3. How To Design With Solar Panels
Designing with solar panels
starts with determining the
size of the system based on
how much sunlight you will
receive and how much
energy you plan to use.
.
4. Solar Radiance
To determine the size of
the system, you will
measure the daily
electrical usage you need
and divide it by your solar
radiance.
Solar Radiance is the
amount of sunlight that
hits a surface, which
changes depending on
the time of the year.
Image credit: g2solarsolutions.com
5. July PV Solar Radiation Map
(Flat Plate, Facing South, Latitude Tilt)
Image: “Photovoltaic Systems” by James P. Dunlop
6. January PV Solar Radiation Map
(Flat Plate, Facing South, Latitude Tilt)
Image: “Photovoltaic Systems” by James P. Dunlop
7. South Facing Solar Array
A South facing solar
array is the best
position to absorb the
most sunlight for the
northern hemisphere.
The suns angle changes
+15° in the summer
and -15° in the winter.
8. Latitude and Angle
Image: “Photovoltaic Systems” by James P. Dunlop
The angle at which a solar array is set to face the southern sun varies based on
your latitude.
In the winter the angle should be 15° more and in summer 15° less or fixed at the
location’s latitude.
Austin’s latitude is 30° so the best winter angle is 45° and Summer angle is 15°.
9. Shade Obstacles
Solar panels should
be free of shade
from trees, objects
and buildings from
9am-3pm or their
performance will be
reduced
significantly.
Image: “Photovoltaic Systems” by James P. Dunlop
10. Solar Pathfinder
A Solar Pathfinder
device is used to analyze
exactly where the
shadows will be at
different times of the
day or year so that the
solar array is placed in
Image: livingindryden.org the best spot.
11. Radiant Energy
Radiant Energy is
electromagnetic energy
that travels in waves,
including visible light, radio
waves,
x-rays and gamma rays.
Example: Sunshine is
radiant energy, provides
warmth and fuel that makes
life on earth possible.
12. What is the solar radiance
for Austin?
• http://solarelectricityha • Which angle has the
ndbook.com/solar- nest solar radiance for
irradiance.html Austin?
13. Electrical Energy
Electrical Energy is the
presence and flow of an
electrical charge, often stored
in a battery and usually
delivered through a wire in the
form of electrons.
Example: Electrical energy is
stored in a cell phone and in a Solar Power Mobile Phone Charger
car battery. It also travels
though power lines and into
your home.
14. Basic Electricity
Electricity has its own set of units. The three most basic in
electrical systems are Voltage, Amperage and Wattage.
Voltage is the measure of the "push" of electric current. The higher the
voltage, the more force there is to push the current
through the wire.
Amperage is a measure of the amount of
electric charge passing a point per unit time.
Wattage gives the rate at which work is
done or energy is used.
Volts x Amps = Watts
15. Water Pipe Analogy
Think of electricity like plumbing.
The voltage is the water
pressure.
The amperage is the rate
the water flows.
The wattage is the size
of the pipe.
16. Circuits
Image: “Photovoltaic Systems” by James P. Dunlop
Electricity travels in closed loops, or circuits. It must have a
complete path before the electrons can move. If a circuit is
open, the electrons cannot flow. When we flip on a light
switch, we close a circuit. The electricity flows from an electric
wire, through the light bulb, and back out another wire.
17. What is the difference between
AC and DC electricity?
Image: www.solarguys.com.au
18. Direct Current (DC)
Thomas Edison discovered
Direct Current (DC) where the
flow of electricity is in one
direction only and substantially
constant in value.
Direct current runs though
battery powered devices, solar
cells, and LED lights.
Photo credit: good.is
19. Alternating Current (AC)
Nikola Tesla discovered
Alternating Current (AC) where
the electric charge periodically
reverses direction at regularly
recurring intervals and is
transmitted to customers by a
transformer. Alternating current
runs though car motors, radio
signals and appliances.
Photo credit: good.is
20. Electric Meter
The electric meter measures the
amount of energy consumed by a
building.
The watt is a unit of power
The kilowatt (kW) = 1000 watts
The kilowatt hour (kWh) is most
commonly used in electric bills by
the utility company
21. Load Analysis
The first step in designing a solar array
system for a building is to do a load
analysis to find out how much energy
your system will need to produce.
The load is the amount of energy an
electrical appliance consumes when
operating and is usually written (in watts)
on the back label.
It is very import to use energy efficient
appliances when sizing a building for
solar energy to minimize the energy need
and cost of the system.
