Why and How to do solar PV site survey?

Solar site survey and Assessment for solar power plant installation

1) Why Solar site survey is most important in solar power plant?
Assessing the site survey can save the Money, time, resource and give provide confidence for solar supplier, it reduce the wastage of time, materials It usually means you have purchased more solar panels than what can fit on the roof, by doing the site survey solar supplier will have the details list of material require for the project, ( Find the check list of last page)
2) What is solar power site survey?
Site surveys are used to collect information about the local conditions and issues affecting a proposed PV installation. This information is documented through records, notes, photographs, measurements and other observations and is the starting point for a PV project. Ultimately, information from site surveys is used in combination with the customer desires as the basis for preparing final quotations, system designs, and planning the overall installation.

A site survey is essential in order to begin planning PV system. The site survey enables the assessment of the basic conditions for the PV system. First, it is important to establish whether the site or the building is suitable for installing a PV system. A thorough initial investigation avoids planning errors.

The installation work for the PV array, the installation site for the inverters, the
wiring routes, the actual laying of cables and the expanding or modifying the meter
cupboard can be better estimated and agreed in consultation with the customer.
Before planning gets under way, the customer should also be asked how much they
expect to spend as well as possible subsidies that should also be taken into account
since those will have a deciding influence in the size of the system.

There are many aspects to conducting a thorough site survey. The level of detail depends on the size and scope of the project, the type of PV system to be installed, and where and how it will be installed. Greater considerations are usually associated with commercial projects, due to the larger equipment and increased safety hazards involved. Obtaining the necessary information during a site survey helps to plan

By the end of the solar site inspection, you should be able to determine the following:

a) Consulting with customer.
b) Possible shading and other obstructions.
c) Physical details of the property where PV panels need to be install like roof, roof inclination, ground, shed etc
d) Installation sites for junction boxes, Earthing, Spark arrestor and inverters,Meter cupboard and space for extra meters.
e) Sanction load from grid, Load installed capacity and voltage transformer, Current monthly kWh consumption.
f) Desired PV power or the desired energy yield..
g) Access, particularly when equipment is required for installing the PV array
(crane, scaffolding, etc.).
h) The financial framework, taking the respective subsidy conditions into
account
i) General information about the customer

Once you have these data, it will be easier for you to do an accurate solar PV simulation and design for the project.

a) Consulting with customer.

The planning and building of a photovoltaic system is generally initiated by a
customer's enquiry. Consultation with the customer is therefore an important and
essential step before commissioning the building of a photovoltaic system. When
talking to the costumer, the PV installer must recognize the customer's expectations
and wishes. Consultation in this case, first and foremost, consists of helping the
customer to make up their mind on the system they want to be installed.

The PV installer should possess technical knowledge concerning structure, function,
sizing
sizing and the installation of photovoltaic systems, as well as knowledge regarding the

financial costs of PV systems and their components. The installer should be prepared
to answer the following questions:

Type of panels and their efficiency ?
What is on grid and off grid solar?
How much electricity the system will produce in a year?
What happens to the power supply when the sun isn't shinning?
How much power the system does produce when the sky is cloudy?
What does 'kilowatts peak' power mean?
Whether the area or the roof is suitable for a system like this.
What happens if the modules get dirty from snow or dust?
Whether hailstones can damage the modules.
Whether it is worthy having a moving mount that tracks the sun.
Which are the necessary permissions for the installation of a PV system?
What will the system cost, including installation?
What are the available subsidies?
How much money the customer gets for the electricity that goes into the main grid?
How long the approximate payback time for a PV system is.
What kind of maintenance the system requires?
Whether a lightning can destroy the system.
How long will the system last?
What the system’s warranties are.

b) Possible shading and other obstructions.

The site should be shadow free, check If there are shaded areas that fall on the solar array during hours of maximum of sunlight i.e. 9 am to 4 pm, which cause more than 40 % of efficiency possible to reduce due to shadow, during the site survey the following shall be taken care for present and future consideration of shadow, where the trees can grow above the PV modules, and also, electrical post, building, cables, hills, telephone tower shadows shall be affect the generation of solar power, Also, the length of the shadow during different times of the day and different seasons (winter and summer) is also to be considered, by using shadow simulation software and show the customer how the system will actually generate electricity

Surrounding areas with angular grid

Calculation of an object's azimuth angle a and elevation angle γ [3, 4, 5].

The elevation angle γ is calculated from the difference between the height of the PV

system ℎ1 and the height of the shading object ℎ2 and its distance d:

tan لا= h2-h1 --> لا = arctan(h2-h1) = arctan(𝚫h)

d d d

The elevation angle is worked out for all obstacles in the area surrounding the

photovoltaic system, requiring the height and distance of the objects from the

photovoltaic system. The azimuth angle of the obstacles can be calculated directly

from the site plan.

c) Physical details of the property where PV panels need to be install

During the site survey check the below which is suitable type

Sloped- Roof mounting
Flat roof/ground mounting
Roof-integrated mounting
Wall mounting

1. Sloped- Roof mounting

2. Flat roof/ground mounting

3. Roof-integrated mounting

4. Wall mounting

If the roof can sustain that much additional weight?
In case your roof is old, needs repair, etc, ensure it is checked before the installation of the PV installation. Also, make the choice of roof mounting and roof integration.

d) Installation sites for junction boxes, Earthing, Lightening arrester and inverters, Meter cupboard and space for extra meters.

Check the sites where the AC and DC junction box need to be install , earthing pit installation area sufficient area available, LA and inverter installation area available,
Select the location for inverter near to the PV panel, try to use as low as DC cable and sufficient air ventilation, and avoid direct sun light and water. and also ensure during the site survey check the available space for Bidirectional meter and accessories in case of on grid system.

e) Sanction load from grid, Load installed capacity and voltage transformer, Current monthly kWh consumption.

During the survey check and note the check list the Sanction load from the gird, Load installed capacity and voltage transformer, Current monthly kWh consumption.

f) Desired PV power or the desired energy yield.

During survey check the available space, based on the space available and require power can suggest the suitable of Mono crystalline panel or Poly crystalline panels

g) Access, particularly when equipment is required for installing the PV array
(crane, scaffolding, etc.).
Check the height of the place where need to install the PV panel, ensure all the safety tools and tackles and in case of height use crane or scaffolding for installation,

h) The financial framework, taking the respective subsidy conditions into
account:

There are different part of country different rules are there, in India for Ongrid system central govt and state government providing subsidiary up to 40 % , for other PV installation like water pump govt, providing around 90 % of subsidary, every thing need to be discussed with customer.

i) Site survey check list

Basic information of site and location
Address and plant name for identification
Satellite image or picture of the site
Details of customer name, Phone number, e mail address
Electrical power single phase or three phase
If Power shading available note down the time
Available area for PV module installation
Sanction load in KVA
Latitude and Longitude of the site
Orientation towards the sun
Height of the Building
Tree shading any other factor affecting the power generation
Type of mounting system required Ground, normal on shed or elevated on shed, roof etc
Inverter placement location details
Protection theft and vandalism
Earthing pit location
Bidirectional meter location
DC cable distance between PV module and inverter
Easy to access to installation and Maintenance.

Any doubt, query please comment below, I will revert at the earliest time

M/s PMM Smart Future solution – Ranipet solar product Supplier, Dealer and Distributor

( Supplied 10 KW solar power system including on grid and off grid in Ranipet District at different locations Navalpur, Ranipet, Walajapet, Arcot, Sipcot, Ammoor, Perumbulipakkam, Panapakkam etc)

Source: Solar electricity hand book

Conclusion:

For site survey shadow shall be the major playing role, other than shadow all check list to be full filed to avoid the rework or additional expenditure

your comment and suggestion and Question are almost welcome