We couldn’t suppress an ironic smile when we read the headline, Los Angeles [County] Assembling Solar Action Committee to Address PV Challenges. “Physician, heal thy self,” immediately popped into mind given the propensity of LA County to create those very challenges! Here’s our take on what LA County is up to.
According to the article at Solar Industry magazine’s website:
The Los Angeles County Department of Public Works (DPW) has created a Solar Energy Action Committee (SEAC) to facilitate an expansion of residential and commercial solar photovoltaic power in the region.
According to the DPW, there are many challenges that are preventing the state and local governments in California from meeting aggressive renewable energy goals. Many of these challenges relate to the interpretation and application of codes and regulations in both the private and public sectors. Furthermore, solar technology is evolving so quickly and with such variety that jurisdictions are having problems determining how to apply codes and standards.
Oh heavens, don’t get me started! Well, ok, too late.
How about this for just one example (from many): we recently completed a commercial project in LA County. When we submitted our single line drawing to DPW (prepared and stamped by a licensed electrical engineer), it came back with nine “corrections". Ultimately we were able to demonstrate to DPW that seven of the nine did not even relate to our project since they all were focused on either the DC side of a PV system (and our Enphase-based system had no such components) or they related to the size of a non-existent load-side breaker. It took three iterations to whittle those bogus objections away, until we got down to the final nut: bonding.
Now one of the two remaining concerns was legit - DPW wanted our plans to call out two grounding rods. Fine, easy, done. But the remaining sticking point was a killer. We were using Everest Solar racking, which has UL 2703 listed splices for its rails that bond those splices together.
DPW refused to accept the splices for bonding, requiring bonding jumpers (like you see in the picture) across each splice. Which begs the question: what is the point of manufacturers building products to meet a national spec, if a local jurisdiction like DPW can simply say, “not in my backyard?”
Everest also had at the time an approved mid-clamp with WEEB solution for bonding between modules. In Pasadena, just across the street, that combination would have been approved without comment. But not DPW, which rejected the WEEB solution, requiring us to run a continuous #6 wire from module to module - all 246 of them!
Now when you talk to the folks at DPW they insist that this is all about safety. To which we respond - rubbish! What is the failure scenario that we are actually protecting against? In theory, you are trying to ensure that no metallic part becomes energized without a pathway to ground. That way if there is a fault, and someone touches the affected metal surface, current will not flow through them to ground (causing injury) because it has a lower resistance path to ground via the system bonding.
That is certainly a noble goal, but did the changes DPW insisted upon improve safety in the real world? This array is on a free standing structure, 14′ above the ground so it isn’t likely that someone would ever casually come in contact with a metal surface to begin with. But even if they did, what would that failure mode have to be? On the one panel that happens to develop a fault, a minimum of two, and in most cases four, WEEB clips would have to fail at the same time! Call me cynical, but I find that a highly unlikely event.
In contrast, the economic consequence of what had to be done to placate DPW was very real, adding thousands of dollars in parts and labor to the cost of the project, for an at best marginal improvement in safety.
So we are all for DPW taking steps to eliminate “PV challenges", but we would suggest they look at cleaning up their own act as the proper place to start.
Intersolar North America 2015 (IS) kicks off this week in San Francisco, and as we have for the past several years, Run on Sun will be there to learn, to mingle with the rest of the Solar Tribe, and yes, to party! Here’s our preview (with more to come after the show).
One of the biggest attractions of IS, the exhibition floor is crammed with every solar-related product and service imaginable (and some you wouldn’t have believed until seen!). Here are some of the things we are actively looking for as we roam the floor (and it really is a “we” this year as Laurel and Josh will be attending as well!)
We have been writing about, and longing for, viable energy storage solutions for as long as we have been attending IS. While the hype around storage has only grown exponentially since, the number of viable products still remains depressingly thin. Will this be the show when that finally changes?
Number one on our cross-your-fingers list is the previously announced, but not yet available, storage offering from Enphase Energy. Given that we have a whole lot of Enphase systems in the field, and a client-base that is rapidly shifting to time-of-use rates, the Enphase product, if it is a product, would be huge. While the timing would surely be right, our anticipation is amped-up by the knowledge that Enphase will have a booth at IS (a first for them, to our knowledge).
Interestingly, neither SolarCity nor Tesla is listed among the exhibitors as of this morning - I guess we won’t be seeing any Powerwalls on display.
Beyond storage, manufacturers are always touting their bigger, better products at the show and this year should be no different. Of particular interest in that regard is the potential release of a slew of new, larger module options coming from our favorite solar panel maker, LG. We have seen the hints on this front for sometime now as the CEC approved list of LG modules includes units as large as 325 Watts - compared to the LG 305’s which are presently the largest thing we are seeing in distribution. So will we now have multiple options for higher efficiency, higher output panels from LG? And if so, when and at what cost?
Meanwhile, Enphase appears poised to announce a new microinverter product, the S280 (just in time to pair with those higher power LG modules?), as it too now appears on the CEC list.
We know that we have clients eagerly awaiting these developments - watch this space!
Racking solutions continue to be an area where the cleverness of the design rarely survives the realities of the roof. We are constantly exploring new approaches for difficult problems such as viable ballasted systems (that will be accepted by AHJ’s like LA City and County) and structure suppliers for the growing interest in carports, pergolas and the like. While we have worked with a number of companies in this area, we are still on a quest for solutions that not only look good on paper, but that our installers can grow to love. We will be prowling the floor of IS with that as our number one must have.
We should note, however, that we remain quite pleased with Everest Solar as our pitched roof solution, and that view was enhanced by the long-awaited release of their UL-2703 listed end and mid-clamps. The inspectors who have looked at that system on the roof have been quite impressed with it, as are we.
It wouldn’t be IS without the opportunity to reconnect with old friends and, hopefully, make some new ones amidst the Solar Tribe. After all, these are people who work every day to make the world a better, cleaner, more sustainable place. They are a great bunch of folks and we are honored to be counted among ‘em!
First up is the Tweetup, hosted once again by solar celeb, Tor - @SolarFred - Valenza, with backing from @Enphase, @RECSolar, and @Grid. This has turned into an annual, and eagerly anticipated event, and we thank in advance Solar Fred and friends for making this happen.
Then comes Summerfest, a huge gathering of folks with lots of different types of food and drink and great views of the downtown San Francisco skyline. Summerfest is a great place to exchange views of what was on display on the exhibition floor, and to plot strategy for the next day, as in, “Did you see what they had over at the XYZ booth? It was amazing you have to check it out!”
But it is Wednesday night that really crowns the show. Starting with the great afterparty/pre-SBOB party thrown by Impress Labs - thanks to Solar Curator Tom Cheyney for hooking us up - we are able to get warmed up for the main event - the Solar Battle of the Bands! For the first time ever we are heading into the show knowing where are ducats are coming from - thanks to Jessica over at Solar Power World for the connection!
It is going to be a busy week, and we look forward to learning a lot. Look for our recap of the show next week!
A little over three years ago (my how time flies), we installed a 52kW solar project at the Westridge School for Girls, here in Pasadena. At the time, the project got a fair amount of attention (including an award from the City), was featured in a video (watch it here), and was the lead story in Enphase Energy’s Summer 2012 Newsletter.
Three years down the road, the folks at Enphase decided to circle back and check-in to see how the Westridge project had performed over the years - both in terms of saving money for the school, as well as being incorporated into the curriculum (another key goal of the project).
The article, titled — Solar on the Roof, Power in the Classroom — details how the Westridge Solar system has outperformed the modeled performance, producing 105% of the expected yield. That overproduction actually benefits the school twice: most obviously by lowering the bills that much more, but secondarily, by providing a larger than expected performance-based rebate payment.
Beyond that, however, the system has also proved to be an effective teaching tool, allowing Westridge students to analyze the copious amounts of data provided by the Enphase microinverters through the Enlighten, cloud-based data reporting service. One science class, for example, was able to discover how analyzing that data could detect the occurrence of a partial solar eclipse.
We are very proud of our partnership with Westridge and we look forward to doing another project with them in the near future.
Likewise, we are grateful for partners like Enphase Energy who are as committed to producing long term solutions as we are. That is one powerful pairing!
Recently a potential client was asking us about an oddity in their Pasadena Water and Power (PWP) electric bill. PWP has a tiered rate structure, but the most visible component of that tiering, the Distribution charge, steps up above 350 kWh of usage in any one month, but it steps down above 750! Which lead us to the question, are PWP’s electric rates regressive?
PWP’s Residential rate structure, like many utility tariffs, is a model of complexity. On your bill there are a number of obvious charges, and a few that are not so obvious. The obvious ones are on the right-hand-side of the bill and include a Customer charge, a Distribution charge, a Transmission charge, and an Energy charge. (The not-so-obvious charges include those related to public benefit programs and paying to put power lines underground.)
All of these obvious charges are tied to the customer’s usage, but only one, the Distribution charge, is tiered. At or below 350 kWh of usage per month, the customer pays just 1.5¢/kWh. Between 351 and 750 kWh of usage the Distribution charge increases dramatically all the way up to 11.65¢/kWh, nearly an eight-fold increase! Ok, the whole point of a tiered rate structure is to discourage higher use by making you pay more as your usage increases. But PWP’s rate then does something truly odd - above 750 kWh/month the rate comes down, dropping from 11.65¢/kWh to just 8.5¢/kWh! What sort of an incentive is that?
That rate design is certainly counter-intuitive, to say the least, but is it regressive? In other words, is there a point at which a large residential user ends up paying less per kWh than does someone who uses less? To find out, we modeled daily usage from 10 kWh/day all the way up to 60 kWh/day. As a reference, a typical Run on Sun client in PWP’s service area averages around 25 kWh/day. Since the Transmission and Energy charges are adjusted higher in the summer months, we broke out the overall rates seasonally as well.
Here are our results (click for larger):
The blue line is the winter rate and the orange is summer. If you use a tiny amount of energy you will pay between sixteen and seventeen cents per kWh, with rates rising sharply until you get to 25 kWh/day. Beyond that, the rate of growth flattens out markedly, but it never dips down. (That is true even if you carry the analysis all the way out to 200 kWh/day!)
Contrast this with the SCE Domestic rate - that is a truly aggressively progressive rate structure with energy charges of 14.5¢/kWh for those using within the smallest (baseline) tier of energy, going all the way up to 30.8¢/kWh for energy used in the fourth tier, which kicks in for monthly usage above approximately 900 kWh.
So no, PWP’s Residential rate is not regressive, but by flattening out the rate for usage above 25 kWh/day, it sends at best a mixed signal if the utility is trying to encourage its customers to reduce their usage.
How does this relate to solar? Well, if your usage is above 20 kWh/day you are spending at least 20¢/kWh whereas the cost of a solar power system will be less than half of that! So yes, in PWP territory - and particularly while they still have rebates in place - installing solar will still pay you big dividends.
So, you are considering a solar power system for your home or business… and why not, given the myriad of social, environmental and economic benefits! But how do you know if your roof is a good candidate? This is one of the top questions to consider carefully before investing in solar.
The size of your solar system is dependent on your usage needs and the amount you want to offset. However, it is not uncommon to find homes and businesses which are “footprint-constrained” - meaning their system size is limited by the space available.
A few things to keep in mind as you look at your roof and ponder how big is big enough… First, while there are many different solar panels they are typically the same size. Run on Sun uses LG panels which are about 65 x 40 inches and can be placed in either a portrait or landscape layout. Panel energy ratings vary, 285-315 watt panels are currently available from LG. For an average home (5 kW) that means you would need around 16-18 panels to offset the bulk of your electricity.
Another limitation is that fire code requires three feet of clear space from all ridges. If you have an irregular shaped roof with many valleys and peaks it may make the layout very challenging. Given that the panels are rectangular and racking is mounted parallel to the roof, rectangular spaces are ideal. However, the 3-foot rule does not apply to uninhabited spaces such as garages and carports making them good options if your home lacks the perfect solar roof.
Shading from trees, tall buildings, chimneys, or even parapets on flat roofs can significantly degrade the energy output from solar panels. Sometimes all that needs to be done is a generous trimming of that tree that’s gotten a little out of control over the years. Other times it means you really won’t get your money’s worth out of a solar system. But, if the shade elements are few and only during a short time each day, your roof may still be a viable candidate.
If this is the case be sure to talk to your solar contractor about inverters. We have written a great deal about the advantages of “microinverters” in handling shaded roofs, particularly those made by Enphase Energy. “String inverters” on the other hand would be a bad choice as the entire system would degrade when any single panel is shaded.
This may be the most important and frequently overlooked question to consider when researching if solar is right for you. Part of what makes solar a great investment is the 25+ year lifetime of the system. But if you have to re-roof during that time there are added costs to remove and re-install the system. If you are planning to re-roof during the lifetime of your solar array be sure you select components, such as the racking system, from companies that…A. will still be around 15-25 years later, and B. will be able to provide compatible replacement parts when pieces are lost during removal and re-installation. Avoid newer companies testing out “state-of-the-art” racking systems and cheap companies banking on the solar boom alone.
For this reason we always ask owners the age of their roof. In southern California, a roof over ten years old should get a makeover before installing solar. If you are unsure of the condition, it is a good idea to have a professional roofer take a look and give you an expert opinion. Sometimes solar contractors can offer this as part of their free assessment. (Run on Sun works with a very reliable roofer who is happy to take a look at any roof in question!) If the roof still has some life left in it but not enough to outlast the solar system you could re-roof only the area where the solar array will cover and plan to do the rest later. An added benefit is that the solar panels will actually protect your roof from the elements, helping it to last longer.
Unfortunately, you will likely be able to find someone willing to put solar on your roof even if it isn’t a good candidate. But if they aren’t discussing the above issues with you, then red flags should be flying! To ensure you get the best investment possible, do your research, take a good long look at your roof, and discuss all of your concerns with your solar contractor.
«climate change» cpuc enphase «enphase energy» «feed-in tariff» fit gwp «jim jenal» ladwp «net metering» pg&e pwp «run on sun» sce seia «solar power» «solar rebates» solarcity usc «westridge school for girls»