Burn Some Daylight

...on my next project.  I met with Ertex Solar when I was in Freiburg in June about their building integrated photovoltaic product.  Glass--glass modules with architectural grade solar cells from Sunways--they call it PV Glass.  The interstitial LED's were a little over the top, but the modules were beautiful. 

Only problem is that the modules are not UL 1703 listed, and Ertex is not planning to do so because of the custom nature of their fabrications.  We would need a UL Field Evaluation if we were using these modules to generate power.

PV is the sizzle that sells green architecture.  I am thinking about a new way of signifying how a building wants to meet its triple bottom line responsibilities.  Visual cues and feedback through the property's information system is a key element of showing how we meet this responsibility.

is a key part of the California Solar Initiative.  The legislative analysts correctly understood that there is a potential weak link between the global technology designed to harvest the power of the sun and the installer's skill set.  Says Christian Bendel at ISET:

"In 80 percent of the cases..., the problem is incorrect integration of the individual components into a system." 

Systems over 100kW--and soon dropping to >30kW--are paid on their output through California's Performance Based Incentive [currently $0.26/kWh].  Solar Renewable Energy Credits [SREC's} are created and traded for each MWh [=1000 kWh] produced.  Performance matters.

I want to know:

• how system performance compares with predicted performance taken from onsite irradiation measurements with a sensor.
• how the system performance varies across inverters.
• I want to be informed of any deviations via email or SMS.
• I want to know if any modules are being removed [stolen] from the string, and
• total performance measured on a revenue grade basis [+/- 2%]

From this data, I can generate the following financial information:

• total SREC's generated from the system for WREGIS reporting,
• avoided peak power energy and demand costs obtained from onsite generation.
• avoided fossil fuel use based on utility company fuel split.

Monitoring adds about 5% to the cost of the system, a relatively small price to pay for peace of mind and knowing how my investment is performing.

As a PV power developer, the yields of the systems I design, construct and operate is the primary determinant of how good I am.  Hence, I was disturbed last night when I read the results of Photon Magazine's module test on Sharp modules.

Sharp ended up at the back of the pack on yield--almost 10% behind the test leader.  Sharp has a reputation for under-promising/over-delivering on power, which held true here--their 175Wstc modules actually tested out at 188Wstc, but the yields were dramatically off when compared to other modules.  The yields are standardized to the actual measured power of the module, not the nameplate power.  I don't understand why the yields are so low.  The test looks really comprehensive--a typically thorough German approach to getting to the numbers.

The other surprise was the Sanyo HIP series modules finished just above the Sharp modules--and this module is marketed as a high yield, triple junction module.   These modules were apparently "samples" but were bought through the distribution chain, so my concern is how do I know that I don't end up paying for "samples" rather than the real deal?  These modules are being retested at the request of Sanyo--stay tuned.

I need to really dig into this as I have several jobs in planning that I was going to specify the Sharp module on.

Update:  I traded emails with Sharp--the main takeaway is that if you look at yield on nameplate, so that they are not penalized for under-promising on power, Sharp moves into the middle of the pack, like so--

A friend recently asked me about how photovoltaics [PV] is best used to meet Marin County's Single Family Dwelling Energy Efficiency Ordinance, or SFDEEO. 

Designed to compensate for grid-tied energy demands from homes larger than 3,500SF, this ordinance requires that

• all homes be designed to California's 2005 Energy Efficiency Standards.
• The delta between the home's calculated energy usage and the energy budget for a 3500SF home built to Title 24 Standards be calculated, and
• this delta must be compensated for by increasing the energy efficiency of the residence and incorporating on-site pv power production.

The larger the home gets above 3500SF, the bigger the energy offset is required to be.  I went through the guide published by the county, went through the actual ordinance, but still couldn't find the relationship between size and PV. 

 Then I found the analysis that Marin County used to backstop the ordinance.  Basically, the county takes the annual production of the system, multiplies it by 4.2 [PV provides power at the same time demand on the power grid is peaking--so they estimate it is 4.2 times as valuable as an alternate power source not producing during peak times--defined as TDV, or Time Dependent Valuation] and then divides by the square footage of the home to establish the offset.

The math is different for each home, but it looks like a 5kW system would offset a prototypical 5,000SF home [1500SF larger than the design standard], an 11kW system would offset a 7,000SF home, and a 21kW system would offset a 10,000SF home.  This assumes no greater energy efficiency improvements and in climate zone 2--where 70% of us in the county live.  A lot of assumptions.

There are a multitude of ways to slice and dice the energy consumption and generation to get to the home you want.  You will want to put all options on the table--such as increasing insulation, using radiant barriers, solar shading, and glazing locations and options.  PV is a great component to any home,  and the wisdom of this ordinance is that it gives you credit for using onsite PV to minimize your effect on our old, obsolete power grid.

The good news is that harvesting your onsite available solar resource to reduce the environmental footprint of a large home makes sense for a lot of reasons. 

The bad news is that each deal must be taken on its own, the best outcome is achieved by iterating through the options, and an increasing amount of PV is needed for each additional square foot of conditioned area.

PG&E recently advised that they will be opening the A-6 tariff in early 2008 for customers that are currently on an E-19 tariff and have, or will have, PV systems installed that are sized to handle at least 20% of their onsite demand.  A-6 was capped at 500kW--the yellow below shows how PG&E is expanding this tariff to PG&E customers with demands of up to 1000kW.

Why should you care?  If you are planning a PV power system that provides greater than 20% of your demand, your service size is under 1000kW, and your peak and off peak demand is about the same, then your PV system just became more  valuable.

Part of PV's value is the ability to take advantage of "solar-friendly" tariffs, lowering your operating costs.

This is a good fit for a large hotel property, retailer, or industrial use with a load shape that doesn't fit with PV's power generation shape of mid-day max production.  Another area are users that are "peaky"--big peak demand charges that are outsized compared to total energy use.

PG&E has limited this to the first 20MW of customers approved for this transfer--so this opportunity won't last long.

E-19[pdf] has both an energy charge [how much you use] and a demand charge [how much you use at any one point--used to size the service].  A-6 is only an energy charge [pdf], with a much higher charge during summer peak periods.

Think this may work for you?  Drop me an email and we can explore it.

...has great potential, but I have yet to find a listed [by UL] system that works architecturally.

PV glass is a compelling material.  Solar cells are sandwiched between two layers of solar glass and can serve as a canopy, curtainwall, or safety glass.  The most recent example of this is Renzo Piano's new Academy of Sciences project in Golden Gate Park.

The problem?  These modules are said to "comply with UL 1703".  They can't be connected to the grid without a UL listing, or a field evaluation using listed components.  The City and County of San Francisco are tough on un-listed assemblies.  UL has stated they will not do a field evaluation on a custom glass/glass pv component, requiring it to go through the six to nine month, $25 to $50K listing process for the entire range of modules being utilized.

There needs to be a better fix--even though this material is more expensive, on a $/W basis, than typical modules, the fact that it is doing double duty as a canopy actually makes it far more valuable.

Schuco and Open Energy were showcasing this type of product at Solar Power 2007.  Both shrugged when I asked if their products were UL listed.  Sounds like an opportunity to me.  You can do a field eval from listed components--but the components of a module are a pv cell, and the connecting conductors.  Maybe that is the solution--get the components listed.

Looked over a retail development project last week--pv adds real value by reducing operating costs.

The strategy is to knock out the parking lot lighting load [house meter] with PV.  In addition to getting a fourteen to sixteen IRR--accretive on a six cap deal--the PV array keeps the roof cooler--lowering AC demand, and provides a nice pop at the time of sale.

Key issue--can the owner can use the 30% ITC and the five year MACRS?  If not, we structure the deal so that the owner buys the power only, and then has the option to buy the system when the tax benefits have been amortized--year six to eight. 

Since these projects are typically on a TOU demand meter--summer peak pricing is close to 3x night and weekend pricing--you tweak the system to maximize value rather than output.

These systems can be wrapped up into the overall construction financing, increasing your returns.

Not tested yet is whether tenants on longer term leases will want PV to power their operations.  If the lease is over ten years, and you can use the tax bennies, the first conclusion is that it may make sense--free power after year six or eight, and you insulate yourself from peak demand price shock.

Had a meeting with an office building developer yesterday and we reviewed a migration path for renewables on their project.

They are merchant builders--they permit, manage construction risk, and then sell--so the long term benefits of pv, and the multiplier effect on residual value, is not compelling for them.  They focus on first costs, not life cycle costs.

"PV ready" was my recommendation to them.  PV ready is defined as:

• the future array area is mapped out, and an array is sized based on general performance data.
• the future inverter location and point of grid interconnection is selected.
• Provide DC only conduits from the array location to the inverter location,
• Provide AC conduits from the inverter connection to the point of interconnection
• The bus at the point of interconnection is sized per NEC for backfeeding the PV power production, and
• We certify the project as "PV Ready" and stand by to reserve the California Performance Based Incentive, and design, permit and provision the system--all the owner needs to say is GO.

When this builder sells the property, their brokers can advertise it as "PV Ready", and the new owner, who will be more focused on life-cycle costs, can reduce their carbon footprint and operating costs through a PV power system--the conduit will already be there.  Now that's thinking ahead.  There is a value to the builder of such thinking ahead.  This property is worth more than one that isn't PV ready--more than the incidental cost of installing the conduits and getting the certification.

is basically about two things--

1. keeping your harvestable area from being shaded from 9A to 3P, and
2. orienting your array for production. 

The numbers below represent percentage harvested vs percentage available of total insolation--so a flat array for example, harvests 89% of the energy an array tilted at latitude would achieve.

Tilting the modules needs to be balanced with the amount of the area you are losing to shade from the tilted arrays.  The angle on this model represents latitude--which for us in NorCal is 37 degrees or a 9:12 pitch, or a 7:12 pitch for our amigos in Southern California.

Spent the last week in the United Arab Emirates on a potential solar development project.  The heart of the issue is that development growth has outstripped the capability of the grid to power this growth.  Is solar power part of the solution?

Part of the solution may be what I saw in Abu Dhabi, at the site of a new Sir Norman Foster designed zero carbon city.  Located in the emirate with the fourth largest oil reserves in the world, Al Masdar (Arabic for "the source") plans to meet a significant amount of its power needs with a 200MW array. 

The question is how well PV will work in the summer heat of the UAE.  PV does not like heat--it produces less power when the cells increase in temperature.

Summer ambient temps can reach 45C [113F] and temperature at the cell [Tcell] can be 25C +/-5C over that.  To determine how PV actually performs, Dr. Abu-Zaid at Masdar is running the largest PV competition in the world--testing over 30 1kW systems from manufacturers in UAE field conditions.  Data from the competition, including

• power output,
• temperature,
• power loss from dust and
• peak power output

using identical inverter and measurement equipment will be used to determine what type of pv power is best suited for desert conditions.

At roughly 9A that morning, with 25kW installed, these systems were collectively performing at over 50% of max--in February!  The UAE has great potential as a market for PV.

Dr. Abu-Zaid is doing the right thing.  There is a dearth of actual performance data available for use when designing systems.  This competition will be a great add to the Photon data.  And it motivates me to incorporate ways to get more performance from my systems deployed in high-heat environments.

Need to round out your understanding of commercial solar projects and how to get the math to work in our current difficult environment?    Check out this course I am instructing at UC Berkeley Extension in downtown San Francisco this spring.  The essence of the course is a team=based exercise in investment grade due diligence for solar photovoltaic [PV] investments in California and the West.  The capstone of the course is the preparation of your team's investment grade feasibility study for presentation to your classmates and a professional jury on 2MAY09.

I do a low gear flyby of current technology, and then get into demand, capitalization, and design of PV systems.  The recent shortage of tax equity--and the increased cost of this essential part of the capitalization stack-- has meant dramatic changes in solar project finance.  Need more info?  Here is the current draft of the syllabus. This will be updated between now and the start of class to reflect changes in component availability, pricing, and tax incentives.  A multi-disciplinary approach to underwriting solar is used--this course is designed for tax credit investors, commercial [ppa] solar integrators, lenders and attorneys to help them get solar deals done in today's difficult environment.

This is the text I use.  Purpose is to build a foundation--it is exhaustive enough you can really dive in, or you can just refer to it when needed.  I find this book the best current overview and reference on PV, and it covers what is happening in Europe and the world, for PV is truly a global application. 

My perspective is that of seasoned solar developer with over twenty years of commercial real estate investment and development experience here in NorCal. 

I hope you can join me for this course.  First session is Saturday 21MAR09 from 9A-5P, then five Tuesday evenings from 630-930P, then presentations on Saturday 2MAY from 9A-5P.

The key to commercial and utility scale solar is finding feasible projects and successfully capitalizing them.  I am the instructor for a UC Berkeley Extension course this fall, taught at the downtown campus, that has precisely this course objective.

Click here for the current draft of the syllabus.  The course commences with a low gear flyby of current technology and then dives into demand, capitalization and design of commercial PV systems.  The essence of the course is a team-based exercise in investment grade due diligence for a solar photovoltaic [PV] investment.  The capstone of the course is the preparation of your team's investment grade feasibility study for presentation to your classmates and a professional jury on 7NOV09.

These are the texts I use.

       and        

Intent is to build a foundation for getting commercial solar projects identified, quickly selecting the feasible ones, and putting them on a track to executing a deal.  Planning and Installing is exhaustive enough that you can really dive in, or just refer to it when needed.  I believe this is the best current overview and reference on PV--it covers what is happening in Europe and the world, for PV is a globally applicable technology.  Strategic Selling was added this semester, because when you do a feasibility study, you want it to lead to a project, and the study isn't going to do it on its own.

Cooperate and graduate is a big part of the course--you will learn a great deal from your fellow classmates, and you are expected to contribute your experience and perspective as well.  In addition, we are fortunate enough to have some great guest lecturers on several evenings.

My perspective is that of a seasoned solar developer with over twenty years of commercial real estate investment and development experience here in Northern California.

Here are a couple of slides from the course:

I hope you can join me for this course.  First session is Saturday, 26 September from 9A to 5P, then five Tuesday evenings from 630P to 930P, capping off with Presentation Day on Saturday, 7NOV from 9A to 3P with a debrief afterward at the Thirsty Bear.

Click here for enrollment information.

Walked one of our sites this week—we did planning, feasibility, design, and proposed on the construction of a 540kW array on the top of a parking structure in Silicon Valley.  Solar over parking garages is a win-win-win.  It enhances property values, doesn’t take away parking, and the way we designed it, it became an architectural touchstone for the entire project, setting a new standard for corporate facilities.

The steel structure looked great—with a camber built into the beams, the proportions felt right and the design was complementary to the parking structure—not an easy move to pull off.

We expect this system to meet roughly ten percent of the adjacent office building’s demand, and with the lease financing we proposed, it was cash flow positive for the first five years, and you own it after ten [with a small buyout].

I was reminded that design is only as good as the execution—and PV is a game of inches—we fight for every percentage point of performance.  We believe module mismatch losses are avoidable—you are building a thirty year system—and throwing away a couple of percentage points of yield just because you don’t have time to sort modules by performance is baffling to me.  In the end, systems deliver a yield, and it seems unwise not to practice the same care in construction that we did in developing the system.

Grounding is an essential, but poorly understood, component of system design.  “Lugless” grounding design is a great concept, but ground faults are such a danger that you need to be sure that no shock hazard exists in module frames, metal structures or enclosures.  Installation should proceed as if everything conductive is at lethal potential to ground—until a megger or multi-meter proves otherwise.

It’s all in the details.

This semester’s UC Berkeley Extension course on getting to feasible commercial and investment PV projects faster starts next Saturday, 2APR.  The focus is on finding profitable PV projects smarter and faster.  Here is the highlights deck:

Using a series of case studies, sample feasibility studies, and a review of technology, financing, sales, and operations and maintenance, we build to a final day when you and your fellow students present your prospective projects.  Click here for the syllabus.

Here is the text you will  use. Planning and Installing Photovoltaic Systems is technically complete enough that you can really dive in, or just refer to it when needed.  I believe this is the best current overview and reference on PV--it covers what is happening in Europe and the world, for PV is a globally applicable technology.

I hope you can join me for this course.  First session is Saturday, 2 April from 9A to 5P, then five Tuesday evenings from 630P to 930P, capping off with Presentation Day on Saturday, 23OCT from 9A to 3P with a debrief afterward over pizza and beer w your fellow students.

Click here for UCBX’s online enrollment site.