Solar power on the top of the world

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Karlstads universitet 651 88 Karlstad Tfn 054-700 10 00 Fax 054-700 14 60 Information@kau.se www.kau.se Fakulteten för hälsa, natur- och teknikvetenskap

Miljö- och energisystem

Linnea Gunnarsson Knutsson

Solar power on the top of the world

Possibilities to provide the school in Thade, in Nepal, with electricity from a solar cell system

Solel på världens tak

Möjligheten att tillgodose skolan i Thade, i Nepal, med elekticitet från ett solcellssystem

Examensarbete 30 hp

Högskoleingenjörsprogrammet i energi- och miljöteknik

Juni 2016

Handledare: Magnus Ståhl Examinator: Lena Brunzell

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Abstract

Nepal, a country located between India and China, is one of the world’s least developed countries.

Access to electricity is a problem throughout Nepal. Both for the grid connected areas that suffer from power cuts up to 16 hours a day during the dry season, and for remote areas where lack of money, infrastructure or even the location itself set limits for the electrification.

In the eastern part of Nepal, around 100 km south of Mount Everest is Thade, a small mountain village with about 200 residents. Until 2015 the village only had an old, dilapidated school building that was in such bad condition that it could barely be used. Therefore, many of the children in the village did not go to school, and it was only the families with enough money that could send their children to a better school. Other children had to walk for hours to reach the nearest school.

With contribution and support from a Swedish-Nepali non-government organisation (NGO)a new school opened in May 2015. One year later there are 42 children at the Grace Academy School.

One of the main problems for the school today is that they do not have any electricity, which places limitations on both teachers and students.

The purpose of this study was to investigate if it is possible, in a simple and sustainable way use a solar cell system with battery storage to meet the basic needs for electricity of the school.

The aim was to build a simulation model, of the energy system, in MATLAB’s Simulink® program and then validate the result from that model to the result from the commercial solar system program PVsyst. Tilt and orientation of the panels was optimized specifically for Thade School to get as much electricity as possible from the prevailing conditions.

Further, the aim was to, through interviews and conversations with the residents in the village and people connected to the school project, gain an understanding of how electrification of Thade School would affect the school, the teachers and the students, as well as the village and its residents.

In general, Nepal has very good conditions for solar power, with around 300 days of sunshine annually. According to the residents of Thade, the weather is usually clear and sunny early in the morning, but after 10am it most often becomes cloudy and foggy. Hence investigation whether solar power in Thade would work is interesting.

Electrification of the school would allow for easier learning and most likely increase the status of the school in the surrounding area. It would be easier for students and stuff to get information from the outside world, especially if their plan for Internet access is incorporated in the future. The interest for teachers to come to Thade would perhaps increase. Today the school has a hard time getting good teachers to come, to teach and live in the small mountain village. The children attending the school would also have a better chance to compete with other children to enter University or further educations. The advantages of electrification for Thade are clear.

Three different cases were simulated, with different assumptions of the solar radiation. The results showed that solar power could cover about 95 % of the annual demand, based on the needs that were reported as needed today.

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Sammanfattning

Nepal, ett land inklämt mellan Indien och Kina, är ett av världens minst utvecklade länder.

Tillgången på elektricitet är ett problem i hela Nepal, både för de nätanslutna områdena som kan ha strömavbrott upp till 16 timmar per dygn under torrperioden, men även för avlägsna områden där bristen på pengar, infrastruktur eller bara platsen sätter gränser för elektrifiering.

I den östra delen av Nepal, ca 100 km söder om Mount Everest, ligger Thade, en liten bergsby med ca 200 invånare. Fram till 2015 hade byn endast en gammal sliten skolbyggnad som var i sådant dåligt skick att den knappt gick att använda. Därför gick många av barnen inte i skolan, och det var bara familjer med mycket pengar som kunde skicka sina barn till bättre skolor. Andra barn var tvungna att gå i timmar för att komma till den närmsta skolan.

Med bidrag och stöd från en Svensk-Nepalesisk icke-statlig organisation (NGO), kunde en ny skola öppna i maj 2015. Ett år senare går 42 barn i Grace Academy School. Ett av de största problemen för skolan idag är att de inte har någon elektricitet, vilket skapar begränsningar för både lärare och elever.

Syftet är att undersöka om det är möjligt att på ett enkelt och hållbart sätt kunna tillgodose skolans grundläggande behov av el genom ett solcellssystem med batterilagring.

Målet är att bygga en simuleringsmodell, över energisystemet, i MATLABs Simulink® program och sedan validera resultatet från den modellen med resultatet från det kommersiella solsystem programmet PVsyst. Lutning och orientering av solpanelerna kommer att optimeras specifikt för Thade skolan för att få ut så mycket energi som möjligt från de rådande förhållandena.

Vidare är syftet att genom intervjuer och samtal med invånarna i byn och personer med anknytning till skolprojektet, få en förståelse för hur en elektrifiering av skolan i Thade kan komma att påverka skolan, lärarna och eleverna, men också byn och dess invånare.

Nepal har i allmänhet mycket goda förutsättningar för att använda solenergi, med ca 300 soldagar per år. Enligt personerna som bor i Thade är vädret ofta råder ofta klart och soligt på förmiddagen, men ungefär efter klockan 10 blir det ofta molnigt och dimmigt. Av den anledningen är det intressant att undersöka möjligheterna för solenergi i just Thade.

Elektrifiering av skolan skulle underlätta utbildningen och förmodligen höja statusen för skolan.

Det skulle göra det enklare för både elever och personal att få tillgång till information, speciellt om planen att i framtiden skaffa internet går i lås. Intresset att vara lärare i Thade skulle förhoppningsvis öka. Idag har skolan svårt att få bra lärare som vill komma och undervisa och bo i den lilla bergsbyn.

Barnen skulle också få en större chans att tävla med andra barn om att komma in på universitet eller vidareutbildningar. Fördelarna med elektrifiering av Thade skolan är många.

Tre olika simuleringar gjordes, med olika antaganden för solinstrålningen. Resultatet visade att solenergin kan täcka ca 95% av den årliga efterfrågan, utifrån de behov som sades behövas idag.

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Preface

This bachelor thesis comprises 30 ECTS points and has been presented to an audience versed in the subject, the work was subsequently discussed at a special seminar. The author of this work participated actively at the seminar as an opponent to another bachelor thesis. This thesis was carried out as the final part of the bachelor program in energy and environmental technology at University of Karlstad.

The field study in Nepal was financed by the Minor Field Studies (MFS) scholarship founded by Swedish International Development Cooperation (SIDA) and by ÅForsk Travel Grand founded by ÅForsk Foundation.

I would like to thank following people:

My supervisors Magnus Ståhl and Wamei Lin at University of Karlstad for support, help and new approaches. Jens Beiron for technical support with the Simulink model and Lena Brunzell for examination of the report.

To Heidi Ek for information about Thade School Project, to Kate Bramley-Moore for help with language correction and an extra big thank you to Hari Kumar Magar and his family for their kindness and for provide accommodation and food during my stay in Thade.

Finally, a special thanks to Saran Subba, owner of HiOnLife and president of Grace Academy Thade, for help with organizations and contacts in Nepal and to the principal, teachers, children and residents at Thade School and Thade village for a warm-hearted welcome, a memorable visit and an amazing adventure in their beautiful country.

Linnea Gunnarsson Knutsson Karlstad, June 2016

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Nomenclature

Symbol Description Unit

A Area of solar cells m²

Et Equation of time min

I Direct solar radiation W/m²

Iglo Global irradiance striking the surface W/m²

INOCT Incident radiation at NOCT °C

Lloc Local longitude °

Lstd Longitude of the time zone °

n Day of the year -

P Output power from solar cells W

Ta Ambient temperature °C

Tc,stc Module temperature at STC °C

Ta,NOCT Ambient temperature at NOCT °C

Tc,NOCT Module temperature at NOCT °C

tsol Solar time hours

tstd Standard time hours

δ Declination °

𝜂c Temperature-corrected module efficiency -

𝜂stc Reference module efficiency at STC -

θi Incidence angle of sun on surface °

θs Zenith angle of sun °

θp Zenith angle of surface, tilt from the horizontal °

λ Latitude °

μ Temperature coefficient of efficiency °C^-1

ɸp Azimuth angle of surface, orientation of the surface °

ɸs Azimuth angle of sun °

ω Solar hour angle °

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1. Introduction

Despite hundreds of millions of people acquiring energy access in the last two decades, 1.2 billion people – 17 % of the world’s population – still did not have access to electricity in 2013. Of those without access to electricity, 95 % live in countries in sub-Sahara Africa and developing Asia (IEA 2015). Electricity is a basic need, but it should not be a source of damage to the environment.

Therefore, it is important that development and electrification are done in a sustainable way. One way is to ensure that developing countries start using primarily renewable energy sources.

To get sustainable development, three things need to be included and integrated: economic growth, social development and environmental sustainability. If all these three come together, the ‘Triple win’ outcomes that strengthen all strands of sustainable development are achieved, as shown in Figure 1 (UNDP 2012).

Figure 1: Sustainable development and "triple win" UNDP (2012)

In 2014 it was estimated that 27.7 % of the global power generating capacity came from renewable energy. The increase of renewable energy mainly comes from wind power, solar PV (photovoltaic) and hydropower. Solar PV had a year of record for growth with 40 GW installed, with a total capacity of 177 GW (REN21 2015).

In September 2015 United Nation’s member countries together adopted the 2030 Agenda for Sustainable Development. It contains 17 new Sustainable Development Goals, called SDGs. SDG number 7 aspires to ensure access to affordable, renewable, sustainable and modern energy for all.

As can be seen in Figure 2 (REN21 2015) the solar PV capacity in the world has increased significantly in the years between 2004 – 2014, from 3.7 GW to 177 GW.

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Figure 2: Capacity of solar PV in the world between 2004 – 2014. Picture from REN21 (2015)

1.1 Solar photovoltaic system (PV-system)

The solar radiation that hits the Earth’s surface is different in different places. It depends on atmospheric effects, like absorption and scattering, local variation in atmosphere such as water vapour, clouds and pollution. The radiation also varies by latitude, location, season of the year and time of day. One hour of solar radiation reaching the Earth is enough to cover the amount of energy used by the whole world’s population over a year (PVeducation 2016).

Solar cells convert solar energy into electricity and have the advantage that they do not have any moving parts or requires no major service. A solar system with battery storage is also easy to expand over time with more solar panels and/or more batteries.

Solar cells are often combined into photovoltaic panels or modules, with around 36 cells, where each separate cell gives a voltage around 0.5 – 0.7 (Solelsprogrammet n.d.).

The panels can be connected in series or in parallel. Panels connected in parallel increase the current of the system (ampere), and the voltage is decided by the panel with lowest voltage. Therefore, it is important that panels with the same nominal voltage are connected in parallel. For panels connected in series, the voltage for the system increases and the current is decided by the panel with the lowest current. Therefore, it is important that panels in series have the same nominal current (Solar Lab Sweden^b 2016).

Solar panels are often labelled with STC (standard test conditions) that shows the panel’s peak power. However, it is very rare to achieve in real conditions. Instead NOC (nominal operating conditions) or SOC (standard operating conditions) are used to get a better understanding of the module’s performance, which make it easier to compare different modules (Timerdahl & Walding 2014). Differences between the test types can be seen in Table 1.

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3 Table 1: Difference between test types STC, NOC and SOC

STC NOC SOC

Wind speed [m/s] - 1 1

Insolation [W/m²] 1000 800 1000 Ambition temperature

[°C] - 20 20

Cell temperature [°C] 25 NOCT^* NOCT^*

*NOCT (nominal cell operating temperature) is the temperature the cell gets to during the test

Solar cells produce direct current (DC), and the most important thing for electrification via solar panels is getting the load right and adjusting the voltage accordingly. However, most systems available that allow you to get the load you need require an inverter to convert direct current (DC) into alternating current (AC), which causes losses in the system. So while it should be technically possible to connect a system up running directly on DC, the currently available solar panel systems do not easily allow for this and as such there will be losses due to conversion.

There are two main types of solar cells today: crystalline silicone and thin-film solar cells. Crystalline is the most common and is available in two variants, monocrystalline and polycrystalline cells.

Crystalline cells have a slightly higher efficiency than thin-film cells, but the price is also higher.

Thin-film cells have the advantage that they are considered to work slightly better in diffused light, for example if the sun is obscured behind a thin cloud (Solceller n.d).

Impact on the solar cells

The ambient temperature affects the temperature of the solar cell and as the temperature of the solar cell rises it reduces the cell’s efficiency.

If one cell in a panel, being serial connected to the others, is in shadow the whole panel gets affected negatively. Just one leaf on the front of one cell, means efficiency of the whole panel is reduced.

The cell with the lowest efficiency determines the total efficiency of the panel and the panel has the same capacity.

If dirt or dust cover the solar cell’s surface, it has a negative impact on the efficiency. The transmittance is reduced and the solar radiation reduces. It is not clear how much profit there is in washing or cleaning solar panels. This depends mostly on where the panels are located and how accessible they are (Timerdahl & Walding 2014).

A solar panel covered with 2 cm of snow reduces the available solar radiation to as low as 20 % of the original radiation. But there is not only a negative effect for the electricity supply from snow, a whiter surrounding reflects solar radiation in the snow, which increases the electricity supply gained through solar panels (Timerdahl & Walding 2014).

Battery storage

Today there are a variety of batteries on the market. For smaller solar PV systems lead-acid batteries are often used. It is a mature technology that works well in systems for undeveloped areas. They are often cheaper, and in those areas the economic aspect is important. It is still worth checking other batteries as the technology advances all the time and the prices drop. For example, lithium- ion batteries in recent years have had a rapid cost decline (IVA 2015).

The life cycle of a battery is defined by the number of charges and discharges that can be made before it loses much of its performance (IVA 2015).

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State of charge (SOC) describes how much energy there is left in the battery. If SOC is 100 % it means that the battery is fully loaded, and if SOC is 0 % the battery is completely discharge.

Batteries should generally not discharge more than a certain percentage of their maximum energy, as it shortens their lifespan. It is recommended to not discharge more than 70-80 % of its maximum effect. This is regulated by the charge controller (Steen Englund 2012).

On “Batteriexperten (n.d)” they have different types of batteries, specifically produced for solar systems, and they rank them after quality. The best batteries are either Absorbent Glass Math (AGM) or gel batteries. They have a recommended discharge percentage of 80 % and a low self- discharge. The gel batteries are also resistant to frostbite. The battery they do not recommend for solar system is the leisure battery. They may be cheaper but have a lower number of life cycles and a much higher rate of self-discharge.

If several batteries are required they should all have the same age, then there is a greater chance that they will break-down at the same time and can be replaced at the same time. Also because the least effective battery is the one that decides the performance (Steen Englund 2012).

The ambient temperature also has an effect on battery performance. If the ambient temperature is high, the battery drops capacity faster, cold temperatures are also not good. In cold ambient temperatures the reactions in the battery get sluggish and the electrolyte can also freeze.

Charge controller

A charge controller will adjust the electricity between the solar panels, the loads and the batteries.

It controls the charging and discharging of the battery. If a battery gets overcharged it will be damaged, and if it discharges too much, or to often it will reduce the life expectancy. There are many types of charge controllers, but the ones with “maximum power point tracker” (MPPT) are recommended in order to get more charge power from the solar panels. A MPPT controller has efficiency of around 97% (Steen Englund 2012). It is the charge controller which may be the limitation in the system. If the current from the panels is too high only one charge controller may not match the high current and several charge controllers may be required. It is therefore important to ensure that all the products in a system are working together.¹

1.2 The situation in Nepal 1.2.1 Background

Nepal is located on the south Himalayan range, between China and India. Nepal is also one of the world’s least developed countries with about 80 % of the population living in rural communities (K.C. Surendra et al. 2011). If everybody in the world would live like an average Nepalese and have the same level of consumption, there would only be a need for 0.5 globes (Globalis^b 2013), compared to Sweden that would need 3.6 globes (Globalis^a 2016).

The majority of the people in Nepal live on agriculture, mainly for their own use. At the beginning of the 1900s the tourism sector growth was rapid, but slowed down during the civil war 1996-2006.

After the war tourists have started to come back again, and today the tourism sector is one of the most important sources of income. Many of the tourists come to Nepal for trekking or mountain climbing. Eight of the world’s ten highest mountains are located in Nepal, including the highest one – Mount Everest (Landguiden 2014).

1.2.2 Electrification in Nepal

Nepal has no reserves of gas, oil or coal, and despite the fact that hydropower is the energy resource they could use most, less than one percent of its potential 83 000 MW is utilized. The energy sector is, according to a government policy document, the main sector for Nepal’s economic growth and to fulfil the Sustainable Development Goals (NEEP 2015). The energy sector also connects all

1 Leif Svantesson, works at Solenergi och Teknik i Åmål AB, contact 2016-05-23

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three pillars for sustainable development – economic, social and environmental development (Government of Nepal 2015).

Nepal’s purposed goal for 2030 is that 99 % of households should have access to electricity.

Further, Nepal aims at installing 2100 MW grid connected solar PV plants until 2030. Today nearly three-quarters of households in Nepal use firewood for cooking and the target is to reduce this number to be only 10 %. According to the governmental report “Sustainable Development Goals 2016-2030” one of the conditions to meet SDG 7, is to increase the hydropower production at least 10 times until 2030.

In 2012, the total installed capacity of all electricity-generating plants in Nepal was 719 MW (Government of Nepal 2013). The same year the percentage of people in Nepal that has access to electricity was 76.3 % (Worldbank 2016). But according to Government of Nepal and UNDP (2013), this number can vary a lot, down to only 53 %. Even if access to electricity is high, the quantity and quality of electricity supply is a problem, due to power shortages and frequent interruptions. Off-grid systems from hydropower or solar PV are often limited and grid electricity is unreliable with many hours of load shedding during the dry season (Government of Nepal 2015).

The country has a very varied terrain, with the lowland called “terai” in the south to the Himalayas in the north, villages and settlements are often spread out, which would make it very costly and almost impossible to connect the whole country to the electric grid. Instead the most sustainable option to fulfil electricity needs is through use of renewable energy sources, which are available on site.

Today, in remote villages in Nepal, diesel or other fossil fuel generation powers many off-grid areas.

It is often expensive and has high emissions (IRENA 2015). As many of the smaller villages in Nepal are quite isolated, and lack infrastructure, it is difficult to ensure fuel supply. Diesel, gas and oil are mainly imported from India. In the autumn of 2015, Nepal suffered a fuel crisis when fuel transportation from India was blocked. It resulted in increasing fuel prices, which affected the poorest and most remote villages and people. This provides another incentive for Nepal to invest in renewable and self-produced energy, and not to be dependent on import.

Compared to other countries in South Asia, Nepal’s electricity consumption per capita is low. In 2010 Nepal’s consumption was only 93 kWh per capita and comparing that to India who had 644 kWh per capita or China that used 2942 kWh per capita (Government of Nepal 2013). In 2011 was the electricity consumption in Sweden 14 030 kWh per capita (Worldbank 2014).

Other program and initiatives for increasing the access to electricity

Examples of organisations and programs that are trying to increase the access of electricity, predominantlywith renewable energy sources, are Renewable Energy for Rural Livelihood (RERL) and Nepal Energy Efficiency Programme (NEEP).

RERL is implemented by the government of Nepal together with UNDP. The programme will run for five years, from July 2014 to June 2019. Their work includes, for example, developing 10 MW of mini and micro hydropower and 2.5 MW of solar PV systems.

NEEP, led by the Ministry of Energy, has an objective to “improve framework conditions for the planning and implementation of energy efficiency measured in Nepal”. The program provides energy efficiency services to both the private and public sectors. They also give direct advice and expertise to the government to promote energy efficiency in the country.

Despite those projects and programmes, implemented or funded by the government of Nepal, there are several others non-profit, volunteer organisations, mostly from other countries, that are helping to implement electricity in villages in Nepal.

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1.3 Thade village and Thade School Project

The trekking and expedition company HiOnLife, owned by Saran Subba and Christina Sandström- Subba, has today many employees from many of the small villages in the Himalayas. 2009 was the first time Saran and Christina visited the village of Thade. It is located about 100 km south of Mount Everest in the eastern part of Nepal, seen in Figure 3.

Figure 3: Map over Nepal and shown where Thade is located, Thade School Project (2016)

Thade village is located at 2700 meters above sea level. Around 200 of Nepal’s almost 29 million inhabitants live in Thade, some of those workers at HiOnLife. In 2009 there was a school in Thade, but it was in such a bad condition that it could not be used. If the children in the village wanted to go to school, they had to choose between walking a couple of hours to the nearest school or leave their families and go to the capital Kathmandu for education.

Figure 4a and 4b: Pictures of Thade

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Heidi Ek was in Nepal in 2013 to do some trekking with HiOnLife and heard about the unusable school in Thade. Back in Sweden she started up the Non-Governmental Organization (NGO) named “Helping Education In Deprived Institutions”, abbreviated HEIDI Nepal. As their own webpage implies they are religiously, politically and economically independent. Through this NGO she launched what later would be called Thade School Project. HEIDI Nepal is divided in two sister-organizations, one in Kathmandu, Nepal and the other in Gothenburg, Sweden (Thade School Project 2015).

Through contributions and support a new school has been built, called Grace Academy Thade, and in May 2015 it was ready to open. The school provides the children with one hot meal per day.

To ensure that the children get good nutrition, they use the Midday Meal Scheme from India. As much as it is possible the food should come from local farmers, which will give local farmers an extra income. The Thade School Projects hopes that this will lead to more parents wanting to send their children to school, including girls. Today it is a gender gap in education in Nepal, and the school in Thade hopes to reduce this gap (Thade School Project 2016).

Figure 5a (to the left): Picture from the classroom at the Thade School.

Figure 5b (to the right): Anita Magar, 8 years old goes in class U.K.G.

In March 2016 42 children, 50 % boys and 50 % girls, study at Thade School divided in four classes;

nursery, L.K.G (lower kindergarten), U.K.G (upper kindergarten) and first class. The children are between 4-10 years old and come from Thade and other villages in the area. Out of the 42 children in the school, 19 come from villages so far away that they live in a hostel in Thade instead. People from the village work in the hostel as caretakers for the children.

According to Country Watch report from 2015 48.6 % of the people in Nepal can read and write (15 years and older), 62.7 % for men and 34.9 % for women. Literacy is one of the most important things if a country wants to develop and is a major reason why the school in Thade is such an important initiative.

Local climate

The climate in Thade can be rough with large differences in temperature between day and night.

The village is located on a ridge that causes clouds to get trapped there. According to people living there it is very common that it is clear and sunny during the mornings and in the afternoon the village is covered in thick clouds.

Electrification problem

Today there is no electric supply to the school, and the lack of electricity is one of Thade School’s biggest problems. Not being able to get light when it gets dark or having no access to computers or Internet restricts the teachers and the students in their education and development.

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8 Alternative power sources for the Thade School

Another source for electricity for the Thade School could be wind power. But as the village is located in a remote area and transportation is limited and infrastructure is still pretty bad, it could be difficult to transport a windmill to Thade. Also there is more maintenance and service for a windmill than for solar panels. Hydropower is also a renewable energy source that could possibly be used, however the conditions for it has not yet been investigated.

1.4 Purpose and aim

For the development of the school and for the education, it is necessary to have access to electricity and to have the opportunity to use computers. The children would have a better opportunity to compete with other students if they want to continue study at University or other further studies.

The purpose of this study is to investigate if it is possible in a simple and sustainable way use a solar cell system with battery storage to meet the basic needs for electricity at the Grace Academy Thade School in Nepal. Generally, the conditions for solar power in Nepal are very good. The question is whether the conditions are as good for Thade as elsewhere in Nepal, because according to the villagers it can be very cloudy and foggy.

Another purpose is to get better and deeper understanding of the general electricity situation in Nepal. What problems are they facing and what is done to increase the use of renewable energy, especially regarding solar power? Moreover, through interviews and conversations investigate what social and economic impact electrification could have on the school and the village, both in a short and long term perspective.

The aim is to build a simulation model in MATLAB Simulink® and then validate the result from that model to the result from the commercial solar system program PVsyst. In the Simulink model climate data (solar radiation and ambient temperature) from Meteonorm was used as preliminary data. Further, from the Simulink model optimize a solar cell system specifically designed for the school in Thade, to get as much electricity as possible with the prevailing conditions. The aim is also to be able to describe the optimizations and clearly show how big the system needs to be.

Further, through the measure of solar radiation and ambient temperature on site in Thade, get an idea of how good the preliminary data are and if some assumptions need to be done.

Questions that needs to be answered:

 What are the basic needs for electricity supply for the school today?

 Is it possible to provide the school with enough electricity for their needs today from a sustainable solar cell system with battery storage? Both from an economic and environmentally perspective.

 How is the electrification in Nepal in general today?

 Are there any subsidies for investing in solar power in Nepal?

 How would it affect the Thade School in general, the teachers, students and the residents in Thade, if the school got electricity?

 If a system would be implemented, what do the villagers and the people connected to the school project need to think about? Present a strategy for a possible implementation, and things to consider before and after implementation.

1.5 Delimitations

The scope of the study is to investigate the potential and profitably of using solar cells at the Thade school, and decide the size of solar panels and energy storage required. It will only include electrification and does not discuss the situation for other types of energy in Nepal, like for example the heating systems and problems with using firewood for heating or cooking.

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There will not be any implementation or installation and the study will not cover the energy needs for the whole village. The energy storage that will be studied includes only battery storage.

Calculations will be based on measurements in Thade during a short limited time. From those measurements, assumptions will be made to adjust the preliminary climate data. Product data from solar cells will be general and not specific to one brand or model. The economic part will only include a general price for the system bought in Sweden since a price of the materials in Nepal was impossible to get.

2. Method

2.1 Literature review

The first stage for this project was to do a literature and background study about both solar systems in general and further try to gather more information about Nepal. A big part before the visit in the country was to prepare as much as possible in Sweden to minimize the risk of problems on site in Nepal. The literature study included a visit to the Glava Energy Centre outside Arvika in Värmland, Sweden. They have a test centre and also one of Sweden’s biggest solar energy plants.

They had many good advices and of course knowledge about off-grid solar systems.

2.2 Model of solar system

A very simple schematic figure of the modelled solar system with the components is shown in Figure 6. This system is what is called an off-grid system. There is no inverter included in the system, but it is possible that it will be necessary in an installation as most of the companies today do not provide systems with a transformer to adjust the voltage for the load.

Figure 6: Simple schematic figure of an off-grid solar system

2.2.1 MATLAB/Simulink®

To take into account both seasonal variation and diurnal variation, data over a year and with hourly information is needed.

Climate data, direct solar radiation and ambient temperature, over a year have been obtained by Meteonorm (Meteonorm 2016). Normally measurement data can only be used nearby a weather station, but Meteonorm can provide climate data for all locations on the Earth. The measurement data from locations far from a weather station is an interpolation, between the three nearest stations, or produced on the basis of satellite data. Because of that, there are uncertainties about the accuracy, local phenomena are probably not taken into account, and this can be seen as a source of error.

An energy system model in MATLAB’s simulation program Simulink® has been done to calculate the optimum size of solar panels and the battery capacity. The model is dynamic with climate data, such as solar radiation and ambient temperature, over a year.

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10 Three cases were tested:

1. Assumption that Meteonorm’s data is correct and used as it is.

2. Assumption to reduce the solar radiation by 25 % after 12 pm, based on Meteonorm’s data.

3. Assumption to reduce the solar radiation by 50 % after 12 pm, based on Meteonorm’s data.

Case 2 and 3 is assumptions to try to emulate the fog and the clouds in the afternoon.

The system will be designed so the electricity in the first instance goes directly to the loads, not through the battery, as that energy conversion has losses. Lessons can be scheduled after this so the power go through the battery as little as possible.

2.2.2 Equations

The Equations (1 – 8) for solar radiation hits an incline surface is based on Kreider and Rabl (1994), and is dependent on the direct solar radiation.

Declination δ is the angle between the equatorial plane and the line from the centre of the sun to the centre of the earth and is given by Equation (1). It can vary from -2345° to 23.45°, with north positive.

sin δ = −sin⁡(23,45°) ∗ cos⁡360°∗(n+10)

365,25 (1)

n = day of the year (with n =1 for January 1).

The standard time in hour, tstd, needs to be translated into solar time, tsol, by Equation (2).

𝑡_𝑠𝑜𝑙 = 𝑡_𝑠𝑡𝑑 +^𝐿^𝑠𝑡𝑑^−𝐿^𝑙𝑜𝑐

15°/ℎ + ^𝐸^𝑡

60𝑚𝑖𝑛/ℎ (2)

Lstd is the longitude of the time zone and Lloc the longitude of the location in degrees.

For Thade village Lloc = 86.52° and Lstd = 86.25°, Lstd is based on the time zone, which for Nepal is +5.45 hours from standard time.

Equation of time, Et, is the difference between solar noon and noon of local civil time and is a function of the time of year and can be calculated from Equation (3).

𝐸_𝑡 = 9,87 ∗ sin 2𝐵 − 7,53 ∗ cos 𝐵 − 1,5 ∗ 𝑠𝑖𝑛𝐵 (3) where B is expressed as: 𝐵 = 360° ∗^𝑛−81

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The solar hour angle, ω, declare the suns location in degrees. At solar noon the solar hour angle is 0°. By Equation (4) the solar time is converted into solar hour angle.

𝜔 = (𝑡_𝑠𝑜𝑙 − 12) ∗^360°

24⁡ℎ (4)

The angle between the sun and zenith (normal to the earth) is called the zenith angle, θs, and is calculated by Equation (5).

cos 𝜃_𝑠 = cos 𝜆 ∗ cos 𝛿 ∗ cos 𝜔 + sin 𝜆 ∗ sin 𝛿 (5) Where λ is the latitude of the location in degrees. For Thade that is; λ = 27.37°.

ɸs is the azimuth angle and declare the deviation from south for the surface. It is related to the hour angle ω, declination δ and zenith angle θs and calculated from Equation (6). Azimuth and zenith angle can be seen in Figure 7.

sin ɸ_𝑠 =cos 𝛿∗sin 𝜔

sin 𝜃𝑠 (6)

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Figure 7: Zenith angle and azimuth angle of sun, calculated from Equation 1-6.

The incidence angle, θi, on arbitrary planes is calculated to orientate the plane in terms of zenith θp

and azimuth ɸp of the surface normal, seen in Figure 8. It can be described as the angle between the incoming sun and the normal of surface and can be calculated from Equation (7). The zenith angle of surface, θp, is the tilt from the horizontal and the azimuth of surface, ɸp, is the orientation of the surface with directly south as 0° and western orientations positive. In this study both will be optimized specific for the Thade school to get as much electricity as possible.

cos 𝜃_𝑖 = sin 𝜃_𝑠∗ sin 𝜃_𝑝∗ cos(ɸ_𝑠− ɸ_𝑝) + cos 𝜃_𝑠∗ cos 𝜃_𝑝 (7)

Figure 8: Zenith- and azimuth angles of surface and angle of incidence of sun on surface, calculated from Equation 7

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The global solar radiation Iglo on a tilted plane is dependent on both direct, diffuse and reflected radiation. In the Simulink model and in those calculations only the direct radiation (I) is included.

For using both direct, diffuse and reflected radiation, different equations had to be used. The assumption of only using the direct solar radiation makes the model a bit undervalued. The direct solar radiation is the solar radiation to a surface perpendicular to the direction of radiation. To get the global solar radiation Equation (8) has been used.

𝐼_𝑔𝑙𝑜 = 𝐼 ∗ cos 𝜃_𝑖 (8)

As the location of the solar cells has not been decided and therefore the surrounding area not known, loses from refection is ignored.

Temperature dependence on solar panels efficiency

The ambient temperature, Ta, has an impact on the panel’s temperature. With increasing ambient temperature, the temperature of the panels also rises and that impairs the efficiency of the solar panels. As the module temperature rise, because of increasing ambient temperature, the efficiency of the solar panels decreases. A simplified equation for describing the temperature dependence on the solar cells efficiency can be seen at (9), (Widén 2011).

𝜂_𝑐 = 𝜂_𝑠𝑡𝑐[1 − 𝜇 (𝑇_𝑎− 𝑇_{𝑐,𝑠𝑡𝑐}+ 𝐼_𝑔𝑙𝑜^𝑇^{𝑐,𝑁𝑂𝐶𝑇}^−𝑇^{𝑎,𝑁𝑂𝐶𝑇}

𝐼_{𝑁𝑂𝐶𝑇} ) (1 − 𝜂_𝑠𝑡𝑐)] (9)

The conversion efficiency of solar cells is usually measured in standard test conditions (STC), where module temperature, Tc,stc, is 25 °C and incident radiation, Istc, is 1000 W/m². Since no specific solar module has been selected in this project the reference efficiency at STC, 𝜂stc, assumed to be 15 %.

General efficiency for commercial solar PV is between 13-16 % (Solar Lab Sweden^c 2016).

Assumptions same as Widén (2011) is done for μ = 0,004 °C^-1, that is the temperature coefficient of efficiency, Tc,NOCT = 46 °C, that is the module temperature at NOCT (Nominal Operation Cell Temperature), Ta,NOCT = 20 °C, that is the ambient temperature at NOCT and INOCT = 800 W/m², that is the incident radiation at NOCT.

The module temperature can also be affected by other conditions such as wind. Through convection the temperature could drop as the wind speed increases, which in turn would improve the efficiency of the solar panel (Timerdahl & Walding 2014). As in Widén (2011) this has not been taken into account in this model.

Output power, P, in watt from a certain area of solar cells is given from Equation (10), where A is the area of solar cells in m².

𝑃 = 𝐼_𝑔𝑙𝑜∗ 𝐴 ∗ 𝜂_𝑐 (10)

Battery storage – charge and discharge

Assumption is done that the battery never discharges more then to 25 % of its maximum capacity, it is a restriction in the simulation model makes sure that the battery never gets overloaded. This assumption and restriction in the model can be seen as the charge controller in the system. The charge controller is assumed to have 97% efficiency (Solar Lab Sweden^a 2011).

Batteries are affected by the ambient temperature and decreases in efficiency if it gets to cold. As the losses and the varying efficiency depending on temperature are very complicated to calculate, and as no specific battery has been chosen, the batteries instead are assumed to have a total efficiency of 80%.

By varying the solar panels area and the number of batteries an optimized size of the system was made. To decide if the system is big enough, state of charge (SOC) was used. SOC should not fall to 0 too many times during the year.

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2.2.3 PVsyst

To validate the model made in Simulink, it was compared to the photovoltaic software program PVsyst (PVSYST 2016). By comparing the Simulink model results with results from PVsyst it gives a good view of how good the Simulink model works. Only case 1, with Meteonorm’s data, was compared as the assumptions of reducing 25 % and 50 % of the solar radiation was not an option in PVsyst.

2.3 Field study

2.3.1 Measurements in Thade

Measurement equipment that was used was a data logger, model Mitec AT40, with two thermistors.

One pyranometer, measure solar radiation in W/m², from Campbell scientific model SP1110 Mitec MU-LB101 and a thermometer to measure the ambient temperature, model Mitec MU-TE105.

Both temperature and solar radiation was measured with an average for every hour. One registration for each hour was made by measurements at three-minute intervals. Those measurements were compiled to an average of one hour, and can be seen in Appendix A.

Solar radiation and the ambient temperature were measured during 13 days, between 2016-03-19 to 2016-03-31, total 289 hours. All the data is provided in Appendix A. Measuring equipment was put on the roof on the school, see Figure 9a and 9b. As the data logger runs on batteries, which could be affected by the cold, a homemade insulation was made to try to protect it as much as possible (Figure 10). So the pyranometer not to be affected by the heat from the sun, it was sheltered by a homemade radiation protection (Figure 11).

Figure 10: Insulation for the data logger Figure 11: Thermometer sheltered by a radiation protection Figure 9a and 9b: Measurement equipment on the roof Thade School

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As the school is located on a small hill and the roof is not shaded by anything, as can be seen in Figure 12, so losses from shading have not been taken into account.

Figure 12: View over Grace Academy, Thade School

2.3.2 Interviews and conversations

The interviews were qualitative and semi-structured. Meaning that the interviews were done with one person at a time, the questions were not exact and instead they were general in the query field and depended on who was interviewed. Questions were made in advance, but supplementary questions were asked during the interview time. It gave the interviewed person space to decide in which order he/she wanted to talk about something, instead of being led by the interviewer. The advantage of this method that the interviewee can expand their answers and talk more openly (Hedin 2011). The ethical and cultural aspects were very important, as there were many verbal and non-verbal differences that could lead to misunderstandings between interviewer and interviewee.

Kvale (1996) has made an outline to facilitate a good structure in qualitative interviews. He divides the interviews into seven stages;

1. Thematising. Why the interview is done and what purpose you have.

2. Designing. Plan the interview. What previous knowledge exists, and how will the interview take place.

3. Interviewing.

4. Transcribing. Prepare the interview material for analysis, transcript from oral speech to written text.

5. Analysing. Decide which methods of analysis are suitable for the interview.

6. Verifying. Ascertain the generalizability, reliability and validity.

7. Reporting. Present the results in the best apply for the study and method.

This structure was applied and followed in all interviews.

Interviews with people living in Thade village and people connected to the school were done to investigate how they look at the opportunity to get electricity in the school and what it would mean for them. Some of the houses in Thade have small solar panels on their roofs to get light. Those people were asked about what they think about the solar system, if they are happy with it, how much it gives and how much they paid for it. That could also give an indication if solar power is a sustainable and good source of electricity in Thade and the Thade School.

An interview was also held with the governmental organisation Alternative Energy Promotion Centre (AEPC). This to get a better and deeper understanding how the electrical system in Nepal in general works, what problem do they face, are there any subsidies for solar power and how do the organisation and government in general look at renewable energy?

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The interviews with people in Thade and people connected to the school (teachers, students) were a bit different then the interview with people from the governmental organization. With the villagers the language was a bigger problem as not many of the people spoke English. The conversations were restricted to times when someone with English skills was available to translate.

2.4 Risk analysis

The risk of earthquakes is great in Nepal, and the after effects often include landslides. Last year’s earthquake (2015) did not affect Thade village or the school significantly. That does not mean that they will be unaffected at another time. Therefore, it is important to place the solar panels in a safe place. Placed on the roof of the school or other buildings the consequences of an earthquake depend on the building’s construction and durability. If solar panels are placed on the ground it is important to control the risk of landslides or falling objects, as well as checking that nothing overshadows the solar panels.

2.5 Limitations

The time spending in Thade and the total time in Nepal was limited. During the time in Thade there was no Internet access and therefore no connection with the supervisor or other possibilities to gather more external information. As the village has a limited amount of electricity and the host family only had enough to supply some lamps and charge mobile phones, the writing process was suspended to when power was available. Also during the rest of the time in Nepal the lack of power and good Internet connection was a big problem.

Another limitation was that after leaving Thade, additional information and measurements were difficult to gather as the equipment was taken down and communication with the people there was limited.

The cultural and linguistic differences became a limitation. Overall people in Thade could not speak English. The father in the host family could speak a little bit and the principal of the school could also speak some English. That made conversations with other people very dependent on when there was a person to translate nearby. Saran Subba was the one with best English skills but he was only in Thade for two days in the beginning of the visit. Therefore, there could be misunderstandings in the interviews.

In order to minimize the risk of these problems the background research in Sweden, the planning and preparation of the visit and the documentation in Thade was performed as accurately as possible. Also the text from interview with AEPC has been sent to and approved by the organisation and information about the school and Thade village has been approved by Saran Subba.

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3. Results and discussion

This field study has been done to get an indication of whether it is technical and financial possible to use solar power to provide the Thade School with the desired amount of electricity. As the measurements were only done for 13 days it is not really representative for a whole year. To do a good analysis over the possibilities the measurements should have been done for a whole year. The results shown in this study should not be seen as exact, but can still be considered as a guide to the overall picture of whether it is possible to use solar power at the Thade School, and any issues associated with it. Before any actual implementation of solar power at the school, a more detailed study would be recommended.

Solar radiation data from Meteonorm showed that per square meter there is a solar radiation of 1694 kWh/year, with an optimized tilt and orientation of the solar panel that hits the surface. A one square meter solar panel, with an efficiency of 15 %, will then give 254 kWh/year. This applies to the original file from Meteonorm, not the reduced ones, case 2 and 3.

3.1 Measurements

According to the people living in Thade the weather in Thade can be very cloudy and foggy, especially after 10 am. That was not the case for most time of the stay. Instead there was very good weather the first 8 days of measurements and it was only very cloudy and foggy during the last two days of measurements (30^th and 31^st of March). Pictures taken from those two days can be seen in Figure 13a and 13b. If the good weather was a coincident, an exaggeration from the people that is use to be very cloudy or the climate change is hard to say.

Figure 13a and 13b: Clouds and fog over Thade, typical “Thade weather” according to the villagers

One problem with the pyranometer was that it has a limitation for maximum incoming solar radiation at 1000 W/m². When the solar radiation got to 1000 W/m² or more it only showed

“overflow” on the display. Assumption that “overflow” corresponded to 1000 W/m² was made.

This could undervalue the results, as the radiation could be more than 1000 W/m². Appendix A shows that the 30^th and 31^st of March, which were cloudy and foggy, still produced a reading of

“overflow”, and shows that even during cloudy and foggy days there is still quite a large amount of solar radiation.

Validating the measured data against Meteonorm’s data

To validate the solar radiation from Meteonorm and the measured radiation an average Wh/seven- days-period was made. The seven days from Meteonorm were taken in March and April, to match the time for the measured radiation. It showed that there was not a big different, 38 844 Wh/m² from the measured data and 38 982 Wh/m² from Meteonorm’s data. It may indicate that Meteonorm’s data is very accurate. It can also indicate that Meteonorm’s solar radiation data is a

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bit high and overvalued, as the weather during the measurements were, according to the villagers, very good.

3.2 Simulink model

According to Saran Subba², project leader of Thade School Project and the president of Grace Academy Thade, and Shyam Chamling³, principal at Thade School, the basic electricity needs for the school at the moment is to have 12 computers (laptops) that are used for 1 hour/day, one printer and an 8-watt lamp in each room (six rooms in total). Total energy needed per day is calculated in Table 2. The wattage for the laptops and printer is taken from “PC för alla” (2007).

Table 2: Needs for electricity according to Saran Subba and Shyam Chamling and total amount of energy needed.

Watt/each [W]

Amount [pieces]

Hours of use/day, each [h]

Total energy needed [Wh]

Computers (laptops) 81 12 1 972

Printer (colour laser) 28 1 1 28

Lamps (low energy) 8 6 2 96

1096

Rounded, the need for the school is 1,1 kWh per day. For a year, with the assumption that the need is the same every day, the total need would be 401,5 kWh. That will not be correct since the school does not run all year, as they have holidays and days off. However, overestimating the need somewhat is sensible as it is likely that needs in the future will be greater than current needs.

Computer use is what requires most power, 972 watthours, and is therefore scheduled in the morning, 11-12, when the solar radiation usually peaks. The printer assumed to be used during 11- 12 am, and the lamps to be on between 14-16 pm.

Results from the three different cases.

Figure 14, 15 and 16 shows the battery SOC (State of charge), where 1 is fully charge and 0 is empty. Empty here means that there is still is 25 % left, as the assumption was to never discharge the battery more than to 25 % of its maximum effect.

“Power provided over a year” in all Table 3, 4 and 5 represents around 95 % of the total need, that is 401.5 kWh/year. Which in this study has been considered to be appropriate coverage of the desired need. And also as the curve for how much it covers leveled out, and a huge system had not been financially sustainable to cover the last five percent during the year.

2 Saran Subba, project leader for Thade School Project and president of Grace Academy Thade. Interview 2016-03- 20

3 Shyam Chamling, principal of Grace Academy Thade. Interview 2016-03-26

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18 1. Assumption that Meteonorm’s data is correct.

Table 3: Optimized system results for case 1

Tilted surface of the solar panel (zenith angle of surface, θp) 30 ° Orientation of the solar panel (azimuth angle of the surface,

ɸp)

0 ° (from south, positive to west)

Solar panels 5 m²

Battery size (12 V) 500 Ah

Power provided over a year 382 kWh

Figure 14: Battery state of charge for case 1, over a year

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2. Assumption to reduce solar radiation with 25 % after 12 pm.

ɸp)

-10 ° (from south, positive to west)

Solar panels 6 m²

Battery size (12 V) 600 Ah

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3. Assumption to reduce solar radiation with 50 % after 12 pm.

ɸp)

-20 ° (from south, positive to west)

Solar panels 6 m²

Battery size (12V) 700 Ah

The Simulink model could have been performed more accurately with more precise losses and efficiencies. Some values that have been assumed can undervalue the results. For example, the assumptions to only use the direct solar radiation in the model and also the efficiency of the solar panels. There have also been assumptions that could overestimate the model, for example the solar radiation. As the weather in Thade during the stay was, according to the villagers, very good and also as Meteonorm’s data for solar radiation probably is an interpolation between weather stations and not exact for the location.

According to Leif Svantesson⁴ at “Solenergi och Teknik i Åmål AB” the prices in Table 6 can be a general pricing for products that can be purchased in Sweden. Additionally, those products have a very good quality, higher life cycle and the batteries are more resistant to high/low temperatures.

Batteries can be purchased much cheaper, maybe half the price or even less, but then the question of what to pay for and what to get.

4 Leif Svantesson, works at Solenergi och Teknik i Åmål AB, contact 2016-05-23

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Table 6: General prices, according to Leif Svantesson, for components in solar system purchased in Sweden, conversion USD (Valutakalkulator 2016)

Solar panel 260 W around 1,6 m² 2500 Swedish crowns (302 USD) Charge controller 2500 Swedish crowns (302 USD) Lead-acid battery 12 V, 100 Ah 4000 Swedish crowns (484 USD)

A system, as in case 1, Table 3, would with the prices from Table 6 cost around 30 000 Swedish crowns. This does not include an inverter.

The difference between the three cases showed that it is mostly the battery size that has to change if the solar radiation is lower during the afternoon. This is probably because the biggest load, the use of laptops, is scheduled in the mornings. If the situation is like the villagers say, with usually very cloudy in the afternoons, the assumption in case 3 could be the most realistic.

3.3 Verify/validate to PVsyst

It is only case 1, with original data from Meteonorm, which was validating to PVsyst. PVsyst also gets their data from Meteonorm, but settings for reduce solar radiation after a certain time does not seems to be possible.

Simulation in PVsyst showed that the optimized tilt and orientation for the panels are 30° and directly in south direction, consistent with the results from Simulink model. This is with setting to optimize the effect for the whole year. If the optimization is done for a summer or winter case the tilt and orientation would be a bit different.

PVsyst simulation showed that only 3 m² solar panels and 12 V batteries, with a capacity of 400 Ah were needed. The difference is most likely because the Simulink model only includes the direct radiation, while PVsyst also includes the diffuse radiation, which probably explains a higher solar radiation and a lower need of panel area and battery capacity.

Figure 17 shows the SOC for the batteries from the simulation in PVsyst. The battery never discharges more then to 25 %, but here is 0 completely empty, not like in Figure 14, 15 and 16 where 0 actually means it is 25 % left.

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22 Figure 17: State of charge for batteries, simulation from PVsyst

The resulted system from PVsyst would with prices from Table 6 cost around 23 000 Swedish crowns, that does not include an inverter.

The climate and location for Thade is a bit special, making it a bit difficult to compare the results to other similar studies in villages in Nepal. In general Nepal has very good possibilities for using solar power, and according to Chaitanya Prakash Chaudhary (2016) at AEPC there are 300 days of sunshine in Nepal normally. Madeleine Beck and Cecilia Schött (2013) investigated the possibility of using different renewable energy sources to electrify a village in western Nepal. As their project included a whole village, the demand amounted to 8.6 kWh/day, which compared to the need in Thade School is significantly larger, and of course would require a larger system. They compared solar power and micro hydropower and their result was that both energy sources were good solutions to cover the demand. Also the total cost, for a 25-year perspective, for solar and micro hydropower delivers the same results. Their final conclusion was that micro hydropower probably would be a better solution. This because the hydropower had some excess over the peak load, and could have been designed even smaller and for a lower cost, they also concluded that if the demand increased hydropower tends to be a better option from an economic point of view.

Since there is lack of rivers or streams around Thade, hydropower alone would probably not meet Thade School’s needs during the whole year, but as argued before, hydropower can be a good addition to solar power.

Parallel to this study Dan Schutzer, from the Royal Institution of Technology in Sweden, has made a study to investigate the possibility of using wind power to provide Grace Academy Thade School with electricity. His result of the study shows that wind power alone is not enough to provide the school with the amount electricity they desire. He writes that wind power could be a good compliment to solar power. The same conclusion is made by Surendra B. Kunwar (2014) that wind and solar power potentially can compensate for each other, which for Thade School could be an option.

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3.4 Interviews and conversations

Interview with Chaitanya Prakash Chaudhary⁵ at the Alternative Energy Promotion Centre (AEPC)

AEPC is a Government institution with the objective of developing and promoting renewable/alternative energy technologies in Nepal. Currently it is under the Ministry of Population and Environment and functions independently with member representatives from the government sector, industry sector and non-governmental organizations (Alternative Energy Promotion Centre, 2013).

In the interview with Chaitanya Prakash Chaudharyat AEPC it was clear that they think solar energy use in Nepal should be expanded. Nepal has in general, over 300 days of sunshine annually with annual average solar radiation at 5 kWh/m2 per day, which would be a good source for using solar energy.

Today 95% of the energy use in Nepal comes from hydropower, only 1-1.5 % comes from solar power. Chaitanya tells that they hope to increase that number to 10 % in the coming years. He also tells that AEPC has installed solar power in 700.000 households around Nepal.

In order to meet the needs of a growing population and the increased demand for electricity AEPC has approved a program called “Urban Solar Energy System Subsidy and Loan Mobilization Directives-2072”. In Nepal they have another calendrer where 2072/2073 corresponds to our year 2015/2016.

For solar technology AEPC provides subsidy in two broad categories, shown in Table 7.

Category 1: Urban solar program for those areas which have national grid connection.

Category 2: Solar program for rural areas that do not have national connection.

Table 7: Loan and subsidy in installation charge for solar systems. Picture from AEPC

Sn. Category of System System Capacity(Wp^*)

Subsidy for system capacity

≥200 Wp

Subsidy in interest bank

Interest rate in credit

1 Domestic Purpose 100-1500 Nrs**.20,000 75%

Maximum 9%

2 Commercial Purpose ≥1500 Nrs**.20,000 50%

*Wp stands for Watt peak.

**Nrs = Nepali rupees. 20 000 Nrs is around 1520 Swedish crowns (Valutakalkulator 2016)

For subsidy on interest rate, the beneficiary first identifies its demand through solar company and prepares the financial and technical proposal. The beneficiary applies for a loan at the partner bank and the bank approves the loan after its screening process. The beneficiary then can go for installation of system, after installation the beneficiary submits the installation report along with invoice copy to the bank and then the bank sanctions a loan.

The user, after installation, needs to fill in the AEPC prescribed Subsidy Application Form and submit it to AEPC. The forms are then process and the subsidy are then paid to the user.

The interest rate on credit will be a maximum of 5% if the government provides the capital for the loan and the interest rate on credit will be a maximum of 9% if banks use their own capital to found the loan

For category 2, commercial purpose, the subsidy program is to those regions which do not have any connection to another source of electricity. This subsidy is provided for Small Solar Home

5 Chaitanya Prakash Chaudhary, engineer at AEPC. Interview 2016-03-15

Solar power on the top of the world

Linnea Gunnarsson Knutsson

Solar power on the top of the world

Possibilities to provide the school in Thade, in Nepal, with electricity from a solar cell system

Solel på världens tak

Möjligheten att tillgodose skolan i Thade, i Nepal, med elekticitet från ett solcellssystem

Examensarbete 30 hp

Högskoleingenjörsprogrammet i energi- och miljöteknik

Abstract

Sammanfattning

Preface

Nomenclature

Table of contents

1. Introduction

2. Method

3. Results and discussion