Solar Junction

What Solar Junction does

Solar Junction, founded in 2007 and headquartered in San Jose, California, is a private solar technology company originally built around the manufacture of III-V multi-junction solar cells based on its proprietary A-SLAM™ materials platform for concentrated photovoltaic (CPV) systems. The company's core technical proposition centered on multi-junction cell architectures, in which multiple semiconductor layers each capture a different band of the solar spectrum to achieve higher conversion efficiencies than single-junction silicon, paired with optics-based CPV systems that concentrate sunlight onto the cells. The company publicly claimed a world-record conversion efficiency milestone in April 2011 and has subsequently expanded its stated product portfolio into adjacent areas including residential rooftop solar, home battery energy storage systems, large-scale photovoltaic arrays for commercial and industrial customers, smart-grid integration software, solar water heaters, solar lighting, portable power stations, off-grid micro-grids, and space solar technology for satellites and spacecraft.

Across roughly $58.6 million in total disclosed venture funding from Advanced Technology Ventures, New Enterprise Associates, Draper Fisher Jurvetson, and IQE between 2008 and 2013, the company scaled a CPV cell program and began broadening into a full-stack solar solutions provider. Its current public go-to-market posture is quote-based for commercial and industrial buyers and direct/website-driven for residential and specialized applications, supported by an SEO and content-marketing engine rather than visible transactional e-commerce. No revenue, customer logos, pricing, or headcount trend data are disclosed, and no new capital has been raised since April 2013, leaving the company's present operating and commercial scale materially uncertain despite an active website presence.

Name

Solar Junction

Legal name

Sj-Solar

Website

https://sj-solar.com

Company type

Private

Founded year

2007

Operating status

Operating

Headcount range

51–100 employees

Short description

Solar Junction is a San Jose-based private solar technology company that develops III-V multi-junction solar cells and has expanded into residential, commercial, off-grid, and space solar products and energy management software. It serves residential, commercial/industrial, and specialized portable-customer segments through a quote-based, content-driven go-to-market model.

Ownership category

akta.pro rank

Product category

Multi-junction solar cells and concentrated photovoltaic (CPV) systems

NAICS

Solar Electric Power Generation (221114)

SIC

Semiconductors & Related Devices (3674)

akta.pro primary industry

Solar PV Module Manufacturing (Cells, Modules, Thin-Film) (EUAMABAD)

akta.pro secondary industry

Next-Gen Photovoltaics R&D (Perovskite, Tandem, Organic, BIPV Materials) (EUAMAOAA)

Keywords

• Multi-junction solar cells
• Concentrated photovoltaic systems
• Solar panel manufacturing
• Photovoltaic cells production
• Solar energy storage

Headquarters

HQ city

San Jose

HQ country

United States

HQ region

North America

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Supply Chain, Personnel, Operations, Marketing or Sales, Infrastructure

Revenue model

1. Solar Panel Sales: Sale of photovoltaic panels including monocrystalline and polycrystalline options for residential, commercial, and industrial applications.
2. Home Energy Storage Systems (BESS): Sale of battery energy storage systems including lithium-ion batteries for residential backup power and energy independence.
3. Solar Water Heaters: Sale of solar thermal systems that use heat from the sun for water heating applications.
4. Solar Lighting Products: Sale of solar-powered lighting including landscape lights and high-efficiency solar street lamps.
5. Portable Solar Power Stations: Sale of portable solar batteries and power stations for travel, remote work, and emergency preparedness.
6. Smart Grid and Energy Management Solutions: Enterprise-level software and hardware solutions for businesses to monitor energy production and consumption in real-time with grid integration capabilities.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels4 records

Core offering

Solar Junction manufactures III-V multi-junction solar cells based on its proprietary A-SLAM™ materials for concentrated photovoltaic (CPV) systems, achieving world-record efficiency by stacking multiple semiconductor layers to capture different portions of the sun's spectrum. Beyond its core cell and CPV business, the company markets residential rooftop solar panel systems, home and commercial battery energy storage systems (BESS), large-scale photovoltaic arrays, solar water heaters, solar-powered lighting, portable power stations, smart grid integration solutions, and space-grade solar technology for satellites and spacecraft.

Product overview

Solar Junction offers a comprehensive portfolio of solar technology products spanning residential, commercial, industrial, and specialized applications. The core offering includes rooftop solar panel systems (monocrystalline and polycrystalline variants) paired with Home Energy Storage Systems (BESS) featuring lithium-ion battery technology. Commercial and industrial customers benefit from large-scale photovoltaic arrays and Smart Grid Integration solutions. The company also provides specialized products including solar water heaters, solar-powered lighting, and portable power stations. Solar Junction's advanced product line features Multi-junction Solar Cells achieving world-record efficiency through multi-layer semiconductor technology, and Concentrated Photovoltaic (CPV) Systems that focus sunlight for enhanced power generation. The company further specializes in Space Solar Technology for satellites and spacecraft, along with off-grid and portable solutions for remote applications. Smart Grid Integration software connects solar installations to broader energy networks using AI-driven prediction models.

Differentiator

Problem solved

Functional benefit

Products and services

• Multi-junction Solar Cells High-efficiency III-V multi-junction solar cells with multiple semiconductor layers designed to capture different sections of the sunlight spectrum, sold for concentrated photovoltaic and high-performance solar applications.
• Concentrated Photovoltaic (CPV) Systems CPV systems that use optical concentration (lenses or mirrors) to focus sunlight onto small regions of multi-junction solar cells, increasing light intensity and power production for specialized solar farm applications.
• Rooftop Solar Panel Systems Residential rooftop solar panel systems designed to integrate with existing home electrical systems, available in monocrystalline and polycrystalline variants for different roof types and energy needs.
• Home Energy Storage Systems (BESS) Battery energy storage systems (BESS) using lithium-ion batteries that store excess solar energy generated during the day for use at night or during grid outages, providing residential energy independence and backup power.
• Large-scale Photovoltaic Arrays Scalable commercial and industrial photovoltaic systems using high-power panel arrays and advanced inverters, designed to meet high energy demands for businesses and industrial complexes.
• Solar Water Heaters Solar thermal systems that utilize heat from the sun for water heating, providing savings on conventional water heating costs for residential and commercial use.
• Solar-Powered Lighting Solar-powered lighting products including landscape lights and high-efficiency solar street lamps, reducing grid electricity dependency for outdoor and public-space illumination.
• Portable Solar Batteries and Power Stations Mobile solar power solutions including portable solar batteries and power stations for travelers, remote workers, and emergency preparedness, providing electricity access on the go.
• Off-grid and Portable Solar Solutions Solar solutions for remote locations and portable applications including solar-powered lighting, personal device chargers, and scalable micro-grids for underserved populations without grid access.
• Space Solar Technology Solar technology designed for space applications including photovoltaic arrays for satellites, spacecraft, Mars rovers, and future Solar Power Satellites (SPS) for Earth-based energy transmission.

Quantifiable outcome

• Modern solar systems can operate efficiently for 25 years or more when maintained properly (per International Renewable Energy Agency)

Segments3 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability1 record

Feature8 records

Partnerships

One partnership is on record.

• AccelycoreImplementation/ SI/ Consulting PartnerAccely is described as an SAP implementation partner that helps solar businesses connect planning, procurement, installation, and maintenance into one ERP system. The partnership enables smoother execution across projects that may span multiple sites, suppliers, and regulatory environments. Accely provides system design, data migration, and user training services for solar companies implementing SAP ERP solutions.

Scale indicators1 record

Recent moves6 records

Expansion highlights5 records

Direct peers

• Spectrolab (a Boeing subsidiary): Spectrolab manufactures high-efficiency multi-junction III-V solar cells, with a heavy focus on space-grade cells for satellites and terrestrial CPV. It is the most direct commercial comparator to Solar Junction's A-SLAM multi-junction cell and CPV offering.
• Azur Space Solar Power GmbH: Azur Space manufactures multi-junction III-V solar cells for space and terrestrial CPV applications, making it a direct peer to Solar Junction's cell technology and CPV system offering.
• SolAero Technologies (a Rocket Lab company): SolAero produces high-efficiency multi-junction solar cells and panels for satellites and terrestrial applications. It is a direct competitor in the III-V cell space market that Solar Junction targets.
• MicroLink Devices: MicroLink Devices manufactures high-efficiency multi-junction III-V solar cells and flexible solar sheets for defense, space, and unmanned aircraft. It is a direct peer in the III-V cell and flexible blanket technology space.
• Suncore Photovoltaics: Suncore is one of the few remaining CPV system integrators globally, deploying multi-junction-cell-based concentrated PV plants. It is a direct peer to Solar Junction's CPV systems business in the utility-scale high-DNI segment.

Broad incumbents

• Sharp Corporation (Sharp Electronics): Sharp is a long-established solar manufacturer with a portfolio that includes both multi-junction cell R&D (e.g., triple-junction compound solar cells) and broad residential/commercial silicon PV modules — comparable to Solar Junction's multi-junction technology and downstream product portfolio.
• Soitec SA: Soitec historically operated a CPV systems business and continues to develop engineered substrates used in advanced III-V and SOI semiconductor processes. It is comparable to Solar Junction both as a former CPV systems peer and as a broader compound-semiconductor manufacturer.
• First Solar, Inc. First Solar is a leading broad-incumbent thin-film (CdTe) PV module manufacturer with utility-scale project development. It is comparable as a major solar cell/module manufacturer operating at much larger scale than Solar Junction.
• Maxeon Solar Technologies (formerly SunPower): Maxeon produces high-efficiency back-contact silicon solar cells and modules for residential and commercial markets, and pursues next-gen tandem/perovskite research. It is comparable to Solar Junction on the high-efficiency-cell and downstream rooftop/storage product axis.

Others

• CSEM (Centre Suisse d'Electronique et de Microtechnique): CSEM is a Swiss R&D center that has repeatedly set multi-junction and perovskite-tandem solar cell efficiency records. It is comparable to Solar Junction as a peer institution working on the same III-V and tandem-cell efficiency frontier, though it is non-commercial.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat3 records

Key risks6 records

Key highlights6 records

Customer concentration

• Xx.com/Solar_Junction
• Facebookfacebook.com/Solar.Junction
• LinkedInlinkedin.com/company/solar-junction

Revenue estimate

Valuation estimate

Number of profiles

Funding overview

Funding rounds4 records

Investors4 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Solar Junction