NASA/TM-2001-211316 

2 00/220103 

5S 4150 

L~~( 

Baseline Testing of the Ultracapacitor 

Enhanced Photovoltaic Power Station 

Dennis J. Eichenbe~g, John S. Kolacz, and Paul F. Tavernelli 

Glenn Research Center, Cleveland, Ohio 

November 2001 

I 

I 

I 

J 

1 

https://ntrs.nasa.gov/search.jsp?R=20020007093 2018-05-15T10:44:33+00:00Z
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NASA/TM- 2001-211316 

Baseline Testing of the Ultracapacitor 

Enhanced Photovoltaic Power Station 

Dennis J. Eichenberg, Jolul. S. Kolacz, and Paul F. Tavernelli 

Glerul Research Center, Cleveland, Ohio 

Nation al Aeronautics and 

Space Administration 

Glenn Research Center 

November 2001 
Trade names or manufacturers' names are used in this report for 

identification only. This usage does not constitute an official 

endorsement, either expressed or implied, by the National 

Aeronautics and Space Administration . 

Available from 

NASA Center for Aerospace Information 

7121 Standard Drive 

National Technical Information Service 

5285 Port Royal Road 

Hanover, MD 21076 Springfield, VA 22100 

Available electronically at http://gltrs. grc.nasa.gov I GLTRS 
BASELINE TESTING OF THE 

ULTRACAPACITOR ENHANCED PHOTOVOLTAIC POWER STATION 

Dennis J. Eichenberg, John S. Kolacz, and Paul F. Tavernelli 

National Aeronautics and Space Administration 

John H. Glenn Research Center 

Cleveland, Ohio 44135 

SUMMARY 

The NASA John H. Glenn Research Center is developing an advanced ultracapacitor 

enhanced photovoltaic power station. Goals of this effort include maximizing 

photovoltaic power generation efficiency and extending the life of photovoltaic energy 

storage systems. Unique aspects of the power station include the use of a solar tracker, 

and ultracapacitors for energy storage. The photovoltaic power station is seen as a way 

to provide electric power in remote locations that would otherwise not have electric 

power, provide independence from utility systems, reduce pollution, reduce fossil fuel 

consumption, and reduce operating costs. The work was done under the Hybrid Power 

Management (HPM) Program , which includes the Hybrid Electric Transit Bus (HETB), 

and the E-Bike. The power station complements the E-Bike extremely well in that it 

permits the charging of the vehicle batteries in remote locations. Other applications 

include scientific research and medical power sources in isolated regions. The power 

station is a'n inexpensive approach to advance the state of the art in power technology 

in a practical application. The project transfers space technology to terrestrial use via 

non-traditional partners, and provides power system data valuable for future space 

applications. A description of the ultracapacitor enhanced power station, the results of 

performance testing and future power station development plans is the subject of this 

report. The report concludes that the ultracapacitor enhanced power station provide~ 

excellent performance, and that the implementation of ultracapacitors in the power 

system can provide significant performance improvements. 

INTRODUCTION 

The NASA Glenn Research Center initiated baseline testing of the ultracapacitor 

enhanced power station as an excellent opportunity to transfer technology from the 

aerospace and military industries to a commercial venture. The project is seen as a way 

to provide electric power generation in remote locations that would otherwise not have 

electric power, provide independence from utility systems, reduce pollution, reduce fossil 

fuel consumption, and reduce operating costs for power generations systems. 

The NASA Glenn Research Center provides overall project coordination and is 

responsible for testing the power station. This includes instrumenting the power station 

and developing instrumentation and control programs. Wherever practical, off-the-shelf 

components have been integrated into the test configuration. 

NASAfTM- 2001-2 1 13 16 1 
TEST OBJECTIVES 

Testing of the ultracapacitor enhanced power station was performed at the NASA Glenn 

Research Center. Of particular interest are power generation capacity, and energy 

storage capacity. The performance of the various power station components, especially 

the photovoltaic panels, solar tracker, energy storage system, and inverter are also of 

interest. 

POWER STATION DESCRIPTION 

The ultracapacitor enhanced photovoltaic power station is a high performance, state of 

the art power generation system. The power station is shown in Figures 1 and 2 and 

described in detail in Appendix A. The block diagram of the power station is shown in 

Figure 3. 

Power is generated from two 5'x2', 16.9 volt, 120 Watt, all weather photovoltaic panels. 

The photovoltaic panels are mounted on a photovoltaic panel solar tracker for tracking 

the path of the sun to improve efficiency. The tracker is a non-energy-consuming device 

that operates from the heating of a thermal medium to change the panel position. The 

tracker can increase the total energy produced by the photovoltaic panels by up to 50% 

more than the panels on a fixed mount. 

Power from the photovoltaic panels is taken to the power station control enclosure. 

Within the control box are the remainder of the power station components. Jumper 

panels are provided to facilitate reconfiguration for various applications. 

The energy storage system consists of four 50 farad , 18 volt ultracapacitors to store 

electrical energy. For the tests, they were connected in parallel for a 200 farad , 18 volt 

capacitor bank or in series/parallel for a 50 farad , 36 volt bank. 

A 250-Watt, 60 Hz sine wave inverter is provided for powering various ac loads. A sine 

wave inverter was used to minimize noise generation, and provide a clean power source 

to the load. 

The E-Bike battery charger is built into the battery pack. The charger is rated at 24 volts, 

1.6 amps DC. The complete battery pack including the charger is shown in Figure 4. 

The battery pack is quickly removed from the vehicle if so desired. This permits the 

quick installation of another battery pack, as well as charging of the battery pack within 

the power station control enclosure. 

NASAffM-200 1-2113 16 2 

----------
Fig. 1 - Photovoltaic Power Station at NASA Glenn Research Center 

NASAffM- 2001-211316 

National Aeronautics and Space Administration 

John H. Glenn Research Center at Lewis Field 

3 
Fig. 2 - Photovoltaic Power Station Control Enclosure 

NASAffM-2001 -2113 16 

National Aeronautics and Space Adm inistratio n 

John H. Glenn Research Center at Lewis Field 

4 
Fig. 3 - Photovoltaic Power Station Block Diagram 

r------------------------

~ ULTRAPHOTOVOL TAlC .. CAPACITORS 

PANEL 

JUMPER 

PANEL 

---. DC 

RESISTIVE 

PHOTOVOL TAlC .. LOAD 

PANEL ~ 

S OLAR TRACKER AC ----------------------- ~ INVERTER ~ ~ RESISTIVE 

LOAD 

J JUMPER 

PANEL 

-. BATIERY 

DATA .... CHARGER 

LOGGERS ..... 

BATIERY 

Fig. 4 - Battery Charger and Battery 

NASAfTM-2001-211316 5 
TEST CONFIGURATIONS 

The DC test configuration of the ultracapacitor enhanced power station is shown in 

Figure 5. It was configured to compare the characteristics of photovoltaic-produced 

power without ultracapacitor energy storage, versus the characteristics of photoYoltaicproduced power with ultracapacitor energy storage. A 5-ohm resistive load was 

connected to each system. This permits each panel to receive the same amount of 

solar energy, and supply power to the same size load. 

Fig. 5 - DC Test Configuration 

r------ --- ---------------~ 

, 

, 

, 

, 3 TO 3.5 AMPS ---+-

PHOTOVOL TAlC , 5 OHM 

PANEL RESISTIVE 

LOAD 

3 TO 3.5 AMPS ---+-

PHOTOVOL TAlC ~~ 5 OHM 

PANEL RESISTIVE 

; LOAD 

" 

s OLAR TRACKER 200 FARAD ----------------------- CAPACITORS 

The AC test configuration of the ultracapacitor enhanced power station is shown in 

Figure 6. In this case, the two 120 Watt photoYoltaic panels were connected in parallel 

to operate a 250 Watt inverter with different loads. Ultracapacitors were used for all tests 

because it was impossible to start the loaded inverter with only the photovoltaic panels. 

Fig. 6 - AC Test Configuration 

r--------------- ------- --~ 

I 

I 

I 

I 10 TO 14 AMPS---+-

PHOTOVOL TAlC I ~ 

PANEL I 

I .41" I 

I 

, 

" ~, I 

I 

PHOTOVOL TAlC I 50 FARAD PANEL I 

I CAPACITORS I 

I 

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I SOLAR TRACKER I 

I ______ -------------------~ 

AS AffM-200 1-21 1316 6 

INVERTER 

~~ 120VAC, 60HZ 

100 OHM 

RESISTIVE OR 

LOAD 

BATTERY 

CHARGER 

BATTERY 
INSTRUMENTATION 

The power station was instrumented to measure the load voltage and the load current of 

each of the two systems. Additional channels measured ambient temperature, each 

photovoltaic panel temperature, and the internal control box temperature. An optical 

pyrometer was used to record the solar insolation during testing. Data were sent to an 

on-board digital data acquisition system. The sample rate was once a minute. The data 

was downloaded to a personal data assistant (PDA) at the power station. The data was 

then downloaded from the PDA to a desktop PC. The instrumentation configuration is 

described in Appendix B. 

TEST MATRIX 

The tests described in this report were conducted at the NASA Glenn Research Center 

in Cleveland, Ohio from June to August 2001. 

Tests 1 to 3 were conduct~d to characterize power station dc performance under various 

conditions . Test 4 was conducted to characterize performance using capacitors, inverter 

and resistive load. Lastly, Test 5 was conducted to characterize battery charging with an 

inverter. See Table 1. 

Table 1 - Photovoltaic Power Station Test Matrix 

Test DC Power Capacitor Sky Tracking 

Number Source (Farads) Conditions Engaged Test Load 

1a 120W PV 0 Clear Yes 5-ohm dc load. 

1b 120W PV 200 Clear Yes 5-ohm dc load. 

2a 120W PV 0 Partly Cloudy Yes 5-ohm dc load. 

2b 120W PV 200 Partly-Cloudy Yes 5-ohm dc load. 

3 120W PV 200 Clear No 5-ohm dc load. 

4 240W PV 50 Clear Yes Inverter & 100-ohm ac load. 

5 240W PV 50 Clear Yes Inverter & Battery Charger. 

NASAfTM- 2001 -211316 7 
TEST RESULTS 

Test 1 - DC Load Test With Clear Sky Conditions 

As shown in Figures 7 and 8, the differences between the two systems only appear at 

the beginning and end of the day. The ultracapacitors are charging in the morning and 

pulling the system voltage down. In the afternoon, when the panel output starts to 

drop, the ultracapacitors continue to provide power to the load until discharged. This 

illustrates one feature of combining photovoltaics and ultracapacitors. If it is necessary 

to power a load overnight, a properly-sized photovoltaic and ultracapacitor system would 

be capable of performing that task. 

Fig. 7 - Photovoltaic System Voltages With Clear Sky Conditions 

(J) 

-

o 

> 

20 

16 

12 

8 

4 

o 

6:40 AM 11 :04 AM 3:29 PM 7:53 PM 

--Panel 1 Voltage - Panel 2 Voltage wI 200 Farad Cap 

16.31 Volts Peak 16.41 Volts Peak 

50 Resistive Load Test Dale 6/28/01 

NASAffM- 2001 -2113 16 8 

I 

-' 
Fig. 8 - Photovoltaic System Currents With Clear Sky Conditions 

4 

U) 3 

Q.a 2 E~ 

«>1 

o 

6:40 AM 11 :04 AM 3:29 PM 7:53 PM 

- Panel 1 Current - Panel 2 Current wI 200 Farad Cap 

3.26 Amps Peak 3.28 Amps Peak 

SO Resistive Load 

Fi . 9 - Photovoltaic S stem Powers With Clear Sk Conditions 

60 

C/) 40 =a 

~t20 

o 

6:40 AM 11 :04 AM 3:29 PM 

Test Date 6/28/01 

7:53 PM 

- Panel1 Power - Panel2 Power wI 200 Farad Cap 

so Resistive Load 

431 Watt-Hr Total · 

53.20 Watts Peak 

NASAffM- 2001-211316 9 

431 W att-Hr Total 

53.86 Watts Peak 

Test Date 6/28/01 
Test 2 - DC load Test With Partly Cloudy Sky Conditions 

As shown in the following figures , the addition of a large ultracapacitor provides valuable 

short-term energy storage for a photovoltaic system. The solar radiation available to the 

systems is shown in Figure 10. Note that there were several times between 3:00 and 

5 :00 PM when clouds caused the available radiation to drop to only 200 watts/meter. 2 

Fig . 10- Solar Radiation With Partly Cloudy Sky Conditions 

1.200 

1.196 KW IrJf Peak 

1.000 

C\J 

:2: 0.800 

S --- o. ~ 

0.400 

0.200 

0.000 

1:30 PM 

8:22 PM 

Test Date 714101 

ASAffM-2001 -211 316 10 

- -----
~--

Figures 11 through 13 show the voltages, currents, and power for the two photovoltaic 

systems under this varying solar radiation. Although the total energy was about the 

same, the voltage swings for the capacitor-equipped system were greatly reduced. The 

data in Table 2 illustrates this result. The shaded areas highlight two times when the 

solar radiation dropped significantly due to cloud cover. Without the capacitor (Panel 1), 

the system voltage dropped from 16.60 to 6 .64 volts and 16.50 to 8.40 volts. With 

the capacitor (Panel 2), the voltage dropped from 16.5 to 15.72 volts and 16.41 to 

16.01 volts. This would be advantageous for a load that requires a minimum voltage 

to <?perate. 

Table 2 - Photovoltaic System Voltage Data for 7/4/01 

Panel 1 Panel 2 Panel 1 Panel 2 

Date & Time Voltage Voltage Date & Time Voltage Voltage 

7/4/01 3:30 PM 16.31 16.5 7/4/01 4:24 PM 16.41 16.5 

7/4/01 3:31 PM 16.21 16.41 7/4/01 4:25 PM 16.41 16.5 

7/4/01 3:32 PM 16.41 16.41 7/4/01 4:26 PM 16.41 16.41 

7/4/01 3:33 PM 16.6 16.5 7/4/01 4:34 PM 16.5 16.31 

7/4/01 3:34 PM 16.6 16.5 7/4/01 4:35 PM 16.5 16.41 

7/4/01 3:35 PM 6.64 16.41 7/4/01 4:36 PM 15.82 16.41 

7/4/01 3:36 PM 11 .62 15.72 7/4/01 4:37 PM 16.5 16.41 

7/4/01 3:37 PM 16.8 16.11 7/4/01 4:38 PM 8.4 16.01 

7/4/01 3:38 PM 16.6 16.31 7/4/01 4:39 PM 16.7 16.01 

7/4/01 3:39 PM 16.5 16.41 7/4/01 4:40 PM 16.6 16.21 

7/4/01 3:47 PM 16.41 16.5 7/4/01 4:41 PM 16.5 16.31 

7/4/01 3:48 PM 16.41 16.5 7/4/01 4:42 PM 16.6 16.41 

7/4/01 3:49 PM 16.41 16.5 7/4/01 4:43 PM 16.6 16.5 

7/4/01 3:50 PM 16.41 16.5 7/4/01 4:44 PM 16.6 16.6 

7/4/01 3:51 PM 16.5 16.5 7/4/01 4:45 PM 16.6 16.6 

NASAfTM- 2001-211316 11 
Fig. 11 - Photovoltaic System Voltages With Partly Cloudy Sky Conditions 

20 

16 

~ 12 

o 

> 8 

4 

o 

5:40 

AM 

8:36 

AM 

11 :33 

AM 

2:29 

PM 

5:26 

PM 

- Panel1 Voltage -Panel2 Voltage w/200 Farad Cap 

17.19 Volts Peak 16.70 Volts Peak 

50 Resistive Load 

Fig. 12 - Photovoltaic System Currents W ith Partly Cloudy Sky Conditions 

4 

en 3 

~2 

«>1 

o 

5:40 

AM 

8:36 

AM 

11 :33 

AM 

2:29 

PM 

5:26 

PM 

- Panel 1 Current -Panel2 Voltage w/200 Farad Cap 

3.44 Amps Peak 3.34 Amps Peak 

50 Resistive Load 

NASAffM-2001-211316 12 

8:22 

PM 

Test Da te 7/4/01 

8:22 

PM 

Test Date 7/4/01 
Fig. 13 - Photovoltaic System Powers With Partly Cloudy Sky Conditions 

60 

50 

CJ) 40 ... 

-; g30 

3="'>20 

1 0 

o 

5:40 

AM 

8:36 

AM 

11 :33 

AM 

2:29 

PM 

5:26 

PM 

- Panel1 Power -Panel2 Power wI 200 Farad Cap 

SQ Resistive Load 

275 W att-H r Total 

59.10 Watts Peak 

NASAffM-2001-211316 13 

261 W att-Hr Total 

55.78 Watts Peak 

8:22 

PM 

Test Date 7/4101 
Test 3 - DC Load Test With Tracking Disabled 

For this test, the solar tracker was disabled and the photovoltaic panels were placed 

in a fixed due south position. Figure 14 shows that the daily total energy (Watt-hour) 

produced with a 5 ohm load was reduced from 670 Watt-hour to 514 Watt-hour under 

clear conditions. 

Fig. 14 - Photovoltaic System Energy With and Without Tracking 

200 Farad Cap 

50 Res. Load 

60 

50 

40 

Watts 30 

20 

10 

0 

7:00 AM 

NASAffM-2001-21 1316 

fB Tracker Dis-Engaged DTracker Engaged 

7/12/01 Data 7/2101 Data 

514 Watt-Hr Total 

59 .10 Watts Peak 

14 

670 Watt-Hr Tota I 

59.72 Watts Peak 

9:30 PM 
Test 4 - AC Load Test With Resistive Load 

For the next test, a 250 Watt inverter with a 100 ohm resistor was used as the system 

load. With the inverter output at 125VAC, this is a 156 Watt load. As illustrated in 

Figures 15 through 17, it was difficult to operate the inverter consistently. Like most 

commercially available inverters, the one tested operates within a relatively narrow 

voltage range (essentially the 12 volt automotive range). It is also protected from under 

and over-voltage by circuits which shut off the inverter. The photovoltaic system that 

powered the inverter has no voltage regulation. A comparator circuit was used to 

enable the inverter when the system voltage was within the inverter specifications. 

Unfortunately, the 100 ohm load was large enough to discharge the capacitor and pull 

down the system voltage to the point where the inverter shut off. The system voltage 

would then recover because of the photovoltaics and the cycle would repeat. By 

adjusting the comparator trigger voltage, the time between cycles could be increased, 

but the inverter would eventually shut off. 

Fig. 15 - Photovoltaic System DC Voltage with Inverter and 100 Ohm Load 

A 

20 

16 I""'-.~ L .f .~ 

U) 12 .... 

g, 8 

4 

o 

2:16 PM 

Load : 1000 

Resistor 

NASAffM-2001-2113 16 

Ad;usting Inverter·"ON " Trigger Level 

2:22 PM 2:28 PM 

- PV Voltage to Inverter 

15 

2:34 PM 

Test Date 8/29/01 

J 
Fig. 16 - Photovoltaic System DC Current with Inverter and 100 Ohm Load 

14 

12 

1 0 ~~ ~ .. -, v 

~.I'- [),M-hN\., v' • ..AA ./'VV\I'Iv 

V 1 

en 

a. 8 

6 

4 

-I--Adjusting Inve rter "ON " Trigge r Level r 

E 

<C 

2 

o 

2:16 PM 

Load: 1000 

Resistor 

2:22 PM 2:28 PM 

- PV Current 

Fig. 17 - Photovoltaic System AC Current with Inverter and 100 Ohm Load 

1.25 

1 

en 

a. 

E 0.75 

<C 0.5 

o 

<C 0.25 

o 

Jl1 Mil 

2:15 PM 

Load: 1000 Resistor 

50 Farad Capacitor 

NASAffM-200 1-211 316 

Adjusting Inverter "ON" Trigger Lev el 

I 

2:21 PM 2:28 PM 

-Inverter 0 utp ut Current 

16 

2:34 PM 

Test Date 8/29/01 

I 

2:34' PM 

Test Date 8/29/01 
Test 5 - AC Load Test With Battery Charger 

For the last test, an AC-powered battery charger and battery combination was operated 

with the PV system . This battery is the power source for EV Global's E-Bike and is a 

good example of a real-world load for this size PV system. Unlike the 100 ohm resistor, 

the battery charger did not reduce the system voltage enough to cause the inverter to 

shut off. The following figures show that the charger operated satisfactorily with the PV 

system. 

Fig. 18 - Photovoltaic System DC Voltage With Inverter and Battery Charger 

20 

16 

U) 12 -

o 

> 8 

4 

o 

1 :55 PM 

Load : E·Bike Battery 

Charger 

NASAfTM- 2001-2 11316 

2:02 PM 2:08 PM 

- PV Voltage to Inverter 

17 

2:14 PM 

Test Date 8/29/01 
Fig. 19 - Photovoltaic System DC Current With Inverter and Battery Charger 

en 

c.. 

E 

« 

10 

8 

6 

4 

2 

o 

1 :55 PM 

Load : E-Bike Battery Charger 

50 Farad Capacitor 

2:02 PM 2:08 PM 

-PV Current 

Fig. 20 - Photovoltaic System AC Current With Inverter and Battery Charger 

0.8 

0.7 

en 0.6 E 0.5 

« 0.4 

(,) 0.3 

« 0.2 

0.1 

o 

1 :55 PM 

Load : E-Bike Battery Charger 

50 Farad Capacitor 

NASAfTM-2001-21 1316 

I 

2:02 PM 2:08 PM 

-Inverter Output Current 

18 

2:14 PM 

Test Date 8/29/01 

2:14 PM 

Test Date 8/29/01 
CONCLUDING REMARKS 

The ultracapacitor enhanced photovoltaic power station as tested and described in this 

report is comprised of commercially available components . Testing performed with 

and without ultracapacitors show the change in photovoltaic system characteristics 

caused by the addition of ultracapacitors. In particular, the comparison tests reveal 

improvements in photovoltaic system performance which are created by the 

ultracapacitors' short-term energy storage characteristics. Testing with an inverter and 

large resistive load illustrates the difficulties presented by a device that operates within 

a narrow voltage range. Operating the inverter with a smaller load, the battery charger, 

shows that the photovoltaic and ultracapacitor system can function well in a real-world 

situation . 

NASAfTM-2001 -21 1316 19 
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1-

APPENDIX A 

POWER STATION SUMMARY DATA SHEET 

1.0 Photovoltaic Panel 

1.1 Manufacturer 

1.2 Type 

1.3 Configuration 

1.4 Voltage 

1.5 Power 

1.5 Dimensions 

1.6 Weight 

2.0 Photovoltaic Panel Solar Tracker 

2.1 Manufacturer 

2.2 Type 

2.3 Configuration 

2.4 Dimensions 

2.5 Weight 

3.0 Ultracapacitor 

3.1 Manufacturer 

3.2 Type 

3.3 Configuration 

3.4 Voltage 

3.5 Capacitance 

3.6 Energy 

3.7 Dimensions 

3.8 Weight 

4.0 Inverter 

4.1 Manufacturer 

4.2 Type 

4.3 Configuration 

4.4 Input 

4.5 Output 

4.6 Dimensions 

4.7 Weight 

NASAfTM- 2001-2 11316 

Kyocera 

PV2898 

Multicrystal modules, two panels on station 

16.9 volts dc each 

120 Watts each 

56.0"x25.7" each 

26.2 Ibs. each 

Zomeworks 

TM3855 

Non-energy-consuming thermal activation 

Accommodates two 56.0"x25.7" panels 

821bs. 

Alumapro 

18PP-8/0,006 

Dual layer, electrochemical, four in parallel 

18 volts dc 

50 farads each, 200 farads total 

8.1 kilojoules each, 32.4 kilojoules total 

6.5"x7.0"x3.25" each 

1 0 Ibs. each, 40 Ibs. total 

Exeltech 

XP-2-1-1-6-0-X7 

True sine wave output inverter 

12 volts dc 

117 volts ac, 2.1 amps ac, 60 Hz 

101bs. 

21 
Page intentionally left blank 
APPENDIX B 

DESCRIPTION OF THE INSTRUMENTATION SYSTEM 

A block diagram of the instrumentation system is shown in Fig . B-1 . 

The ultracapacitor enhanced photovoltaic power station has an integral instrumentation 

system. The instrumentation system includes three portable data loggers. Each data 

logger has fou r analog inputs. The first data logger monitors the dc load voltage and 

current of each of the two photovoltaic panels. The second data logger monitors the 

temperature of each photovoltaic panel , as well as the ambient temperature, and the 

internal cabinet temperature. The third data logger monitors the solar radiation and AC 

current to drawn by inverter loads. These data are sampled at one sample per minute 

and stored on the data loggers. This data is downloaded weekly to a personal data 

assistant taken to the photovoltaic power station. The personal data assistant is then 

transported to the desktop PC where the data is downloaded via a serial interface. 

All voltages are derived from voltage dividers. DC currents are derived from current 

shunts. AC current is derived from a Hall-effect transducer. All temperatures are 

derived from active semiconductor temperature probes. 

Fig. B-1 - Ultracapacitor Enhanced Photovoltaic Power System Instrumentation System 

I 

I 

I I 

PANEL 1 VOLT I I ... I 

I 

I PANEL 1 CUR I _ ... 4 CHANN EL I I ... I DATA I 

I I LOGGER DESKTOP PANEL 2 VOLT I I PC I 

I I 

PANEL 2 CUR I I ... I 

I 

I ~ I 

l I 

PANEL 1 TEMP I I ... I 

I .. I PANEL 2 TEMP I .. 4 CHANNEL ... I .... PERSONAL I DATA I DATA I UL TRACAP TEMP I I ---.. LOGGER ASSISTANT I ... I (PDA) ---.. 

I I .. ... LOAD TEMP J I .... I 

I 

I 

I 

I I .. SOLAR RAD I I 

I 

I 

I AC CURRENT I .. 4 CHANNEL J I 

I DATA I 

I LOGGER I 

I 

I 

I 

I 

VOLTAIC POWER STATION I PHOTO I 

I 

: _ ____ _______ __ _____ _ _ __ ____ _ _ ____ ___ 1 

ASAffM- 2001-211316 23 
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Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. 

1. AGENCY USE ONLY (Leave blank) 

1

2

. 

REPORT DATE 

1

3

. 

REPORT TYPE AND DATES COVERED 

November 200 1 Techni ca l Memorandum 

4. TITLE AND SUBTITLE 5. FUNDING NUMBERS 

Baseline Testing of the Ultracapacitor Enhanced Photovoltaic Power Station 

6. AUTHOR(S) ~-25 -30-O7 00 

Dennis J. Eichenberg, John S. Kolacz, and Paul F. Tavemel[j 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION 

REPORT NUMBER 

National Aeronautics and Space Adrninisu'ation 

John H. Glenn Research Center at Lewis Field E-13 127 

Cleveland, Ohio 44135 - 3 19 1 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING/MONITORING 

AGENCY REPORT NUMBER 

National Aeronautics and Space Adrninisu'ation 

Washington, DC 20546-0001 NASA TM- 2001-2 11316 

11. SUPPLEMENTARY NOTES 

Responsible person, Dennis J. Eichenberg, organization code 7720, 2 16--433- 8360. 

12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE 

Unclassified - U nlimited 

Subject CategOIies: 32, 33, and 44 Distributio n: Nonstandard 

Available electl'Onically at htrp:llg It rs.grc .n a~a.aov/GLTRS 

This publication is available from the NASA Center for AeroSpace InfoIll1ation. 301 -62 1-0390. 

13. ABSTRACT (Maximum 200 words) 

The NASA John H. Glenn Research Center is developing an advanced u!tracapacitor enhanced photovolraic power station. Goals of 

th is effort include maximizing photovoltaic power generation effic cy and extending the life of photovoltaic energy storage systems. 

Unique a pects of the power station include the use of a solar tracker. and ulu'acapacitors for energy storage. The photovoltaic power 

station is seen as a way to provide elecnic power in remote location that would otherwise not have elecnic power, provide independence foml utility systems, reduce pollution, reduce fossil fuel consumption, and reduce operating costs. The work was done under the 

Hyblid Power Management (HPM) Program, which includes the Hybrid Elecnic Transit Bus (HETB), and the E-Bike. The power 

station complements the E-Bike extremely well in that it permits the charging of the vehicle batteries in remote locations. Other 

applications include scientific research and medical power sources in isolated regions. The power station is an inexpensive approach to 

advance the state of the an in power technology in a practical application. The project u'ansfers space technology to terresnial u e via 

nontraditional partners, and provides power system data valuable for future space applications. A description of the ultracapacitor 

enhanced power station, the results of performance testing and future power station development plans i the subject of this report. The 

report concludes that the u1tracapac itor en.hanced power station provides excellent performance, and dlat the implementation of 

ultracapacitors in the power system can provide significant performance improvements. 

14. SUBJECT TERMS 15. NUMBER OF PAGES 

27 

Photovoltaic conversion 16. PRICE CO DE 

17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACT 

OF REPORT OFTHIS PAGE 

U nclassified Unclassified 

NSN 7540-01-280-5500 

OF ABSTRACT 

Unci assifi ed 

S ta nda rd Form 298 (Rev. 2 -89) 

Prescribed by ANSI Std. Z 39- 18 

298-102