© February 2012

Crystallization Improvement of Polycrystalline Modules February 2012

QUALITY I VALUE I INNOVATION

Certain statements in this presentation including statements regarding expected future financial and industry growth are forward-looking statements that involve a number of risks and uncertainties that could cause actual results to differ materially. These statements are made under the "Safe Harbor" provisions of the U.S. Private Securities Litigation Reform Act of 1995. In some cases, you can identify forward-looking statements by such terms as "believes," "expects," "anticipates," "intends," "estimates," the negative of these terms, or other comparable terminology. Factors that could cause actual results to differ include general business and economic conditions and the state of the solar industry; governmental support for the deployment of solar power; future shortage or availability of the supply of high-purity silicon; demand for end-use products by consumers and inventory levels of such products in the supply chain; changes in demand from significant customers, including customers of our silicon materials sales; changes in demand from major markets such as Germany; changes in customer order patterns; changes in product mix; capacity utilization; level of competition; pricing pressure and declines in average selling prices; delays in new product introduction; continued success in technological innovations and delivery of products with the features customers demand; shortage in supply of materials or capacity requirements; availability of financing; exchange rate fluctuations; litigation and other risks as described in the Company's SEC filings, including its annual report on Form 20-F originally filed on June 8, 2009. Although the Company believes that the expectations reflected in the forward looking statements are reasonable, it cannot guarantee future results, level of activity, performance, or achievements. You should not place undue reliance on these forward-looking statements. All information provided in this press release is as of today's date, unless otherwise stated, and Canadian Solar undertakes no duty to update such information, except as required under applicable law.

Safe Harbor

Conventional Wafer Manufacturing

The most popular method involves a process with molten silicon directly casted into a mold and allowed to solidify into an ingot. Multi crystalline crystallization starts by gradually cooling the crucibles from the top. The ingot is square and is later sliced into wafers. Surface texturing is applied to wafer to minimize reflection. For poly wafer, acid texturing is applied since there is no fixed crystalline orientation. The worm-like "roughening" of the surface helps to reduces reflection by absorbing more light that is bounced back onto the surface.

Conventional process of crystallization and texturing of the wafer

Conventional DS Furnace

Improved Wafer Manufacturing Process

Improved process of crystallization/ texturing

Different from conventional poly ingot growth, a mono crystalline seed layer is put on the bottom of the DS furnace. During the growth, the seed layer is partially melt. High quality poly ingot is grown with the partial melt seed layer as the crystal structure template. The middle region of the ingot contains mono crystalline structure, while the edge regions contain poly-like structure. For improved poly wafers, since most of the volume contains mono structure and has fixed crystalline orientation, alkaline texturing is applied. The generated pyramids effectively reduce the surface reflection.

Wafer Manufacturing – Improved Process

From the improved process, most of the wafer volume contains mono crystal structure with very little poly area. A conventional wafer contains a large number of small grains with much more grain boundary surface.

Improved Poly Wafer Conventional Poly Wafer Mono Wafer

Texturing in Cell Manufacturing

Acidic texturing for poly wafer

Pyramids couldn’t be made because different grains contain different crystal orientations in poly wafers. Instead, acidic texturing is used for poly wafers to form cavities to absorb more light and increase the cell efficiency.

Alkaline texturing for mono wafer Due to the uniform crystal orientation, pyramids produced by alkaline texturing lower the surface reflection and yields more photovoltaic effect.

Alkaline texturing (for mono wafer)

Acidic texturing (for poly wafer)

Improved Poly Cell Appearance

The improved poly cell appears dark blue for most of the surface due to the uniform crystal orientation and alkaline texturing with limited small shiny areas. Cell quality is improved: 1. Alkaline texturing reduces the surface reflectance and increases cell efficiency 2. Reducing grain boundaries, impurity defects and leaky current.

Improved Poly Cell Conventional Poly Cell

Module Manufacturing

What is the standard process of module manufacturing?

Single cell is soldered with ribbon, and then connected in series. Then, the glass, EVA, cell string, EVA and backsheet are stacked and cells strings are connected by the bus bar. The layered stack of components is then laminated and framed. The junction box is then fixed to the back of the module and electrical tests are done. Finally the modules are packaged and sent to customers all around the world.

Single Cell

Soldering

Series

Soldering

Lay Up Laminate

Frame Up Jbox Fixed Electrical Test Packing

Module Appearance

When mounting modules with improved poly cells, the module surface color can appear more uniform due to improved crystal orientation.

The crystal has random orientation and uneven size, resulting in module with a mix of colors and shapes thereby yielding less photovoltaic effect. conventional random orientation of crystals of different sizes

Except for some small areas, the crystal has better orientation and even size, resulting in a solid module color, thereby yielding more photovoltaic effect improved crystal orientation and size, little randomness

Module Reliability

While aesthetic variations exist, the quality, reliability, performance and warranty of modules using the improved polycrystalline cells remains the same as all other modules that fall under the same product category and are covered by our warranty. Modules under all aesthetic varieties are held to the same quality, safety , environmental and performance standards :

Certifications & Standards • IEC 61215 • IEC 61730 • CE, MCS • ISO 9001: 2008 • ISO 14001: 2004

• IEC 61701 ed. 2, Salt Mist Test, Severity 1 • Ammonia Resistance (CS6P-P) • REACH Compliance

For any additional information please contact your Canadian Solar sales representative.

Warranty • 10 year product warranty • 25 year linear power output warranty • Backed by a 25 year

PowerGuard insurance coverage for increased bankability

Full Member of PV CYCLE

Canadian Solar EMEA GmbH Landsbergerstr. 94 80339 München Germany Phone: +49 (0) 89 51 996 89 – 0 www.canadiansolar.com

© February 2012

QUALITY I VALUE I INNOVATION

Thank You! Canadian Solar Inc 545 Speedvale Avenue West, Guelph Ontario, Canada, ON N1K 1E6 Canada Phone: +1 519 498 2707 www.canadiansolar.com