Tesla’s solar panel suppliers have changed rapidly

Facebook
Twitter
LinkedIn
Reddit
Email
Panasonic's heterojuction (HIT) panel. Image: Panasonic

In the hotly contested Californian residential solar market, new data compiled by ROTH Capital Partners highlights, amongst many data points, that Tesla’s solar panel supply base and suppliers is undergoing a major transition and that it has been changing for several years.

PV Tech has well documented the dynamic US residential market and its key public listed installers, which used to be dominated by SolarCity but since its acquisition by Tesla, sales and business strategies have radically changed in an effort to create a sustainable business, instead of being market share driven.

This article requires Premium SubscriptionBasic (FREE) Subscription

Unlock unlimited access for 12 whole months of distinctive global analysis

Photovoltaics International is now included.

  • Regular insight and analysis of the industry’s biggest developments
  • In-depth interviews with the industry’s leading figures
  • Unlimited digital access to the PV Tech Power journal catalogue
  • Unlimited digital access to the Photovoltaics International journal catalogue
  • Access to more than 1,000 technical papers
  • Discounts on Solar Media’s portfolio of events, in-person and virtual

Or continue reading this article for free

US market leadership has changed hands in the past year but at the same time installation growth has been hard to achieve for the leading publically listed US installers. 

US market leadership has changed hands in the past year but at the same time installation growth has been hard to achieve for the leading publically listed US installers.

Tesla’s quarterly solar installation figures have declined rapidly but showed a small upward trend in the second quarter of 2018.

Tesla’s quarterly solar installation figures have declined rapidly but showed a small upward trend in the second quarter of 2018.

Data compiled by ROTH Capital, highlights that Tesla’s panel supplier base has changed rapidly from the SolarCity days. 

Back in 2016, Kyocera and REC Group had been the main panel suppliers to the company, accounting for 31% and 35% of supply to California installs, respectively. A much smaller share came from two ‘Silicon Module Super League (SMSL) members, Trina Solar and Canadian Solar with 7% and 6%, respectively. 

In that year, the company also sourced panels (only in the fourth quarter) from Hanwha Q Cells and LG Electronics, 1% and 3%, respectively. Unspecified ‘other’ suppliers accounted for 7% of the total through 2016. 
  
However, a lot of changes occurred in 2017.

The chart below shows Tesla’s module suppliers that were used for installations in California since the beginning of 2017 through to May 2018. 

Tesla’s module suppliers that were used for installations in California since the beginning of 2017 through to May 2018.

In 2017, the company increased its use of Canadian Solar, Trina Solar and LG Electronics considerably. By year-end Canadian Solar’s share was 15%, while Trina Solar’s totalled 28%, but to highlight the growth, Trina Solar accounted for only 3% of supply in January, 2017 and ended with a share of 33% in December.

In the case of LG Electronics the supply would seem to have been a short partnership, having mainly started strongly in the fourth quarter of 2016, it peaked in February, 2017 (30% of supply) and leaned out significantly by December (2%) and accounted for 14% of supply in 2017.
 
Long-term trusted suppliers, Kyocera and REC Group lost out in 2017 as their shares declined to 4% and 10%, respectively. The others also were whittled down from the 7% share in 2016 to just 1% in 2017. 

But the supplier base has changed again in 2018. Although data is only available through May, the chart highlights that Canadian Solar’s erratic share through 2017, ended abruptly at the beginning of 2018 and only recovered to 2% of the total by May. 

Trina Solar, which had been the largest supplier to Tesla from the second quarter of 2017 saw its share fall from a peak of 45% in October, 2017 to 28% by May, 2018.

Although Hanwha Q CELLS share started relatively strongly in the first quarter of 2017, the chart shows an erratic pattern, similar to that of Canadian Solar. The only difference here is that Hanwha Q CELLS share suddenly bounced back from zero in April, 2018 to 17% in May this year. This is the only supplier to have gained meaningful share through the first five months of 2018.

Tesla’s own modules

However, the most dramatic change comes from within Tesla. Starting in March, 2016 it would seem that panels produced in-house at its Fremont facility (formerly Silevo), which was known to have around 100MW of annual capacity started supplying panels to projects in California. 

This ramped (dark blue line in the chart) through the rest of the year, accounting for an 11% share. However, Tesla’s own panel supply to California installs took a notable dive through May, 2017 but bounced back strongly, peaking in November with a 35% share and share for the year of 18%, which also highlights the capacity constraint of the Fremont production facility. Only Trina Solar had a bigger share (28%) in 2017. 

The supply dramatically changed again at the beginning of 2018, when Tesla’s panel share rocketed to 56% in January and peaked at 64% in April. This could be attributed to panel production finally ramping at the Panasonic managed Gigafactory 2 in Buffalo, New York state. 

Interestingly, reports of some re-tooling at Gigafactory 2 could be reflected in the peaks and troughs seen in 2018, as production levels may have fallen during equipment changes. 

Although still early to be sure, the chart also indicates that Tesla has in the first five months of the current year, narrowed down its panel supplier base, depending very much on its in-house capacity but retaining two SMSL members, Trina Solar and Hanwha Q CELLS as its major external suppliers. 

It should also be noted that Hanwha Q CELLS (Korea) has announced the building of at least a 1.6GW assembly plant in Whitfield County, Georgia. 

Finally a special thank you call-out to Philip Shen, financial analyst at ROTH Capital for sharing the volume of data that also covered companies such as SunPower, Sunrun, Sunworks, SolarEdge and Enphase.

 

Note: The California Distributed Generation Statistics publishes all IOU solar PV net energy metering (NEM) interconnection data from the three large California Investor Owned Utilities (IOUs) which include Pacific Gas & Electric Company (PG&E), Southern California Edison Company (SCE), and San Diego Gas & Electric Company (SDG&E). 

California Distributed Generation Statistics also publishes all IOU data from the California Solar Initiative incentive program and other publicly available incentive program data sets.

21 October 2025
New York, USA
Returning for its 12th edition, Solar and Storage Finance USA Summit remains the annual event where decision-makers at the forefront of solar and storage projects across the United States and capital converge. Featuring the most active solar and storage transactors, join us for a packed two-days of deal-making, learning and networking.

Read Next

April 29, 2025
Chinese solar manufacturing giant JinkoSolar posted net losses of US$181.7 million in the first quarter of 2025 amid low product prices and “changes in international trade policies.”
April 24, 2025
US material recovery firm OnePlanet has closed two financing deals to aid the development of a solar module recycling facility in Florida.
Premium
April 23, 2025
Analysis: Carrie Xiao explores the factors behind the recent cancellation of China’s PV module mega-tender and their wider implications for equipment procurement.
April 22, 2025
The US Department of Commerce has issued anti-dumping and anti-subsidy tariffs on solar cell imports from Southeast Asia.
April 22, 2025
Australia’s University of Queensland has claimed a new world-record efficiency for a tin halide perovskite solar cell, certified at 16.65%.
April 10, 2025
Germany's proposal to allow international carbon credits to reach EU decarbonisation targets “risks undermining the target’s credibility”, according to think tank Agora.

Subscribe to Newsletter

Upcoming Events

Media Partners, Solar Media Events
May 7, 2025
Munich, Germany
Solar Media Events
May 21, 2025
London, UK
Solar Media Events
June 17, 2025
Napa, USA
Solar Media Events
July 1, 2025
London, UK
Solar Media Events
July 1, 2025
London, UK