The document summarizes how solar photovoltaic (PV) panels work to convert sunlight into electricity at both the micro and macro levels. At the micro level, sunlight knocks electrons loose from semiconductor materials, creating a flow of electrons and direct current. At the macro level, this current is regulated and stored in a battery bank, then inverted to power homes or return to the grid. The document also provides context on solar panel installation costs and savings over time from reducing electricity bills.
What are Solar PV Panels? The Solar Photovoltaic Panel Process Explained
1. The Solar Photovoltaic Panel Process:
Technical definition and description
By Catherine Daccache
What are Solar PV Panels?
Photovoltaic panels (PV panels) conduct energy from
the sun and convert it into electricity. Photo stands for
light, while voltaic means electricity. The panels are
made up of PV cells which consist of semiconductor
material, such as crystalline silicon, which absorb
sunlight and store it. The cells are typically combined
into modules or panels to create solar panels.
Did you know?
PV cells have been around
for ages! You have probably
seen them in watches,
calculators, and electric
road signs. But it wasn’t until recently that engineers have turned to them to produce solar electricity for
houses and utility grids. The main reason for this is because they lower the amount of oil and natural gas
used to power and heat homes. Moreover, they are 100 % environment-friendly as they emit absolutely
no pollution into our atmosphere once in use.
Are Solar PV Panels Right For Your Home?
Geographical location matters! Considering how many
peak sun hours your system will get is important. The
ideal sun exposure time is from 9 am to 3 pm. People
living in stormy, cloudy, and foggy areas might have
more trouble getting sufficient power from their solar
panels, and in turn might need to install more solar
panels on their rooftops. However, because solar electric
systems only produce power during clear skies, many
consumers connect their solar system to a utility power
grid in their region. Utility power grids are local solar
power suppliers that provide additional electricity if need be. This type of system is called a grid-tied
system, as opposed to an off-grid system, in which you do not pay for additional power from a local
supplier.
2. Fig. 1: The 13 "PV hotspots" in each province and
territory in Canada in terms of yearly PV potential
for South-facing PV panels with latitude tilts.
Fig. 1. Source: Natural Resources Canada.
Where are PV panels installed?
Most PV panels are installed on solar south-facing
roofs, or can rotate on an axis, as illustrated in Figure
2. They are parallel to the roof’s slope in the northern
hemisphere, and are installed on solar north-facing
roofs in the southern hemisphere.
Fig. 2. Source: Natural Resources Canada.
Solar Panel Costs Solar Panel Savings
Installation depends on whether your system is Reduces costs of energy over time and adds
grid-tied or off-grid. Typical off-grid installation value to the household.
amounts to an approximate $ 15,000 to $ 20,000
It is cheaper to save electricity than to generate
CAN per kilowatt hour.
it. Solar energy is free once solar panels are
Electricity bill fees depend on how much of the installed, which makes it rewarding in the long-
household is powered by solar panels. Also, the run.
more energy-efficient the household is prior to
Savings depend on two factors:
the installation, the smaller and less expensive
the system will be since there will already be a 1) The amount spent on current electric bills.
reduced consumption of electricity.
2) The amount your solar panels will provide.
Installation fees also differ by location. If you For instance, if a household uses 1000 KWH per
reside in a state or area with generous incentives month and it costs $ 200 CAN, then installing
to install solar panels, you are more prone to solar panels that provide 250 KWH each month
rebates, low interest loans, and perhaps tax will reduce $ 50 CAN off the bill.
exemptions for “going green”.
3. How Do Solar Panels Work?
At the Micro
Level
Image Source: http://www.starpost.tv/solar-cells-work
• The solar cells absorb the sunlight. The solar cells are composed of two semi-conducting
layers called the p-type and the n-type. The former is composed of excessive electrons
1 while the latter consists of few electrons.
• The sunlight knocks off a few negatively-charged electrons from atoms in p-type
semi-conductor.
2
• The electrons flow through electron-barren n-type material.
3
•The constant one-way flow of electrons creates a direct current (DC). The direct current
flows through circuits and power light bulbs or charge batteries and is sent back into the
4 p-type to be energized again.
4. At the Macro
Level
1. Light comes
in from the sun.
5. Electronic 2. The solar cells
devices can now produce a direct current
draw power from (DC) which is then
the system. regulated by the charge
controler to protect the
battery bank.
4. The electric
current is inverted 3. The battery
from DC to AC in the bank stores the
inverter and sent to electric charge for
power AC outlets. later.
Resources:
Solar panels photo: http://en.wikipedia.org/wiki/File:Nellis_AFB_Solar_panels.jpg
Solar panel on house roof photo: iStockphoto.com/Andreas Weber
For More Information, visit:
Solar and Sustainable Energy Society of Canada Inc. <http://www.sesci.ca/?q=node/35>
Canada’s Solar Electric Specialists: <www.heshomeenergy.com> and <www.solartgroup.com>