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Frequently Asked Questions about solar panels

General questions

Can a solar cell system cover the total electricity needs of a bigger family?/ How much electricity can a system supply?
The size of the system is planned according to the amount of power consumption. It is advisable to calculate exactly how much electricity (kWh) we use a month / year. While a smaller,  household-sized power plant (up to 50kVA) does not require a building permit, it can supply energy to several families or even smaller communities. Any system exceeding 50 kVA will have to be built and installed in compliance with different regulations. The amount of electricity provided by the solar cells in each case depends on the power of each cell, the number and orientation of the solar panels installed and the number of hours of sunshine. Before designing a solar energy system to a Corporate Client, we recommend getting in touch with us.
How much time and money does it take to maintain solar cell systems?

We will have almost no problems or tasks with maintaining the solar panels. Since they do not contain moving parts, we do not have to expect them to fail. The only problem may be replacing the inverter, which may need to be replaced every 5-10 years – with this device, you may want to consider extending your warranty.

Do we need to clean the solar panels sometimes?

Experience shows that in most cases there is no need to clean the solar panels. Exceptions can be made if we live in a very dusty neighborhood or if birds regularly visit our roofs.

And what about winter? What should we do when it snows?

Snow is easily slipping off modern solar panels and if the roof angle is right, we won’t really have a problem with the snow layer. If it still stays up, it’s a good idea to wipe the boards gently with a cleaning tool. For a family-sized solar energy system, this will be a 5-10 minute task.

DO-IT-YOURSELF Best Solar PanelKit

Making a solar panel is not an easy task, but installing solar panels is possible at home. Recently, it has also become an important goal for us to provide all possible tools and knowledge to those who would like to take some of the tasks connected to solar panel installation into their own hands. However, it is important that the installation of the solar panel itself is always carried out by a qualified person because faulty installation can be dangerous: it can cause fire or accidents.

“Solar air-conditioning”? “Solar floor heating”? Do they exist?

It is worth clarifying what we mean by the above terms, as they are often incorrectly used. These devices are not special solar-powered machines, but the same electrical equipment as their traditional counterparts, the name simply refers to the way they are operated: if our household is supplied with electricity by solar panels, then also these systems will use the energy of the sun.

What trends can be expected in the solar market?

Over the past 10 years, the demand for solar panels has grown at a rapid pace and all indications show that the trend will continue. For a long time, the silicon and certain precious metals (e.g. silver, tin) that are required for production will not limit the production volume. The competition between manufacturers is intensifying and more and more advanced, material-saving systems are being launched. The growing demand can also be felt in Hungary. According to many experts, the solar market is facing a huge growth, and this is mainly due to the ever-better-priced, increasingly profitable and constantly evolving solar cell technology. Despite the current economic downturn, the production capacity of the world’s largest solar panels is constantly expanding.

If I move to another place, can I take the solar cell system with me?

Of course, in case of moving, both the cells and the inverter can be dismantled and transferred.

Do you also serve individuals?

Yes. Although since our launch (2007) we have been working mainly on larger investments, we have recently been making available solutions to individuals and families that we have been able to implement only in a cost-effective industrial environment so far.

Basic terms and technical questions

What are the components of a solar energy system?

The main parts of the system include solar panels, roof mountings, inverters, surge protectors and special cables, connectors for solar panels. In the case of an on-grid solar cell system, a two-way electricity meter is also an essential part of the system.

What is an inverter?

Through photovoltaics, solar cells can only produce direct current. The task of the inverter is to convert the direct current into a 50 Hz, 230 V alternating current compatible with the electricity network and the needs of our household appliances. In addition, the device is responsible for some “minor” functions as well: it protects against overvoltage and overheating. Nowadays we can also buy smart inverters: with the help of these we can monitor the current status and performance of the solar cells on our smartphone.

What is a small household-sized power station?

Home power stations are for generating electricity up to 50 kVA (~ 50kW). This term includes home wind turbines or solar energy systems up to the specified maximum power. No building permit is required.

What is the difference between thin film, monocrystalline and polycrystalline solar cells?

The main raw material for solar cells is crystalline silicon (Si). Depending on the application and structure, we can speak of thin film, monocrystalline or polycrystalline solar cells. Overall, the efficiency of crystalline solar cells is higher than with thin film counterparts.

The names of the types of crystalline solar cells derive from whether the semiconductor wafers are made of one (mono) or more (poly) silicon blocks for each cell.

Although the monocrystalline panels perform slightly better in terms of solar energy utilization efficiency, the actual performance is also greatly influenced by production in cloudy weather (scattered light).

For this reason, in regions with a hotter climate and where there is much more direct sunlight, monocrystalline solar cells perform better. Polycrystalline solar cells are more usual in northern parts of the Earth and in more cloudy weather areas (like in England for example). In Hungary, there is no significant difference between the two types in terms of overall performance, so other aspects tend to be decisive in the choice. In terms of their prevalence, polycrystalline solar cells are leading, as it is the oldest technology manufactured, but in recent years the proportion of monocrystalline cells has skyrocketed.

What permissions are required to install solar panels?

In case of a small household-sized power station (max. 50kVA) no building permit is required. Above the mentioned limit, an investment permit is required.

In case of solar panel systems connected to the grid (“on-grid solar systems”), the written permission of the electricity provider is also required. To do this, we need to send the plans and technical documentation. Licensing is usually arranged by solar companies (of course, by Best-Solar Kft. too).

Special permits are required for heritage listed houses and condominiums.

What is the difference between a solar collector and a solar cell?

A solar collector system, with the help of tanks, absorbs and stores the heat of the sun by circulating some liquid. Solar cells convert solar radiation into photovoltaic electricity. From a practical point of view, the main difference between the two things is that the former can be used mostly for heating and hot water supply of the house, and the latter for the operation of any household-machine that consumes electricity.

The efficiency of solar collectors is usually much higher (it can be even 60-80% in summer), but it depends much more on the seasons and the fluctuations of the daily weather. In contrast, a solar cell system produces less energy at once, but does so more reliably, more evenly.

The large amount of energy produced by the solar collector cannot be stored for a long time, but the surplus produced by the solar energy system is taken over by the electricity supplier.

The maintenance of solar collectors requires a little more care, the pH of the circulating fluid and the system pressure must be checked every 2-3 years. Circulating pumps carry the risk of failure as they also contain moving parts. In contrast, solar energy systems will have almost no problem because they do not include moving parts.

The two energy systems are an investment of similar magnitude, it is worth considering what our primary goal is: overall, solar collectors can significantly reduce the heating bill, while solar panels can replace the electricity bill. (But by using electric heaters, of course, solar panels can reduce your heating bill as well.)

What is an off-grid solar cell system and when is it usually installed?

The essence of off-grid solar systems is to store the generated electricity in batteries. Such systems are usually used where it is not possible to feed back into the network: in places further away from the utility network, like in a homestead. This way we cannot return or sell the surplus electricity to the grid.

What is an “on-grid solar system” / “solar on grid system”?

In the case of solar panels producing electricity for the grid, the surplus is taken over from us by the electricity supplier, as it is required by law today (theoretically until 2024). During installation, this type of solar energy system must also be approved by the service provider, including the inspection of bidirectional measuring instruments (“two way meters”).

What does surge protection mean and why is it important?

We can talk about overvoltage if a higher voltage is displayed on the terminals of the electrical device (in this case a solar cell) than the mains voltage. In the case of solar panels, this can be caused primarily by lightning and it can cause damages to the panels. Therefore it is definitely worth protecting in advance. It is a good solution to provide the DC lines with a surge arrester one by one before the inverters.

Calculations

What is the investment cost of a solar panel system?

The price of a solar cell system depends primarily on the capacity of the designed system, the quality of the panels, the components and the inverter, and the fee of the contractor. If we want to reduce the electricity bill of a family of 4-5 people, it is usually worth considering a one-time investment of around 1.5 – 2 million HUF.

How long does it take to pay off the investment of solar panels?

In Hungary, the payback period is usually 8-12 years, but of course the local conditions of the installation, the typical weather, the consumption rate, the size of the planned power station and of course the current electricity prices must be taken into account to see how much electricity we are expected to save over the years.

How much value does it add to my house if I have a solar panel on my roof?

If a family house is equipped with a solar cell system, it can increase by 15-20% of its value due to its better energetic classification. Of course, the value-adding effect of solar panels is much better if they have been installed recently, especially if the warranty is available for solar panels, inverters. Naturally, the extra value of a 20-30 year old solar panel system will no longer be outstanding.

What does “balance accounting system” mean?

Regarding solar power systems, the balance accounting means that when settling with the service provider, the service provider takes into account not only the price of the energy withdrawn from the network but also the energy fed back into the network. The service providers located in Hungary (E.ON, ELMŰ, ÉMÁSZ, NKM) are currently obliged by law to purchase the surplus electricity generated by the solar panels from the users. Although the purchasing is done at a net price, the sale is done at gross prices. In the case of an optimally designed solar cell system, we can still count on electricity bills of around zero HUF. The bill will show the difference between the electricity consumed and the electricity produced, which we will have to pay to the electricity supplier. Of course, there may be cases when the service provider pays, but only for that reason it’s usually not worth installing solar panels. The condition for balancing is a two-way electricity meter, which is put into operation during the approval of the solar cell.

Will the balance accounting system really be abolished from 2024?

Although the legislation does not yet specify, it seems that the accounting of electricity generated by household solar cells to service providers will change. How and the exact details of this are not yet known, but the opinion of many experts is that those who install a solar energy system by 2024 will definitely do better, after which the conditions will be slightly more unfavorable. If we feel the need for a capacity expansion, it is worth doing also before 2024, as the subsequent inverter replacements will no longer be registered in the “balance accounting system”. Another question is whether the changes will apply to those who are currently benefiting from the balance system, our answer is: probably not.

Should I pay taxes after the overproduction and after the price received from the service provider?

Yes. Since it counts as income, we must pay taxes afterwards. It is important that the size and capacity of the ideal solar cell system are accurately estimated in order to achieve an optimal ROI (return on investment). It is not really worth designing a system much larger than our average consumption – do not expect to get rich from the sale of the extra electricity!

Is it worth taking out an insurance for our solar energy system?

It might be useful. In general, solar panels can be added as an extra to the basic home insurance package. It is worth inquiring about the individual terms and conditions of solar insurance with our own insurer.

Warranty issues

How many years guarantee do we get for a quality solar cell system?

In the case of solar cell systems, we usually come across the term of “performance guarantee”. Most manufacturers currently offer a 20-25 year performance warranty on solar cells, which means that the performance of the cells cannot deteriorate by more than 20% during that time.

How many years of warranty do we get for an inverter?

In case of inverters, a long-term warranty is not typical. However, in most cases, it is possible to extend the warranty for an extra fee. Fronius inverters, which we also sell, have a 5-year warranty.

What about out-of-warranty service?

Every manufacturer has a service network and service partners who are happy to help with out-of-warranty service. Manufacturers also offer a 20-30 year warranty on most of today’s solar energy systems, but presumably thanks to more modern technologies, the power generation devices will be able to operate even longer. It is worth mentioning that many solar panels installed in Germany in the early 90’s still work smoothly to this day. And since then there have been countless developments in the field of solar technology.

In case of failure, does the whole inverter have to be replaced or is it enough to replace the faulty parts?

Replacing only the parts often proves to be a more cost-effective solution. But every situation is different, you have to see exactly what it is about. There are also cases where we are better off replacing the entire inverter.

Environmental issues

What is the CO2 footprint of a solar panel?

In addition to wind energy, solar panels currently have the smallest carbon footprint and are one of the cleanest energy sources. Monocrystalline solar cells emit only around 42 g / kWh while polycrystalline ones emit around 44 g / kWh. By comparison, today’s modern cars average emission is between 100 and 130 grams of CO2 per kilowatt hour.

How long does it take for a solar cell system to “neutralize” the environmental impact of its production?

Several foreign studies have examined the issue. Today’s modern solar cell systems can be considered carbon neutral in 1-3.5 years. In Northern Europe it can be in 2-3 years, in Southern Europe it can neutralize itself within one year, so in 90-95% of their lifecycle (30 years) they are net CO2 absorbers.

This has not always been the case. Producing the panels manufactured in the 90’s required 10 times more energy than today’s models. This is why the skepticism that “it costs more to produce than it produces” has remained in the public consciousness. There is also a significant difference in the carbon footprint of panels manufactured in Europe and the Far East in favor of the former.

What about a used solar cell? What about recycling?

Although solar panels are expected to operate on our roofs in 30-40 years (maybe with lower efficiency, slightly decreasing performance from year to year), if someone switches to a more modern system every 20-30 years, solar panels are almost 100% recyclable. Proper recycling of the various components (plastic, aluminum, silicon, copper, tin, silver, glass) is still a bit cumbersome, but more and more patents are coming up promising cost-effective solutions.