1. “ Solar Energy Systems
(Photovoltaics) in comparison
with the conventional
Generators”
(Basics)
(Basics)
Prepared by:
Hassan Ahmed,
System Engineer,
AE Department,
Welt Konnect
Document # AE-KHI-PDO-0002
2. Scope of the Presentation
Reasons of the Presentation:
– Being a part of the Alternative Energy Department, one
should have basic know-how about the working of the
systems it deals in.
– To acquire basic knowledge about How Solar Energy System
(Photovoltaic) works?
– To be able to take part or engage in conversations related to
working of Solar Energy systems.
– This presentation is purely to understand the technicality of
the Photovoltaic.
Why Generator:
– Because we all are familiar with a conventional Generator
and it is easy to learn something by comparing it to a familiar
object.
3. A Conventional Generator
1 kW Generator 1 kW Appliance
Fuel
Generates 1 kW Consumes 1 kW
continuously continuously
So we can tell the client:
“Here is your 1 KW Generator for your 1 KW Load”.
4. The Ideal Condition for a Solar Panel
1 kW Appliance
1 kW Solar Panel
Mr. Sun 90˚
Generates 1 kW Consumes 1 kW
continuously continuously
“IF” this condition were true we would have told the client:
“Here is your 1 KW Solar Panel for your 1 KW Load”.
5. What Actually Happens
• A Solar Panel does not generate its Peak Power through-out the
day.
• The Power Generation at a specific time depends on the
position of the sun at that time.
1 kW
800W 800W
500 500
West East
1 KW Peak Power
Solar Panel
6. Equivalent Sun Hours (Insolation)
10 Hrs.
90˚
1 kW
800W 800W
500
500
West East
A Perpendicular Sun
1 kW Solar Panel would have Generated
this Energy (5 kWH) in
But total Energy Generated in 10hrs.
5 hrs. only.
= 5 kWH
Insolation depends purely on the Location and season eg, Karachi
has average 5.44 hrs of Insolation.
7. How much Solar Panels do we need for
our Appliance ?
• The answer is we calculate Energy per day.
1 kW Appliance Equivalent Sun Hrs. : 5 Hrs.
1 KW Solar Panel
So Energy generated is,
Runs 10 Hrs. per Day 1 kW * 5 Hrs. = 5 kWH per Day
So Energy consumed is, Conclusion: Energy req. = 10 kWH
1 kW * 10 Hrs. = 10 kWH Energy gen. = 5 kWH
per Day So, Number of Panels required = 2
8. Battery Back-up & Other Accessories
• The Energy is Generated by a Solar Panel only
during day-time.
• Even during day-time, Generation is non-uniform.
• However we might need to run the appliance
during night and during a cloudy day as well and at
uniform power.
• For these reasons we use Batteries to store Energy
and provide when required.
• We use Charge controllers and inverters to provide
desired and uniform power to the appliance.
9. Conclusions
• A Photovoltaic system does not generate
continuous Power like a Generator.
• Photovoltaic systems are specified in terms of
Energy Consumption and Generation per Day.
• Solar Panel Output depends upon the Location
and Season as well.
• Batteries and other accessories are added to
the system depending upon the type and usage
of the load(appliances).
