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Solar PV (Photovoltaic)
Overview
Types of Solar Cells
Global Highlights
What’s Happening in BC?
Net Metering
What Does it Cost?
Environmental Matters
Technical matters
Can I Use it at Home?
Links Overview
Photovoltaics are the simplest form of alternative energy.
There are no moving parts in photovoltaic modules and little
maintenance is required. A photovoltaic converts the sun’s
energy into electricity which is either used immediately (grid
intertie or water pumping) or is stored for future use (batteries).
Solar electric systems are modular, allowing you to start
with a small system. As your power requirements grow, you
can easily add more modules.
There are many different types of solar cells available,
with many new developments expected in the years to come.
The whole trick to PV's widespread adoption is getting the
dollar per watt lower.
Types of Solar Cells
Single Crystal
Single crystal silicon cells are extremely thin wafers of
silicon cut from a single silicon crystal. These are the most
efficient type of silicon cells and have a life expectancy
exceeding 25 years. The cells are fragile and must be mounted
in a rigid frame. You can tell it is a single crystal due
to the uniform, rounded individual cells.
Multi Crystal
Multi crystal silicon cells are also extremely thin wafers
of silicon but are cut from multiple crystals grown together
in an ingot. They are similar to single crystal cells in
life
expectancy and fragility. However, they are slightly less
efficient than single crystal cells and require more surface
area to produce a given amount of electricity. These types
of cells are usually square and will have a varied appearance.
Amorphous Silicon(a-Si) Solar Technology
Amorphous
silicon cells are made by depositing a micro thin layer
of silicon directly onto a sheet of stainless
steel.
Because amorphous absorbs light more efficiently than its
crystalline counterpart, the amorphous solar cell thickness
can be 100 times less, thereby significantly reducing cost
of materials. By utilizing a flexible, stainless steel
substrate
and polymer-based encapsulates, products utilizing this
technology can be very lightweight, flexible, and durable.
No parts are
broken during shipping and units are easy to transport
to remote rural areas, thus saving on shipping costs.
Spheral Solar™
Spheral
Solar™ technology is a revolutionary solar electricity
technology breakthrough that provides an extremely versatile
and cost-effective method of generating solar electricity.
The result of over 40 worldwide patents, this unique proprietary
technology comprises thousands of tiny silicon spheres,
bonded between thin flexible aluminum foil substrates to
form solar cells which are then assembled into durable,
lightweight modules that can be applied to virtually any
surface.
Global Highlights
- Canada lags behind the rest of the world in PV deployment
for two main reasons: Cheap power and lack of political
drive to promote renewable energy in general.
What’s happening in BC?
Currently, PV modules largest use is for remote sites that
have no access to grid power. These include, but are not limited
to: Radio repeater stations, Remote monitoring stations, remote
homes and cottages.
As opposed to other technologies such as Wind or Microhydro,
solar PV requires much less maintenance - generally limited
to keeping the panels clean and perhaps a seasonal tilt adjustment.
Net Metering
The good news is net metering, or grid intertie is now permitted
in BC. What this means to you, is that if you wish to install
PV modules on your home or business, and feed that power directly
into he utility grid, you can do so (legally). Take a look
at BC
Hydro's website where you can download all the information
and application forms
What Does it Cost?
Solar PV modules in Canada currently retail in the $6-$8
per watt. Additional costs include "balance of system"
components such as mounting hardware, wire, controllers, batteries,
etc.
For many remote sites, solar PV can compete aggressively
with the costs of electricity derived from conventional sources.
Many sites that require extensive power line construction
will find solar systems may be more cost effective. If you
are spending more than $20k on power lines, you should consider
PV.
For people that are on the grid, one does not currently buy
solar PV for Return on Investment (ROI). There are many purchases
we make that are not purchased based on ROI, but other concerns.
Cars, entertainment system and furniture are generally not
purchased with ROI in mind.
Environmental Matters
Greenpeace conducted an audited study of the PV production
process used by Siemens, around 1999. The conclusion was the
energy required to produce a PV module was recovered in approximately
14 months of use of said module.
Technical Matters
Solar PV modules require specific orientation. They need
a clear, unobstructed, unshaded view of the sun for optimal
performance. There are many considerations that go into the
design of a solar PV system. It is suggested you contact a
professional for a system design and installation.
Installation of solar PV systems is governed by the Canadian
Electrical Code (CEC). One must have the appropriate permits
and inspections just as with any other electrical project.
For more information:
Can I Use it at Home?
Possibly. Solar PV systems can be quite complicated. Installation
requires a bit of roof work, some carpentry, some metal work,
some electrical work. PV modules are very fragile and must
be installed in the optimum location for best results. That
being said, if you have taken the time to properly educate
yourself on the various aspects of the installation and are
competent with power tools, electricity and roof work you
may have a fun project to work on.
Links
Credits
Written by Kevin Pegg for the BC Sustainable Energy Association
Text updated Sept 4, 2004
Links updated October 5, 2007
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