GreenMountain Engineering

Highlights from the 5th Conference on Clean Energy in Boston

Matt, Jon, and I went to the Conference on Clean Energy at the Hynes Center in Boston today. This morning, I watched a series of investor pitches from a group of cleantech startups. The mix was interesting-- smart grid startups were dominant, which is a big change from the last few years, where solar, wind, and biofuels were the big players.

To my ear, the most interesting pitch was from the least clean of the startups-- Silicon Basis. They're an integrated circuit company; the "clean" angle is that their chips will have lower power consumption.

Dave Richards, a charming Englishman from the University of Bath, spoke in place of CEO Rob Beat. Silicon Basis is trying to implement a new type of chip that has lower power consumption and better performance (600 MOPs/mW) than the typical chips used in cellphones, ipods, and the like, but with a reconfigurable technology that will reduce development time and cost substantially below the usual 18-24 months and $10M. In technical terms, they say they've figured out how to manufacture FPGAs that reconfigure themselves between clock cycles. If they have actually pulled this off, they are insanely smart. About 2 months ago, they were issued patent GB2457912 in the UK. Silicon Basis also announced a partnership with Actina Imaging, who will help them test their first chips.

Here are brief summaries of the other startups that pitched.

Jason Hanna, President and Founder of Coincident Smart Energy Technology

Jason is a computer engineer out of EMC. I talked with him for a few minutes after the talk; he seemed like a smart engineer. Coincident is developing two things: an online marketplace for HAN devices and services and a hardware gateway. From my perspective, the hardware gateway was more interesting-- an embedded Linux board with a Zigbee wireless module. On looking at their website, I realize that I had found it a few months ago-- I'm impressed that they managed to get coincident.com.

Steven Filler, Director of Business Development, Prism Solar

Prism Solar is building holographic concentrators for solar panels by replacing 70% of the silicon with strips of holographic film. I was inclined to like Filler's presentation because it included a lot of numbers. Their holographic film selects part of spectrum for efficient heat rejection, which results in 10 C cooler cells at high noon in Tucson as compared to a conventional solar panel. Filler claimed that their holograms have better acceptance angle and can use bifacial cells. He claimed a 70% increase in energy production. Prism is selling modules domestically, but really wants to sell holographic film under license. They think they can hit 1.04 $/W by 2012.

Rory Gaunt, CEO, Lifecycle Renewables

The most interesting part of Rory Gaunt's presentation was the bullet: "negligible technology risk." Lifecycle Renewables' plan is to convert waste vegetable oil into fuel for commercial electricity and heat.
Whole Foods Market will be their first oil supplier and customer in 2010 when they bring up a 500 kW station, taking a 45,000 ft² kitchen facility off the grid. Their claimed advantages over other biofuel heat/power startups are low cost processing, efficient logistics technology, and state and federal incentives. They're seeking $750k and plan to be profitable in year 2. I like Mr. Gaunt's straight-forward style: "Funds will be used to get the oil."

Roselyn Romberg, Electronic Housekeeper

Founded in Denmark in 2005, Electronic Housekeeper launched in Europe in Q1 2008. They plan to establish a new headquarters in the US shortly. They make smart grid hardware hub for apps and services with backend database. They've had $1M in sales so far, and they claim that their customers' have seen usage reductions of 10-15% in electricity, 15-25% in gas, and 20-40% in water. I thought it was interesting that Ms. Romberg emphasized their device's passive nature: "We don't rely on behavior modification."

Roger Faulkner, Electric Pipeline

Cost-effective underground power transmission. I'm afraid don't know much about power transmission, so I didn't listen to Roger carefully. Sorry, Roger.

Dave Howell, COO of Practical Solar

Practical Solar is making heliostats with a total cost of $200/m². Howell viewed the proprietary firmware in their controller as a strength, and he boasted about how difficult it would be to reverse engineer it, taking more than a year and a million dollars to do so.

Mitch Wondolowski, Grid Solutions

Weather, market prices, and utility rates integrated into a residential demand response system.
"Enabling residential load balancing for the grid"

Richard Chase, Future Solar Systems

If I understood Mr. Chase correctly, Future Solar will install solar panels using an arrangement similar to that used by the City of Berkeley in California-- they put up the capital to put solar panels on your roof, and then you pay them for the electricity over the next 20 years. (Not exactly the same as Berkeley, but similar.)

That was all in the first session on Thursday. If i have the time, I'll add more summaries from the rest of the conference tomorrow.

VC feedback on startup pitches (notes from the NREL Industry Growth Forum)

For the past few days, I've been in Denver at the NREL Industry Growth Forum, where cleantech companies ranging from pre-seed startups to more funded companies present to panels of investors, get feedback on their pitches, and network and try to raise money. As in my previous blog post about the 24th EU PVSEC, this post will focus on information and impressions you can't just get from press releases after the fact, distilled from Q&A sessions and informal one-on-one discussions with companies and investors. In fact, I won't even talk about any of the specific companies that presented.

Let's jump right in:

The questions VCs most frequently asked included: 

Who are your customers?

• Do you have a clear idea of what the primary product and target market are? Or are you a 'technology in search of a problem'? 
• Do you have specific feedback from potential customers on your product or technology? ("The best way to answer a VC's question is with the customer's words.")
• Is this a need-to-have or nice-to-have for your customers? If you're selling to businesses, who gets a promotion, makes money, or doesn't get fired because they choose to work with you or buy your product? Does anything negative happen to companies if they don't work with you?

What is the exit strategy?

• How much capital will really be required to get the company to an exit (IPO, or more commonly these days, M&A) for the VC? Are significant manufacturing scale-up or project development finance part of your path to exit? (Requiring significant future capital isn't necessarily a bad thing long term, just be ready to defend your value pitch compared to less capital-intensive investments the VCs will be considering.)
• How many years will this take? (VCs have seen their timelines from first investment to exit steadily increase over the past decade.)

Do you have an experienced team, especially on the executive side?

• Do you have anyone with experience running a company (not just experience at the MBA level or in a sales organization)?
• Do you have people with experience scaling up R&D and manufacturing organizations?

VCs know they're always taking technology risk; they don't want to also be taking basic risks in the areas of ability to run a company, make deals with large organizations, and execute on sales. In particular, VCs gave positive feedback to a technical founder who said he would step down as CEO in a few years once the company grows.

Less common investor questions included: 

Who are your competitors? Do you understand the competitive landscape, who has momentum, and where competitors will be in the several years it takes you to get to market?

Do you have a strong IP position, and are you working in a market where customers and competitors will respect this? 

What are your cost models, margins, and 5-year revenue projections? When do you hit first revenue? When do you become profitable? 

What market and % penetration are built into these projections?

Finally, some of my personal opinions: 

Feel free to take the following with a grain of salt-- my focus is really more on engineering and technology development than business. That being said, I've worked with dozens of startups and other cleantech companies, and worked full-time at two early-stage startups in the past. And my recommendations are: 

Pick one technology and product, and do it well. Sure, you have to be flexible and willing to make a major course change if an early path doesn't pan out, but don't spread yourself thin by pursuing many products in parallel, or pursuing a low-value, unexciting product in the near term "just to generate some revenue". It will take longer than you think to develop even a first product, and delay your long-term focus.

Be ready for resistance to capital-intensive business plans. In the past, some VCs haven’t fully understood energy businesses or appreciated the magnitude of capital and time required for scale-up compared to IT/software/web businesses. So expect a near-term backlash against business cases that will require $100M to execute (one investor was overheard asking a company if they could develop some sort of software related to their industry instead). At the same time, this is a backlash and not a fundamental reason to avoid this type of business: energy is a huge, growing industry, and building anything large and physical at scale takes a lot of capital.  Ten years from now when you look at the energy companies that grew orders of magnitude and became billion dollar businesses, behind them will have been investors with a vision. But VCs may not always be the best investment match for these types of businesses.

When presenting to investors, confidence is key. But there's a fine line between projecting confidence and ignorance.

Do positively present your value proposition, cost models, team capabilities, and timelines. If you can't don't believe that your company is a huge win for everyone involved, why should investors believe you, and believe you'll do whatever is needed to succeed?

Don't appear ignorant of the competition (including established companies and other startups, even stealth-mode ones), or of history and past investments that did not pan out. As just a few examples to illustrate the point:

• To be blunt, if you're starting a solar photovoltaics company, what is your competitive proposition compared to First Solar's 2012 projections? Sure, their projections are just that, projections, but they and other competitors have track records of executing operationally and growing a business year after year.  
• If you're working on a non-Lithium battery technology, how do you stack up against future improvements in Li batteries, and are any weaknesses of Li batteries you mention fundamental ones that you can be confident won't be solved? 
• If you're pitching in the area of algae biofuels, what is your explanation for why the large amount of investment to date has not led to any runaway successes? How are you different?
• If you're working in medium-concentration PV, what were the fundamental issues with EUCLIDES and how does your technology address them? 

I think all of the above questions have reasonable cases that can be made as answers, and not always technical ones, but they aren't trivial.

Conclusion

Overall, the conference was positive. While the current economic situation is still very challenging for investors and companies, and we are still below the levels of investment and valuation in 2007 and 2008, cleantech investment has been rising over the past six months. In addition, several investors mentioned that there is significant additional capital “waiting on the sidelines” for conditions to improve, so it seems possible that once the market recovers further, there will be an inflection point and sudden uptick in investment.

As always, I welcome feedback here or by email to mdavis at greenmountainengineering.com

EUPVSEC Presentation and Poster Highlights

As a follow-up to my post a few weeks ago about the 2009 EUPVSEC (EU PVSEC 24), the following presentations were the ones I personally found most interesting (I've also uploaded a copy of the program for the oral sessions, which contains author information for these).

• 2AO.3.4 Boron-Oxygen Related Defects in Cz-Silicon Solar Cells: Degradation, Regeneration and Beyond
• 2AO.3.5 Quantitative Stress Measurements of Bulk Microdefects in Multicrystalline Silicon
• 2BP.1.3 High Efficiency n-Type Si Solar Cells with Front Side Boron Emitter
• 2CO.3.2 Crystalline Si Solar Cells with Selective Emitter for Industrial Mass Production
• 3CO.6.3 Epitaxial Thin Film Silicon Solar Cells Fabricated by Hot Wire Chemical Vapor Deposition Below 750°C
• 3CO.7.2 Epitaxy Wrap-Through Rear Contact Solar Cell Fabrication and Results
• 4CO.5.3 World Record Module Efficiency for Large and Thin mc-Si Rear Contact Cells
• 4CO.5.4 Analysis of PV Modules by Electroluminescence and IR Thermography
• 2DP.2.2 Kerf-Free 20-150μm c-Si Wafering for Thin PV Manufacturing
• 2DP.2.5 Physical Mechanisms of Breakdown in Multicrystalline Silicon Solar Cells 
• 4EP.1.3 Results of 5 Years Module Manufacturing Research In European ‘Crystal Clear’ Project    

I also browsed or skimmed nearly 900 posters while there; below are just a selection of ones I found interesting (see the program for the visual presentations for more information):

• 2CV.2.2 Investigation for 19% Efficiency at Multi-Crystalline Si Solar Cells by Industrially Probable Approach 
• 2CV.2.3 Advances in Electroless Nickel Plating for the Metallization of Silicon Solar Cells Using Different Structuring Techniques for the ARC
  
• 2CV.2.8 Laser Processes for Industrial Manufacturing of Solar Cells
• 2CV.2.13 Microstructure and Mechanical Properties of Aluminum Back Contact Layers
• 2CV.2.78 High Efficiency HIT Solar Cell on Thin (<100 μm) Silicon Wafer  
• 2CV.5.83 Inkjet Texturing for Multicrystalline Silicon Solar Cells
• 3AV.1.12 Hybrid Excimer Laser and Aluminium Induced Crystallisation of Silicon Thin Films
• 4AV.3.2 The Evaluations of Physical Properties and Lamination Process Parameters of EVA Encapsulants by Thermal Analysis 
• 4AV.3.39 Characterization of Thermo-Mechanical Behavior of Ribbon and Solder Materials
  
• 4AV.3.54 The Effect of Accelerated Aging Tests on the Optical Properties of Silicone and EVA Encapsulants

EUPVSEC Highlights

As I thought about how to summarize my week at EUPVSEC 24 in Hamburg, I decided to (mostly) not talk about what record efficiency results were reported by what group. This type of information is already reported by many other blog posts, press releases, and news aggregators, and specific efficiency numbers can be misleading taken out of context. For these sorts of numerical summaries I recommend checking out this PDF of Heinz Ossenbrink's summary presentation given on Friday at EUPVSEC. 

Instead, I'm going to summarize my impressions of the show in several technical areas, and talk about other things that may be harder to get a feeling for by just reading the published papers later. This post will also primarily focus on the technical and poster sessions and related discussions, not the trade show. If you have any questions, feel free to email me at mdavis (at) greenmountainengineering.com, or leave a comment on this blog post.

As this is a fairly long post, here is an overview of the topics:

• Silicon cells and modules
• Thin film
• Wafer equivalent thick film / thin film cells
• Reflectors
• Characterization and modeling
• Inverters and grid interconnections
• Other technologies
• Changes in the business climate [future blog post] 

Silicon cells and modules:

There continues to be substantial exploration of—and room for innovation in—new cell designs and manufacturing-scalable fabrication processes in the primary solar technology: crystalline silicon. This includes improved or lower-cost materials (for example, adaptation of metallurgical-grade silicon to solar cells, reduction of the effects of Boron-Oxygen defects in p-type material, and so on), as well as improvements in cell architecture (such as improved texturing for light trapping, metallization, selective emitters, surface passivation, and more significant changes in cell architectures such as rear-contact cells and heterojunctions).

While a variety of improvements in all of these areas have been demonstrated by research groups in the past and integrated into some manufacturing processes, a number of proposed improvements have not yet been widely adopted. This is both because there is still engineering to be done to come up with scalable, cost-effective implementations, and because any new material or process comes with some technical risk and thus must be demonstrated as reliable in the field before major scale-up. Selective emitters do continue to be an area of scale-up, with at least one Chinese manufacturer now using them in a production module design, and other companies selling turnkey wafer manufacturing lines that include a particular selective emitter process.

Progress also continues to be made on fabrication of thinner silicon wafers (e,g, Silicon Genesis’s cleaving process, as well as a number of wire saw optimization projects), and cells (a number of presentations were made on results obtained on cells 120 microns or thinner, including Sanyo’s poster on their impressive >22% efficient, 98um-thick cell based on their HIT technology).

However, reliable, high-yield integration of cells this thin into modules will be a challenge. Towards this end, the EU Crystal Clear project—particularly, sub-project 5: modules—showed some success using rear contact cells with electrically-conductive adhesives and a printed-circuit-board-style backplane to enable a lower-temperature, closer-packed, lower-stress method of module fabrication. Advent Solar is also an example of a company integrating rear contact cells onto a backplane (described and shown in a video on their web site).

Image: ECN monolithic backplane for use with rear contact cells

There were also a number of companies discussing—and in some cases demonstrating manufacturing tools for—non-contact metallization techniques (e.g. jet printing combined with electroplating, for example), other non-contact processing techniques (e.g. laser soldering, use of laser ablation or jet-printed resists for patterning of dielectrics), and low-stress wafer handling methods. 

Non-contact processing techniques are one way of reducing wafer damage during processing, but there are a range of other challenges to fabricating reliable modules with thin cells.

Thin Films

There were fewer presentations on CdTe and CIGS than I’m used to at conferences, though that doesn’t mean that substantial work isn’t being done in that area; the thin-film production leader First Solar rarely presents at conferences, for example, and we’ve worked with a number of other CIGS and CdTe startups at various levels of stealth that also choose not to present on their work.

There were a number of presentations on thin-film silicon, though, both from research groups and manufacturers. In summary, groups are getting to stabilized module efficiencies of 6 - 7% for a-si (amorphous silicon) and 8.0 - 9.5% for micromorph (a tandem junction a-si/uc-si). But there are many measurement and reporting details to look at carefully when people report thin-film silicon efficiencies (e.g. initial vs. stabilized, aperture area vs. full area, overall size, and what the deposition rate was and how reasonable a throughput that is for manufacturing– to name just a few). I'll comment further on interpreting and understanding thin-film efficiencies in a future blog post

Thick Films / Wafer Equivalent Thin Films

One of the most notable changes—which may partly just be a change in my perception—was the number of people pursuing what were sometimes called “wafer equivalent” devices. These are crystalline cells typically in the 10-30um thickness range, grown on a substrate (one example architecture is shown below).

Image: one architecture for wafer-replacement crystalline silicon, presentation 3CO.6.3 by NREL

For example, a cell could be grown by gas-phase epitaxy on a lower-quality metallurgical-grade silicon cell “template”. Or, an amorphous silicon layer could be deposited on a substrate by some rapid, lower-than-usual-quality CVD process and then crystallized, using a laser, metal-induced crystallization, or solid phase crystallization. These methods could even be combined, to deposit and crystallize a thin seed layer by one technique, and then use epitaxy to grow a thicker crystalline layer on top of the seed layer. Companies like CSG Solar have pursued one approach towards polysilicon cells (deposition of a-si on glass followed by solid phase crystallization), but there a variety of significantly different approaches being pursued—this is a fairly broad technical category.

There were a number of presentations in this field, and I’m also aware of a number of stealth companies pursuing variations on these techniques. I find this interesting because the semiconductor industry has addressed similar challenges in the past, and there is potential for the solar industry to bring in experience from research in the IC and LCD TFT backplane industries.

Reflectors

Reflectors are important for improved light trapping in technologies including thin-film modules, thick-film “wafer equivalent” cells described above, and even conventional multicrystalline silicon wafers.. This is an area where there will continue to be significant development beyond the basic chemical texture etches that are effective for single-crystalline silicon wafers.

Materials, Characterization, and Modeling

Most of the usual characterization techniques for materials, cells, and modules were discussed, such as EBIC, EBSD, SIMS, XRD, IR imaging of various types, EL (electroluminescence), PL (photoluminescence), Raman spectroscopy, and so on. But I also saw presentations on some methods new to me, such as: photoelasticity (a mechanical-optical method for examining defects by looking at the stress fields produced by them) and Dynamic ILM (infrared lifetime mapping, but based on a chopped light source and looking at the shape of the resulting waveform).

There were also a number of discussions about dopants and impurities in silicon, as well as various methods for characterizing, modeling, and reducing the effects of them.

Inverters and grid integration:

The European inverter standard EN50530 has finally been released, and includes some provisions for how to characterize the behavior of inverters’ MPPT (maximum power point tracking) algorithms, a method by which the inverter tries to operate a solar module at the current and voltage of maximum power rather than at a fixed voltage.

As solar (and other intermittent-supply renewable energy technologies such as wind) grows to be a more significant contribution to electricity production in some countries, utilities are taking it more seriously. This leads to additional requirements (and opportunities to add value) for inverters, including the ability to supply reactive power and in other ways contribute to grid stability, as well as the ability to stay connected and ride through low voltage events or grid failures, in part to avoid cascading shutdowns of more and more plants if grid voltage drops (Germany has learned some lessons in this area with the growth of the wind industry there and some grid issues).

Other Technologies:

Some further progress has been made in areas such as intermediate band cells (using quantum dots or bulk materials) and organic photovoltaics, as well as in building integrated PV, but I don’t see any of these becoming significant in the near term.  That is not to say they won’t have niches that are profitable for the companies involved, but they are unlikely to contribute a significant portion of the total gigawatts of installed PV capacity.

 

 

New Tracker Accuracy Paper

I just finished up a busy week with Chris at the EUPVSEC 24 in Hamburg. I plan to post something more about the conference in the coming week, but several people have asked me for a copy of the poster we presented about solar tracker accuracy (co-authored with assistance from ISFOC)-- so the paper is now available for download on our papers page.

It includes a dozen sets of measured, real-world accuracy data for a variety of different solar trackers by different manufacturers (mostly trackers designed for concentrating photovoltaic applications with more strict accuracy requirements). If you have any feedback or questions, I'd be interested to hear them-- you can email me at mdavis (at) greenmountainengineering.com

Last-Minute Talk at SPIE

We just found out that Chris Cortez will be filling in for a canceled speaker during the High Concentration Systems session at the SPIE Optics + Photonics conference tomorrow morning (Tuesday, Aug. 4th) at 9AM.  Good luck, Chris!

Update: the talk will be entitled "Real-World Tracker Error."

IEEE PVSC 34 Paper Available

My sources tell me that Brandon and Max had a great time mingling with the "solarati" at the IEEE Photovoltaic Specialists Conference last week, and the presentation was a success!  The full paper (abstract below) is available on our Papers page.

Solar Tracker Accuracy: Field Experience, Analysis,
 and Correlation With Meteorological Conditions

B. Stafford1, M. Davis1, J. Chambers1, M. Martínez2, D. Sanchez2
1GreenMountain Engineering, LLC, San Francisco, CA, and Somerville, MA, USA
2Instituto de Sistemas Fotovoltaicos de Concentración S.A., Puertollano, SPAIN

Abstract: Tracker performance is a significant factor in the energy production of PV systems, especially concentrating photovoltaic (CPV) systems. The nonlinear relationship between CPV optic pointing accuracy and energy production means that simple metrics such as mean pointing accuracy are not sufficient for predicting performance of these systems.

Additionally, trackers are currently a significant component of system cost. Understanding the real causes of tracking errors in the field (as well as which types of errors have a less significant impact on energy production) is an important step towards the development of lower-cost tracking systems.

In this paper we present a collection of real-world data, including tracking error and corresponding meteorological data, gathered over a period of months from commercial solar trackers installed at Instituto de Sistemas Fotovoltaicos de Concentración S.A. (ISFOC) in Puertollano, Spain. We present several relevant mathematical tools for analyzing this data, and draw conclusions about the implications of tracking errors for system energy production.

Full Paper

GreenMountain to Present at PVSC 34

Breaking News! There's been an addition to the program at the IEEE 34th Photovoltaic Specialists Conference next week in Philadelphia.  Brandon Stafford will be presenting data on tracker performance in CPV field installations that was collected in collaboration with ISFOC. Below is an image of the poster and here is a link; we'll upload the paper shortly.

Tracker Accuracy: Field Experience, Analysis, and Correlation With Meteorological Conditions
Area 3: Concentrator Panels and Systems
Tuesday, June 9, 3:30 PM

Two Opportunities to See Us

Two Mountaineers will be speaking at events in the Bay Area in the next few days.  We hope you can join us for one of these engaging discussions!  On Thursday, Brian Atchley is speaking on the changing landscape of renewable energy infrastructure at a one-day seminar presented by the Society of Manufacturing Engineers, An Engineer's Guide to Green: New Rules - New Tools.  Then next Wednesday, David Hague will be participating in a panel exploring innovation and financing for clean technologies, Clean Tech Companies in Growth Mode: Challenges, Opportunities, and the Competitive Landscape in a Global Marketplace. Full details and registration information are included below.

An Engineer's Guide to Green: New Rules - New Tools
Thursday, May 21 8:30 AM - 3:30 PM
Santa Clara, CA

Clean Tech Companies in Growth Mode
Wednesday, May 27 6:30 PM - 9:00 PM
San Francisco, CA

Slides from Business and Society Conference

David Hague and Brandon Stafford spoke at the Business and Society Conference at Dartmouth on Thursday, the 15th. After the panel, there was some interest in slides Brandon presented. Some thoughts from Brandon:

The panel on which I spoke was intended to focus on sustainability in supply chains, but my presentation covered the Jevons paradox and the relatively low power density of renewable energy as compared to the high power density requirements of contemporary civilization (click images below for full size).

The other gentlemen on the panel-- Peter Girard from Timberland, Chris Hacker from Johnson and Johnson, and Paul Ligon from Waste Management Upstream-- were from large companies that are faced with the enormous challenge of figuring out how to square their genuine interest in reducing the environmental impact of their businesses, with the reality that they operate in market sectors where their impact scales directly with their sales. (Arguably, this is not the case for Waste Management, but it's certainly true for J&J and Timberland.)

I was heartened to see the leaders of industry professing genuine environmental concern. I was particularly struck by Johnson and Johnson's credo (PDF), which is even more impressive given that it was written in 1942. Even the most honorable of sentiments do nothing to reduce the impact of commerce based around the sale of newly-manufactured goods, but those sentiments are certainly a prerequisite for developing more sustainable business models. I look forward to continuing the debate about how we can balance our need for jobs and consumable goods against the finite supply of resources available.

Images above are based on charts in Vaclav Smil's Energy At The Crossroads, 2003.