Steps for the Realization of a Medium-power Photovoltaic Park

SORIN IOAN DEACONU1, MARCEL TOPOR1, ALEXANDRU MIHAI BLAJ2, FEIFEI BU3

1Electrical Engineering and Industrial Informatics Department, Politechnica University of Timisoara,

Timisoara, ROMANIA

2College of Engineering, Al Asal University, Dammam, SAUDI ARABIA

3Nanjing University of Aeronautics and Astronautics, Nanjing, CHINA

Abstract: - The design of photovoltaic parks has become in Romania, now, one of the most profitable and safe

investments in the field of renewable energy sources, not only at present, but even more so in the future. Solar

photovoltaic parks are favored by maximum exposure to solar radiation, a minimal impact on the environment,

allowing the production of energy with a cost per kWp lower than that of other installations. The execution period

of a photovoltaic park varies between 3-6 months depending on location and weather conditions. Romania has a

high degree of solar radiation, suitable for investment in photovoltaic parks. There are three categories of documents

required for the establishment of a photovoltaic park: those related of the land on which the park is build, the solution

study for obtaining the technical approval for connection (ATR) to the electrical grid and obtaining the

establishment authorization. The realization costs involved in building and designing a photovoltaic park are

between 1.1-1.9 Euro/Watt. The quality of the equipment used in construction, the shape of the land, the costs of

connection to the national electrical grid, are factors that can constitute the cost of realization. Another important

factor in terms of income is the level of operational expenses, which is between 2% and 8% of the annual income

and includes security, equipment and land maintenance, system monitoring. The paper will present a technical and

economic calculation for a photovoltaic park with a power of 400 kW.

Keywords: -photovoltaic park, irradiation and solar electricity potential, green certificate, RETScreen Expert

Software

Received: October 7, 2023. Revised: August 16, 2024. Accepted: September 7, 2024. Published: October 7, 2024.

1. Introduction

Numerous countries and regions have incorporated

substantial solar energy capacity into their electricity

grids to complement or provide an alternative to

traditional energy sources. Solar power facilities utilize

one of two technologies: photovoltaic (PV) systems,

which employ solar panels placed on rooftops or in

ground-based solar farms to directly convert sunlight

into electrical power, and concentrated solar power

(CSP, also known as "concentrated solar thermal")

plants, which harness solar thermal energy to produce

steam, subsequently transformed into electricity using a

turbine [1], [2]. The global expansion of photovoltaics

exhibits significant dynamism and varies considerably

from one country to another. As of the conclusion of

2019, a cumulative total of 629 GW of solar power had

been installed worldwide [3]. By early 2020, China led

the world in solar power capacity with 208 GW [4], [5],

constituting one-third of the global solar energy

capacity. In 2020, at least 37 countries across the globe

had a cumulative PV capacity exceeding one gigawatt.

The prominent solar power installers from 2016 to 2019

were China, the United States, and India. The first 10

countries in photovoltaics industry, [4-7], are presented

in figure 1.

Fig. 1. The first 10 countries in photovoltaics industry

in 2021

In Romania, there are more and more solar power

plants based on photovoltaic panels and a tripling of the

photovoltaic capacity is expected, until the year 2030,

when coal-based energy will be almost completely

eliminated - shows a Global Data report, which

estimates that, in the next 8 years, Romania will have a

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DOI: 10.37394/232027.2024.6.16

Sorin Ioan Deaconu,

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photovoltaic capacity of 4250 MW, compared to the

1400 MW it currently has [8].

Speaking of the advantages of solar panels, the list is

quite comprehensive. First, the energy produced is free.

Lighting and heating the house or domestic water will

have very low costs. Depending on the size of the

photovoltaic system used, the savings on electricity bills

can be very large. Moreover, if the system generates

more energy than you can consume and you are

connected to the electricity grid, the surplus can be

exported and you will be rewarded for it. Secondly, solar

panels are easy to mount and maintain. They can be

placed on the roof of the house or even on open fields.

They have an extended lifespan, over 20 years, and their

maintenance is not complicated at all. In addition, the

components that deteriorate or break over time can be

replaced very easily. The inverter has a somewhat

shorter lifespan, between 5 and 10 years, because it

works continuously. The other elements used for

connections and cables can also deteriorate over time,

but they can be easily replaced. Finally yet importantly,

another great advantage of photovoltaic panels and

systems is the reduction of pollution. Because they use

an inexhaustible resource, such as sunlight, they are

considered the friendliest solutions for the environment.

Classic fuels, such as gas or coal, with the help of which

electricity is obtained, are increasingly limited, more

expensive and more polluting resources [9].

On-grid photovoltaic systems require some essential

conditions for a good operation, related to the national

electrical grid to which it is connected. Thus, an on-grid

photovoltaic system, even if it represents an electrical

energy production unit, implies a permanent connection

to the electrical grid, like an ordinary consumer.

However, unlike consumers, the connection to the

network of an on-grid photovoltaic system is used in

order to deliver the surplus energy produced by it. The

national electricity grid takes the place of a battery in an

off-grid type system. This brings both advantages and

disadvantages. The main advantage is the significantly

lower cost of a system that does not involve batteries.

Another advantage is the lack of risks associated with

larger capacity batteries, such as the risk of explosion,

overheating, low performance in different weather

conditions, etc. In addition, an accumulator has a limited

storage capacity, and if the energy in it is not consumed,

the production potential of the panels is lost. However,

there are disadvantages related to connecting a

photovoltaic system to the national electricity grid. The

main disadvantage is related to the fact that the voltage

in the electricity grid differs greatly depending on the

area. The causes that lead to the appearance of voltages

over 240V are: the location of the house where the

photovoltaic system is mounted relatively close to the

transformer station, several photovoltaic systems

installed on the same street mean, on the one hand, a

source of clean energy, but in the absence of

consumption, they negatively influence the level of

electrical voltage in the grid, another reason for the

increase in voltage may not be related to the power lines

of the national grid but to the cable used by the final

customers, respectively the cable between the output of

the bidirectional meter and the input to the general

electrical panel of each customer; if the section of this

cable is too small, the voltage drop will be greater and

then the inverter is forced to increase the voltage level

more than it would normally be in order to inject the

voltage into the grid, and last but not least, there are

specific problems because the electrical network

infrastructure is precarious and where there are problems

even without photovoltaic installations, and adding them

only worsens the already existing situation [9-16].

2. Project Location, Irradiation and

Solar Electricity Potential

Optimal sun exposure and minimal environmental

impact make photovoltaic parks an attractive energy

source, with profitability hinging on factors like income-

to-construction costs ratio. Primary revenue sources

include energy sales and green certificate trading.

Fig. 2. The location and the corresponding climatic

data

The green certificate signifies the production of

1MWh of renewable electricity. These purchased

certificates cover the obligatory renewable energy

portion in total consumer supply, determined annually

by ANRE. They remain valid for 16 months. The

Environmental Fund Authority imposes a 110 euro fine

per unpurchased certificate on non-compliant suppliers

and producers. Solar energy producers (comprising

power plants and photovoltaic parks) receive six green

certificates per 1MWh of delivered electricity.

Presently, a green certificate's maximum market value is

50 euros.

The project is situated near Geoagiu Bai town, with

a southern orientation. Figure 2 depicts the location and

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Sorin Ioan Deaconu,

Marcel Topor, Alexandru Mihai Blaj, Feifei Bu

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associated climatic data, while figure 3 illustrates daily

solar radiation and temperature. A 20 kV medium

voltage electric line traverses the area.

Fig. 3. Daily solar radiation and temperature in the

location of the project

3. Categories of Documents Required

for the Establishment of a Photovoltaic

Park and the Steps Required Becoming

a Prosumer

There are three categories of documents required for

the establishment of a photovoltaic park: those related to

the land on which the park is built, the solution study for

obtaining the technical approval for connection (ATR)

to the electrical grid and obtaining the establishment

authorization [13].

The first category includes the deed of sale, purchase

of the land, concession or lease, then the zonal urban

plan (PUZ) if the land is removed from the agricultural

circuit, the urban planning certificate (with the approvals

requested by it) and the opportunity study for the

evacuation of the power in the existing grid [13].

The second category includes the technical

documentation for the construction authorization

(DTAC), obtaining the construction authorization, the

technical project that starts with the DTAC and the

technical project for the power evacuation in the grid

[14].

The third category of documents involves obtaining

the ATR, then obtaining the establishment authorization

(given by ANRE), obtaining the commercial

exploitation license, registration on the regulated

electricity market (OPCOM) with (accreditation for

green energy), obtaining the Transelectrica approval for

the transport of electricity, if the connection is made

directly to their grids [15].

If you produce electricity from renewable sources and,

apart from your own consumption, but not necessarily

deliver the surplus electricity to the national electricity

distribution network, this means that you can become a

prosumer. The regulatory authority in the field (ANRE)

monitors the evolution of prosumers based on data and

information collected monthly from distribution operators.

The distribution operators have duties regarding the

connection to the electricity grid, the certification of the

prosumer quality, the measurement of the electricity

consumed/injected from/into the grid and the transmission

of information to the supplier in order to bill the electricity.

In order to become a prosumer, you must go through

several necessary steps: a connection request is

submitted to the electricity distributor; following the

submitted request, a connection solution is established

and the technical connection approval (ATR) is received

from the distribution operator; the connection contract is

signed; the system of photovoltaic panels with an

installed power of no more than 400 kW per place of

consumption is installed by specialized personnel; the

file of the usage facility and the request to energize the

usage facility for tests are submitted to the electricity

distributor; the report of receipt of commissioning of the

user facility is sent, after tests, to the electricity

distributor; it receives the connection certificate from the

distribution operator and the prosumer certification; a

sale-purchase contract for the electricity produced and

delivered in the grid is signed with the electricity

supplier [10].

If it is not necessary to change the connection

solution for the installation of the photovoltaic panel

system at the place of consumption, then the notification

regarding the connection to the existing place of

consumption of the photovoltaic panel system is sent to

the distribution operator, after its installation. In this

case, the distribution operator updates the existing

connection certificate without the need to issue the

technical connection approval [11].

4. Using the RETscreen Expert

Software for Design and Economic

Assessment

RETScreen is a Clean Energy Management Software

system designed for assessing the feasibility of energy

efficiency, renewable energy, and cogeneration projects,

encompassing power, heating, and cooling. It empowers

professionals and decision-makers to swiftly evaluate

the technical and financial viability of potential clean

energy projects, aiding in decision-making. This

software platform also simplifies performance

measurement and verification for facilities while

identifying additional energy savings and production

opportunities. RETScreen stands as the most

comprehensive tool of its kind, enabling engineers,

architects, and financial planners to model and analyze

a wide range of clean energy projects. Decision-makers

can conduct a five step standard analysis, including

energy analysis, cost analysis, emission analysis,

financial analysis, and sensitivity/risk analysis. Fully

integrated into these analytical tools are benchmark,

product, project, hydrology and climate databases (the

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Volume 6, 2024

latter with 6,700 ground-station locations plus NASA

satellite data covering the entire surface of the planet),

as well as links to worldwide energy resource maps.

Moreover, to help the user rapidly commence analysis,

RETScreen has built in an extensive database of generic

clean energy project templates [17].

We will divide the park into four modules with equal

power of 100 kW each. We will do the analysis with the

RETScreen program for one module and then generalize

the conclusions for all four modules. Figure 4 shows

information about a module of the facility and Figure 5

shows the production cost in Canadian dollars of energy,

compared to other types of power plants.

Fig. 4. Information about a module of the facility

Fig. 5. The production cost in Canadian dollars of

energy, compared to other types of power plants

It is observed that for a photovoltaic park with fixed

panels the cost of electricity production is 0.05 CAD =

0.044 USD = 0.199 RON / kWh. The following figures

(6, 7, 8, 9, and 10) show the results of the analysis with

the RETScreen program for a 100 kW module of the

fixed photovoltaic park.

Fig. 6. Energy calculation data power plants

Fig. 7. The proceeds from the energy produced, the

annual costs and the investment recovery period without

green certificates

Fig. 8. The receipts from green certificates, the initial

cost and the annual cost

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Fig. 9. Emission Analysis

Fig. 10. The final values of the analysis

Equipment chosen for execution: The photovoltaic

panels used are of the Canadian Solar monocrystalline

type, with an efficiency of 19% and a power of 320 W.

1248 panels are used. The MPPT type regulators are

from Victron type MPPT150/70. 100 such regulators are

used for the entire park. The inverters used are

HUAWEI-SUN 200-50 KTL-M3 three-phase with a

power of 50 kW. In total, there are 8 such inverters.

5. Conclusions

With the data corresponding to the chosen location,

the annual electricity production of a 100 kW module is

136 MWh. An average cost of 1900 CAD / kW was

chosen, resulting in a total investment cost of 758784

CAD. For the electricity produced, an average price of

0.15 CAD / kWh = 0.12 USD / kWh = 0.54 RON / kWh

was chosen. It results in an amount of 20427 CAD

collected per year for one module, respectively 84708

CAD for the entire photovoltaic park. If the green

certificates are not taken into account, the annual park

maintenance cost of 9984 CAD and the payment of the

loan in the amount of 58316 CAD per year (for 15

years), the investment recovery period is 10.6 years. If

we take into account the green certificates at a market

price of 34 CAD, 3264 certificates will be collected

annually for the whole park, which gives us an annual

income of 144240 CAD. In this situation, the investment

recovery period is 4.1 years.

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[9] *** SR EN 50160:2011 Characteristics of voltage

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[13] *** SR CEI/TS 62257-6:2010 Recommendations

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[15] *** SR CEI/TS 62257-7-1 Recommendations for

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Contribution of Individual Authors to the

Creation of a Scientific Article (Ghostwriting

Policy)

The authors equally contributed in the present

research, at all stages from the formulation of the

problem to the final findings and solution.

Sources of Funding for Research Presented in a

Scientific Article or Scientific Article Itself

No funding was received for conducting this study.

Conflict of Interest

The authors have no conflicts of interest to declare

that are relevant to the content of this article.

Creative Commons Attribution License 4.0

(Attribution 4.0 International, CC BY 4.0)

This article is published under the terms of the

Creative Commons Attribution License 4.0

https://creativecommons.org/licenses/by/4.0/deed.en

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International Journal of Electrical Engineering and Computer Science

DOI: 10.37394/232027.2024.6.16

Sorin Ioan Deaconu,

Marcel Topor, Alexandru Mihai Blaj, Feifei Bu

E-ISSN: 2769-2507

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