Over the last four years VC investment in solar has gone from a modest trickle to a roaring flood. In 2005 VCs invested about $200 million in solar startups. When the dust settles at the end of 2008, they will have invested about $4.5 billion in about 150 new solar startups in the four years from 2005 to 2008.

We've compiled a list of these firms with funding info and a few words on each startup's technology.

In Part 1 we’ll cover:

  • Silicon Wafer Technology (c-Si)
  • Solar Installers and Solar Financing Firms
  • Solar Balance of Plant (Inverters etc.)
  • Solar System Monitoring, Manufacturing Tools and Software

In the coming installments we'll cover

  • CPV
  • Next Gen PV
  • Thin-Film Solar
  • Concentrating Solar Thermal
  • Winners and Losers
  • And look ahead to 2009

The list includes VC-funded firms as well as other private firms looking for funding. We’ve divided it up by technology. If we’ve missed any let us know – remember this list is private companies only.


Silicon Wafer Technology Startups

1366 Technologies: MIT spin-out 1366 boasts of a new cell architecture and a light-capturing ribbon interconnect to increase the efficiency of multi-crystalline solar cells. Funded with more than $12M from North Bridge Venture Partners, Polaris Venture Partners, et al.

21-Century Silicon: Low cost solar-grade polysilicon manufacture via a proprietary furnace design. $1M from Solar EnerTech in September 2008.

6N Silicon: 6N Silicon is a developer of solar grade silicon purification technology. More than $26M in funding from Good Energies, Ventures West, and Yaletown Venture Partners.

Advent Solar: Emitter-Wrap Through (EWT) back-contact solar cell technology. Its 2007 $73 million roundwas from @Ventures, ZBI Ventures, Sun Mountain Capital, Globespan Capital Partners, Battery Ventures, Enertech Capital Partners, New Mexico Co-Investment Partners, and Firelake Capital.

AE Polysilicon: Production technology to lower the cost of polysilicon using an integrated, closed-loop, fluidized bed reactor production process. Funding from private, strategic, and government sources.

Blue Square Energy: 14.6 percent efficient solar cells from upgraded metallurgical grade (UMG) silicon. It has received about $3 million from the DOE’s Solar America Initiative but boardroom shake-ups seem to have delayed closing further VC funding.

CaliSolar: CaliSolar uses less expensive metallurgical grade silicon to make solar cells. Founded in 2006 with more than $110 million in 2 rounds of funding from Advanced Technology Ventures, Globespan Capital Partners, and Hudson Clean Energy.

Confluence Solar: High-quality single crystal silicon at a lower cost. $12.7 million Round A from Convexa Capital, DC Chemical, Scatec Adventure, Oceanshore Ventures, et al.

ET Solar: More than $50 million raised in two rounds from NewMargin Growth Fund, China Equity Links, et al. for this Nanjing-based integrated manufacturer of PV products including ingot, wafer, module, and dual-axis tracking systems.

Gamma Solar: Private firm building 200 micron thick bifacial silicon solar cells with a reported efficiency of >16%. Angel funded and seeking venture capital.

NorSun: Scatec-founded firm, building single crystal silicon wafers with $8.5 million from Itochu and $23 million from Norsk Hydro.

Peak Sun Silicon: Peak Sun Silicon looks to produce granular polysilicon using a tribromosilane-based continuous manufacturing process operating at near atmospheric pressure and at lower temperatures with improved energy efficiency. They closed a Round A in 2008 that included a $14M loan from the Oregon Department of Energy.

RSI Silicon: RSI claims to have developed a process to manufacture solar grade silicon with a purity of 99.9999+ percent (6N’s). It is funded by David Gelbaum’s Quercus Trust.

SBM Solar: 90W and 140W PV modules using a polymer cover sheet instead of glass that reduces the weight of the panel by 50%, allows for customization, and enables BIPV applications. Seeking VC funding.

Senergen Devices: Stealth startup with funding from VantagePoint Venture Partners, et al. for Si PV cells.

Silicon Genesis: Kerf-free silicon wafers for solar markets (and other technologies). Most recent round in 2007 was $23 million from Convexa, H&Q Asia Pacific, Lake Street Cap, Riverside Management, Firsthand Tech and Spencer Energy.

Solar Notion: $10 million round A funding from hedge fund Third Point for solar panels and silicon manufacturing.

Solaicx: Solaicx’ manufacturing technology yields higher quality single crystal solar ingots and wafers optimized for PV applications, designed for the high volume, continuous production. Its $27 million round C in 2007 was led by the D. E. Shaw group with Mitsui Ventures, Applied Ventures, Firsthand Capital Management, Big SkyVentures and Greenhouse Capital Partners.

Solar Cell Repower: Improving solar cell efficiency – “repowering non-prime solar cells" with a $1.5M Round A from NorthZone Venture in December 2008. Based in Norway.

SpectraWatt: An Intel spin-out planning to manufacture and supply photovoltaic cells to solar module makers with $50 million in funding from Intel Capital, Cogentrix Energy, PCG Clean Energy and Technology Fund and Solon.

Suniva (a.k.a. Solarity): Nano-structured high efficiency polysilicon solar cells with more than $55M in funding from NEA., Goldman Sachs Group, HIG Group, Cogentrix and Quercus, et al.

Twin Creeks Technologies: Twin Creeks Technologies is an early stage, VC-funded solar start-up founded in January 2008. Using silicon fabrication processes.  Received $13.1M Round A from Crosslink Capital and Benchmark in Q1 2008. $52M Round B led by Artis Capital and DAG Ventures at 7X series A price in Q3 2008.  Attempting to make Si cheaper than CIGS or CdTe.  CEO is Siva Sivaram.

Wriota: Novel silicon processing technology for PV, ICs, memory, and FPDs with funding from Intel Capital, Allen & Buckeridge.


Solar Installers, Integrators, Financiers, BIPV

Aquus Energy: Commercial and residential solar energy systems integrator in the Mid Atlantic and Northeast US received funding from Oppenheimer & Co. Aquus acquired installer Mercury Solar Systems and Energy Enterprises.

Armageddon Energy: Armageddon’s hexagonal module is easier to handle and better accommodates the contours of a rooftop and includes an integrated microinverter.  Armageddon claims that its’ affordable systems enable mainstream consumers to buy into solar with much lower installation time and cost.  Currently seeking VC funding.

Axio Power: Axio Power develops, finances, and constructs large-scale solar projects.  Taking on private equity funding in 2009.

Clean Power Finance: In 2007 CPF acquired Solar Pro Tools, a subscription-based software service which enables PV, solar domestic hot water, and solar pool heating pros to generate sales quotes and incentive forms. CPF provides “Point-of-sale" residential solar financing and is working with Conergy.

Cleansource Power: Cleansource’s “Solar Energy Service" – under an SES contract, CleanSource Power pays all costs incurred in the design, installation, commissioning and maintenance of a solar energy system. In return, the client purchases all of the energy produced from that system.

Envision Solar: Building solar car-ports and projects, partnered with Kyocera with ~$3 million in VC and angel funding.

Eshone Energy: Founded in 1995, Eshone is a solar power integrator providing turnkey, grid-connected systems for public and commercial sectors

GreenSun Energy: Angel funded commercial-scale solar projects with integrated financial solutions.

GroSolar: Solar installation and service with $10 million Round B funding in 2007 from NGPETP, SFJ, Calvert, Allco, on top of a $2 million Round A in 2006.

Helio Mu: A “micro utility" selling power not solar panels with no upfront costs. Funding for Helio Mu’s projecs comes from the Green Energy Community Investment Fund, a fund jointly owned by Helio Micro Utility and Citi Community Capital, a division of Citi.

Mondial Energy: Private, Canadian solar firm offering installation and PPA financing for solar thermal systems.

MP2 Capital: Financial services firm focused on the renewable energy industry arranging PPAs, finance and development.

Orb Energy: With funding from Zouk Ventures and the Singh Family, Orb Energy is a residential and commercial solar system integrator and financier and installer (?), looking to franchise it’s business although it’s difficult to tell from the company's very annoying Website. It is focused on India.

Ready Solar: Modular PV with pre-installed micro-inverters (from Enphase), claiming 50% reduction in installation time with >$300K in angel funding and seeking VC.

Recurrent Energy: Solar services and system financing for commercial roofs with more than $85 million in funding from Hudson Clean Energy and MDV. Recurrent Energy is a developer and owner of onsite solar power systems, selling energy to customers at competitive rates via a PPA.

Redwood Renewables: Integrated solar roofing tiles with built-in electrical interconnects that use recycled polymers as their base. The company's investors include a roofing manufacturer. They are seeking Round B funding.

Renewable Funding: Renewable Funding develops and delivers solutions for renewable energy and energy efficiency financing. Cities raise funds through bonds, and the consumer pays it back through property taxes. Renewable Funding provides on-line application processing coupled with a financial package that provides reasonable interest rates and low risk.

Sierra Nevada Solar: ~$4.5 in angel funding in 2007 from EarthBright et al.

SoCore Energy: With $1.5 million in private funding, SoCore is a solar system developer promoting PPAs focused on commercial, low-rise buildings.

Solairedirect: French integrated solar power provider recently raised $25M from Demeter Partners, Schneider Electric Ventures, TechFund, et al. Raised $8 million in 2007.

Solar Century: Funded by VantagePoint Venture Partners, Scottish and Southern Energy, U.K.-based Solar Century builds solar homes, commercial and public sector projects

SolarCity: SolarCity claims to be the largest installer of small residential solar in California. Investors include Draper Fisher Jurvetson, JP Morgan and Elon Musk. A $21 million Round C closed in 2007 and $30 million was invested in 2008 by First Solar, et al. The firm recently created a solar leasing program as well.

Solar Red: A solar installation company seeking VC, looks to lower cost of residential and small solar installation by integrating the process into the construction or renovation of a house and by using micro-inverters.

Soltage: Soltage finances and installs solar panels on the roofs of its customers, maintains and operates the systems, then sells the power back to the clients.Series A funding closed in late 2006.

Solar Power Partners: SPP develops, owns and operates distributed solar energy facilities and sells solar-generated electricity through PPAs. SPP has received $100M of equity and debt financing to date from United Commercial Bank, Globespan Capital Partners, The Enlightened World Foundation, Carrelton Asset Management, Dry Creek Ventures, Silicon Valley Technology Group, and Energy Investors Funds.

Standard Renewable Energy: Solar panel installation for businesses and homeowners funded with an $8 million Series A in 2007 and a $7.2 million Series B in 2008 led by the Quercus Trust.

Standard Solar – Raised $8.5M in October and $3.5M in March 2008 from Truecast Capital, et al. They are a turnkey solar system developer and integrator.

Sterling Planet: A retail provider of solar and renewable energy. It received investment from Low Carbon Accelerator in 2007.

SunEdison: Solar electricity as a service, not a product with more than $160 million in debt and equity funding from Goldman Sachs, Allco Finance Group, MissionPoint Capital Partners, Greylock Partners, HSH Nordbank, Applied Ventures, Black River Commodity Clean Energy Investment Fund

Sungevity: Sungevity provides price quotes and enables installation, coordination, and service of PV systems. It raised $2.7 million in funding in 2007 from German solar companies Solon and I-Sol Ventures plus several angel investors.

SunRun: $12 million round in June 2008 led by Foundation Capital and a commitment for up to $105 million in financing from an affiliate of US Bancorp in November 2008. SunRun owns the solar panels it installs on residential roofs and sells its customers electricity at a low fixed rate, eliminating the need for homeowners to purchase solar hardware.

Tioga Energy: Tioga’s $14 million Series A in 2007 included investors NGEN Partners, Draper Fisher Jurvetson, Rockport Capital, DFJ Frontier, and Kirlan Ventures. Tioga provides solar power purchasing services for large and small commercial customers.


Solar Balance of Plant

1-Solar: A winner of the 2007 CCTO, 1-Solar is developing a lighter-weight and more reliable inverter architecture that converts DC to AC in a single step and with fewer components than conventional HF inverters. The design “eliminates the need for an intermediate high voltage DC bus and its associated storage capacitors.�? 1-Solar claims to have signed a 60,000-unit distribution agreement with a Southern California solar distributor and plans to offer inverters in the 1 to 50kW range.

Accurate Solar: Inverters and MPPT "Smart Cards"

Apollo Solar: Modular inverters, charge controllers and energy management systems, and communications for residential solar electric systems.  Privately held firm with DOE SEGIS funding and a $4.5M equity round in October 2008. Apollo is a spin-off of Electronic Design Lab.

ArrayConverter: Currently seeking VC funding, ArrayConverter is designing “self-monitoring AC modules�? with a distributed inverter architecture.

Azuray: Microinverter startup received $8 million from NEA in May 2008. Rohini Chakravarty of NEA is on the company’s board. Terri Fiez, a former Oregon State University professor, is the CEO.

EnPhase: Distributed inverter architecture incorporates micro-inverters into each solar panel instead of on each “string" of solar panels, potentially generating more power and providing additional monitoring and security benefits. Its most recent VC funding round led by Rockport was $15 million in Sept 2008 in addition to the $6.5 million previously raised. Other investors include Applied Ventures and Third Point Ventures.

EOS Renewable Technologies: EOS' PC board-based module uses "dynamic impedance matching" to extract more usable power from solar panels, particularly in low-light conditions.  EOS is a self-funded holding company using technology invented by XET. The product has been used as a per-panel charge controller in conjunction with batteries for off-grid military "solar back-pack" applications although the technology has been licensed to Cool Earth Solar for CPV systems.  EOS claims that in light conditions of 150W/m2-400W/m2 they can provide 100% more usable power.

Green Ray Solar: GreenRay received $2.2 million from the DOE SAI program and closed a $500,000 seed round in 2007 from the Massachusetts Technology Collaborative. Their micro AC inverter allows a DC solar electric or PV module to produce AC power.

MPPC Technology: For distributed MPP and inverter architectures, Maximum Power Point Control (MPPC) is the exact calculation of the Maximum Power Point (MPP) coordinates (voltage and current and therefore power). MPPC Technology is conducting on and off-grid tests in Europe and India.  Pre-VC.

Petra Solar: Petra received $14 million in first round funding from DFJ Element and BlueRun Ventures in April 2007. They are attempting to improve PV Balance of System performance and cost with fast maximum power point tracking (MPPT). Their power electronics IP is licensed from UCF.

Princeton Power Systems: Inverter and power conversion technology with Round C funding from GHO Ventures in 2008. PPS also received funding from the DOE Solar Energy Grid Integration Systems (SEGIS) program for a 100kW demand response inverter with integrated control capabilities for dynamic energy storage and demand response through load control.

PV Powered: Privately held PV Powered builds inverters for residential and commercial PV as well as data monitoring modules. The company claims to be the largest U.S.-based manufacturer of solar power inverter technology and has received $5 million from the DOE’s Solar Energy Grid Integration System (SEGIS) program, a $24 million effort to develop advanced inverters and balance-of-system components as well as funding from the DOE SAI program.

SmartSpark Energy Systems – Received a Series A from Battery Ventures with technology licensed from the University of Illinois. Their SolarBridge product is a PVAC micro-inverter. Other investors include Illinois Ventures and ITEC.

Solar Edge: Distributed inverter architecture using custom chip sets, junction boxes, and inverters built to maximize the energy harvesting capability of PV systems by correcting MPP mismatch, minimizing shading loss, etc. The firm has received $34.8 million in funding from Walden International, Opus Capital, and Genesis Partners, et al.

SunLink: SunLink closed a B round with funding from Clean Pacific Ventures and the Angeleno Group for their aluminum mounting systems for commercial PV.

Sympagis: DC to DC boost funded by NGEN

TerraWatt Power: A solar-inverter startup, is in the midst of raising a $1.5M round of funding, President Gary McDaniel told Greentech Media. They claim to have raised $1.5M in angel funding and $1M in grants. Their inverter technology, like many other entrants, uses Maximum Power Point Tracking (MPPT). Additionally, their inverter disconnects from the grid during outages and feeds electricity directly into the home.

Tigo Energy: Israeli startup Tigo raised $6 million in funding from Matrix Partners and OVP Venture Partners in June 2008. Tigo Energy’s products can improve output power, up-time, and reliability on existing and new solar installations Tigo claims to improve power output (kWh) in excess of 20 percent depending on weather conditions.


Solar Monitoring, Software, Manufacturing Tools and Processes, Etc.

BT Imaging: BTi improves solar cell efficiency and manufacturing yields by applying luminescence imaging to the manufacturing of silicon wafers and solar cells. Seed funding and a $2 million Round A from Allen & Buckeridge, Uniseed, and NSi.

Deck Monitoring: Monitoring commercial solar systems with a rich web-enabled interface.

Energy Recommerce: Web-based solar monitoring and management solutions for the commercial market. Funding from Dry Creek Ventures.

Five Star Technologies: Cavitation technology-based ink formulations for screen-printable solar inks for front surface contacts. VC funding from Morgenthaler Partners, Industrial Technology Ventures, Reservoir Venture Partners et al. for a number of markets including solar.

Draker Labs: A renewable energy monitoring company, raised a Round A from strategic investor Campbell Scientific and FreshTracks Capital in August 2008.

Fat Spaniel: Fat Spaniel provides monitoring, reporting, and remote management for PV and other renewable energy systems. It closed an $18 million Series B in January 2008 from investors Ignition Partners, Element Partners, Chrysalix Energy, PCG Clean Energy & Technology Fund, and Applied Ventures. The firm closed a $7 million Round A in 2006.

Locus Energy: Low-cost, revenue-grade, web-based performance monitoring for solar systems and distributed generation.

Mythos Solar Power: Funded by The Hartley Family Trust, Mythos builds web based renewable energy monitoring applications designed to monitor and manage any widely dispersed renewable energy power supply supporting large scale IP video surveillance systems and wireless infrastructure.


SiC Processing: Recovering and conditioning of the slurry used in the wire sawing process of solar silicon production. Their most recent round in 2007 was ~$73 million from Zouk Ventures, Merrill Lynch Corporate Principal Investments Group, CC Private Equity Partners, Masdar Clean Tech Fund, Foursome Investments, et al.

SiXtron Advanced Materials raised ~$12M in VC from Ventures West, iNovia Capital, Innovatech sud du Québec, FIDD, and MSBi Capital to develop a silane-free process for producing anti-reflective coatings for silicon solar cells. SiXtron is working with an NREL optical furnace to optimize the metallization process for the antireflective coatings. SiXtron’s process uses a solid, silicon-based polymer.

Xjet: Xjet raised $9 million from Gemini Israel Funds, Good Energies and Spirox, et al. for deposition technology used in solar cell manufacturing.


Kotak (India): With $8M in financing from KPCB, Sherpalo Ventures, and Applied Materials, Kotak deploys solar power installations, and builds and distributes solar appliances such as solar water heaters, water pasteurizers and solar drying systems.

Snow Peak Energy: Solar parking structures

Veranda Solar: Low-power output, consumer-oriented on-grid solar modules.  With integrated inverter.  They’ve received seed funding in business plan competitions and are seeking VC funding.

Next up is Part 2, CPV startups.