per
million gallons
Another plant just as large is proposed for Huntington Beach
Saudi Arabia is building a plant that will produce 264
million gallons per day
9
Pipe Losses
•
Pipe losses are usually expressed in terms of
equivalent head, with values increasing roughly with
the square of the flow rate
–
Example values are given in Table 6.17, with Table 6.18
including additional losses for valves and elbows
Units are feet
of water per
100 ft of pipe
Plastic pipe losses
10
Pipe Losses
Frictional Losses for Valves and Elbows Expressed
as Equivalent Length in Feet
•
Total head is the static head plus the frictional head
11
Example 6.16
•
Determine total head for below system as function
of flow rate
Total pipe length, including
elbows and valves is 251.5 ft
12
Example Efficiency as a Function of
Flow Rate, Head and Voltage
Operating
points would
be determined
by the voltage
and the total
head (static
plus frictional)
Figure 6.42 Jacuzzi SJ1C11 Pump
13
Example 6.16 Operating Points
Pump current
can be determined
from the head,
flow rate, efficiency
and voltage
V = 60, H = 210 ft,
Q = 9 gal/min,
efficiency =0.44
0.1885  210  9
Pelect 
0.44
Pelect  810 W
I
810
 13.5 A
60
14
Putting it Together With Solar PV
•
Pump operating points can be determined for a range
of voltages; these are superimposed on a solar PV V-I
curve
This is used
to determine
how much
water the
configuration
will pump
15
Microgrids (4th Solar Configuration)
4.
•
Microgrids
A small electric grid with several generation sources
–
•
•
The microgrid can be configured to operate either connected
to the main grid or standalone
The military is a key proponent of microgrids, since
they would like the ability to operate bases independent
of any grid system for long periods of time
Renewable generation by be quite attractive because it
decreases the need to store large amounts of fossil fuel
–
Time magazine reported in Nov 2009 that average US solider
in Afghanistan requires 22 gallons of fuel per day at an
average costs of $45 per gallon
16
Hydro Power (Most Widely Used
Renewable Resource)
• Hydro power is the most widely used renewable
•
•
resource in the world. In US we got 2.3 quad from
hydro in 2014 (versus 2.6 quad in 1970). This value is
often given in billions of kWh or TWh = 259 TWh in
2014; this is a little less than 3% of total energy, about
6.3% of total electricity.
Worldwide hydro dominates for some countries (values
in billion kWh (TWh) for 2012): Canada (377, 61%),
Brazil (411, 76%), Norway (140, 97%), China (856,
18%), Worldwide (3646, 16.9%)
South America is about 61% hydro (715 out of 1177)
http://www.eia.gov/cfapps/ipdbproject/iedindex3.cfm?tid=2&pid=33&aid=12&cid=regions&syid=2008&eyid=2012&unit=BKWH
17
Growth in Hydro Worldwide
Image: www.iea.org/publications/freepublications/publication/hydropower_essentials.pdf
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Hydroelectric Power in US/Canada
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Largest Hydro US: Grand Coulee, WA
•
Largest hydro power station is US is on the Columbia
River in Washington State. It was opened in 1942, and
now has a total capacity of 6.8 GW
–
Its hydraulic head is 380 feet; reservoir size is 125 sq miles
http://en.wikipedia.org/wiki/Grand_Coulee_Dam
20
World’s Largest Hydro: Three
Gorges, China
•
•
Total capacity is 22.5 GW
30 main generators, each
with 700 MW capacity
http://en.wikipedia.org/wiki/Fil
e:200407-sandoupingsanxiadaba-4.med.jpg
http://en.wikipedia.org/wiki/File:Sanxia_Runner04_300.jpg 21
Lighting Africa: Current Situation
•
Total electric consumption in all of Africa for 2008 is 579
TW-h, less than Canada (614). Also, taking out South
Africa (240) and Egypt (118) the value is only 221 TW-h
for more than 850 million people, a value of about 260
kWh per capita, an average consumption of 30 watts.
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Note, this value includes industrial, commercial and residential
consumption
For Uganda (33 million people) the per capita is 78 kWh!
Total electric capacity in Africa (excepting South Africa and
Egypt) is less than 60 GW, about 1/3 of which is hydro.
Yet Africa has hydro electric capacity of 100’s of GW
22
Lighting Africa, What Could be
Coming: Grand Inga, DR Congo
• Hydro at the Inga dams in Congo (on Congo River) currently
have a capacity of 1.8 GW, but the location has a potential of
more than 43.5 GW, with energy production of up to 320
TWh! World Bank pledged their support in 2014 Inga 3,
which would be first phase of Grant Inga (4800 MW)
23
Possible Pan-Africa Transmission
Grid Integrating Grand Inga
Over time various
projects have been
proposed to develop a
“Pan-Africa”
transmission grid, with
Grand Inga playing a
major role. Funding
and political stability
are key concerns.
Picture source: http://www.eia.doe.gov/emeu/cabs/inga.html
24
Potential Growth in Hydro
•
•
•
In 7/2014 EIA projected
little future US hydro
growth, though potential
is there
Worldwide projects are
for about a 50% growth
over the next 40 years
Costs of other sources,
such as wind and solar,
pays strong role
http://www.eia.gov/todayinenergy/detail.cfm?id=17051
Image: www.iea.org/publications/freepublications/publication/hydropower_essentials.pdf
25
Types of Hydro
•
Impoundment (or Storage) is the most common,
usually with a dam used to store river water in reservoir
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Multiple dams can be chained together
Management of water usage can get quite complex, with lots
of side issues such as flood control and maintaining flow
rates for fish
Water released from one
reservoir becomes available
to the one downstream
reservoirs (and plants)
Constraint on total water
available over a year (or longer)
Image: http://energy.gov/eere/water/types-hydropower-plants
26
Impoundment Example: Columbia
River Basin
• The Columbia River
Basin provides about
1/3 of the total US
hydro; needs to be
jointly managed
with Canada
Image: www.eia.gov/todayinenergy/detail.cfm?id=16891
27