Power factor boost: Make sure to maximize revenue in design, data monitoring

inverer power factor

Remember the Seinfeld episode where the rental car company took Jerry’s reservation, but still didn’t have a car for him“You know how to take the reservation, you just don’t know how to hold the reservation. And that’s really the most important part: the holding. Anybody can just take them.”

That’s a way to think about monitoring performance of a solar site. (Just go with me here) Anyone can just monitor data, but the key is knowing what to do with it – being proactive versus reactive. Here’s two considerations for being proactive involving inverter selection.

Factoring for power factor

Utility-scale sites often come with reactive power requirements, which usually means reducing the real power produced to provide reactive power support. Because of this, be sure to check the power factor or Max AC Output Power of inverters you spec.

“When you reduce active power, you’re not getting paid at what you designed the system for,” says Sarah Ozga, product manager at CPS America. “We want customers to get paid for the nameplate rating of the inverter and not get dinged for reactive power requirements.”

CPS inverters, for example, come with kVA overhead and will supply 100 percent active power while accommodating reactive power requirements. For a 100-kW inverter, this is listed as 100 kW / 111 kVA at PF greater than 0.9 and 125 kW / 132 kVA at PF greater than 0.95 for the 125-kW inverter. Let’s play out some scenarios.


“If we had a 100 kW/111 kVA or our 125 kW/132 kVA rated inverter and the utility company said we need to run at .95 power factor (PF) we could do this without sacrificing real power (kW),” Ozga says. “For example, if we have enough PV power coming in from the array to produce at max capability on the 125kW/132kVA inverter we would be producing 125kW active power and the apparent power would be 132kVA.”

But what if this overhead wasn’t built into the inverters? If the inverter’s apparent power was capped at 125 kVA, at 0.95 power factor (PF), it would be producing 118.75 kW active power. This is about 7 kW less than it could be producing if it had overhead capacity.

“That’s not real significant for a single inverter but these inverters are generally installed in a multi-MW system,” Ozga notes. “So for a 10 MW site that would be 570 kW, which is a significant loss of power.”

Maximize revenue

Over the life of a system, discovering issues early and fixing them quickly can make a huge difference in site performance and, what everyone is here for, revenue. If an inverter goes down or performance is low, make sure the manufacturer is able to remotely troubleshoot, push updates or make setting changes to the inverters without needing to visit the site, like CPS Ameri-ca can within its Flex Gateway. This gets the inverters back up and performing as it should fast-er and cheaper.

“Whether a company is managing its own data or is using a third party monitoring package it is important for the data to be actively monitored,” Ozga says. “That doesn’t mean someone needs to sit in front a computer watching production graphs all day. Set up automated emails/SMS for alarms or warnings for each site that is managed. These warnings could alert you when an inverter is not performing as expected.”

We will also dive into this in MUCH greater detail in this upcoming free webinar. Sign up here.

Utility-Scale String Design

Wed, Jun 20, 2018 2:00 PM EDT

When designing a large site one consideration is String or Central. Both have well defined benefits. Historically, the large utility-scale sites have mainly relied upon central inverters. Now a third option, the Virtual Central, is paving the way for string inverters into this space. In this webinar, we will discuss the benefits and disadvantages to both the distributed and centralized string architectures and how the design choice affects installers, developers and site owners. Sign up here.

— Solar Builder magazine

Solar carport developers find low-cost opportunity despite the tariffs

Quest Renewables

“But whatever the reason [for the tariff], the consequences probably won’t be severe. The solar revolution is happening so fast that the tariff will make little difference.” — Noah Smith, Bloomberg.

This quote from Bloomberg is certainly true, but the immediate effect has unquestionably caused some projects that were “on the bubble” financially to be canceled, and significantly reduced the profitability of others. The uncertainty of the tariff came when the industry didn’t know the final amounts. This made financing difficult because no one knew what projects were ultimately going to cost. In reality, the module tariff turned out to be a relatively small increase of about $.15 per watt to the cost of solar projects.

There are multiple ways to save more than enough money to make up for the tariff increase. Installation labor efficiencies and civil engineering work provide opportunities to increase efficiency so much so that if these levers are pulled, solar installers will be able to decrease the total cost of their projects even with the module tariff in place.

At Quest Renewables, we are attacking the module tariff by improving installation efficiency in solar carports in four ways:

1. Reducing installation labor costs by 50 percent by assembling our systems on the ground, and then lifting completely assembled carports by crane. The cost of the crane is only about 5% of the traditional cost of labor, so the crane pays off by a lot.

2. Using standard pre-engineered array sizes and configurations. This enables us to optimize and reduce foundation count, so that our products have half the number of foundations of systems of comparable size. Not only does this reduce the overall cost of foundations, but it also reduces the overall project variability costs caused by uncertain soil conditions.

Quest Renewables

3. Leveraging local labor crews to reduce installation costs. When our customers manage the project labor or provide their own crews, they gain two big advantages. First, they eliminate markup from construction. Second, they use a skilled local crew that can install our standard systems over and over and become more efficient over time.

4. Increasing project size by covering parking spaces and drive aisles enables a system to deliver up to twice as many watts as a T-canopy. Our customers can install more watts on a project allowing them to spread fixed costs across more wattage which improves profit margins.

With these cost saving efficiencies in place, developers and installers alike are certainly in a great position to continue growing the solar carport space. As utilities realize the unique ability of distributed generation to reduce myriad grid upgrade costs, several states are supporting solar canopy projects. Quest is seeing a lot of new projects coming to fruition in states like New Jersey, Massachusetts, and soon New York. In the coming months, Massachusetts will announce the final version of the state’s SMART Program. The current version of the program includes favorable incentives for carports.

What about the steel tariff?

With the module tariff proving to be manageable, albeit a little uncomfortable, now we bring focus to the steel tariff.

“President Donald Trump’s foray into trade protectionism heartened a handful of manufacturers in a deeply challenged industry but upset a much larger group of thriving downstream businesses that say they will lose sales and shed employees during what should be a boom time.” — James Rainey, NBC News.

Although Quest’s products are made with 100 percent American steel, the price of all steel is going up, foreign and domestic. The unique design of Quest’s canopies enables Quest to help customers overcome the increased cost from the rising price of steel. Quest is partnering with customers to ensure that the industry can succeed in this environment by not raising prices on our products in response to the steel tariff. Further, foundation reduction in projects using QuadPod solar canopies will overcome the increased cost of steel.

The industry is breathing a sigh of relief because the tariffs, both module and steel, have proved to be more of a speed bump and not a stop sign for project development. The bulk of the harm done by the tariffs was the difficulty to get projects financed, but financing can be found. According to the Department of Energy’s website, it remains “committed to leveraging America’s abundant solar energy resources — driving research, manufacturing and market solutions to support widespread expansion of the nation’s solar market.” Even so, the solar industry needs to remain vigilant in its’ advocacy to make sure that solar is here to stay.

Finn Findley is CEO of Quest Renewables.

— Solar Builder magazine

Saving costs with large-scale string inverter design, part 1

CPS 60kW Ground AZ

String inverters are now a staple of the commercial and industrial and small utility-scale segments, which was solely the domain of central inverters once upon a time. The trend started about six years ago when string inverters souped-up to 1,000 volts and developers and EPCs saw the value in chasing the higher efficiencies, multiple MPPTs and greater energy harvest rewards provided by distributed string architecture.

But two years ago, the shift to an even lower cost 1,500-volt architecture started, and the math shifted right back to central inverters because 1,500-volt three-phase string inverters weren’t available.

“A year and a half ago, string inverters were about 8 cents per watt and central plus combiners were 6 cents per watt, so that seemed cheaper,” says Ed Heacox, GM, CPS America. “Central plus combiner boxes seemed cheaper.”


But string inverters have souped-up again, and that economic story has flipped again. Instead of string vs. central, the discussion is changing to distributed string vs. “virtual centralized” string. In the Solar Builder Inverter Buyer’s Guide this year, you’ll see a bunch of string inverters in the 100 to 125 kW range, and those that aren’t rated at 1,500 volts will be soon. The cost is now closer to 5 to 6 cents per watt, with central inverters still sitting at a cost per watt similar to two years ago. That aforementioned 3 to 5 MW cap is about to be a thing of the past. CPS has its 1,500-volt product coming out in June and says it is rocketing past that 3 to 5 MW sweet spot.

“We are having regular discussions about projects 20 to 30 MW in size now when before, that was extremely rare,” says Sarah J. Ozga, product manager North America for CPS America. This could possibly go as high as 100 MW in the not-too-distant future.

Now, all costs being equal, some will still gravitate to central inverters because of operations and maintenance preferences: Lots of walking or driving all over to address each O&M issue spread across a 30 MW site, and god help you if the site was mapped incorrectly. String inverters can feel unwieldy if you’re unprepared for them.

“A lot of time O&M depends on the developer or EPC’s personal experience with inverter reliability,” Heacox says. “Those who had a lot of downtime on central, are for sure leaning to string. But those who have had great experiences don’t feel they need to change for projects larger than 5 MW. But some see that if they go down the string path, there is more interchangeability among suppliers with relatively similar products — and the engineering and workload need for swapping out string inverters is a lot easier than reengineering a 3 MW power station.”

In part 2, we will look at two different string solutions that offer the lowest cost path and meet any O&M preferences you may have. We will also dive into this in MUCH greater detail in this upcoming free webinar. Sign up here.

Utility-Scale String Design

Wed, Jun 20, 2018 2:00 PM EDT

When designing a large site one consideration is String or Central. Both have well defined benefits. Historically, the large utility-scale sites have mainly relied upon central inverters. Now a third option, the Virtual Central, is paving the way for string inverters into this space. In this webinar, we will discuss the benefits and disadvantages to both the distributed and centralized string architectures and how the design choice affects installers, developers and site owners. Sign up here.

— Solar Builder magazine

Crowd Sourced: Details on a plan for drastic cost reductions, wide deployment of community-scale solar

community scale solar

Community solar to this point has been more of a riddle than a segment. Generally referring to shared solar development that accepts capital from and provides output credit to subscribers and other investors, the potential of the community solar segment is massive. Removing roof and space constraints from the equation, the Smart Electric Power Alliance (SEPA) puts the potential market for community solar from a floor of around 3 million households to more than 12 million, depending on program design and marketing.

Ah, program design. Here comes the riddle. How do you design a solution that taps into that potential when often no single stakeholder sees enough benefit to drive project development? Barriers surrounding cost, access and demand continue to drag on the community solar sector’s overall growth when simpler, proven PV models are already established.

More and more answers to the riddle are emerging though, and community solar is moving on a steeper upward trajectory. In 2017, a year in which both utility-scale and residential segments decreased, for the first time since 2010, community solar boomed.

“Minnesota headlined a banner year for community solar, with more megawatts installed in that state than total U.S. community solar installations in all of 2016,” said Austin Perea, GTM Research solar analyst and co-author of the U.S. Solar Market Insights Report for 2017. “We expect community solar to diversify geographically in 2018, with Maryland and New York to be key growth markets for the sub-segment beginning this year.”

Zooming out to the broader community-scale solar (CSS) segment, defined as 0.5- to 10-MW projects that include co-op, municipal and IOU rate-based projects along with large C&I and shared solar gardens, reveals even more potential. In fact, we might be on the verge of an Occam’s razor model for CSS that has a five-year roadmap to 50 cents per watt total installed cost — a cost level that could drive the potential for community solar and other mid-sized solar installations to 30 GW installed by 2020.

RELATED: Solving C&I Solar: How boutique financing is growing this underserved solar segment

What the what?

This concept starts with the Rocky Mountain Institute (RMI), a renewable energy think tank located in Boulder, Colo. RMI believes CSS sits in a sweet spot in the market and represents an economic opportunity of as much as $30 billion. CSS systems are large enough to access low costs through economies of scale and small enough to efficiently interconnect into distribution systems. The potential is in projects between 500 kW and 10 MW in size.
“We believe the medium-size market is poised to accelerate very rapidly,” says Jules Kortenhorst, CEO of RMI. “It has significant advantages in that it can be placed close to electricity load, doesn’t need as much space, can go on top of parking lots or be more in the middle of communities. So, therefore the opportunity is very significant.”

In a new report, The Progress and Potential for Community-Scale Solar, RMI offers new approaches to help drive additional development and buyer adoption of this locally sourced resource. The report relays data and insights from RMI’s work supporting co-op solar procurement in Colorado, New Mexico and Texas, and focuses particularly on the CSS opportunity for rural electric cooperatives. The eyebrow raiser inside the report is RMI’s research that shows a path to reduce CSS costs by 40 percent and enable a 30-GW CSS market — the equivalent of about 50 average-sized coal plants — by 2020.

It’s not all theory, either. In November 2017, RMI gathered 35 diverse stakeholders from across the solar industry to devise a collaborative concept that would realize this vision.

“In demonstrating the ability today to already deliver clean energy at or below 5 cents per kWh on the distribution grid, CSS can be the killer app for cooperatives, supplying a cost-competitive, locally sourced, clean energy resource that also provides resilience benefits to their members,” says Thomas Koch Blank, a principal at RMI. “Seizing on the additional cost-reduction pathways that we identify will help ensure buyers have access to the best CSS offerings.”

The outcome of that November summit was a clear understanding and identification of one path to reduce CSS costs. In full, the plan involves working with manufacturers, communities, utilities and solar developers to build a more transparent, standardized approach that expands market access for CSS installations — functioning, in a sense, as its own community. Here’s how it will happen.

Supply side streamline

The plan starts with the rollout of one or more regionalized assembly plants of modular mounting systems. The goal here would be standardization and factory-assembled units that can be delivered and installed quickly.

“What we really needed to get people to rethink is how solar currently gets solar installed in the field, where all of the components from a diverse set of sources arrive on the site and then everything gets assembled, often at height, which makes it difficult to assemble,” Kortenhorst says. “We needed to get people to think of completely different ways of doing this — a whole system design effort to industrialize the process of assembly, and the big idea that came out is creating a standardized unit that fits on the bed of a flat-bed truck and is easily transported into the field.”

Taken together, RMI estimates a reduction of 20 cents per watt from these regionalized factories. RMI issued a request for information (RFI) to get one or more of them built, and while they are in motion and close to announcing, as of presstime, no specifics were official. Kortenhorst is 100 percent confident one will be in place and deployable by the end of 2018.

“Our concern is to make sure that this solution becomes commercially available at scale and cost effective as quickly as possible,” he says.

RELATED: Solar wealth gap: New reports show size of low-income solar market, solutions to boost installs

Demand side driver

While the supply side is crucial, many of these system cost reductions might have happened organically from the manufacturer side, and those innovations aren’t quite as impactful without the second piece of the puzzle: a reduction in soft costs. Easier said than done, especially with complex community solar deals.
To achieve this, RMI is collaborating with co-ops, municipal utilities and buyer aggregations to build more buyer-side efficiencies.

“The biggest opportunity, in our view, is to help co-ops and municipal utilities realize if you put an RFP out and bring together the site, interconnection, the permitting, the financing and then you go to tender, you are likely to get a much more competitive offer from the developer because you have significantly reduced the risk,” Kortenhorst says.

Putting it that way makes it sound so simple, and it’s not a stretch to expect a municipality to do such legwork at the outset. The more traditional way is kind of silly, really, with the RFP process requiring the developer to take responsibility for permitting and land acquisition pieces that the municipality is in a better position to organize.

“As a municipality, you may know of the appropriate site, you may be able to work with the utility to get a clear commitment on the interconnect, you may be able to deliver the permits upfront and thereby reduce the time and risk for the developer,” Kortenhorst says. “As a collective, as a co-op, you can drive the price down very aggressively.”

These organizations are also best suited for driving awareness and buy-in. Based on market research involving 2,001 residential utility customers and 252 small business customers across the country, a SEPA initiative funded by the U.S. Department of Energy found that while 59 percent of customers were interested in solar in general, only 20 percent were familiar with community solar. In some states, policy dictates that community solar is for the most part a non-utility offer, but in most states, utilities play a leadership role in acquiring the solar resource and offering it as a customer program. According to SEPA, some 170 utilities nationwide currently offer or are planning to offer community solar.

RMI estimates that municipal partners following this blueprint will drive another 30 cents per watt installed out of the cost. Add that to the supply side and voila, a 50 percent per watt install cost reduction.

Current status

Lastly, the concept needs champions at the development, EPC level. Seeds are already being planted.

“We’ve invested roughly $1.5 billion in solar in the last 18 months. If there are cost reduction opportunities that come up, we are willing and able to be there as an interested customer,” says Jenya Meydbray, VP of solar technology, Cypress Creek. “Whatever gets us the lowest cost trajectory while maintaining reliability is the way to go. The product can be pulled through very quickly if the value proposition is compelling enough and the validation is there.”

RMI has been working on this for more than a year, but the timing looks fortuitous in the wake of the #TrumpTariffs news. At worst, just one piece of that two-step cost reduction would more than counter the artificial inflation in module prices.

“This administration has put tariffs on solar panels that amount to 12 cents per watt installed in the first year, and this therefore elegantly aims to overcome that step back in cost effectiveness of community solar,” Kortenhorst says.

A new 3-MW solar project in New Mexico will soon be selling its output below 4.5 cents per kilowatt-hour, a price RMI believes is the lowest reported contract for distributed PV in the United States. RMI provided project analysis and supported the competitive procurement process for Otero County Electric Cooperative Inc.

“This is a solar size that does not exist at competitive rates currently and could really be a breakthrough for all types of energy buyers, for grid resilience and for the opportunity to explore different ownership models at a scale that has real impact,” says Kassie Rohrbach, associate director, Ready for 100 Campaign, Sierra Club. “The applicability of being able to find a small acreage area in any urban or rural place, the siting possibilities, open up the opportunity to bring solar to scale in places we haven’t been able to before.”

— Solar Builder magazine

Attack the Tariff launches in June to highlight solar industry ideas, innovations

Projections show decreases in solar installations and job growth for the next four years because of the #TrumpTariffs. The good news is: the solar industry thrives at squashing projections, and we at Solar Builder would like to help in that effort.

Attack the solar tariff

Starting in June, we are launching a mini-series online called Attack the Tariff. Over 30 days, Solar Builder is teaming with several sponsors to present 30 ideas for solar industry contractors, EPCs and developers to improve solar project economics and reduce costs.

Each day on solarbuildermag.com, we will post a new tip, idea, best practice, financial concept, product solution, etc., that will address PV system installation, development, logistics and soft costs — everything beyond the price of modules.

We have much of this lined up and ready to go, but we’d love for this to inspire even more conversation and ideas. So, feel free to submit your own Attack the Tariff post to ccrowell@benjaminmedia.com for consideration in the series.

If you are already a subscriber to our e-newsletter, you’ll start receiving the Attack the Tariff e-news in addition to your regular weekly edition, but if not, you’ll want to head to here to sign up. Just look for the logo above.

— Solar Builder magazine