Questions and Answers - Photovoltaic Training Session 2

PV TRAINING – DESIGN, CONSTRUCTION, OPERATION AND MAINTENANCE

Q&A SESSION 2 September – October 2010 http://www.leonardo-energy.org/node/5948

iperez: Do you install de panels

Usually, it is used the same type and

randomly

the same brand of panel in the

or

do

you

take

into

consideration the IV curves of each

accomplishment

panel to make the different strings

strings.

with similar MPP characteristics?

variation of power between modules

As

of

the

the

different

percentage

of

usually does not overcome +/-3 %, it is not necessary to select the panels at the moment of mounting the strings.

Sometimes

nevertheless,

groups of modules are done, based on the flash list provided by the manufacturer and depending on the (little differences of) power . Some studies

have

arrived

to

the

conclusion that this selection does not guarantee a real increase of [email protected]: do

you

do

when

you

What see

a

production in the plant If the tests of thermography have been

done

by

we

a will

specialized

thermography with hot points? How

company,

follow

the

do you take a decision for change it?

recommendations it gives to us. In case we do the tests by ourselves: a) if the fault is clear, we will return the panel to the manufacturer. b) If we have

doubts,

we

can

send

the

thermographies to a laboratory in order

they

confirm

us

the

Bouaziz: Do you measure P-V curve

seriousness of the problem It is interesting to get the curve I-V

for some panels before installation as

for the whole photovoltaic facility. If

a check before installation?

we obtain it every year with similar atmospheric conditions, we will be able

establish

degradation

2

of

the

annual

the

facility.

CONCERNING THE CONTRACT: If the contract with the manufacturer fixes a price per real supplied Wp, it can be interesting to select a set of samples and pay him depending on the average power of the selected Silpa Babu: The anchored type of

samples Usually,

structures can be used up to what

elements can do the study of the

wind speeds?

type of anchorage to use depending

the

supplier

of

these

on the wind, as well as other very relevant

conditions

to

take

into

account as the soil resistance and number ashrafhafiz:

there

modules

for

every

anchorage You can need to limit the ratio:

is

any

adjustment to be done with

solar

Power

panel

solar

(inverter). If not, you could lose

or

Is

of

regulator

in

high

peak/

Nominal

Power

radiation areas

certain energy in certain moments of

padam 2: how can you make sure

the day with higher radiation You can select a few samples and

that every module procured, is good

test them, but it is more useful and

enough for installation?

practical the voltage measuring in every

string

during

the

facility

commissioning and thus to detect Aviram: what is the recommended

possible failures It is usual, in countries with medium

generator/inverter ratio?

radiation

(Southern

Europe

for

example), the facility design with a ratio of 1.15 or 1.20. This ratio can decrease

in

areas

with

higher

Malik: should the minus termination

radiation (1-1.1) In this case, it is necessary to follow

(-) be connected to the earth?

the indications of the manufacturer of panels. In a usual way: in a

3

crystalline

module

facility,

the

negative pole is not connected to earth and in thin film ones (A-Si), it is Vuyo Mzini: How do these concepts,

The approach of civil works, the

especially those related to ground

technology of the plant and the

mounted PV plants, differ from those

design

related

enormously, and it is not easy to do

to

Concentrated

Solar

of

the

comparison.

facility

Thermal Power Plant? I would assume

a

there to be similarities in terms of

plants

Civil works, Environmental effects

concerning the minimal size and can

etc

be

do

not

mounted

The

differ

photovoltaic

have on

limitation

roofs,

the

thermoelectric ones need a minimal high power and must be mounted in not urban areas. In addition, water avikul:

This

is



Avi

for their working is needed. Your exposition is correct,

a

from

favorable slope can turn out also

Toronto. Why should the site be flat?

favorable in order to reduce the

If it is possible to have a south

distances between rows of modules,

sloping

as in the case that you are referring

site

(in

the

northern

hemisphere), will it not allow less shadowing? Look forward to your response. Thanks.

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