Title: Advanced Power Systems
1Advanced Power Systems
- ECE 0909.402-02, 0909.504-02
- Lecture 7 Distributed Generation Energy
Economics - 5 March 2007
- Dr. Peter Mark Jansson PP PE
- Associate Professor Electrical and Computer
Engineering
2Aims of Todays Lecture
- Cover other Current Topics
- Upcoming FE Exam registration deadlines
- Mid Term Exam 19 Mar
- APS Final Project Options
- Overview of Chapter 4 5 concepts
- Finish Up Distributed Generation Technologies
- Introduce Economics of Energy Systems
3Aims of Todays Lecture (cont)
- Stretch Break
- Finish Chapter 5 and Engineering Economics of
Investments - Next Week
- Have a Safe and Restoring Spring Break
4FE Examination Announcement
- The College of Engineering strongly recommends
students sitting for the Fundamentals of
Engineering (FE) exam. There is a July 3rd
application deadline for sitting in the FE exam
given on October 27. However, we urge you to get
your application completed much earlier than the
July 3rd deadline, and preferably in late March
or early April. It will be easier to locate
faculty members for references before summer
begins, and there will be more leeway to fix
issues that may arise. - Please contact the persons above if you have any
questions. More information on application fees
and exam dates can also be found on the website - http//www.state.nj.us/lps/ca/pels/pelsfees.htm
- The application form and instructions can be
found at the following website - http//www.state.nj.us/lps/ca/pels/pelsinfo.htm
5APS Mid Term Exam
- Last half of period Monday 19 March 2007
- Exam Topics Covered
- Lectures 1-7 (including AIC and last weeks
Teleconference Lecture and Meeting) - Chapters 1-5
- HW 1-6
- Articles Researched and Reviewed
- Recommended Study above and LCs
6APS Final Project (30)
- Select Teams (2 max per team for UGs Grad Only
1 pp) - To get an A select a APS and a specific site /
get approval for scope by 19 March 2007 (HW 6) - Sample Projects
- Wind Farm Potential for 1200 acres in Cumberland
County - PV system design for Dr. Janssons Pitman
Home/Garage - Wind turbines for Berkeley Township, Ocean County
- Offshore Wind System design (Del Bay or Atl Ocean
off AC) - Fuel cell for Rowan campus building
- Microturbine/Cogen system for local industry
- Micro-Hydroelectric facility for Farm in Pa.
- Solar Concentrator in desert southwest
7Final Project Content
- All APS projects must include
- Specific site collect data on energy use, and
other key site information critical for effective
design of your advanced power system. - Detailed advanced power system design
specifications, size, model, equipment, plans,
interconnection, alternatives considered, etc. - Cost benefit analysis SPB, SIRR, NPV, IRR,
NPV/IRR w/ fuel escalation and cash flow.
8Final Project Format
- (Team) Technical Paper (10)
- 6 pages maximum (4,000 - 6,500 words)
- 2 column technical paper IEEE format
- Due 16 April 2007 (A max), 23 Apr (B max), 30 Apr
(C max) - 25 - minute (Team) Presentation (20)
- 22 minutes of Slides/Demo etc. (min 30 slides)
- 3 minutes QA
- Random date selection
9Microturbines
- Very small gas turbines (NG or waste gas)
- Typically 500 W to 300 kW
- Typical Microturbine Components
- Compressor
- Turbine
- P-M generator
- Combustion chamber
- Heat exchanger (recuperator)
Often all on one shaft
10Leading Manufacturers
- Capstone Turbine Corporation
- One moving part common shaft 96,000 rpm
- C30 - 30 kW unit
- ? LHV 26, Heat Rate 13,100 Btu/kWh
- C60 - 60 kW unit
- ? LHV 28, Heat Rate 12,200 Btu/kWh
- Elliot Microturbines
- TA100R - 105 kW unit
- ? LHV 29, Heat Rate 11,770 Btu/kWh
- 172 kW thermal potential for hot water ? TTE gt
75
11Leading Mfgrs. (continued)
- Ingersoll Rand
- Design Life 80,000 hours with overhauls
- MT250 - 250 kW unit
- ? LHV 30, Heat Rate 11,380 Btu/kWh
- MT70 - 70 kW unit
12Elliot Microturbine Application
- The Elliot TA 100A produces its full output of
105 kW when burning 1.24 x 106 Btu/hr of natural
gas. Its waste heat is used to supplement an
existing boiler by raising its temperature from
120 -140 oF. It operates for 8000 hours/year. - A) If 47 of the fuel is transferred to boiler
what should the waters flow rate be? - B) If boiler is 75 efficient and NG is 6 per
MMBtu how much money will microturbine save in
displaced fuel? - C) If electric costs 8 / kWh what is annual
savings? - D) If OM is 1,500 per year what are net
savings? - E) If microturbine costs 220,000 what is Initial
RR and SPB?
13LM 1
- A) If we can not use the waste heat is it
economical to install a microturbine in this
application? - (assume you require lt 10 yr Simple Payback)
- B) What if your electric costs are 11 / kWh?
- C) What is lowest price electricity can be to
still meet your 10 yr simple payback requirement?
14Microturbines in CHP applications rules of
thumb
- Electric Production ? E 29
- Waste-heat Recovery ? WH 47
- Overall LHV conversion efficiencies can be gt 75
15Reciprocating IC Engines
- Very small piston-driven, 4 stroke ICEs
- Typically 500 W to 6,500 kW
- Typical Operation
- Intake, Compression, Power, Exhaust
- Spark ignited (Otto cycle)
- Compression ignition (Diesel cycle)
- Multi-fuel gasoline, natural gas, kerosene,
propane, fuel oil, alcohol, waste gas
16Advanced Reciprocating Engines
- Current design is cheapest of all DGs
- Efficiencies are good
- Today electrical ? 37-40
- Turbocharged Thermal fuel ? horsepower
- Otto cycle ? LHV 41, ? HHV 38
- Diesel cycle ? LHV 46, ? HHV 44
- ARES Targets ? ELECTRIC 50, ? CHP 80
- HRSG can increase overall ? CHP 85
17Stirling Engines
- Energy is supplied from outside the system
- External combustion, can run on any heat source
- Invented in Scotland and patented in 1816
- Used quite extensively until early 1900s
- Eliminated from market by efficient technologies
- Current efficiencies relatively low lt 30
- Size ranges from 1 25 kW
- No explosions, relatively quiet devices
- Good match with solar dishes
- Four states of Transition in Stirling Cycle
18Concentrating Solar Power
- Solar Dish / Stirling Power Systems
- Parabolic Trough Systems
- Solar Central Receiver
- Disadvantages All these technologies require
direct solar beam radiation. Many regions of the
US have a large fraction of diffuse solar
radiation
19Solar Dish / Stirling Power System
- Multiple mirrors concentrate sun to one pt
- Thermal receiver converts sunlight to heat
- Heat is delivered to Stirling engine
- Stirling engine drives electrical generator
- ? 20 typical, ? 30 peak
- Sterling engine in this 725 oC application gt 36
- Potential stand-alone power plants
- Still have very high capital costs and electricity
20Solar Dish Sterling
21SES site
- http//www.stirlingenergy.com/whatisastirlingengin
e.htm
22Solar Parabolic Troughs
- Parabolic reflectors concentrate sun to one tube
- Stainless steel tube (g-ins) converts light to
heat - Heat transfer fluid delivered to heat exchangers
- Steam turbine drives electrical generator
- ? 10 typical, costs 12 / kWh
- Advanced applications lt 5 / kWh
- Development ongoing in Spain, Greece, Italy,
India and Mexico
23Solar Parabolic Trough
24Solar Parabolic Trough
25Solar Central Receivers
- Multiple computer controlled mirrors concentrate
sun to one central receiver tower - Central receiver (Power Tower) converts sunlight
to heat - Heat is delivered to Steam Generator
- Solar One Water/steam system not well matched
- Solar Two Molten nitrate salts (97 match)
- Extremely high capital costs to prove economics
26Solar Two
27Solar Two
28Concentrating Solar Power
- Technology Concentration Ann Effic.
- Solar Dish Stirling 3000 x 21
- Solar Power Tower 1000 x 16
- Parabolic Trough 100 x 14
29Biomass
- Current global installed capacity 14 GW
- Low efficiencies lt 20
- Wet fuels, low HV, small plants located near fuel
- High costs 9 / kWh
- Future Options to reduce costs
- Co-firing with other fuels (coal)
- Syngas production via pyrolysis
- Anaerobic digesters common in wastewater TP
30LM 2
- Order these concentrating solar power
technologies from least to most efficient - A) Solar power tower
- B) Parabolic trough
- C) Solar dish Stirling
31Micro-Hydropower
- 19 of worlds electricity today is hydro
- Many countries in S. America and Africa are gt90
hydro - Typically Hydro plants are above 30 MW
- Micro-hydro is lt 100 kW
- Run-of-the-river
- No expensive dam construction
- Penstock (pipeline) delivers water under pressure
to a turbine generator lower down
32Micro-hydropower
33Micro-hydropower potential
- Three types of energy
- Potential z (height m or feet)
- Pressure p / ? (pressure / specific weight)
- Kinetic v2 / 2g (velocity / grav. constant)
- THEORETICAL POWER (rules of thumb)
- Power (W) 9810 Q (m3/sec) H (m)
- Power (W) Q (gpm) H (ft) / 5.3
34Net Head
- Net Head (HN) Gross Head Pipe Loss
- Gross Head elevation
- Pipe Loss depends on Pipe size and Flow rate (
see Figure 4.19 p. 199) - Assuming a 50 efficient turbine generator
- P (W) Q (gpm) HN (ft) / 10
- P (kW) 5 Q (m3/s) HN (m)
35Example of micro-hydro
- Assuming a 200 gpm flow rate and a 3-in PVC
penstock, what is the site potential if it is a
200 foot run to an elevation 100 feet lower? - HG 100 feet
- Pipe loss 6 ft of head per 100 feet of run (p.
199) - HN 100 (6 x 2) 88
- P (W) Q x HN / 10 200 x 88 / 10 1.76 kW
36LM 3 Assess your own site
- A) How much water must you divert from your
stream (gpm) to achieve a 2 kW output (assume
rule of thumb calcs) if the elevation drop on
your farm is 160 feet and you assume a penstock
of 300 feet of 3 polypropylene (see page 199)? - B) How much would you be saving annually if your
electric costs are 13 / kWh?
37Aims of Todays Lecture
- Part Two Chapter 5 concepts
- Economics of DG resources
- Energy Economic Methods SP, ISROR, NPV, IRR, NPV
and IRR w/ fuel escalation, AI and Cash Flow
38Economics of Distributed Resources
- Simple Payback
- Initial (Simple) Rate of Return
- Net Present Value (NPV)
- Internal Rate of Return (IRR)
- NPV and IRR with Fuel Escalation
- Annualizing the Investment
- Cash Flow
39Simple Payback
- Extra first cost () / annual savings (/yr)
- Initial cost () / annual savings (/yr)
- Units Years, months
- Example CFLs cost 15 more than their 100 watt
counterparts but will save 8 per year in the
application you are considering. What is their
simple payback? - 15 / 8/yr 1.875 years
40CFL real data
- Dr Jansson bought the following CFLs at Home
Depot and Kmart - 23 watt CFL (7000 hours) at 4.94 (Kmart)
- 23 watt CFL (10,000 hours) at 4.22 (Home Depot)
vs. - 100 watt incandescent (1000 hours) at 0.40
- Assuming he pays 12 cents per kWh and has a
light in his home that needs these lumens for 3
hours each day, what is his simple payback?
41CFL example
- Initial Cost difference
- Kmart - 4.94- 0.4 4.54
- Home Depot - 4.22- 0.4 3.82
- Lifetime of analysis (assume 10 years _at_ 1096
hrs/year 10,960 hours) - Kmart (10,960/7000) 1.57 lamps
- Home Depot (10,960/10,000) 1.10 lamps
- Incandescent (10,960/1,000) 10.96 lamps
42CFL (cont)
- Simple Payback (capital only)
- Kmart CFL ? 1.57 x 4.94 7.76
- Home Depot CFL ? 1.10 x 4.22 4.62
- Incandescent ? 10.96x 0.40 4.38
- Simple Payback (energy savings)
- Kmart CFL ? 1.096 khrs x 23w 25.2 kWh
- Home Depot CFL ? 1.096 x 23w 25.2 kWh
- Incandescent ? 1.096 khrs x 100w 109.6kWh
43CFL Simple Payback
- Annual electric savings
- Either CFL saves 109.6 25.2 kWh /year
- 84.4 kWh/year _at_ 0.12/kWh 10.13 / year
- The Kmart Light has a simple payback of
- 4.54/10.13 0.448 years or 5.3 months
- The Home Depot CFL has a simple payback of
- 3.82 / 10.13 0.377 years or 4.5 months
NOTE In neither example did we take into
consideration the lifetime savings of either CFL
to do that we need to consider how long each
will last
44CFL Lifetime savings
- Kmart CFL savings compared to Incandescent
- 7000/1000 hour life saves 7 lamps _at_ 0.4
2.80 - Energy savings 7000hrs x (100-23 watts saved)
539 kWh over life _at_ 0.12/kWh 64.68 - Total Savings 67.48 - 4.94 62.54
- Home Depot CFL savings compared to Incandescent
- 10000/1000 hour life saves 10 lamps _at_ 0.4
4.00 - Energy savings 10000hrs x (100-23 watts saved)
770 kWh over life _at_ 0.12/kWh 92.40 - Total Savings 96.40 4.22 92.18
45LM 4 your next PC
- You are considering a new desktop PC and have all
the options determined, but there is one energy
efficient option you want to look into. The
feature says your PC will save 26 watts (on
average) if it is installed. The option costs
19.95. Will you take it if you only keep your
PCs for two years and your cost of electricity is
12/kWh? (Assume your PC is used continually and
you are an economically rational person) Show
your simple payback calculation and then explain
why, or why not.
46Initial (Simple) Rate of Return
- This calculation is the inverse of simple payback
- Annual savings (/yr) / extra first cost ()
- Annual savings (/yr) / initial cost ()
- Units per year
- Example 1-kW of PV costs 1800 after rebates but
makes 1350 kWh per year and earns more than 30
cents per kWh due to SRECs and electric savings.
What is the initial (simple) rate of return for
the system? - 405/yr / 1800 22.5 per year
47Net Present Value (NPV)
- Considers the fact that money has value today
which is higher than it will likely be in the
future. (Inflation is not zero) - Consider what an investment P in an account
earning interest i will be worth - P Pi P (1i) next year
- P Pi (PPi)i P(1i)(1i) the year after
that - In Fact Its Future value F P (1i)n
48Present and Future Value
- Future Value Current Sum and interest rate
- If I give you 700 today how much is it worth in
five years? (assume you could earn interest of
4.5) - F P (1i)n ? 700(10.045)5 700(1.24618)
- 872.33
49Present and Future Value
- Present Value Future Sum and discount rate
- If I give you 1000 in 7 years how much is it
worth today? (assume inflation or the discount
rate is 5.5) - P F / (1i)n ? 1000/(10.055)7
- 1000/(1.454679)
- 687.43
50LM 5
- Determine the following quantities and say which
is larger PV of A or FV of B - A) 15,000 8 years from now with inflation
running (or a discount rate of) at 7.0 - Determine its Present Value
- B) 6,500 deposited in a CD today that earns 6.1
interest annually for 5 years - Determine its Future Value
51Net Present Value (NPV)
- Considers a stream of benefits (/yr) that
persist for n years (life of device or
improvement) but will need to be discounted back
to today. - A benefit (/yr), d discount rate, n years
52NPV example
- Two 200-HP motors are being considered
- High-efficiency 155 kW - 5800
- Normal Efficiency 158 kW - 4800
- Power costs are 8/kWh, motor runs 1800 hours per
year. Assume 20-yr life, 10 dr. - Which should you buy?
-
53NPV example
- The two motors annual costs
- High-efficiency 155 kW x 1800 x 0.08 22,320
- Normal Efficiency 158 kW x 1800 x 0.08
22,752 - With a 20-yr life, 10 discount rate
- PVF (1.1)20 1 / (0.1)(1.1)20
5.7275/0.67275 8.51 - Which should you buy? - Compare NPVs
- High-efficiency NPV 8.51 x 22,320 189,943
- Normal Efficiency NPV 8.51 x 22,752 193,620
54NPV example
- Which should you buy? - Compare NPVs
- High-efficiency NPV 8.51 x 22,320 189,943
- Normal Efficiency NPV 8.51 x 22,752
193,620 - Incremental First Cost 1,000 for high
efficiency, NPV of future savings 3,677 - NET BENEFIT to your company
- 2,677 at your companys 10 discount rate
55LM 6
- Determine which of these two investments are best
for your company on a net present value (NPV)
basis, assume a discount rate of 7 - A) A 13,000 hi-efficiency cooling system upgrade
that lasts 11 years and saves 1,800 per year - B) A 21,500 PV system that lasts for 20 years
and saves 2,200 / year
56Internal Rate of Return (IRR)
- Rate of return analysis is probably the most
frequently used exact engineering cost analysis
technique used in industry. Its major advantage
is that we can calculate a single figure of merit
that is readily understood and it requires no
interest rate, bond rate or discount rate to be
determined.
57IRR
- What is it?
- The internal rate of return for any investment is
the discount rate that makes the present value of
the investments income stream total to zero
58IRR applet
- http//hadm.sph.sc.edu/COURSES/ECON/irr/irr.html
59Another IRR approach
60IRR example
- A premium air conditioner costs an extra 1000
and saves 200 per year in electricity. It has a
lifetime of 10 years. What is its IRR? - SPP - 1000/200/yr 5 Years
- Lifetime is 10 years look in Table 5.4
61IRR
62LM 7
- Determine which of these two investments has best
IRR for your company - - A) A 13,000 hi-efficiency cooling system upgrade
that lasts 15 years and saves 1,808 per year - B) A 19,500 PV system that lasts for 25 years
and saves 2,660 / year - Write IRR for each and then make your selection
63NPV with fuel escalation
NPV We calculate an equivalent discount rate
64IRR with fuel escalation
IRR We calculate an equivalent rate of return
65Annualizing the Investment
- Since money may be borrowed internally or
externally considering the capital investment as
a loan is always a helpful economic analysis
method - A P x CRF (i,n)
- CRF 1/PVF
66Annual Cost example
- A 4-kW PV system in NJ generates 5,200 kWh per
year, it costs 8,500 after rebates. Assume a
6, 20-year loan. Assume your electric price is
12 cents/kWh and the SREC is worth 20 cents/kWh.
What is your annual cost and what is your
benefit-cost ratio? - Annual Cost A P x CRF ( 0.06, 20)
- Annual Cost 8,500 x 0.0872 741 / year
- Annual Benefits 1,664 / year
- Benefit-Cost Ratio 1,664/741 2.25
67LM 8
- Determine which of these two APS investments has
best COST - BENEFIT ratio for your company.
(assume 8 loan) - A) A 12,000 wind turbine that saves 1,800 per
year and lasts 20 years. - B) A 18,500 PV system that lasts for 30 years
and saves 2,250 / year - Write Annual Cost for each and then make your
selection based on B-C ratio
68Cash Flow
- Most comprehensive and flexible way to consider
an investment. - Accounts for
- Fuel escalation
- Tax-deductible interest
- Depreciation
- Periodic maintenance
- Salvage value
69Wind Turbines
- Wind energy is proportional to V3, Why?
70Simple Rule of Thumb
- Annual Energy (kWh) 1.64 D2 V3
- D rotor diameter, meters
- V annual average wind speed (m/sec)
71New homework
- HW 6 due Monday after Spring Break
- Now posted on web
- Plus Final APS project proposal
72New homework
- HW 6 due Monday after break 21 Mar
- now posted on web
- 5.3, 5.4, 5.5, 5.6, 5.8, 5.10, 5.14, 5.15, 5.16
- Also MUST INCLUDE
- Final Project Proposal (and Team Members)
- Identified APS Technology (ies)
- Identified Site and Prospective Customer -
Contact - Approach, tasks, schedule, Gantt chart, etc.