8/2/2019 Energy 2nd Draft Alex

1/14

Power G g eneration P p otential and Cost of a

R oof T op S s olar PV S s ystem in Kathmandu,

Nepalon a KTM roof

Abstract

The paper presentsosses a comparative study of the 3 mostcommonly used solar PV

module technologies in Nepal, which are Si-mono-cristalline, Si-poly-cristalline and

Si-amorphouspanels for the roofs in Kathmandu Valley. The aim of the paper is to

present and discuss the recorded Global Solar Radiation, received in the Kathmandu

valley analyze Global solar radiation captured by three different, , Si-mono-crystalline,

Si-poly-crystalline and Si-amorphous calibrated solar cell pyranometers and to

proposefind out the best-suited solar PVphotovoltaic module technology panel for

roof top solar PV systems inside the Kathmandu valley. Data recorded over the

course of one year, thus covering all the various seasonal meteorological conditionsdetermining Kathmandu valleys gGlobal solar radiation reception are presented. The

results indicate that the captured by Si-mono-cryystalline pyranometer capturedis

1.67% more global solar radiation higher than the Si-aAmorphous, pyranometer and

16.44% morehigher than Si-pPolycrystalline pyranometer over the course of the year.

Whereas, global solar radiation captured by Si-Amorphous pyranometer is 15.01%

higher than Si-Poly-crystalline pyranometer. Among the three pyranometer

technologiess the maximum cell temperature was measured by the is attained by Si-

aAmorphous pyranometer , which is 48.130C and thewhile the minimum temperature

measuredattained was with theis by Si-Mono-crystalline pyranometer, which is

15.520C.

. Following the technical data and discussion, an economical analyses, using the

versatile software tool PVSyst 4.36 is used to calculate the life cycle costs of a 1kW

roof top solar PV system through simulations, using the actual recorded data and

investigated market values for each solar PV module and peripheral equipment costs.

8/2/2019 Energy 2nd Draft Alex

2/14

Keywords: PV panels, Global solar radiation, Pyranometers

8/2/2019 Energy 2nd Draft Alex

3/14

1. Introduction

It is well known that access to improved energy services is one of the key factor

for sustainable development. Energy is the ultimate necessity of life. Its been

decades since we as human beings have been taking energy for granted.The more

urbanized areas around the globe, and till recent years as well in Nepal, have taken

it for granted that they have access to electricity around the clock, without really

considering what and when they plug in their equipment. Even nations have ignored

the energy availability factor in their policy-making and Nepal is no exception. But

tThe recent 20 hours/ per day load-shedding during the dry season and 1-2 hour

load-shedding during the rainy season has forced us to learn the hard way the actual

value of having readily access to electricity. Its not that Nepal has not the needed

natural and renewable resources. In contrary, Nepal is blessed with one of the most

abundant renewable water resource to generate electricity. The average is quite

evident to show the negligence of energy in Nepal; this is despite the fact that on

8/2/2019 Energy 2nd Draft Alex

4/14

overall count, Nepal has the second largest hydropower potential, which is attributed

to an annual discharge of the over 6000 rivers with about 225 billion cubic meters,

out flowing rivers ffrom the high altitude Nepal Himalayas down to India about 225

billion cubic meters from over 6,000 rivers with many rivers, losing an average

height of about around 4000 meters 4,000 meters just within a north-south distance

of just 100-200 km, create an economical feasible power generation potential of

around 42000 MW. .

Apart the hugefrom such behemoth potential of hydropower, Nepal has localized

wind resources, geothermal resources, biomass and receives abundant solar power,

equally distributed all over the country. Undoubtedly, hydro power plants areis one of

the best, long-term sources to fulfill Nepals growing the total load demand of Nepal,

be it as RAPS systems, medium or large scale power plants. Bbut there are some

particular issues with the building and maintaining of large scale hydro power plants

which are important and thus have to be taken in due time into consideration.it is

accompanied by some shortcomings, which are often associated with installation of

hydropower plants. Some of these issues are:

The utilization of h Since the hydropower is very site specific and thus

needs detailed feasibility studies, including the studies of the impact to the local

communities and fragile environment.

In most cases the needed energy is geographically different from

where the hydro resource is, demanding long, expensive to build and maintain

transmissions lines.

Hydro power plants are long-term projects and take years to be built

and completed. This has to be considered throughout the planning and execution. Thus

a strong and realistic energy planning is needed at the government level, as no sudden

energy gap can be met with a large scale.

Hydro power plants , especially built in remote , high altitude areas , pose

significant changes to the aquatic system of a river. Nepals different climatic zones, with

each zones own unique and pristine flora and fauna, are sustained and kept alive by

the streams flowing through them. Thus, any significant changes to the flow and

8/2/2019 Energy 2nd Draft Alex

5/14

landscape poses unpredictable long-term stresses and changes to the rivers

downstream ecosystem.

The building of hydropower plants is very cost intensive. This is in

particular the case for Nepal, with its rouged and remote areas, geological instable rocks

and mountain layers. Thus not just the building of the power plant, but as well the

transport costs are immense.

Nepals fragile and unique environment present new and very

challenging engineering problems, which can not mostly not be tackled with standard

engineering solutions, it costs a lot for transporting to the demand site. .

In the context of Nepal, with its remote areas and steep valley s, hydro

power plants with storage dams often demand considerable resettlements of the local,

indigenous people groups. It is well known that this poses always unforeseen social and

cultural problems.

The building and operating of large scale hydro power plants in remote

areas in Nepal poses great challenges in regard to the protection and maintaining of the

wildlife. Access roads, often changing the local landscape significantly, cause often

significant environmental as well as social issues. They are not taken as serious as they

should be due to the lack of needed policies (such as minimal laborer and

environmental protection policies), sound planning and engineering, as well as

accompanying the needed infrastructures.

While hydro power is and will continue to be Nepals main energy

generation resource, tApart from this, installations of big hydropower plants provoke

resettlement problems and dramatic environmental issues, mostly affecting marine

ecosystems.

he utilization and conversion of the abundant, at the place of the needed energy,

availableRather, solar energy through solar photovoltaic arrays, poses often

underestimated good opportunities.

Solar PV power plants, which is abundantly available, and can be installed in

almost any specific site, thus generate power wherever required.

8/2/2019 Energy 2nd Draft Alex

6/14

With the todays available different solar PV technologies it is , and is suitable

for most of the any geographical and climatic locations.

, as Nepal lies in Solar Belt. The building of a solar power plant can take place

within a time frame of weeks or months rather than years, and thus a potential

forthcoming short term energy demand growth can be taken into consideration.

Due to the solar PV technologys nature there is a clear boundary to each

solar PV project, making it save for the local communities and environment, with no

impact beyond its geographical project location. Thus solar PV arrays or power plants

pose no grave danger to the ecosystem up- or down-stream.

Being a motionless technology, once built and in operation, a solar PV

system demands only minimal operational and maintenance effort, which can be easily

carried out by locally trained people.

Being locally built, operated and maintained, with the power locally consumed,

solar PV system are also often owned by the local community. That creates a strong

ownership, an important social parameter for a long-term sustainable project.

No applied technology has only positive points, thus also solar PV systems do have

their shortcomings and inherent limitations which need to be known and taken into

consideration for any project. The main shortcomings and limitations are:

Solar energy is an intermittent energy resource, thus demanding some kind of

energy storage (usually lead acid batteries) if power is needed during the no-sunshine

periods.

Solar energy is, mainly compared to the non-renewable , fossil energy

resources, a low density energy resource, with around 1000 watt/m2 incoming global

solar radiation at a good, sunny day. This inherently demands much bigger plant sizes

for bigger power demands.

Presently , the solar PV technology is still an expensive technolog y,

considering the kWh unit life cycle conversion cost.

For most of the present available so la r PV technologies, Its true thatexcessively high ambient temperatures and high air pollutionly polluted environment

8/2/2019 Energy 2nd Draft Alex

7/14

affects the power production from solar PV. So, it is best suited in less polluted

environment and moderate and lower ambient temperature.

The present power shortage under which in particular the more urbanized areas

suffer, is not a short term problem. Rather it is a long-term problem we have become

the victims of, due to wrong and inadequate decisions taken 10-15 years ago

regarding the urgent needed expansion and building of new hydro power plants.

Further, the narrow focus, to concentrate all effort on the exploitation of a single

energy resource, is also inadequate and needs to be revised, so that all local

available renewable energy resources can be tapped in to enhance and improve the

access to electricity.

In order to work towards this change, this paper addresses the important issue of

understanding the different power and energy production possibilities of the three

major, in Nepal available, solar PV technologies, which are Si-mono-crystalline, Si-

poly-crystalline and Si-amorphous.

Among all the solar photovoltaic panels there are 3 different kinds of widely used

solar photovoltaic panels namely Mono-crystalline solar photovoltaic panels, Poly-

crystalline solar photovoltaic panels and Amorphous solar photovoltaic panelsIn

order t. Too find out the best solar PVphotovoltaic module technology with regard to

the highest energy generation for the Kathmandu valley meteorological conditions

over the year, RIDS-Nepal and the Kathmandu University have started a long-term

research project. In the main RIDS-Nepal office in Imadol, Kathmandu, panel

regarding the power generation in Kathmandu; we conducted a research at RIDS-

Nepal office at Kathmandu. We carried our test on three different types of

Pyranometers, each one Si- (mono-crystalline, one Si-poly-crystalline and one Si-

amorphous have been installed in November 2008. U) under the same ambient

conditions these three different calibrated solar PV cell pyranometers will measure

the actual captured global solar radiation, thus providing first hadn field data and

results to identify the most efficient and highest energy producing solar PV

technology for the Kathmandu valley context. .

8/2/2019 Energy 2nd Draft Alex

8/14

2. Methodology

2.1 Research Station

The geographical location of RIDS-Nepal office at Kathmandu (the research station)

is

Latitude : 2740'04.70" North

Longitude : 8520'31.55" East

Altitude : 1311 meter above sea level

Three pyranometers, namely Si-mono-crystalline, Si-amorphous, and Si-poly-

crystalline are installed in the roof of the research station, each accompanied by a

thermocouple type (TT-type) sensor. The pyranometers measure the global solar

radiation and the sensors measure the back temperature of each pyranometer.

2.2 Data-Taker DT80 (Data logger)

The data-Taker DT80 is a smart data logger that provides an extensive array offeatures that allow it to be used across a wide variety of applications. The DT80 is a

robust; stand alone, low power data logger featuring USB memory stick support, 18-

bit resolution, extensive communications capabilities and built-in display. The data-

Taker DT80s Dual Channel concept allows up to 10 isolated or 15 common

referenced analog inputs to be used in many combinations.

2.3 Solar Path Diagram

Solar path diagram in rectangular and polar co-ordinates for the research site at

Imadol, Kathmandu (RIDS-Nepal), as plotted by software PVSYST4_37 are as

shown below:

8/2/2019 Energy 2nd Draft Alex

9/14

Fig1. Solar path diagram of the research station (RIDS-Nepal) in Rectangular Co-

ordinates

8/2/2019 Energy 2nd Draft Alex

10/14

8/2/2019 Energy 2nd Draft Alex

11/14

8/2/2019 Energy 2nd Draft Alex

12/14

Fig3. Hourly average Radiation along with the back temperature of pyranometers

2.4 Collected data

Pyranometer

type

Hourly average

global solar

radiation

(kWh/m2/day)

Minimum

temperature

attained (0C)

Maximum

temperature

attained (0C)

Si-mono-

crystalline4.928 15.52 46.44

Si-amorphous 4.845 16.13 48.13

Si-poly-

crystalline 4.117 18.43 47.83

2.5 Analysis of the collected data:

Hourly Average global solar Insolation captured by Si-Mono-crystalline pyranometer

is 4.928kWh/m2/day.

(+1.67% higher than Si-Amorphous pyranometer and +16.44% higher than Si-

Polycrystalline pyranometer)

Hourly Average global solar Isolation captured by Si-Amorphous pyranometer is

4.845kWh/m2/day.

(+15.01% higher than Si-Poly-crystalline pyranometer)

Hourly Average global solar Insolation captured by Si-Polycrystalline pyranometer is

4.117 kWh/m2/day.

8/2/2019 Energy 2nd Draft Alex

13/14

3. Conclusion

This paper resembles the abundant availability of solar power and the importance

for using the renewable energy resources. It also suggests the best possible system

along with all necessary accessories to meet the energy demand of a house for the

family of four. The paper analyzes the global solar radiation measured by different

pyranometers, and temperature measured by thermocouple type (TT) sensors in the

roof of RIDS-Nepal office at Kathmandu. It identifies the best photovoltaic panel and

the system for power production in the roofs of Kathmandu valley.

8/2/2019 Energy 2nd Draft Alex

14/14

References

1. http://www.datataker.com/products/dt80.html

2. http://www.ntu.edu.sg/home/mspokharel/Energy%20in%20Nepal.pdf)

http://www.datataker.com/products/dt80.htmlhttp://www.ntu.edu.sg/home/mspokharel/Energy%20in%20Nepal.pdfhttp://www.ntu.edu.sg/home/mspokharel/Energy%20in%20Nepal.pdfhttp://www.datataker.com/products/dt80.htmlhttp://www.ntu.edu.sg/home/mspokharel/Energy%20in%20Nepal.pdf