Shave and a rate cut: How solar + storage solutions are shaving peaks, saving big bucks

shave and a rate cut

Shaving the peaks off commercial and industrial (C&I) electric bills is the top revenue stream for energy storage systems, and given the trend in increasing utility charges for time-of-use consumption, peak shaving can pay for a system in as little as three years, system providers say.

Just how high the peaks need to be in order to justify the investment in an energy storage system varies with geography and jurisdiction, but in general, demand charges of $15 to $20/kW or more are clear candidates, says John Merritt, the director of applications engineering at Ideal Power.

“The vast majority of converters we sold for storage systems in the past year went to California, with eight out of 10 used in applications for peak shaving,” Merritt says. “With the California incentives and the federal tax break, C&I customers can get a payback in as little as three years and in other cases in four or five years.”

A $15/kW demand charge threshold for economic feasibility also necessitates a 50-kW monthly usage level within the peak charge range, suggests Ellen Howe, VP of marketing and corporate development at JLM Energy, based in Rocklin, Calif. Her colleague, Nate Newsom, VP of enterprise sales, says, “Commercial entities that spend 3 percent or more of their monthly budget on electricity and/or experience 40 percent to 50 percent [higher than normal] demand charges typically are a good fit for energy storage.”

The C&I market is virtually untapped

Analyzing the C&I market for energy storage usefulness, the National Renewable Energy Laboratory in Golden, Colo., started with the assumption that demand charges of $15/kW or higher typically result in favorable economics for energy storage projects. Then, counting rooftops, NREL determined that “Of the nearly 18 million commercial utility customers in the United States, almost 5 million of them are exposed to, or could be exposed to demand charges of $15/kW or higher that would indicate cost-effective opportunities for energy storage.”

While not every potential C&I customer will bite the bullet for a stand-alone energy storage system, aggregation through community solar projects, or virtual power plants (VPP), is increasingly an opportunity.

Tesla is among the storage providers that is now active in community solar, with a high-profile October rollout of its commercial-scale Powerpack system at Puerto Rico’s Hospital del Niño, a children’s hospital in San Juan. As of April, Tesla had provided commercial Powerpacks and residential-scale Powerwalls to over 600 locations, with the count rising daily. The company has been quoted stating a goal of providing up to 40 percent of the island’s power storage needs via community solar system build-outs.

One new provider of VPP services is solar converter maker SolarEdge Technologies, which in May announced a solution for grid services and virtual power plants, thanks to its recent acquisition of Gamatronic Electronic Industries. The solution includes grid services of aggregative control and data reporting that enable the pooling of PV and storage in the cloud for the creation of VPPs.

demand charge example

Fig 1. Example of the steep savings achieved just through shaving peak demand.

Storage + trackers (plus pumps, plus…)

A relatively new storage configuration for C&I customers is the use of storage with solar trackers, like the 1.1-MW project at the Maharishi University of Management in Fairfield, Iowa. This project will use the NEXTracker NX Flow integrated solar-plus-storage system, in combination with an Ideal Power SunDial Plus converter and a Vanadium flow battery. The project is NEXTracker’s first large-scale installation of the NX Flow solution.

Another budding C&I application for storage is with water authorities, which can typically generate energy from solar for less than it costs to pump water uphill for a discharge to a generator turbine. The San Diego County Water Authority, for example, won $1 million from the California Public Utilities Commission to install intelligent energy storage that will tap the energy from solar panels already installed at the SDWA’s Twin Oaks Valley Water Treatment Plant.

The SDWA energy storage project, being operated by Santa Clara-based ENGIE, is expected to save an estimated $100,000 per year by storing low-cost power for later use during high-demand periods for peak shaving. The storage will help the plant cope with its highest energy use period, during peak afternoon hours. ENGIE acquired majority control of energy storage management software leader Green Charge in 2016.

RELATED: Solar + Sharing: Connect groups of homeowners, renters via one solar + storage network 

The backbone of storage: data crunching

It is tricky enough to coordinate a community solar or VPP operation, providing power on demand to participants and storing the rest until the utility calls for help. But knowing precisely what times, and advising customers as to when it is most optimal to use grid energy, or substitute with storage, is another matter, thanks to U.S. utility rate mayhem.

NREL notes that “There are almost 3,500 electricity providers in the United States, and each one has their own set of tariff sheets, rate structures and pathways for compensating non-utility-owned energy generation.” Add a dynamic dimension of rate evolution arising from rate cases, and it becomes a bit difficult to keep up with when it is most economic to use how much power.

Here the data crunchers enter the fray. Stem, for example, recently launched its Athena analysis product, which uses artificial intelligence to learn, predict and optimize energy in real time. Athena collects data at a rate of 400 megabytes per minute to continually fine-tune its algorithms. The system also has learned from operating systems for over 5 million hours, from processing nearly 200 million data intervals and from running over 35 million project simulations. As a result, the system decides and tells the battery when to store and to discharge power, responds to demand response opportunities and methodically shaves peak utility rates.

Stem has working relationships with eight utilities thus far and expects that number to grow significantly as the company helps shave peak demand, which is costly on both sides of the transformer. Stem has been dispatching batteries into California’s wholesale energy markets where it responded to more than 600 calls from state grid operator CAISO last year, according to the company.

On top of new legislative challenges, the industry has faced high and growing customer acquisition costs over the past few years. According to GTM Research, customer acquisition costs on average now represent a disproportionate 17 percent of the total system cost. This is where a new service from Urjanet, a global leader in utility data aggregation, comes into play. Its new Utility Data for Solar, a data-as-a-service solution that provides on-demand access to residential and commercial energy usage, cost and location data from more than 900 electric utilities in over 15 countries. Urjanet Utility Data for Solar enables a more cost-effective, customized approach to selling solar systems that allows vendors to effectively focus on the needs, requirements and situation of each residential or commercial buyer.

map of demand charges

Fig 2. Here’s where the harshest demand charges are across the U.S., courtesy of NREL.

Storage as a service emerges

When solar leasing became popular, the common knowledge about actual savings from such arrangements was about 15 percent of a residential utility bill, if that. With C&I customers, the savings opportunities are as high as the sky or at least whatever the utility bill looks like pre-storage.

JLM Energy is one of the latest energy storage solution providers that offers financing for energy storage customers through a $25 million project financing fund. The company uses a lease structure to achieve shared savings on a monthly basis for 20 years, with no upfront cost. JLM owns, maintains and guarantees system performance.

Stem has long been financing storage solutions, and now has a $500 million investment pool from which it can draw to finance a project, thanks to a host of private sector investors, including the Ontario Teachers’ Pension Plan.

Wall Street may not have climbed onto the PV wagon when the industry began to mature, but the storage peak-shaving proposition apparently seems as clear and understandable to such investors as the bottom line of the utility bill.

Charles W. Thurston is a freelance writer covering solar energy from Northern California.

— Solar Builder magazine

NEXTracker, First Solar team on 600 MW of Series 6 projects, to feature new ‘error-proof’ panel clamp

NEXTracker First Solar

The NEXTracker mounting solution for the First Solar Series 6 panel features patent-pending panel clamps that company says provides error-proof rail alignment and rapid module installation.

NEXTracker will begin collaborating with First Solar to provide its racking technology for the upcoming Series 6 panel rollout this year. The First Solar engineering procurement construction (EPC) group also selected NEXTracker’s NX Horizon for multiple utility-scale projects in the southwestern United States, totaling 634 MW using the Series 6 module: Rosamond, Calif. (193 MW), Willow, Calif. (129 MW) and Phoebe, Texas (312 MW).

What’s new?

The NEXTracker mounting solution for the First Solar Series 6 panel features patent-pending panel clamps that company says provides error-proof rail alignment and rapid module installation. NEXTracker’s mounting solution can be configured to accommodate a wide range of site conditions that may see wind speeds up to 130 mph, up to a 15% north-south slope, and also high corrosion environments. NEXTracker has further enhanced NX Horizon for future First Solar Series 4 projects, with optimized logistics and cost saving features.

RELATED: How NEXTracker ‘decapitated the duck’ with its new solar-plus-storage tracker design

“With First Solar’s Series 6, they have created an elegant, superior thin film technology, with high efficiency and a beneficial temperature coefficient,” said Dan Shugar, founder and CEO of NEXTracker. “The excellent diffuse light response of First Solar’s photovoltaic cells pairs perfectly with TrueCapture, NEXTracker’s proprietary smart control system, to increase yields in PV power plants.”

“For the past year we’ve invested in partnering with the right suppliers who could complement our Series 6 technology in terms of innovation in system performance,” said Georges Antoun, Chief Commercial Officer of First Solar. “As part of our core ecosystem, NEXTracker is not only the global market share leader in solar tracking technology, but also delivers unparalleled design and customer service. We look forward to more successes together.”

— Solar Builder magazine

Iowa university to install NEXTracker solar+storage power plant

NEXTracker solar storage

Iowa-based Ideal Energy is constructing a 1.1 MW power plant at the Maharishi University of Management (MUM) in Fairfield, Iowa, using the NEXTracker NX Flow integrated solar-plus-storage system. The project will be built on University land and, when completed, it is projected to be one of the largest solar-plus-storage power plants in the state, producing enough energy to cover nearly a third of the University’s annual electricity usage. In addition to those savings, NX Flow will use peak-shaving to significantly reduce MUM’s utility bill during high-demand times.

NX Flow’s energy storage system integrates battery, solar tracker, inverter, and software technologies to improve return on investment for owners of solar power plants. At the core of the system lies an advanced vanadium flow battery (VFB), which is DC-coupled with the photovoltaic array. With NX Flow, the battery charges directly off the array, enabling the battery to store “clipped” energy up to its capacity limit. Energy that has been lost to clipping can now be used to generate additional kilowatt-hours of revenue. Ideal Energy will also be installing NEXTracker’s award-winning smart solar tracker, NX Horizon, for decentralized active tracking.

RELATED: Massachusetts’ first community solar plus storage project now operational

“We’re excited to be a part of the solar project serving Maharishi University of Management and working to help further solidify Iowa’s spot on the renewable energy leader board,” said Amy Van Beek, cofounder of Ideal Energy. “When it came time to recommend a solar-and-storage solution, NEXTracker was not only the clear choice with its next-generation technology and trackers, but its customer-first approach is second to none, and the short product delivery lead times on an accelerated schedule were essential. We look forward to furthering Iowa’s promising solar future.”

With 37 percent of Iowa’s electricity coming from wind power, Iowa is no stranger to producing renewable energy. And, according to The Solar Foundation’s 2017 National Solar Jobs census, with an increase of 45 percent of solar jobs in 2017 alone, the state is expanding its clean energy production to include solar energy.

As Iowa has relatively high demand charges (typically above $20/kW), it is an ideal state for solar plus storage, according the National Renewable Energy Laboratory.

— Solar Builder magazine

Podcast: How NEXTracker ‘decapitated the duck’ with its new solar-plus-storage tracker design

solar builder buzz NEXTracker photo

Being the No. 1 tracker worldwide according to GTM Research, I will assume you’ve heard of NEXTracker and its decentralized tracker design by now. What you may not know about is the company’s giant leap into the storage arena with two solutions — NX Drive, a standardized battery enclosure system for generation-plus-storage or stand-alone storage applications, and NX Flow, a modular, integrated solution designed for long duration solar-plus-storage applications.

NX Flow in particular intrigued us – a solution so unique the company worked on and created a new UL standard to test for and prove what it does (more on that below). We stopped by the Fremont, Calif., offices to chat with Chief Technology Officer Alex Au about the concept, maximizing MWh over pure MW, decapitating the duck curve and the effect tariffs might have on all of this.

Be sure to download the full podcast interview below (and subscribe!), but here are three big takeaways.

1. The NEXTracker NX Flow is a 30-kW tracker row with a battery coupled just to that row, making it a modular power plant that achieves a renewable base load. There are two keys to its value proposition. One is the battery.

Au: “Two years ago we started an RFP called ‘Decapitate the Duck’ specifically to address the storage market. We reviewed north of 40 technologies. We had an aggressive demand profile, tested units and agreed to move forward with the Avalon battery — a vanadium flow battery. As of Christmas last year, we were able to pass the point of 10 years worth of cycles. Approximately 1.25 cycles per day, 100 percent depth of discharge. We haven’t been able to detect any degradation. With other batteries there are maintenance cycles and equalization time, but we haven’t had to do any of that either.”

“The Avalon product mates perfectly with one of our 30-kW rows; it is a 6,000 lb unit, can ship completely wet and has actually gone through a burn-in cycle in the factory. That testing and burn-in period means you literally just plug in the DC wires for the modules and then the AC grid. Takes less than an hour and 15 mins to do the full installation with piers and everything.”

2. The second key is the work done with PG&E and UL to create a testing standard that proves the system is only using the grid to power a few electrical components and not charging the battery or sending electrons back into the grid.

Au: “The NEM program, the (self-generation incentive program) SGIP and ITC, have a common theme: If you’re going to participate, you cannot take the energy from the grid and sell it back. You have to have 75 to 100 percent of the power generated from a renewable energy source. To do that, you need meters to show how much of the PV is being produced, and how much is being put on the grid.

“That’s not an integrated solution. You literally have to split everything out and have to put a meter there for added cost. And then to govern that, there is additional labor and time required. We wanted to do everything natively. We took our Self-Powered Controller and put it inside the battery, so we’re talking to the battery and to the inverter, which is on our native SCADA platform.

“Two weeks ago the utilities and PUC came in and said we could start moving forward with this. This is a true milestone for us. We said we will take on the extra burden of creating a power plant – a renewable base load – and we’re going to get it approved by utilities and we’re moving forward with that. We’ve essentially changed the industry.”

3. In the end, NX Drive isn’t necessarily generating more power, but smoothing out production much better over time. But, because of the modularity and the system’s tracking algorithms and data analytic capabilities, more production is possible too.

Au: “You no longer have clipping loss. A lot of guys design DC to AC ratios north of one. In our case, any time you go north of one, it gets stored and could be used in the later part of the day. That’s why we called our RFP ‘Decapitate the Duck’ because the energy is stored and shifted to later times when the head of the duck [curve] would pop up.

“We can go out and apply for an SGIP type program and can put more than 1 MW of PV panels out there because a flow battery actually falls into the fuel cell category. All we care about is nameplate rating. So we have a UL listed inverter with guts that are 30 kW but de-rated to 15 kW. So, instead of 40 tracker rows, we have 60 tracker rows and take a lot more of the energy produced in the day, store it, and then release it later in the day when the sun sets.”

Be sure to listen to the full interview for more on the concept of TrueCapture, what NEXTracker is doing with its advanced analytics and more on the complicated but game-changing proposition of including storage at the point of generation.

— Solar Builder magazine

Global solar tracker shipments up 32 percent, another 30 percent increase expected

Solar trackers continue to take more market share in large-scale PV design, and the #TrumpTariffs may even encourage more tracker deployment, in order for more conservative investors who traditionally installed fixed-tilt under pre-tariff pricing look to boost long-term project value. Even before accounting for that possibility, according to new data from GTM Research, global solar tracker shipments hit a record 14.5 gigawatts in 2017. This represents growth of 32 percent year-over-year.

The data comes from GTM Research’s new report, Global Solar PV Tracker Market Shares and Shipments 2018.
The report notes that NEXTracker maintained its spot at the top of the shipment rankings, accounting for a third of all solar PV trackers sold worldwide in 2017. Array Technologies ranked second, and Soltec third. For the first time, Latin America was the largest market for solar trackers, followed closely by the United States.

GTM solar trackers

“Mexico and Brazil are two of the fastest growing solar markets in the world, each accounting for over 1.5 gigawatts of tracker shipments in 2017, notes Scott Moskowitz, senior analyst at GTM Research and author of the study. “The U.S. utility-scale market was significantly stunted last year due to tariff uncertainty, so it took a backseat to Latin America.”

GTM Research solar tracker shipments

In spite of strong growth, GTM expects to see continued consolidation in the industry. The report notes that vendor margins continue to compress as the market grows, making profitable growth a significant challenge. There has already been one significant acquisition in 2018, with steel giant ArcelorMittal acquiring Exosun out of French bankruptcy court in January.

However, analysts at GTM Research remain optimistic. “Fundamentals in the global utility-scale solar industry are excellent, and trackers are an obvious choice in most developing solar markets,” said Moskowitz. “We expect 30 percent growth in 2018, with shipments approaching 20 gigawatts.”

— Solar Builder magazine