Enphase had its IPO on March 30, with shares priced at $6.00, and the IPO raised total gross proceeds of $61.9 million.  As of the market’s opening today, Enphase (ENPH) was trading at $8.33/share.  On May 10 the newly public company published its first quarterly earnings report with some strong numbers.  Total net revenues grew 136% from the first quarter of last year, going from $18.1 to $42.6 million.  Units sold in the quarter more than doubled from 123,000 last year to 292,000 this year, and gross margin increased from 14.7% to 21.8%.

As impressive as those revenue and growth figures are, they have yet to translate into a profit for the company, with the quarterly loss increasing to $10.2 million, up from $9.3 million last year.  That loss worked out to $-5.38/share.   Nevertheless, that loss was significantly less than the consensus prediction of the four analysts covering the company (by $3/share), and the stock is presently rated as a “strong buy” by two and a “buy” by the other two.

The keys for Enphase will be to continue growing market share (even in the face of growing - if dubious - micro-inverter competition from string/central inverter players like SMA), continue to innovate and keep costs down.  It will be intersting to see how they build on this strong start in the coming years.  (Full disclosure - I do not own any Enphase stock.)

Which brings us to SolarCity which announced on April 30 that it had filed a “draft” registration statement with the SEC on April 26.  While normally a filing with the SEC is a matter of public record, under recent changes in the law, companies with less than a billion dollars in annual revenue can file draft registration statements with the SEC, revise the document based on the agency’s feedback, and only make the filing public once it is actually approved by the SEC.  This is particularly interesting given that it had been reported that SolarCity had delayed its filing while working out “accounting issues” related to its business model of leasing solar power systems. (As one pundit put it, “Apparently not all lease accounting is the same.")  Also still outstanding, apparently, is the issue of Sunpower’s lawsuit for theft of trade secrets against SolarCity.

The purpose of the pre-IPO disclosures to the public is to allow potential investors to get a look at how the company is actually doing - revenues, profits (or losses), costs, salaries, etc.    This is of particular interest in conjunction with SolarCity given its unusual business model that has lead to questions about its practices being raised from a number of quarters (including this blog).  Unfortunately, SolarCity has opted - as is its right under the law - to keep that information secret, at least for now.

Assuming that at some point SolarCity actually has to put its cards on the table, we will follow-up on this story.

Pasadena Water & Power (PWP) is rolling out on a temporary, experimental basis, new Time-of-Use (TOU) based rates for customers with electric vehicles.  The new rate structures, designated EXP-TOU-EV-1 and -2 are available to existing residential customers (either single family or multi-family service) who can demonstrate proof of ownershipof a plug-in electric vehicle.

The two TOU rates differ from the existing R1 residential rate structure in that they provide discounts for energy consumed during mid- or off-peak hours.  (Mid peak runs from 8 a.m. to Noon and from 9 p.m. to midnight.  Off peak runs from midnight to 8 a.m.) 
Here is how the two rates compare:

The second rate has much greater discounts for energy use outside of the On Peak window, but it is combined with a significant penalty for energy use during the On Peak window.

Of course, this is where a solar power system comes in.  Since a solar power system produces the bulk of  its energy during the On Peak window, it could prove highly beneficial to EV owners who add solar to their homes.  We will do a more complete analysis of how these two rates could work for a solar powered home in a future post.

To learn more about the program, check out PWP’s webpage devoted to these new rates.

You can follow this link to see the complete series:
Installing Solar at Westridge.

Titled, “Solar Flair: New solar installation at Westridge School brings environmental lessons to life,” the piece features interviews with Westridge’s Head of School, Elizabeth McGregor, Facilities Manager Brian Williams, and three students who are part of the school’s environmental group known as the Green Guerrillas.  The story reveals the school’s deep commitment to sustainability in everything from solar power to drought tolerant plants.

This first of what we hope will be many solar projects at Westridge really highlights the value of these projects for all schools, especially those in the Pasadena Water and Power service territory.  Good rebates and a solar company that really understands your goals makes a solar power system installed by Run on Sun a “no-brainer.”

Contact us today and let’s get going with YOUR solar project!

Projection

Solar projects actually begin on a computer screen as the designer tries to map what is known about the roof, the utility service, and the client’s needs into a coherent proposal.  As the project progresses through the rebate and permitting processes, that design is refined - and as we have seen, sometimes altered.  But the trick of any implementation is to go from the designer’s plan to an actual system on the roof - starting with getting the attachments in place.

Nearly ancient methods, tape measures and chalk lines, are the essential tools in this process.  Since a solar array is essentially a grid, the trick is to project what is on the plans into a corresponding grid on the roof.  Precision and accuracy are the key to making this work, but roofs are notoriously inconsistent places!  What seemed to be square, isn’t always.  What appeared to be flat, actually has its own peaks and valleys.  While our projection onto the roof proved easy enough, we were about to discover that what you see - or were told - isn’t always what you get!

There’s What You Plan and What You Get

Our biggest design challenge had been the need to account for the somewhat unusual roof construction that we had to accommodate.  In particular, our underlying roof structure was a  20 gauge, type B steel deck, overlayed with multiple layers of plywood, foam insulation and roofing materials.  Given the thickness of those layers we had determined that we would need to use four,  8-inch-long, self-tapping screws to secure our “FastFoot” anchors to the roof.  We had purchased hundreds of those screws - along with a top-of-the-line Hilti cordless driver - to do the job.  But something wasn’t right.

As we started making our first few attachments it was clear that not all of them were reaching the steel deck!  Apparently in some places the actual thickness from the roof to the deck exceeded the 8″ reach of the screws.  Visual inspection from a scissors lift inside the building confirmed what we suspected - clearly not all of the screws were penetrating the deck, yet in other places, all four screws penetrated without difficulty.  There was only one solution to the problem of our inconsistent roof - longer screws!

Fortunately, we were able to order some 9″ screws from the manufacturer - the longest that they made.  They did the trick - now we could be certain that every FastFoot plate was properly secured.

Lean on Me

The changes to our plans imposed during the permitting process meant that we were very tight on space.  At the top of our array we had to install 3 sub-panels, each of which had to handle three branch circuits that made up that sub-array.  Our original plan was to build a triangular cross brace out of unistrut to support the sub-panels. Unfortunately, given our close quarters, the solar panels needed to come right up to the supports for the sub-panels - a cross-brace system would take up too much space.

Instead, we designed a set of steel braces that were bent at precisely the angle that we needed - 103° - to allow our sub-panels to be perfectly vertical on our 13° sloped roof.  The design was easy, but could we get them fabricated fast enough to keep the project on track?  We knew of a small metal shop near our offices and we took the design to them - yes, they said, they could produce the six parts that we needed for $100 and they would have them in the morning - would that be soon enough?!!!

This turned out to be a very elegant solution to our problem.  Using two FastFoot anchors, we attached unistrut to them and then bolted our braces to that.  When combined with the rigid conduit feeding the sub-panel, we ended up with a very solid solution. 
Next problem!

Need a Lift?

The roof of our building was reachable by a series of three ladders traversing three different roof levels.   While this was acceptable for getting personnel to and from the roof, it would never work for transporting hundreds of feet of rails, to say nothing of 209 solar panels!

Enter the boom lift - the same one that was unceremoniously dropped off for us by parking it under a No Parking sign!

Whether transporting rails, solar panels, or the Enphase micro-inverters as you see in this picture, the boom lift provided us with an efficient means of moving large amounts of gear up to our work site on the roof.  Operating a device that articulates in multiple dimensions in relatively tight quarters takes skill and great attention to detail.  (It also makes for some pretty cool looking photos!)

Connect the Dots

Once the rails were installed, the Enphase micro-inverters could be mounted and the process of running a continuous ground wire and the creation of the Enphase map could begin.

Since this was an Enphase system, we would be able to monitor the performance of the array down to the individual solar panel/micro-inverter pair.  (Indeed, this monitoring ability was a key selling point for the system to the school as it nicely meshed with the school’s educational mission - more on that in our upcoming video!)  Each micro-inverter has a serial number that was carefully peeled off and affixed to a “map” that showed where each inverter was located on the roof.  As part of the commissioning process, we transferred the map data onto the Enphase website and built a true representation of how the system was laid out on the roof.

Now all we needed was to install the solar panels themselves!

Careful attention to detail during this last step is rewarded with an array that aligns precisely and fits as planned.  Using the Enphase Envoy and a laptop computer, we could verify that each and every panel was properly connected and functioning as expected.  We could be confident that there would be no surprises that would need to be resolved later!

That gave us one last task for the boom lift - finished photographs.  Here’s our favorite:

Three inspections later - fire, building & safety, and PWP - and we were ready to officially go live.  Here’s how the system appeared on the Enphase Enlighten website one recent sunny day:

The students at Westridge will be able to analyze the performance of this system for years to come, providing a first hand experience of how renewable energy works and can make a difference in our lives - what a great lesson to learn!

Chapter the Last

Which brings us to the end of this series - almost.  In our final installment you will see the video that we have produced for this project and you will hear from the Head of Westridge School, Elizabeth McGregor, Facilities Director Brian Williams, and three wonderful students talk about how this project plays into the larger mission of the school.  You won’t want to miss it!

A project the size of what we were going to install at Westridge - 52.3kW - involves thousands of parts, all of which not only must go together properly for the system to work and be safe, but they must arrive in a timely fashion!  For example, here’s just a sample of the parts that were needed for this job: hundreds of FastFoot plates, thousands of screws, hundreds of flashings, standoffs, and flange connectors, dozens of rail sections, mid-clamps, end-clamps, ground lugs and splices, to say nothing of 209 micro-inverters and solar panels!  Collectively these products came from five different distributors in four different states.

Needless to say, not everything goes as smoothly as you might like when you are pulling together all of these pieces.  UPS likes to brag about Logistics, but we found some of their logistics to be highly illogical.  Such as their sending two shipments that were sitting in an LA warehouse on a frolic and detour down to San Diego for the weekend, instead of driving them the twelve miles up the road to our job site!

Equally baffling were the folks who delivered our boom lift to the job site late on a Friday evening without even a phone call and just parked it out on the street - in front of a No Parking sign!

Seriously…

Would you leave this…

Here?  Right - neither would we!  (And yes, the keys were in it!) The unscripted appearance of our boom lift prompted a puzzled call from the facilies director at Westridge:

Brian: “Were you folks expecting a boom lift to be delivered?”

RoS: “Yes, they are delivering it tomorrow morning.”

Brian: “Well, it’s here - and they left it on the street next to a No Parking sign.”

RoS: (Eek!) - “Really?  We’ll be right there!”

Like I said, not everything can go exactly as planned, but soon enough, everything arrived and in good condition.

Our staging area was set with:

LG Solar Panels

Enphase Micro-inverters

Unirac Solarmount (Evolution) racking parts

And lots of wire!

Transformation

Our first main task on the ground, now that everything was at hand, was to install our transformer.  This project required a transformer to step-down the voltage from the utility service (480 volts, three-phase) to the voltage that would be used by our micro-inverters (208 volts, three-phase).

Setting the Stage

Our transformer was a 700 lb beast that had to be installed on a concrete pad (that we had to pour) in the equipment storage area on the East side of the building.  To secure the transformer to the pad, we would imbed bolts into the pad and then maneurver the transformer on top of the bolts and anchor it with washers and nuts.  Two key challenges there - first was to guarantee that our bolts were precisely positioned in the pad since the transformer gave us very little margin for error.  Second was to get the transformer in place on top of the bolts without damaging them.

We solved the first problem by drilling into the existing concrete and securing our bolts into the ground with heavy duty anchors - as you see here with the framework for the pad surrounding them.

Then, when we were ready to fill in the form with concrete, we added some framing at the top to try and keep the bolts as plumb as possible, as you see here:

The Big (Not So) Easy

That took care of problem number one, but what to do about problem number two? Now that the pad was dry, the challenge became getting our transformer into place.

Our solution would make any student of ancient cultures proud - we crafted a wooden platform over the pad and slid the transformer from its pallet onto the platform.  Then we lifted each edge, one at a time, and placed blocks of wood under each corner.  That allowed us to remove the platform and then begin lowering the transformer over the bolts by carefully removing a block at each corner.

As we removed each block, the transformer came closer to the bolts protruding from the pad.  We could push the transformer - gently - so that it aligned with the bolts.  Ultimately, the last block was removed and the result was a complete success with just the right amount of angst along the way!

But as you can see, we really didn’t have much margin for error!

The Art of Conduit

In addition to our transformer, there were several other pieces of gear that had to be mounted on the ground including a 200 Amp sub-panel, two disconnect switches and a performance meter.  Linking them all together is the conduit through which our conductors would be pulled.

Pasadena requires rigid metal conduit (instead of EMT) to be used for solar power systems wherever it is accessible on the outside of a building.  That offers some additional safety, but it comes at a cost - especially given that we were using 1.25″ conduit for most of our runs.  Rigid conduit of that dimension is heavy and cannot be bent by hand.  Instead, a motorized pipe bender was the order of the day - and it took some really skilled craftsman named Don and Josh to get our conduit in place and looking good.

It really is an art, as much as a science, and when done with care and precision, the result is quite appealing!

Pulling it Together

Our final ground-based task was to pull the conductors through the conduits.  Our longest pull was 245′ - not quite a football field, but close!  Moreover, that longest pull had multiple bends as we routed the conduit to make it as invisible from the ground as possible.  (To complete the task of making the conduit “disappear” to the greatest extent possible, the client painted the conduit to match the walls and the trim!)

At the end of a very long, drizzly Saturday, we were rewarded with having our conductors fully in place from the utility disconnect switch and performance meter socket:

… to our disconnect switch adjacent to the transformer:

Our penultimate installment will take you to the roof where the real action takes place.  So buckle in, the next chapter isn’t for the faint of heart!

Assembling the Necessary Materials

The permit process addresses an entirely different need than does the rebate application.  The permit process is intended to guarantee that the proposed system, as designed, satifsfies all applicable codes and standards.  In theory, once you have successfully pulled the permit, the inspection process should simply be a matter of showing the inspector that you built the system as it was approved when you pulled the permit.

It looks conventional enough!

This project presented one signficant challenge - the actual attachment of the system supports to the roof.  While the roof looked conventional enough, that was not a wooden truss underneath those shingles.  To the contrary, our roof was built from a 20 gauge “Type B” steel deck with two layers of 5/8″ plywood, followed by 3″ of solid foam insulation, followed by 3/4″ of plywood to which the roofing materials themselves - membrane, felt and shingles - were attached.  So the question arose: what would be a sufficient way to attach our standoffs to this roof to provide the requisite resistance to wind loads - the effect of which had recently been demonstrated in Pasadena in such a disastrous fashion?

Unirac Fastfoot Attachment

To help answer that question we turned to the structural engineer (SE) who had originally done the load calcuations for our building.  Could we use a “FastFoot” and simply put multiple screws into the wooden decking materials?  Surely with enough screws - the FastFoot will allow for up to eight - we could reach the required pull-out resistance.  Unfortunately, that wouldn’t work since the engineer could not guarantee the manner  by which the plywood materials were secured to the underlying steel deck.  In other words, while we could be sure that our array would remain attached to the plywood, we couldn’t be sure that the plywood would remain attached to the building!  Images of Wizard of Oz roofs flying through the air filled my mind - clearly we would need another way!

The engineer suggested that we could use carriage bolts that ran all the way through the steel roof and were bolted together on the back side.  Certainly such an approach would guarantee that our array and the roofing materials stayed connected, and indeed, you would have to separate the steel deck from the steel framework of the building for that method to fail.  Unfortunately, that wouldn’t work either since there was no way to access the back side of the roof in order to complete the connection.

“Nine-Inch Nails” Meet 8-Inch Screws!

There was one other approach - a company by the name of Triangle Fasteners sells some very strong, very long, self-tapping screws (called “Concealor screws“) that could drill their way into the steel deck and provide us with the required pull-out resistance. The bad news - our distributors only sold screws up to 7″ long - and that would not be long enough to guarantee that our screws made it through the decking. A call to the manufacturer revealed that in fact, they did make 8″ screws, they even made 9″ screws!  Excellent!  We now had a solution that our SE could bless.  It was time to go pull our permits.

Fear and Loathing at the Permit Center

Anyone who has ever pulled a permit knows the combination of emotions that you encounter upon entering the building: fear that something you haven’t considered will suddenly become A Really Big Deal, loathing for the interminable waiting, and of course, the pain of paying for it all.  Dentists’ waiting rooms tend to be cheerier places.

Pasadena’s permit center is certainly better than most: it is a comfortable old building across the street from the beautiful City Hall.  They have a clever scheduling system that routes you among the different windows: Building and Safety, Zoning, Historical Preservation (very big in Pasadena but not a factor for solar projects), Fire, Permit Processing and, last but certainly not least, the Cashier.  A solar project applicant must navigate their paperwork through every one of those windows before exiting with your Grail - a stamped set of plans and a bright Yellow permit folder where inspection sign-offs will be recorded.

First stop - Building and Safety.

Building and Safety

The building and safety folks are responsible for reviewing your plans for conformity with state and local codes and standards - a really important task.  First, however, you have to speak with someone who knows what you are showing them and on our first trip to the permit center, no such person could be found!  The gentleman behind the B&S desk was very polite, and you could tell that it pained him to inform us that after our thirty minute wait, he couldn’t help us.  Moreover, none of the people who “understood solar” were available - we would have to come back tomorrow.

Tomorrow dawned cloudy but we were determined to press forward.  This time our 35 minute wait was rewarded with an appearance before someone who was prepared to pass judgment on our plans!  We walked him through each of our sixteen 24″ x 36″ pages, explaining as we went exactly what we were doing and where the answers to his questions could be found.

All seemed fine, but then he started throwing us some curves.

Our SE had done his calculations for a basic wind speed of 85 mph - the same wind speed we had always used for load calculations in Pasadena.

“No,” said the man behind the desk, “You have to use 100 mph.”

“Really?  Since when?”

“Since the windstorm in Pasadena at the end of November,” we were told. (Never mind that the wind speed never reached 85 mph in Pasadena, let along 100 mph, during that terrible event.)

“Really?  Where was that published?”

“It wasn’t,” he conceded, but simply told us that we needed to revise our calculations for 100 mph or he wouldn’t approve them.  That meant another iteration with our SE and another trip back to the permit center.

Now the good news here is that we were certain that our system would easily handle 100 mph winds (or 120 mph, for that matter) so this change in policy did not pose a danger to the project going forward.  But changing the basic wind speed for an area from 85 to 100 mph is something of a big deal and will add to the expense of many projects that need permitting.  Shouldn’t there be a more public process before such a change is implemented?

The other curve sent our way was really just odd.

We did a detailed drawing showing our attachment method as it penetrated the various layers of roofing materials and made contact with the steel deck beneath.  We drew that straight up on the page and included multiple elevations  in our sixteen pages that showed the pitch of the roof and indicated that the array was installed on top of our attachment method, parallel to the roof.

“Not good enough,” we were told.

“Why?  What’s missing?”

“You need to show the attachment at the slope of the roof.”

“Really?  We show you the slope of the roof, we gave you the detail of how the attachment connects to the roof and we told you that the array is parallel to the roof.  How is that not sufficient?”

“You need to add a drawing that shows the array attachment and which reflects the slope of the roof.”

“Really?  So what you want is for me to rotate the image of our attachment 13° to reflect how it will be pitched on the roof?”

“Yes.”

Sigh.  Ok, back to the drawing board (or more accurately, the computer screen).

Fortunately, our SE was able to redo his calculations in short order.  And not surprisingly, it was also pretty easy to take our attachment image and rotate it.  We printed up the revised plans and headed back to the permit center.

Surprise - there was yet another person behind the counter this time.  Whereas his predecessor seemed to be actively looking for little things to complain about, this fellow could not have been more helpful. He looked at our revised load calculations - veryifying that they had been done for 100 mph and that the SE had concluded that all was well - and then proceeded to stamp our plans.  (I had pointed out our added, rotated drawing, but it was clear that he wasn’t interested in that at all.)  After he stamped our plans, he then took them himself to the zoning and historical preservation desks and secured those sign-offs as well! Wow!  He saved us an hour of waiting in those queues and he seemed genuinely helpful and concerned.  What a pleasant contrast!  We were well on our way with just one real substantive hurdle remaining - the Fire department.

Fire

The California State Fire Marshall developed a set of guidelines that provide guidance as to how fire departments should permit and inspect solar installations.  The guidelines call for space to be set aside for pathways around the array and for venting of smoke in case of a fire.  The guidelines call for different restrictions based on the size and shape of the roof and whether it is a residential or commercial building.

(While the document from the Fire Marshall is labeled “guidelines", most localities seem to treat it as gospel.  Even more curious, the guidelines clearly say that they are just that, guidelines that do not have the force of law until a local jurisdiction passes an ordinance adopting the guidelines as regulations.  We have yet to see such an ordinance.)

Our building plan included a three-foot set aside around both sides of the array and from the ridge, and was augmented by automatic smoke ventillation devices already built into the roof.  But that was not sufficient - the fire official wanted us to provide a four-foot clearance on all three sides.  Yet another trip to the computer.

We returned with our revised drawing, showing four feet of clearance as requested.  But now there was another concern - the same fire official now wanted us to open a walkway in the middle of the array.  (We already had access paths for potential maintenance, but they were not wide enough to be considered a walkway.)  No matter that our roof was not at all like the flat roof with parapet shown in the guidelines, we still needed to provide a walkway.  There was only one way to do that - take out a column of panels.  Together we X-ed out seven panels and thereby created a walkway.  The fire official was now satisfied - she signed off on our plans.

Done

And just like that, we were done.  Well, not quite - there was still the little matter of paying for all this.  Here we made out surprisingly well.  Unlike some cities that gouge solar applicants (and you know who you are!), Pasadena’s fees were quite reasonable.  Total cost for our now 52.25kW solar project?  $732.  Sadly, we know of residential projects one tenth that size in other cities where the permit fees have exceeded $1,000!  (But that’s a story for another day.)

Altogether, it took us four separate trips to the permit center, three plan revisions, and a little over $900 in expenses to secure our permit.

Now all we needed to do was get the materials to the job site on time, and complete the installation in the two week window that we had to mesh with the School’s schedule.  The real work was about to begin…

The Rebate Application

The rebates being offered from Pasadena Water & Power (PWP) for this non-profit project were scheduled to step-down on December 1, 2011.  Indeed, this was a substantial rebate reduction - 26% - such that failure to secure the existing rebate rates would have amounted to a hit of tens of thousands of dollars for our client.  And PWP had made it very clear - unless applications were 100% complete and correct, they would be rejected and when resubmitted would be subject to the reduced rebate rates.  Clearly the pressure was on to get this right the first time!

The application package consisted of eight parts - most of which were straight-forward, but a couple required substantial work to guarantee that the application as submitted would be acceptable the first time.  Here are the parts that went into the rebate application: 1) Signed Rebate Application (PWP’s form, signed by client and Run on Sun under penalty of perjury!); 2) Single Line Diagram for the electrical components of the system (more on this below); 3) Site Plan; 4) CSI Report (as produced by the California Solar Initiative’s rebate calculator); 5) Shading Analysis (i.e., a Solar Pathfinder report to support the shading values used to create the CSI Report); 6) PWP’s Net Metering Agreement (executed by the client); PWP’s Net Metering Surplus Compensation form (for AB 920 compliance); and 8) Installation Contract between the client and Run on Sun.  Also, since this was a non-profit client, proof of non-profit status was also required.

Shading Analysis & CSI Report

PWP wisely requires the submission of a shading analysis in addition to the output from the CSI rebate calculator.  Since the amount of shading at the site directly impacts the performance of the system - and hence the CSI AC Watts of the system (or the predicted annual energy output in the case of a PBI rebate) - it really doesn’t make sense for a utility to simply trust that the installer is telling the truth about shading.

The output from the Solar Pathfinder proves that the shading numbers claimed are the shading values present at the site.

Site Plan

The site plan needed for the rebate application is a much simpler plan than what will ultimately be required for the permit, really only requiring an indication of where the various components of the system will be relative to the overall site.   However, our system occupies three different areas of the PAC: the roof where the array itself is located, a ground-level storage area where our step-up transformer will be, and the utility switchgear, located on the far north end of the building.  Thus our site plan included drawings for each location.

The array drawing showed the three sub-arrays and the clear space allocated for fire department access.  Each sub-array consisted of three branch circuits, each of which was “center-tapped” to reduce the voltage drop in the associated branch circuits.  Each branch circuit landed at a sub-array service panel which then fed a master “solar-only” sub-panel in the transformer area.

The transformer area drawing detailed the conduits coming down off the roof (one each from each sub-array sub-panel), the master sub-panel which feeds our step-up transformer (to change the 208 VAC three-phase power coming from the roof to 480 VAC three-phase supplied by the utility service) and then a safety disconnect switch located adjacent to the transformer.  From the safety switch a fourth conduit carries the required conductors back across the roof to our service switchgear area.

The service panel area drawing showed the placement of our lockable PV AC Disconnect, the associated performance meter, and our circuit breaker for the system located in the existing service switchgear.

Single Line Diagram

Our most significant deliverable in the rebate application packet was the single line diagram (SLD) for the electrical circuits.   Since this diagram shows how all of the electrical components of the power generating system interconnect - including the tie into the utility’s grid - we knew that this would be the most closely scrutinized piece of the submission.  To be sure, PWP has a generic SLD that installers can use (in fact, we helped develop it!) but that drawing does not cover the use of Enphase Micro-inverters which we were featuring on this job, nor does it allow for a step-up transformer.

Fortunately, we had developed a very flexible SLD format from prior jobs that we could readily adapt for this project.  However, before we submitted it to PWP, we forwarded it to the application engineers at Enphase Energy to make sure that they were comfortable with what we had designed.  Enphase was more than accomodating - given our tight time frame they bumped us to the front of their engineering review queue and came back promplty with the good news - the design was good as we had drawn it and no revisions were needed.  Of course, that was no guarantee that the utility would agree, but it is always nice to have a P.E. on your side!

Included in the SLD preparation was a complete set of voltage drop calculations.  This was complicated by the fact that we had 9 different branch circuits, three different sub-panels and two different operating voltages!  Good design calls for limiting total voltage drop to less than 3%.  To keep our worst case scenario within that limitation (covering the branch circuit farthest from the main “solar-only” sub-panel) we ended up with 4 different gauge sizes of conductors at different legs of the run: #12 in the branch circuit cables (supplied by Enphase), #8 from branch circuit jbox to sub-array sub-panel, #2 from sub-panel to main “solar-only” sub-panel, #3/0 from that sub-panel to the transformer and then #2 from the transformer back to the service equipment area.  (One change that occurred during the install process increased the length of some of these runs - and that necessitated some wire size changes to insure that we stayed comfortably below our 3% limit.  Those will be discussed in future episodes.)

One Big Present

All of those documents, plus pages and pages of cut sheets describing all of the key products being used, were then submitted to PWP - one day before the deadline!  With no margin for error, our submission had to be perfect.  Thankfully, it was - PWP gave us their official blessing to proceed three weeks later, just three days before Christmas.  One big present, indeed.

Our first hurdle successfully surmounted, it was time to prepare for the most nerve wracking part of the process - pulling the permits!  That’s the subject of our next installment - stay tuned!

The California Public Utilities Commission (CPUC) is deciding how much customer-owned renewable energy is allowed to get the bill saving benefits of net metering.  This statewide clean energy credit program has empowered over 100,000 solar energy systems to be installed on homes, businesses, schools, libraries and other buildings around the state.

The Commission has proposed allowing for more homeowner solar– and some utilities are trying their best to restrict continued access to it.

Click here to tell the CPUC that you support their preliminary decision to give more Californians access to solar net metering: I support net metering!

Here is the full text of LADWP’s press release issued today:

FOR IMMEDIATE RELEASE    DATE: April 17, 2012 3:38:42 PM PDT

Board of Water and Power Commissioners Approve LADWP Solar Feed-in-Tariff Demonstration Program

New Program Expands Ability to Tap into City’s Abundant Sunshine

The Los Angeles Department of Water and Power (LADWP) Board of Water and Power Commissioners today approved the creation of a Solar Feed-in Tariff (FiT) Demonstration Program for 10 megawatts (MW) of solar power, further opening up solar power generation to a broad array of customers and solar developers in Los Angeles.

A workshop is scheduled tonight at LADWP’s downtown headquarters to ensure that interested participants understand how the new program will work. Additional workshops are slated for Thursday afternoon at the Century Plaza Towers and April 24 in Bishop for those interested in developing solar in LADWP’s Owens Valley service area.

The FiT Demonstration Program will allow solar power to be developed by third-parties and then sold to LADWP for distribution on the city’s power grid. Once the initial 10 MW of solar has been deployed, LADWP will roll out a program of between 75 MW and 150 MW based on information learned from the demonstration phase, rate support and stakeholder input.

“We are blessed with sunshine nearly year-round here in Los Angeles so starting this program has been a priority for this Board and the Department,” said Board President Thomas S. Sayles. “Tapping into local solar power is the right approach for Los Angeles as we increase green energy in our power mix and work to comply with state mandates that set renewable energy levels.”

The Los Angeles City Council previously gave its blessing of LADWP’s FiT Demonstration Program by adopting an ordinance that gives LADWP’s Board of Water and Power Commissioners administrative discretion to enter into the many long-term standard contracts that previously required a more lengthy process of Council approval. The action also permits the Board to delegate that authority to LADWP General Manager Ronald O. Nichols. Mayor Antonio Villaraigosa signed the ordinance last Thursday.

The LADWP Board today approved the FiT Demonstration Program Guidelines, along with the standard purchase agreement and interconnection agreement that will be required of FiT projects. The Board’s action also delegated authority for General Manager Nichols to approve the FiT contracts.

The FiT Demonstration Program will allow third-parties to generate solar from small and medium-scale projects, and sell the power to LADWP for distribution on the electric grid. Projects will be selected based on competitive bids, which will determine a set contract price per kilowatt-hour, for up to 20 years. The program will set aside a prescribed amount of smaller and larger solar generation projects.

The new program will complement LADWP’s existing Solar Incentive Program, an incentive-based, net-meter program. Through the net-meter program, customers displace energy that would otherwise be supplied by LADWP and receive a credit on their bill for solar generation that exceeds the amount of energy they consume.

“In addition to residential customers, the FiT program will open up local solar development to rooftop real estate, such as warehouses, multi-family developments and other large rooftop structures beyond those that currently benefit from our Solar Incentive Program,” said Aram Benyamin, Senior Assistant General Manager, LADWP Power System.

“The fact that we’ve received a tremendous amount of interest from folks wanting to attend the workshops confirms just how vital this program is for Los Angeles,” Mr. Benyamin added.

In developing the FiT Demonstration Program, LADWP incorporated key feedback received during a series of public workshops over the past year. LADWP also took from lessons learned by other national and international FiT programs.

The FiT workshops are designed for interested persons and prospective bidders to explain the bidding and contracting process prior to accepting project proposals/bids in May. Dates and locations of the workshops are as follows:

Downtown Los Angeles
Tuesday, April 17 – 6:30 p.m.
LADWP Headquarters
111 North Hope Street
A-Level Auditorium
Los Angeles, CA 90012

West Los Angeles
Thursday, April 19 – 2:00 p.m.
Century Plaza Towers
2049 Century Park East
Concourse Level, Conference Room A/B
Los Angeles, CA 90067
RSVP closed - meeting at capacity

Owens Valley
Tuesday, April 24, 2012 - 6:30 p.m.
First United Methodist Church
205 North Fowler Street
Bishop, CA 93514
RSVP Owens Valley Workshop

For additional information on solar power in the City of Los Angeles, please click the following links:

The Department’s solar webpage, www.LADWP.com/solar
More about the FiT program, www.LADWP.com/FiT

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(Interestingly, PBI rebates are not declining which would mean that for clients who can tolerate waiting to receive their rebate payments over five years, they will do much better than clients needing the lump-sum EPBB rebate after June 1.)

UPDATE - Turns out that after we wrote this, PWP decided to also slash its PBI rebates for residential customers from the current $0.302/kWh down to $0.212/kWh effective June 1. Did our previous suggestion (now in strike-out type above) contribute to this policy change?

Unaffected are commercial and government/non-profit rebate rates, which were most recently reduced as of December 1, 2011.

We always experience a crush of inquiries about possible solar projects in advance of a major rebate reduction like this one and potential clients are encouraged to act quickly to avoid the hassle of trying to get necessary paperwork completed at the last minute.

To access the webinar, click here: LADWP FiT Workshop Webinar.

It is official - LADWP is formally launching its Feed-in Tariff Demo Program with a series of workshops to be held over the next two weeks.

We have written at length about the work that has been done to develop a feed-in tariff program at LADWP.  Last week the Los Angeles City Council approved the demonstration phase of the program and the workshops next week are designed to give potential participants the information that they will need to submit program applications.  We will be attending the first of these meetings and we will report back afterwards.

Here’s the schedule and contact information:

Tuesday, April 17, 2012

 6:30 p.m.

LADWP Headquarters

111 North Hope Street

A-Level Auditorium

Los Angeles, CA 90012

RSVP Downtown LA Area Workshop

(200 guests maximum)

Thursday, April 19, 2012

 2:00 p.m.

Century Plaza Towers

2049 Century Park East

Concourse Level

Conference Room A/B

Los Angeles, CA  90067

RSVP Century City Workshop

(100 guests maximum)

Tuesday, April 24, 2012

 6:30 p.m.

United Methodist Church

205 North Fowler Street

Bishop, CA 93514

RSVP Owens Valley Area Workshop

Will you be attending?  Let us know your thoughts in the comments.

Well here it is, Easter Sunday, and we are pleased to report that the promise has been fulfilled.  Here’s the view from roughly that same spot today:

Needless to say, a project of this size does not happen overnight, nor is it the effort of any one individual.  So, over the next couple of weeks, we will be bringing you a multi-part series documenting how this project came together.  The series will culminate in another Run on Sun video featuring client interviews and even some observations from the students of Westridge about what this means to them.

Spring is indeed a time for new beginnings - and some successful endings!  We look forward to sharing this adventure with you and we welcome your comments.

Paul Douglas is a Minnesota meteorologist and, as he puts it, “I am a moderate Republican, fiscally conservative; a fan of small government, accountability, self-empowerment, and sound science.  I am not a climate scientist.  I’m a meteorologist, and the weather maps I’m staring at are making me uncomfortable.  No, you’re not imagining it: we’ve clicked into a new and almost foreign weather pattern.”

Douglas then goes on to layout the reasons why he believes that climate change is real - and no, he doesn’t rely upon Al Gore.  But neither is he swayed by Bill O’Reilly or talk radio.  Instead, he relies upon the scientists who have studied this for thirty years and who have gone from, again in his words, “concerned [to] bordering on apoplectic.”

It is really a wonderful piece - well written and well-reasoned.  Here is one more (extended) quote:

Climate Change: The Ultimate Test for Capitalism. Let The Markets Work

I’m an entrepreneur. The eight Minnesota companies I’ve created ultimately employed hundreds of professionals. Where others see chronic problems I see opportunity. One of my companies is Smart Energy, with a new level of wind forecast accuracy for global wind farms. Last summer, in response to the most severe two years since 1816, my partners and I launched a new, national cable weather channel (“WeatherNation Television”) – to keep Americans updated with 24/7 storm reports. “Global Weirding” has arrived. Why bother? Because it’s the right thing to do. And because going green will generate green. As in profits. We won’t drill our way out of this challenge; we’ll innovate our way into a new, lower-carbon energy paradigm. Something we’re pretty good at. Professional skeptics will hold up Solyndra as a reason why this will never work. For the sake of our nation’s future – don’t believe them.

“The Mother of All Opportunities”: Turning America Into The Silicon Valley of Energy

We can figure this out. Frankly, we won’t have a choice. But I’m a naïve optimist. We can reinvent America, leaving us more competitive in the 21st century, launching thousands of new, carbon-free energy companies – supplementing, and someday surpassing anything we can expeditiously suck out of the ground and burn, accelerating an already-warming planet. We don’t have to bury our heads in Saudi sand – we’ll never “frack” our way to a sustainable future. It’s time for a New Energy Paradigm. There’s no silver bullet. But there’s plenty of (green) buckshot, if we aim high and point America in the right direction.

As one of those “new, carbon-free energy companies,” at Run on Sun we completely agree with this reasoning.  And frankly, we don’t understand how one can claim to be conservative but not be concerned about conserving the environment upon which everything else in life is based.  Thankfully, some like Douglas totally get it and we can only hope that by speaking up - and having their statements repeated by others - they will encourage other true conservatives to step forward and acknowledge the simple truth - you don’t have to be a liberal to believe in climate change.

You owe it to yourself to give the entire piece a read.  Here’s the link: A Republican Meteorologist: Acknowledging Climate Science Doesn’t Make You a Liberal.

The tariffs that were imposed this past week were quite modest - far lower than some had predicted - and range from 2.9% to 4.73%.  Given that some had predicted tariffs of as much as 50%, these modest penalties were generally greeted with sighs of relief in the industry.

At Run on Sun, the majority of the solar panels that we specifiy are unaffected by the tariff decision since Sanyo panels (Japan and Mexico) and and LG panels (South Korea) are not manufactured in China.  Of our featured products, only Suntech panels were affected, and they at the lowest rate imposed.

The vast majority of our clients will not see any impact from this decision.  Still, anything that can potentially drive up the price of solar equipment at a time of diminishing rebates and tax incentives (such as the expiration of the section 1603 grant program) is a cause for concern.  As this decision established, prices for solar panels have been falling worldwide because of a stronger manufacturing supply chain combined with a weakening demand in some markets, particularly in Europe, and not because the Chinese government was massively subsidizing its solar manufacturers as some had claimed.

Anyone who has ever been to a solar trade show has seen hundreds of Chinese panel manufacturers sitting in small booths, waiting for potential customers.  (Indeed, the New York Times reported that there are presently more than 700 solar panel manufacturers in China!)  The vast majority of those products are third-tier, cut-rate products that are used by companies who only care about the lowest possible cost - not reliability, performance, or safety.  In solar, like everything else, you get what you pay for.  If clients demand quality, they will get it - whether from high-quality domestic producers or top-tier importers like Sanyo, or LG, or Suntech.

We are proud of all of the products that we feature - including Suntech solar panels - because we believe that they offer great quality for our clients.  But for those who only care about finding the cheapest dollar per watt solution, they will continue to put undue pressure on quality manufacturers around the globe - whether in the US or China.  Consumer demand for quality is the ultimate way to improve this situation - and that means educating consumers as to what quality means in this market - but tariffs are not the answer.

Having figured out what went wrong with the old installation, it was time to make it right! This post - and the video that follows - will introduce you to our homeowner and to the folks from Unirac who stepped in to help us get this homeowner back online producing clean, reliable and safe solar power!

It was great to work with the folks at Unirac and we are very touched by the sentiments expressed by Rachel.

Of course, that is always our goal - to leave our clients feeling that we have done more than what was expected, more than just what the job called for us to do.  It is the little extra steps taken that not only insure a happy client, but a system that we can point to with pride.

Here’s an image of the finished system:

And here are some details - check out these clamps, especially the end clamp:

Unirac Solarmount Evolution Mid-Clamp between two Sanyo solar panels

Unirac Solarmount Evolution End-Clamp holding a Sanyo solar panel

It is easy to see why Unirac calls this Solarmount Evolution because this product really has moved beyond what was available just a year ago.  With gear like this, we are confident that these clamps will never allow a panel to separate from the rails - “come loose from its moorings” to quote Rachel - and thus, we feel that this is the safest system we have ever installed.  This will be our new standard going forward.  Great job, Unirac, and thanks!

In the first installment of this series, we looked at the solar system of Mrs. C which had been entirely destroyed in Pasadena’s terrible windstorm.  Given that the racking itself was still securely attached to the roof, the critical question was: Why had this system failed?

As we began to dismantle the now scrap system, we examined the panels, the railing and the bolts that had held the system together.  This array had been crafted out of a hybrid combination of unistrut steel parts - that created a 26° tilt - with Unirac rails and clamps.  The array was on a flat roof on the northern section of the house - which meant that it was completely exposed to the full force of the wind with no other part of the roof to interfere with the flow.  Under such circumstances, any mistake in the installation would be put to a very extreme test.

Our examination revealed that the forces on the panels had been so intense that the railing itself had failed.

This is how an end-clamp normally appears when holding a panel to the rail. You can see how the edge of the clamp grips the panel, the base of the clamp rests on the rail, and the bolt coming up from the rail is tightened down to hold the panel securely.

Now look at this end-clamp as we found it - away from the panel it was supposed to hold and only barely connected to the rail. (Other clamps were ripped from the rails altogether.)

The portion of the clamp at the bottom right of the picture was supposed to grip the side of the panel but now it is gripping nothing.

Let’s take a closer look at this point of failure:

The t-bolt is made of stainless steel, whereas the rail in which it sits is aluminum.  Under the extreme forces that occurred that night, the uplift from the panels caused the t-bolt to chew its way completely through the rail!  You can also see how the bottom of the end-clamp had started to deface the top of the rail, as well as the scratch marks created by the solar panel (to the right of the rail failure.)

That answered the question of what had failed, but it didn’t answer the question of why.  After all, when properly installed, that rail combination is designed to withstand forces far beyond what were experienced that night.  In the days following the windstorm, Run on Sun inspected all of our projects that used this same combination of bolts and rails and none of them showed the slightest sign of failure.  So why was this installation different?

We brought this system failure to the attention of Unirac and Pasadena Water and Power.  We wanted Unirac’s sense of why this had failed and we wanted PWP to encourage its solar customers to have their systems inspected for possible signs of unexpected wear.

We got a great response from Unirac, who took this issue very seriously and helped us diagnose what had ultimately caused the failure.  One possibility was that the last person that worked on those panels might have over-torqued the bolts.  Unirac provides specific torque settings for the clamps used to hold the panels to the rails.  Those setting have been tested to assure the maximum strength without running the risk of damaging the parts.  But not all installers use a torque wrench when they are tightening their panels to the rails.  Without a torque wrench, an installer has to tighten by feel alone, and a careless - or harried - installer could easily over-tighten the bolts which could weaken the rail and lead to a possible failure.  Did that happen here?  We will never know.

And yet, a different culprit ultimately emerged which almost certainly played a major role in the failure of this system.  Indeed, it was right in front of us all along (you can see it if you look closely at the first picture in this post), but we didn’t notice it until we were starting to take the damaged panels off the roof.

Did you figure it out?  Take a look at this photo:

Right there in the middle of the photo is a nut on the end of a bolt - these two panels were bolted together!  Indeed, the installer had bolted all of the panels together into pairs.  Why was that done?  No idea - but the impact of that decision was profound.  Now each panel - as “seen” by the rails - was twice as wide as normal. For each row of 10 panels, the number of mid-clamps available to resist the uplift force dropped from 18 (two each in the nine gaps between panels) to just 8.  As the wind force increased to historic proportions, the loading simply exceeded the down-force that those 8 mid-clamps could provide.  The result was a smashed solar power system with panels flung across the roof.

A Tale of Two Solar Installers and an Insurance Company

We were pleased to have discerned why Mrs. C’s system had failed and she was eager to get it replaced.  She contacted her insurance company which contacted us and asked us to provide an estimate to repair the system.  Given that there was lots of old gear to be removed and hauled away, in addition to installing what was pretty much an entirely new replacement system on a tilt-up rack, we gave them what we considered a fair bid  that worked out to ~ $7/Watt.  Not surprisingly, the insurance company informed us that since the amount was so large, they would need to get a second bid.  Which they did - and that bid came back $11,000 more than ours! What’s more, they charged $250 just to provide the bid!

Mind you, we proposed using Sanyo panels and Enphase micro-inverters for this project - which is the absolute top-of-the line gear that we could have chosen.  So how on earth does a competitor look at the same project and propose a system price nearly twice what we did? One can only assume that they saw that an insurance company would be paying for this and so they decided to go for a jackpot.  To which we have just one response: PATHETIC!

Coming Up - the Happy Ending as Run on Sun Makes it Right!  (With a little help from our friends!)

Happily, the insurance company stepped up to the plate and Mrs. C awarded us the contract to “repair” her system.  The folks from Unirac chipped in and agreed to provide the replacement racking for the project.  In the final installment in this series, we will tell you about how that system came together and we will even have a totally cool video to share.  Stay tuned!

We already discussed the first of these solar repair projects; today’s story is the first installment of a three-part series about our work on the second, and it has a bit of history so we will start there.

In 2008, Run on Sun had a contract with our local utility, Pasadena Water & Power, to go out to some of the existing solar power systems throughout the city and assess their performance.  We had developed a methodology that incorporated the temperature of the solar panels, the actual amount of solar radiation present in the plane of the panels and actual voltage and current measurements to determine what percentage of the predicted system output was actually being realized.  It was a great project for us (and for PWP) as it not only gave us lots of opportunities to learn from the glaring errors others had made in putting together solar power systems, but it also let us speak with dozens of system owners who, without exception, were passionate about having gone solar.

Which brought us to the home of Mrs. C.  Her solar power system had been designed and installed by her late husband back in 2001.  From the ground it looked solid enough:

We found out from Mrs. C that her system had gone through two inverters already - the now infamous Xantrex GT 3.0 model - and that the entire array had to be removed once to repair roof leaks.  Still, Mrs. C was very proud of her system which had been designed and originally built by her late husband.  Our testing from the ground showed that the system was operating normally for its age and Mrs. C was greatly relieved to learn that since the last solar company that had worked on the system - replacing the second failed inverter in 2004 - had since gone out of business.  We left her with a copy of our assessment and said goodbye.

Fast forward three years to the week following the windstorm when I received a phone call from Mrs. C, telling me that her system had been damaged during the storm.  I asked her if her panels were still on the roof and she said they were, but that they had “come loose from their moorings” and could I please come out to take a look.  I agreed to do so - and was simply shocked by what I found:

The solar panels that in 2008 had appeared to be so securely fastened to their “moorings” had been ripped loose and scattered across the racking.

As the wind came from the northeast, it had peeled the panels away from the railing (which was still firmly in place) and left the panels in a twisted heap of broken glass, silicon and metal.

As with our other windstorm damaged system, it is extremely fortunate that this damage occurred at night when no power was being generated.

That this system was totally destroyed was beyond dispute.  But how exactly had it failed?  The framework that was assembled to hold the panels in place - an unwarranted, yet not uncommon, mixture of unistrut and Unirac rails on Unirac standoffs - was still firmly anchored to the roof.  So why had the panels torn free?  When properly assembled, the Unirac rails are engineered to withstand wind speeds well beyond what was measured in Pasadena that night - so why had this gone so badly south (literally)?

In our next installment we will find the answer to that question and also learn a little bit about how two different solar companies approached working with the insurance company to resolve this claim. (It is a cautionary tale, to say the least.)  Finally, we will conclude this series with a happy ending - complete with interviews and a cool time-lapse view of the new system being installed thanks to the support of Unirac.  Stay tuned!

The SolarBlend tiles (an image of which is shown above) were manufactured and distributed throughout the United States from October 2009 through March of 2011.  The recalled model numbers include:

• STP050D-5/ZCB (brown)
• STP050D-5/ZCF (terra cotta) and
• STP050D-5/ZCG (gray).

Consumers who believe that they have such tiles installed should contact their installer or Suntech directly at (888) 770-7122 between 5 a.m. and 4 p.m. PT, Monday through Friday or email to: services@suntech-power.com.

The Recall Alert suggests that there are only 300 or so installations of these tiles.  We decided to see what the CSI data would tell us about these products and who installed them.  Here are our results:

The good news here is that these products only account for a very tiny fraction of solar installs during the recall period.  The bad news is that - at least from a web search - it appears that many of these companies are no longer in business - meaning affected home owners will need to contact Suntech directly.

Run on Sun has never used these products - not because of a fear of potential fires, but simply because the roof tile product has a lower efficiency meaning that you need a larger roof area to provide the same amount of power.  You can check out our preferred solar products at our solar products page.

The suit alleges that the five employees - all of whom previously worked for SunPower before being employed by SolarCity - illegally accessed SunPower computers and stole tens of thousands of computer files.  Indeed, it appears from the documents filed with the court, that SunPower has some fairly extensive forensic evidence of the theft, noting the specific types of USB drives that were used to acquire the stolen files and where and when the downloading occurred.  Assuming that evidence holds up to review by computer experts, it could be pretty damning against the five former employees.

Far less clear, however, is whether there is actually any case to be made against SolarCity.  Having lititgated a number of corporate espionage cases (in one of my earlier lifetimes), I know that it can be difficult to connect the dots between the illicit conduct of the former employees and their new employer.  It is the classic question of “What did SolarCity know, and when did it know it?“  Interestingly, SolarCity put out a statement regarding the suit, but did not expressly deny any of the allegations. Instead, it simply noted that:

SolarCity upholds high standards in operational integrity for itself and its employees. SolarCity takes trade secret issues very seriously and we will ensure that we act in accordance with the law.

(Curiously, that statement does not appear on the SolarCity website’s list of press releases, but you can find the entirety of the statement here.)

It is unfortunate to see two well-known solar companies involved in such a dispute, but it was probably inevitable.  Indeed, the history of Silicon Valley is replete with similar lawsuits and as the financial stakes in the solar industry increase, the potential for such actions will also increase.

Of course, the public is unlikely to ever learn the whole truth behind this story - as common as such lawsuits are, public trials are a rarity.  Factor in SolarCity’s rumored desire to go forward with an IPO this year and the likelihood of a settlement increases dramatically.

We will keep you posted as new developments unfold.