Balance of system (BOS) to module pricing ratio opens up from 50:50 in 2011 to 68:32 this year as on: NOVEMBER 15, 2012-a report.

Balance-of-system mean (BOS) components include the majority of the pieces, which make up roughly 65%-70% of solar purchasing and installation costs, and account for the majority of maintenance & operation requirements.

Major Components in a Solar Photovoltaic PV System designed by Sun- Sol (India) are as under:

Solar PV systems are like, any other stimulating power generating system; only the equipments used are distinctive. However, the mechanism of operation and interface that are related to electrical systems remain the same, which on the other hand are guided by a well-established body of electrical codes and specifications.

According to the Functional and Operational requirements of the system; the evident peripherals that are required might include components such as:

  • PV module/Panels.
  • Mounting systems.
  • DC-AC power inverter.
  • Connectors.
  • Wire & Cables.
  • Control panels.
  • Compound box.
  • Transformer.
  • Switchyard.
  • Weather Station Equipments.
  • Data Logger system.
  • Sensor boxes.
  • HT panels.
  • AC & DC Isolators.
  • Battery bank.
  • System and battery controller.
  • Monitoring & metering setup.
  • Auxiliary energy sources with, some occasionally used, specified electrical loads (appliances), followed by an assortment of balance of system (BOS) hardware, inclusive of overcorrect surge protection and disconnect devices, and some other power processing equipment.

A few of which are defined below:

Module or Panel:

A particular PV cell produces a small amount of power; in which several cells are bounded in a series to generate, more amplitude in order to form a photovoltaic (PV) module or solar PV panel; in the process to manufacture a 'LAMINATE'.
The Laminate: is put together, into a protective weatherproof enclosure; which in succession makes a photovoltaic (PV) module or a solar PV panel. Module or Panel is a number of photovoltaic cells wired together in accordance to form a unit. Usually in a sealed frame of accommodating sizes, this handles and simultaneously assembles into arrays.

Modules may then be strung together into photovoltaic arrays to generate, yet more power. One set of modules connected in a series is known as a 'String'.
How many modules can be connected in a series?
Usually depends on heterogeneous parameters constituting a string.
The numbers of strings usually depend on the magnitude of the project envisioned.

Currently, crystalline silicon PV cells are the most commonly used all around the world. They are also respected as the original successful PV apparatus. We use multi crystalline solar Module/Panels with a proven track record from reputed domestic / international manufacturers with retention of 240-250Wp in either roof-tops or business new / proposed solar PV projects. We use them with moderation as PV systems can be designed to meet any electrical requirement, no matter how large or how small.

At present, photovoltaic modules are extremely safe and reliable products, with minimal failure rates and projected service lifetime of 20 to 30 years. Most major manufacturers offer warranties which are stretched from 10-20 or even more years in order to maintain a higher percentage of initially rated power output.

These Modules or Panels are usually in obedience with Standards/Approvals from National and International certificating organizations. Some of the codes are: IEC 61215-Ed2 &IEC 61730-1 72 etc.

Mono-crystalline Solar Panels
Poly-crystalline solar panels

The performance of PV modules and arrays are generally dependent on their maximum DC power output (watts) under Standard Test Conditions (STC).

Standard Test Conditions are defined by a module/cell by operating its temperature of 25o C (77o F), and through the incident solar irradiance level of 1000 W/m2 and under Air Mass 1.5 spectral distribution. Since these conditions are not always typical as to how PV modules and arrays operate in the field; the actual performance is generally; 85 to 90 percent of the STC rating.

Although, a PV array produces power when exposed to sunlight, it is nevertheless important for a number of other components to work appropriately, in control, to convert, and distribute in order to store the energy produced by the array.

Mounting systems:

The modules are assembled in an organized manner, on distinctive mounting systems. A field large rack is mounted to the ground whereas the modules assemblage is mounted to the rack. Taking buildings into consideration, many different racks have been designated for pitched roofs. Whereas, building integrated solutions are utilized for flat roofs, racks and bins. Modules are mounted on an MS Galvanized pre fabricated structural fragments along with Aluminum sections
The mounting system plays a theatrical role in terms of: Cost, Quality, Affluence and the Productiveness of the power plants. The systems are being treated as one of the key components in relations to BOS.

Our, next generation mounting systems are framed by a squad of gifted engineers who are fabricated in a well-equipped plant, that harbor’s third generation infrastructure, gears and robotics..

Our, MS galvanizing process is built in a modern galvanizing plant equipped with automatic temperature control process in order to achieve zinc layering up to 100 microns.

Mounting systems are either centrally supported or simply supported structures; with minimum bottom point of module fixing up to 500mm (1/2mtr) from ground, (in case of field mounting).

Sun-Sol (India’s) installation team acquires boundless experience in erection of solar mounting structures. Our team installs the mounting structures in such a way that enables lower contamination of dust, spoilage of rain water with easy access to the operator followed by an easy removal of grass manually or by machine.

Sun-Sol (India) makes no compromises when it comes down to adaptation of the codes, and we also set high quality standards in order to achieve maximal service life. Mounting structures shall be able to endure wind momentum as per the Indian standards specified in the wind zone data. These structures are usually in compliance to the IS 3601, etc.

For the roof-top mounting systems; fragments of our designs are universally adaptable, easy to use, and are awarded as the system that reduces installation time over conventional systems.
They are executed by ingenious technology with, essential number of parts. Depending on the landscape zero levels, the structures either can be directly installed or fabricated to provide customized solutions with strong results on a wide array of pitched roofing applications, including asphalt shingles, roof tile or metal roofs.

We frame next generation mounting systems for numerous projects ranging from mega watts to as small as 1kW. Our company is globally honored for our Excellence, Expertise, Engineering, Formation and Installation of mounting structures ranging from residential rooftops to mega power plants.

Our Advantages

DC-to-AC Inverters:

An inverter is thought-out as the ‘heart’ of any solar system. The inverter is a device that converts the Direct Current (DC) electricity produced by the solar panels to the Alternating Current (AC) which is required for the National Grid and for the operation of most electrical appliances. Inverters take the low-voltage and high-current signals from the PV panels in order to convert them into 120VAC (or 240 VAC), which is directly compatible with grid power.

The inverter accommodates a (fail-safe) link amid the solar generator and the main electricity network. If there is a problem with the PV system or [more usually] a fault on the electricity network, the inverter would make the system intact.
The inverter’s role is to be the interface between two energy sources: the DC network, and on the other hand the AC utility grid. In addition to the conversation, the inverter is furthermore responsible for system control, quality power and performance optimization.

Inverters that are connected in a network must supply AC electricity in a synchronized form, harmonizing the grid frequency, limiting the voltage not higher than the grid voltage and disconnecting from the network if the grid voltage is turned off.
Islanding inverters only need to produce regulated voltages and frequencies in a whirly wave shape as no synchronization or co-ordination with grid supply is required. In today’s fashion the vast majority of such devices used in the renewable energy sector are ‘micro electronically’ designed. Inverter allows renewable energy (wind, solar, etc.) generation plant owners to bargain power with the utility.

For the grid tie systems or grid connected systems, the input rating of the inverter should be the same or should be +10% as PV array rating to allow safe and efficient operation. For stand-alone systems, the inverter must be ample enough to handle the total amount of Watts you will be consuming at the point of time.
For safety reasons, the Grid-tie inverters are designed to shut down automatically upon loss of utility supply. They do not provide backup power during utility disruptions.
Battery backup inverters are the only inverters which are designed to draw energy from a battery; they help manage the battery by charging them via an onboard charger, and export excess energy to the utility grid.
These inverters are capable of supplying AC energy to the selected loads during a utility blackout, and require a anti-islanding protection.

Growing Solar PV in India:

Photovoltaic cells have a complex relationship between their operating environment and the maximum power they can produce. The photovoltaic (PV) system's output power needs continuous tracking of the maximum power point (MPP).The MPP depends on irradiances conditions, the panel's temperature, and the load connected. MPP is the automatic adjustment of electrical Load(s) in order to obtain the utmost capacity out of the connected solar panels. The yield from a solar panel varies every moment due to the factors like weather conditions, clouds coverage, cell temperature, air mass, module characteristics etc. Our team is rapidly doing endeavors in order to develop, through analysis and possible solutions for MPP to conquer maximum system output.

The quality of the inverter output waveform can be expressed by using the Fourier analysis data in order to calculate the Total Harmonic Distortion (THD). The most important inverters limitations are rated in DC and AC power; maximum power point (MPP) voltage range, ultimate DC/AC current and voltage along with rated DC/AC current including voltage.

The attribute of output waveform that is needed for an inverter depends on the characteristics of the connected load. Some of the loads require an approximate perfect sine wave voltage supply to work properly even though other loads may work quite well with a square wave voltage. Rectifier circuits are generally classified by the number of current pulses that flow to the DC side of the rectifier per cycle of AC input voltage.

The Grid-tie inverters; are designed to shut down automatically upon blackout for safety reasons. They do not provide backup power during such blackouts. Battery backup inverters are the distinguished inverters which are designed to draw energy from a battery in order to charge the battery via an onboard charger; exporting the excess energy to the utility grid. These inverters are capable of supplying AC energy to the selected loads during a blackout, and require anti-islanding protection.

Inverter competences are typically rated at 94%–98%, although actual field efficiencies may be less. Other parameters such as, no. of strings, amperage, MPPT voltage, yield etc; are considered at the proper design optimization project.
We are considering the inverters of 250kW/500kW make some change in the world’s market segment.

Classification of Solar PV systems:

Photovoltaic power systems; are classified according to: their functional and operational requirements; their elemental configurations, and how the equipment is connected to different power sources and electrical loads. Photovoltaic systems can be designed to provide DC and or AC power services and can operate independently or by being interconnected with the utility grid. They can also be connected with other energy sources and energy storage systems. Figures below show examples of some configuration designs:

Net-metering system

An individually measured

With emergency backup

To check more combination please visit our off grid page
Sun-Sol (India’s) coordinating and styling team acquires affirmed experience in configurations of a solar PV power system particularly the type of system our costumers’ need.

Images and Figures of other balance-of-systems (BOS):

Above, we provided you with a quick overview of the basic components that are used to build a solar PV system; we also suggested some blueprints of fundamental choices that could be used to revise a solar PV system design of several sizes.
Factors such as:

  • Location.
  • The power requirement.
  • The characteristics of the mounting area and Aesthetic preferences

All of the above play a role in determining as to which could be the correct element to be selected and to be installed?
As we apprise earlier Photovoltaic systems have a number of merits and solo advantages over conventional power-generating technologies. PV systems can be designed for a variety of applications and operational requirements. Energy independence and environmental compatibility are two attractive features of PV systems as the fuel i.e. (sunlight) is free, and no pollution i.e. {Air, Water, Noise} is composed from operating PV systems. Basically disclosing that the PV systems that are designed well and are properly installed require minimal maintenance and are durable.
After the installation process the whole system is automatic. It will start working early in the day as soon as there is enough light and switch off at night. When you are generating electricity this can be used to run your appliances.
If you are producing more than you need it is fed back into the grid so that other people can use it, and if you need more than you are generating you can take electricity from the grid. The only difference you’ll notice is lower electricity bills.

BIG money and Solar Green Profit!!!

The financial benefits of solar power present an interesting opportunity for the savvy investor looking to diversify his/her portfolio or end use.




Solar will make sense for you financially if investing. The two main ways to invest/acquire your solar power system(s):

  • Solar system purchase
  • Solar as a service

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