Genel

Considerations for Purchase of Solar Power Plants

Turkey in the unlicensed solar power plants, became a popular trading commodity and reached an installed capacity of 5GW due to the dollar-indexed income scheme
However, trying to install some of the power plants at the end of 2017 with a fast pace and the use of poor quality products at some power plants brought investors in a different state.
At this stage, Solarian is offering our consultancy services to the people who want to buy or sell unlicensed solar power plants as follows.

1 – Regulatory Competency

There are many legislative problems that need to be taken into consideration during the construction and commissioning phase of the unlicensed solar power plants. Many problems can arise, including technical issues, which include both the trade issues and the commitments given during the zoning approval of the application type, the approval of the municipal construction permit. At this stage, Solarian takes over the commissioning process of the power plant from the development stage; we offer you with detailed descriptions of the risks you may face.

Power plant billing at the moment doesn’t mean you have no problems in the future from a legislative perspective.

2 – Production Performances

When purchasing unlicensed solar plants, it is considered as the simplest control method to look at the past 1-2 invoices and look at the desired amount and payback in a few years. This calculation is misleading. Every month of the year, solar energy falls to our world in different proportions. For this reason, a SPP plant produces different rates every month of the year.

At this stage, it should be checked whether past productions are compatible with expected production, whether this power plant produces the energy that it needs to produce, or whether it is subject to loss of energy (power transmission line, transformer problems). As a result of this study, it is learned clearly how much a debt payment the plant can overcome and how much it can pay to its investors.

The fact that the power plant is able to pay its debt with the production in the past does not mean that it continue that again .

3- Field Tests

The products used in solar power plants are expected to have a life span of about 25 years. However, many products are being damaged in the first two years, and they are far below the performance they should perform. There are traces of snails on the solar panels, cracks and hot spots are formed. In the first two years, these problems cannot be noticed.

In the field inspection, we test the technical situation of your solar power plant with the other specific tests and measurement devices and report, if there is any other damage. At this stage, you may have learned and prevented the potential problems of the solar power plant you bought at the time of your plant’s production.

Although the paperwork suitable for the guarantee and solar panels can also available in Turkey or elsewhere, in accordance with customs regulations some brands no longer be able to bring goods to Turkey. Having a warranty certificate does not mean that you can benefit from this warranty.

In this context, if you want to buy an unlicensed solar power plant, you can contact us by filling out the form below

Solarian 2018 Year-End Audit

Solarian 2018 Year Assessment

The first quarter of 2018 was very active and rapid for the solar sector. When the projects carried out in 2017 were forced to adapt to the new legislation, projects were suspended, or attempted to be completed in a hurry. The emerging result led investors to understand the importance of independent auditing firms. Although the rest of the year was painful for the sector, it was intense for us.

As Solarian throughout the year, we contributed to over 250 MW projects. Approximately 130 MW of these are audit and inspection and the rest are consultancy services. In this process, more than 100 companies entrusted their projects to us.Under the name of consultancy; We tried to provide added value to the projects of all stakeholders of the sector, including producers, financiers and investors. On the producer side, we conducted technology researches, project management on the investor side, and plant valuation and feasibility studies on the financier side.

Under the name of inspection; We checked the solar power plants in accordance with the IEC 62446 standard. In this service delivery, we carried out analysis maps beyond the auditing and reporting, and continued to analyze the plants after the actions taken and tried to deliver the plant in a manner that did not solve the problem. We believe that this is the most important feature that distinguishes us from other audit firms and we are proud of our audit team due to the positive feedback received from our investors.
As a result of the inspections, we have prevented loss of 3000 kWp installed power and 5000 MWh production. We have seen that many different causes due to various reasons, such as low performance because of improper engineering due to shadows caused by incorrect engineering, low performance because of not using suitable technologies and cell damage caused by loss of production . You can see more detailed results in our infographic.

To avoid some of the problems mentioned above are unfortunately not possible for power plants which are already commissioned. Disassembly of the construction, approximately 4,000 panels per MW, or approximately 20 inverters, the technically inadequate cables to remove and replace, such as creating a drainage system can not be performed in commissioned power plants.
The only way to avoid this is to work with an independent audit firm not only when there is a problem, but it is necessary to work with an audit firm in entire process of investment in order not to leave a measure in all processes of the investment. We, as a team, aim to pioneer long-term efforts together with investors and business partners and see our customers as a real stakeholder. For this reason, we have created our vision by aiming not only needs-based, but also progressive-based progress.

Solarian 2019 Year Goals

We are also preparing to provide our domestic consultancy and inspection services for solar energy investments abroad.
under the brand identity and independent local audit firm with the audit team by expanding the services we perform in Turkey, will perform abroad.
Since we have gained experience and clearly see that the reason for each plant’s incomplete production is different, we plan to support investors in a more affordable, faster and value-added way by creating more flexible audit scopes than the problems of the power plants.

What we come across during inspections of Solar Power Plants

One of the questions faced by EPC companies during the solar investment phase is “How much money is the total?” It is the question. When it comes to this point, the quality of the work begins to be questioned. At this stage, you will hear the investor saying that if the panels and inverters are German brand, they do not care about the rest. Does using only these product groups in German brand make the SPP investment really high quality?

I’ve tried to adress some items below that we encountered in some occasions. Wishing it to be useful.

1- Production defects of panels and compliance with warranty

I think this part is the most important part. Solar panel manufacturers offer an instruction manual on panel mounting. It’s about how to install the panel. Although the panel is the same panel, different manufacturers have different discourses. First of all, we notice that these warnings are sometimes ignored. At this stage, how much damage the wrong application may cause to the panel will vary depending on the application, but the main issue is that the panel is out of warranty.

So? If there are cell breakdowns in the panel and there is a low production, the manufacturer can take you out of warranty as you are putting the clamps on the short side. Two independent issues, but a malicious manufacturer can use it in its favor.

In addition, degredation and internal fractures in the panels. Relatively “poor quality” panels that cause energy losses occur in many places. There are many producers in Tier-1 section however production in this way is unfortunately available.

We encounter this problem many times in the power plants builted.

2- Grounding is important. Your SPP will not be eligible because Megger has given compliance with the equipotential-bar.

Grounding is very very important. In both the leakage current protection and the insulation measurements of the inverters and in many parts of the whole system, its important. You don’t have to master this issue, but think of it, the electric current has to go a way. You’re going to make it easier for you to get there so that you don’t go the way you don’t want it to go. If you don’t make it easy, then it starts to go in ways you don’t want it to go. It will damage your devices and power plant.

Make sure that your construction and electrical devices are well grounded. Use bimetallic material if there are transitions such as copper / aluminum in the grounding elements. Grounding is not a joke, the price is heavy.

3- The construction must be nailed correctly. It should not be stretched to fix it later, it must be fixed to the clamps.

When the piles are misplaced during the nailing process, the error is either not noticed or it is hard to pull out and repeat the process. At this stage, the upper construction is stretched with the belts until it engages. At the end of this process a high force is formed in the panels. The panel surface is cracking at the slightest snow / wind load.

The clamps that are not fastened with torque cause the panels to fly in the wind. It is necessary to ensure that all clamps are secured.

4- Pay attention to the cables. It shouldn’t bend too much, be protected from the sun.

DC cables sometimes become very flexible and sometimes under the sun. These cables will be damaged in the long term. It also shows the first indication of the isolation by giving the inverter the error of isolation. If not controlled, the leakage current may go from damaging the panels to damage to other panels on the same MPPT. This error was a mistake that we encountered very often. It is an important section to be taken care of.

5- Bird droppings, damaged panels and general site cleaning

After investing a million dollars, it shouldn’t be that difficult to clean the grass. Herbs that have reached the height of the panels and bird droppings damage the panels. At the point of shading, the temperature rises and the hot-spot is formed and that part of the panel loses its functionality. Hotspot problems reach the other cells over time, making the panel unusable.
Solar panels which damaged by stones or bullets should be replaced immediately . Although the cell input output voltage is at the level of 0.6V, the potential differences with the earth are in the 300V-400V range. Water leakage, short circuit etc. When coupled with such problems can lead to very serious damages and fires. Damaged panels should be removed from the system and replaced immediately.

6- Shading problems

Shading causes very high temperature increases in shaded parts of panels. Hotspot occurs and production loss occurs.

7- Strings not connected to the inverter

This is one of the most interesting situations we’ve encountered. The investment is made but the strings are not all connected. You know, maybe some of your strings have never been activated?

8- Mounting Errors

We come across with many SPP facilities with mounting errors. How accurate is the connector placed inside the water-holding C-profiles, even though it is waterproof? In case of leakage of water into the connectors, both the plant will be deactivated and high voltage or current in the system will cause risk of death. Unfortunately, there is not much protection against the electric shocks on the DC side.

Cutting edges of the metals on the cable routes are not sufficiently rasped? AC cables that expand and contract in hot-cold transformations are cut by contacting these points. After a short period of time, the short circuit of the phase-to-earth system will disable and create the risk of death.

8- Business & amp; Maintenance is planned during the construction and purchasing phase. It is not a service that is easily retrieved later.

Whether it is a SCADA infrastructure in SPP facilities, monitoring infrastructure, cable channels and transformer layout, the design is always designed for easy control and intervention. For many investors who are not in the process at this stage, seeing a production value above the inverter is enough for satisfaction. This is a very erroneous approach. If the access roads and cable routes are not designed properly, if the transformer’s values are not monitored remotely, if the voltages and reactive power are not monitored, it is not easy to avoid problems. There are extra costs in every process to be done in the future.

So there is no well operated Solar Power Plant?

A friend from the solar sector recently get in touch. Their customer who invested in SPP thinks that the production levels are less than expected, whether I can communicate with them or not. Replied of course I can and got the contact information.

Even though there was a lot of low performance in solar energy investments, the situation of this customer was slightly different. He had used three different panels and three different inverters with a capacity of 6MW. It’s kind of a research topic.

First, we connected the central infrastructure of the monitoring system and received data files. Unlike many investors in the field; radiation sensors, ambient and panel temperature sensors were installed. Since we do not see a data logger, a pyranometer / reference cell in many fields, we’re happy to see it now 🙂

First we downloaded the data and converted it into data that the software could understand and process, and then we put it into the PR(performance ratio) analysis.

The raw data of the sensor data [/ caption]

After receiving and compiling the sensor data, we compiled SPP conjugate production data.

An example of the data we followed on excel before transferring it to the software. [/ caption]

If there is a problem, you can catch some of the deviations between the inverters, but there is no major deviation between the inverters. We completed the data compilation process in a short time and passed the analysis.

In our first review, the productions were below expected. A situation that should be a nuisance in the entire field, but I also came across a very problematic field.

When we look at the production breakdown in the analysis, it was possible to see some loss of temperature, but it was also possible to produce less than the loss of heat in the analysis? Something’s not right. It was not possible to go into more detail with the data. We decided to move to the field and make more detailed analysis. At the beginning of these analyzes were the measurements we call the IV-Curve curve.

When we got to the field, they welcomed us with tea. After a pleasant short chat, the team started to fulfill our duties in the field. We gave priority to inverters with relatively low production status. My priority was that skeptic panels had a manufacturing defect, but the fact that the problem had spread throughout the site was in contradiction with this suspicion.

While the IV Curve measurements were taking place, the data was flowing to our analysis station on the back side. At first, a few IV-Curve failures made us think that the question was still in the panels.

As a result of our investigation, we have come to an explanatory reason why the inverter is lower than the others; The lightning arrester in the immediate vicinity of the sequences made a shadow and distorted the IV characteristics of the arrays. Reminded me that why I don’t like lightning rods to friends who have worked with me before, why I insist on catch bars?

This explains why the inverter produces less than the others, but it does not explain the low PR area wide. When we continued the IV measurements, the graphics were very smooth.

My suspicion had disappeared, the panels were intact, where was the problem?

Our promise to the companies that received service from us never been sending a test report only, we were there to solve this problem; we had no intention of returning.

In the meantime, the first thermal images are receieved in the data station. The drone thermal had only a few ghosting and dust-induced hot-spot and was consistent with IV-Curve measurements. In the case of hand-held measurements, we could only detect that several junction-boxes were overheated and that several cables were exposed to the sun.

EPC has fulfilled all obligations. The cables were drawn very well, the construction was not forced, the clamps were not applied much force. Cable heads, connection components, switchgear materials, panel designs were very smooth. If I wanted to write a deficiency that would be forced to write for that reason.

The main tests used in the examination of SPP facilities are Thermal (Infrared), Current-Voltage curves (IV-Curve) and EL (Electroluminescence) tests. The hand-held test and IV-Curve test are related to each other. This is reflected in the IV-Curve test if there are problems in the EL test. After dark, we performed EL measurement by energizing the arrays. It is not possible to measure the EL test in the entire field, so we have examined certain points in the morning in the IV-Curve tests. There was still no serious problem with the panels. We found a few micro-cracking panels in the EL test, but they were too small and did not affect production.

EL Test [/ caption]

And why? There was only this question in mind when we were going to the hotel in the evening. There were three different panels on the field, but all were smooth.

The next morning we started the day by measuring the performance of the inverters. We watched an inverter for about 4 hours regularly with our special devices. I would like to point out a wrong point about the inverters. The efficiency of the inverters is not one-dimensional but two-dimensional.

The efficiency of the inverters is shown by the change of the instantaneous output power, but this is not enough.

The efficiency of the inverters also varies according to the voltage of the array. Taking into account this fact, we carried out the measurements per second and examined the behavior of the inverters. There was no problem in the inverters; they were acting just as they should.

I realized that we were looking for the error in the wrong place. The problem was in another place that escaped our eyes.

I shifted my focus to the SCADA system reporting low PR at the plant, maybe there was something wrong there? I first directed the team to check the calibrations of the sensors in the field. There was no problem in the calibrations of the devices and they were compatible with the y = ax + b curves. I had to enter the SCADA system in more detail when the sensors were intact.

That’s right there; Hundreds of pages of SCADA looked at me, smiling, error “Gradient”.

Sensors were analog devices if not specifically ordered with RS485 connection
They provide a resistance, current or voltage across the measured value. We convert these analog values to digital values with devices. There are two parameters during this conversion

Y = Gradient * X + Offset
The gradient and offset values are determined by the sensor manufacturers. An error in the offset is easily detected in the analysis phase (the sensor gives the values that should not be given, for example, night light), but it is very difficult to detect an error in the Gradient by looking at the data. 0 is 0 where it should be, but a radiation sensor with 800 w / m2 during the day can easily show 850 w / m2. When the error is detected, it is easy to correct the retrospective data.

It was obvious what we had to do at that moment. The value to enter 100 was entered into 110, then the sensor values were incorrectly reported to the SCADA system and the PR calculations were made incorrectly.

At this stage, both the system’s gradient was corrected and we rearranged the data to be 100. The result was more than 85% PRs. The only obstacle in this well operating power plant was the faulty introduction of the sensor to the system.

Executive note: EPC companies can lower the gradient value of the power plant and increase the PR value of the power plant. As an investor, it is very important to check the accuracy of this variable. 🙂
So far, we had the opportunity to perform control over 130MW in Turkey. As we found many errors in these plants due to lack of maintenance, EPC error and material error. We also come across excellent plants which have no errors to report. Do not be afraid of investing Turkish solar power because of some rumours like “All the plants were poorly constructed, panel dumpster”; there are domestic suppliers, EPC companies that produce very nice products and produce very good materials in this country. The important thing is to get the right people to do your right and convenient choices. In the case of supplying 25-year performance-guaranteed panels, this investment should not be considered short-term.

I would like to extend my sincere thanks to you if you are a semi-technical investor who has read this article so far. Very few people can come to this stage. 🙂 If you think that your Solar facility produces less than it needs or you have any problems, please contact us. Let’s find the problem in your facility together.

You can fill in the form below to contact us.

Solar Power Plant Control and Measurement Services

Tests must be carried out under IEC 62446 and IEC 60891 to monitor and measure the performance of solar power plants. These tests are mainly IV-Curve measurement, drone thermal tests, EL (electroluminescence) test, insulation test, grounding test and performance measurement. Below you can see what information you will receive as a result of these measurement and inspection services. Please send an email to [email protected] to receive an audit service from us.

1- IV-Curve Measurement – IEC 60891

As a result of the IV Curve measurement below, you will see the IV curve measurements of all the solar panel arrays in the field. we can check if there is a problem. These metrics also serve as a registry, and will help you to see how small the solar panels are in the future. Solar panel, the solar power plant is missing the answer to the question about the answer to the part of the solar panels with this test.

As a result of the IV test, you can have information about:

Find out the actual strength of your panels. You can check whether it is consistent with the factory data.

Do you have any losses from LID (Light induced degredation) in your solar panels?

Is there a loss of PID (Potential induced degredation) in your solar panels?

Your DC cables have ground contact or leakage due to any cut / mouse ingestion

Are there any problems with the by-pass diodes of your solar panels?

Detection of shading problems

Possible faulty connections in panel series

2 – Hot-spot Measurement with Drone – IEC 62446 / IEC 61215

Hot-spots may occur after the solar panels are switched on. Again we perform this control with both drone and hand thermals. At this stage, you can declare the IS2 files given to us by the software to the panel factory. The thermal monitoring of solar power plants is important in determining the problems.

As a result of the thermal measurement, you can have information on the following subjects;

Do I have damaged cells in my solar panels

Is there an unexpected warm-up in panel materials such as bypass diodes, junction-boxes?

Did shading environmental factors damage panels?

Do you have any unattended arrays

3 – EL (electroluminescence) Test of Solar Panels – IEC 61215 / IEC 61646

EL panels of solar panels are presented to the customer. The future occurrence of the cells used in this phase can be considered as an x-ray with respect to probable problems. You can see whether the cells are damaged during both manufacturing and GES installation.

As a result of this measurement, you can learn about:

Structure of cells

A broken in cells v.s. whether

Impacts or overheads during overhead EPC installation

This test does not give you information about the strength of your panel. It can only give information about its source if there is a problem in the IV curve measurement.

4 – Insulation Tests – IEC 62446

Solar panels are subjected to a voltage of 1.000V and the insulation resistance between Panel-Ground is examined. This is important in order not to have any leakage on the panels and not to cause any harm to the people and also to prevent the inverters from being switched off. The damage caused by the EPC companies during the wiring process is also determined at this stage and is very important during the commissioning process.

As a result of this measurement, you can learn about:

Do you have any damage to your cables?

Is there any phase-to-earth fault on the DC current side of the solar panels?

Is there any problem affecting the insulation resistance to disable your inverter?

5 – Earthing Measurement

Grounding is of great importance in all electrical installations, especially in solar power plants. Grounding is of great importance both in leakage current protection and in general protection especially in lightning in the power plant. A disconnection in grounding and co-potentials can cause serious damage to the system. In this context, the megger grounding measurement of the equipotential busbar should be recorded by carrying out earthing measurements of both the construction and the solar panels and the necessary measures should be taken in case the problem is detected.

6 – PVSYST Simulation Using Actual Values

Based on the recorded radiation and panel temperature data of the power plant, simulation is performed on the software by using PAN files presented by the manufacturer of the panel and compared with the energy produced and produced. With these results, it is examined whether the system is overlooked (transformer, inverter, etc. losses) and a general production expectancy profile is extracted. As a result of this test, a system-wide problem is checked. With this calculation, the performance of solar power plant is measured and the performance value of the power plant is determined.

Following this study you will get the following results:

How much your plant should produce according to the data we have

Performance measurement of our power plant. How strong is our power plant?

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If you would like to receive audit service or other questions at this stage, please fill out the form below.