FAQ - Frequently Asked Questions

The joint venture of Evergreen Solar Inc. (Marlboro, USA), Q-Cells SE (Thalheim, Germany) and REC ASA (Hovic, Norway) founded in 2005 functioned as EverQ in the past purely as a production setup. Its name was derived from the two companies Q-Cells and Evergreen.

EverQ was given as the project name. The products were not marketed under the EverQ label but sold as Evergreen products.

Since November 24, 2008, EverQ GmbH has been trading as Sovello AG. The quick growth and the size the company has reached today made the shareholders of the joint venture decide that the company must enter the market independently in the future. Therefore, Sovello AG began in early 2009 to position and market its solar modules on its own account.

With the new, internationally relevant name, the independence of Sovello with customers, suppliers, partners and employees is expected to be highlighted.

On April 26, 2010, Sovello AG was taken over entirely by Ventizz Capital Fund IV, L.P. The company was renamed Sovello GmbH in December.

The name Sovello takes its origin from the words "Sun" and "Well" (i.e. good) and also indicates towards the location at Solar Valley.

The material of the draw threads is a carefully guarded company secret.

The wafers are 190 µm thick. Sovello continues to attempt to reduce this value.

The visible difference is because of the drawing process during the wafer production. Since the wafer is given its final thickness directly from molten silicon and is not sawed (enabling less use of energy and material), the natural silicon crystal structure is retained which, however, has no negative impact on output and life.

What are the advantages of the silicon modules over thin film modules?

Crystalline silicon modules have a higher degree of efficiency than thin film modules as well as a reliable and advanced technology that has been employed successfully for decades.

No, but our cells have the know-how for cell fabrication from the Q Cells SE as the former joint venture partner as well.

Sovello GmbH has a recognised, certified quality assurance system according to DIN EN ISO 9001:2008 and a recognised, certified environment management system according to DIN EN ISO 14001:2004 and also an energy management system according to DIN EN 16001:2009.

Our glass thickness is 3.2 mm. Sovello uses special glass with an extremely durable and resistant nano anti-reflection coating which prevents collection of water and dust to ensure that the yields of your Sovello solar power unit are maximised for a long time.

According to the assembly instructions, a mechanical load of up to 5.4kN/m² is guaranteed for for T and X series Sovello modules and 3.8kN/m2 for the L module (TÜV standard: 2.4 kN/m²).

Do the installed modules need to be cleaned regularly and which cleaning agents can be used for the module's glass?

The PV modules themselves are efficient in operation when they are never washed. Nevertheless, the output increases if dirt is removed from the glass surface. The coated module glass surface must however never be cleaned with corrosive cleaning agents/chemicals.

Since Sovello special glass uses a highly durable and resistant nano anti-reflection coating, it is important that the following instructions are followed to ensure that the module's surface is not damaged while cleaning:

• The Sovello modules are free of any deposits most of the time. However, if your module does gather dust, dirt or other deposits, you can use normal drinking water to remove them. Please remember that very hard water can lead to mineral deposits (e.g. calcium residue) on the surface of the glass and is therefore not recommended.
• A microfibre cloth and ethanol or conventional glass cleaner can be used to remove really persistent deposits.
• Corrosive cleaners such as scouring agents must never be used. It is also recommended that no alkaline chemicals be used. Always wear insulated rubber gloves while servicing or cleaning solar modules and follow the safety regulations while climbing roofs and observe general and regional ordinances and laws.
• Normally, glass surfaces can also be cleaned using a high-pressure cleaner with low water pressure and adequate spray distance, but never with hot water in winter temperatures since the difference in temperatures might cause cracks in the material (loss of warranty). Please ensure that the drainage holes on the module frames are open and not clogged. This is to help the water flow out and prevent its collection in the frame and subsequent freezing. Sovello normally recommends removing the snow in winter only with a soft broom or hand brush without any use of water or chemical de-icing agents.

Are Sovello modules suitable for stable roofs (i.e. areas with high ammonia exposure)?

Our modules are certified according to the common standards IEC 61215 and IEC 61730 (Protection Class II), and there are no negative reports on use of Sovello modules on animal stables. The Sovello module cleared the performance test DLG focus test for ammonia resistance in early 2010 with the best result ++.

The test result after intensive treatment with ammonia certifies the Sovello module:

• The loss of output is very low.

• The insulation resistance under wet conditions remains high.

• There are no visible damages or significant abnormalities.

The test confirms that Sovello Pure Power solar modules are very suitable for use even on stable roofs.

The modules must, however, not be installed exactly above or in immediate proximity to the exhaust fan and plan a footbridge to be able to regularly clean the modules when required.

All Sovello modules have SMK or SMK-compatible plugs ex factory.

Module size length x width x height:

T series: 1571 x 951 x 41 mm ; weight: 17.4kg

L series: 1817 x 951 x 46 mm ; weight: 20.1kg

What is the degree of efficiency of the modules as compared to the competitors?

Module efficiency e.g. SV-T 205: 13,7%

Temperature coefficient Pmpp -0.45%/°C

Is there corrosion on metal/metal seams with different materials (e.g. on earthing)?

Corrosion on metal/metal seams cannot be completely ruled out on account of the physico-chemical interaction between the metal and its surroundings. Corrosion behaviour on the seams depends on the metals/materials used (the reactivity series of metals must be kept in mind). Base metals tend more towards corrosion than the noble ones. In case of electric connections of the same metal, the tendency to corrosion is lower.

Within the ICE 61215, factor 3 is calculated for safety.

High-frequency electric and electromagnetic fields are critical for pacemakers. Since the solar modules generate direct current (no alternating fields) during the day and thereafter only a weak electrical field, no interference to the pacemaker needs to be expected from the installed solar modules.

Sovello products have been tested independent of the manufacturer in an RAL certified process and have the RAL mark of quality RAL-GZ 966 for solar power systems independent of the manufacturer.

Are your PV modules suitable for the operation with inverters without transformers (without galvanic separation) or do you recommend the operation with a galvanically separated inverter?

The design of the inverter type (with/without transformer) depends on the Sovello module type installed. The modules of type "fa" and "fc" are meant for inverters that are without and with transformers. However, we recommend inverters without transformers since they have a higher degree of efficiency than inverters with transformers.

Modules of the "fb" type should always have inverters with transformers since they exhibit a galvanic separation. It is required to meet the earthing requirements for this module type.

In the limited manufacturer's warranty by Sovello, the "Limitations and Terms" sections states that:

"This limited warranty does not cover the costs arising from installation, removal, testing, packing/unpacking, transport and reinstallation."

All Sovello modules can be installed on roofs with east or west orientation. The yields here are however lower than the ideal south orientation. This must be considered in the calculation of amortisation. The expected yields can be calculated on the Sovello website as well as in various design programs as part of the system planning.

Sovello modules comprise polycrystalline silicon solar cells. The terms cis and ctlte do not describe materials, but a manufacturing process for thin film modules. This manufacturing procedure is not used by Sovello.

What happens to a string if it is not used because of shading? Does the entire unit stop functioning?

The intelligent connection of the cell strings in our solar modules significantly reduces the undesirable effect of shading on solar systems with solar modules in a landscape arrangement.

In the design of the Sovello module three strings are connected in parallel. In case of diffuse shading running parallel to the path of the current, Sovello Pure Power solar modules generate up to 10% more power than other solar panels. As the energy reduction can affect all other solar modules interconnected in rows, this clever arrangement can significantly improve performance and output.

Cables and components in the PV system continue to carry electric current to the inverter when exposed to light. I.e. only the AC side is de-energized by turning off the inverter and the AC voltage protection.

In addition, if there is a DC disconnection unit, which is activated, cables and components of the PV system continue to carry electrical voltage up to this point under exposure to light.

Basic information for the fire department: The unit carries up to 1,000 volt

DC! Procedure same as for 230/400 Volt AC units.

Use of fire extinguishers by the fire department will be according to DIN VDE 0132: Fire fighting in the area of electric units.

Is the 25 years output guarantee also applicable to installations on the sea where the wearing out is much higher due to the high salt content in the air?

TÜV Rheinland has confirmed that Sovello PV modules have successfully cleared the salt mist corrosion testing of photovoltaic modules according to DIN EN 61701:1995. Therefore, the 25 year output guarantee is also applicable in coastal regions.

The substrate for installing a solar power unit is secondary. It is crucial that the static stability of the roof first and then of course of the system is ensured. The latter is dependent on the base frame on which the modules rest.

Are there good buffers and what do electricity buffers cost?

The economic practicability of a buffer depends on the size of the unit it is connected to. Currently very few buffers are practicable with small units.

Is it possible to install photovoltaic unit on a gazebo without official e-connection and to supply the electricity to receive funding?

The prerequisite for the compensation of the current fed through the Renewable Energies Act is an electrical connection point to the local energy supplier. This is irrespective of the nature of the building, as long as it is a "building" (a shed for cars is not a building, for instance). If the gazebo has no transfer point, so for lack of in-feed into the grid, the electricity generated will not be compensated and can be consumed only internally.

Are hybrid modules being planned by Sovello? Are thin film modules, bricks or roof-integrated modules in planning?

The development of hybrid or thin-film modules is not planned, since this requires a completely different manufacturing principle. We constantly improve our product under our technology.

How far is it possible to monitor the unit through www.sunnyportal.de (SMA Solar Technology)?

A monitoring system is possible with existing hardware and software, depending on the inverter type and manufacturer.

What are the voltage and power behaviours of Sovello modules under extreme ambient temperatures such as +70 ° C or -20 ° C?

Voltages and currents at temperatures different from the standard conditions are calculated with the corresponding temperature coefficients a, b, g, as specified in the data sheets.

Example (SV-L-230-fa1):

Umpp(STC=25°C): 20,4V
β Umpp: -0,42%/°C

Umpp(-20°C): ΔT = -20°C - 25°C = -45°C
ΔU = β Umpp * ΔT * Umpp(STC=25°C) = 3,85V
Umpp(-20°C) = U(25°C) + ΔU = 24,25V

Umpp(+70°C): ΔT = +70°C - 25°C = +55°C
ΔU = β Umpp * ΔT * Umpp(STC=25°C) = - 4,71V
Umpp(+70°C) = U(25°C) + ΔU = 15,69 V

What should be the minimum module installation angle to guarantee self-cleaning in rain?

While manufacturing of our solar modules, we use a highly transparent solar glass with a special "nano-power anti-reflection coating," which, in addition to excellent optical properties, has an improved self-cleaning effect. When it rains, the film of water spreads over the glass surface evenly, at the same time efficiently washing off dust particles and other dirt.

There is no fixed specification for the minimum angle for Sovello modules. The modules could be without any angle, even if, considering the power and cleaning aspects, it is not ideal. Our experience shows that the modules at angles from 10° have good self-cleaning effects.

Why do Sovello modules demonstrate lower levels of degradation in the first years of use than most of the competitors, and why do long-term yields usually either exceed forecasts or compare favourably to competitor products with similar (or even slightly better) nominal yields?

One of the main culprits causing the initial degradation of ingot modules is the build-up of metal boron oxygen compounds as a result of diffusion. These compounds then form imperfections, which induce the recombination of free charge carriers. The oxygen here comes largely from crucibles used for the molten ingot installations.

STRING RIBBONTM uses other materials as crucibles (graphite), which do not add any oxygen to the melt. This means that Sovello wafers contain hardly any oxygen, significantly reducing the build-up of the aforementioned compounds in the STRING RIBBONTM material.

Due to moisture, moss and algae have grown on the rear frame section of the module. Does that have a negative impact on the module and its performance?

This phenomenon is not unique, it is clear from the various photovoltaic modules in the market and can be explained as follows:

First, condensation builds up on the back sheet in certain weather conditions, and second, it is possible rainwater seeps from the module's front side through the laminate around to the back of the framing.
The "gasket" between laminate and frame is not provided for sealing purposes, but only for the mechanical fixing in the module frame.
Due to the good heat dissipation of the module frame on account of its design, a relatively cool surface and with the indirect solar radiation on the back of the module, the third condition for a good moss and algae growth is easily met.

The drainage holes in the frame profiles are intended only as a drainage facility for ventilation and condensation from inside the hollow chamber.

There are no concerns over impact on durability or performance of the modules.

QIt is possible in most cases. Please contact your tax advisor or fiscal authority for the same.

The costs depend on the type of insurance (e.g. pure investment insurance, operator liability insurance or insurance for the structure - for the installation of the unit only). For a specific product or service, contact the insurance agency of your choice or for special conditions for Sovello, please get in touch with

Allianz Beratungs- und Vertriebs-AG
David Löchner
Tel.: +49 40 30 85 801-50
sovello-pv@allianz.de

It is best to contact a bank and ask for participation models. It is also possible to go through large unit manufacturers or investors to become a participant/member.

Your local supplier to whose grid you feed the power you produce will give you this information.

Normally, building insurance is not affected by the solar unit - please contact your insurer for this information.

You initiate your query through the contact form on our website, we then direct you to the sales partner or installer responsible for your region.

Sovello modules can of course be installed with subsequent systems.

Are you planning smaller modules for use on mobile homes and ships?

We have no plans currently to extend our product portfolio in this direction. However, since we at Sovello have a number of clever minds, the idea is not completely ruled out.

What are the rules for removal or disposal of the modules after 20 or 25 years of use?

With effect from 1 January 2010, Sovello has become a member of PV-Cycle, a voluntary system for removal and recycling that represents 85% of the European solar companies. As a member of PV-Cycle, Sovello is obligated to remove the modules free of cost at the end of their service life.

For more information, please visit www.pvcycle.de.