Inverter supplier Sungrow has signed a contract to supply its fully integrated energy storage system (ESS) ST4200KWh-2000 to a 15-MW/32-MWh solar-plus-storage project in Massachusetts.

The project will participate in ISO-New England wholesale markets after completion and is one of the first solar-plus-storage offerings to contribute to the Solar Massachusetts Renewable Target (SMART) Program, setting the benchmark for Massachusetts’ solar-plus-storage projects.

The future-proof Sungrow ESS solution ST4200KWh-2000, which integrates separate PCS and lithium-ion battery, energy management system, local controller, HVAC and FSS in a 40-ft container, will bring together the plant’s production processes within a one-stop-shop to allow flexible transportation and on-site installation, as well as ensure unified communication, system safety and optimal system efficiency.

The combined solar and storage portfolio is operated by Stem and owned by Syncarpha Capital. “We are happy to partner with Sungrow which has a trusted 20-plus-year track record in this industry for the first batch of SMART projects and many more in the future. We felt strongly about Sungrow Samsung SDI’s product offering, especially with the fully integrated concept, which really helped us reduce the LCOE and operational costs,” said John Carrington CEO of Stem.

“As a technical leader in power conversion, Sungrow offers innovative solar-plus-storage solutions that are future-focused. We have already completed prestigious projects in the U.S. and across the globe, connecting renewables to the grid to bring sustainable and reliable power to people,” said Hank Wang, President of Sungrow Americas.

The project, which is deployed across five distribution grid-connected sites, is planned for commissioning in Q2 2020. Sungrow’s announcement differs from Stem’s original announcement in June.

Enthusiasm about solar energy and battery storage projects is reaching celestial heights. And for good reason. Thanks to the falling costs of lithium-ion batteries and new government policies designed to promote clean energy, deployment of utility-scale solar-plus-storage is growing rapidly.

But as developers and utilities approach this technology in contract negotiations, they should ground themselves in reality with a clear and shared understanding of what batteries can and cannot do (and for what price). If they fail to do so, parties risk talking past each other, resulting in cost miscalculations, missed opportunities and unmet goals.

As batteries become more mainstream, this concern is no longer theoretical. After utility-scale battery capacity in the United States quadrupled between the end of 2014 through March 2019, it is projected to more than double by 2023, according to the U.S. Energy Information Administration (EIA). Record solar-plus-storage projects have been announced this year in California, Nevada and Arizona.

Still, integrated battery storage projects represent a tiny share of the overall market in the United States, and it’s still very early in the development of the technology. Its nascency may help explain why some fundamental aspects of it are lost in translation and not fully appreciated.

I’ve seen it happen. Developers and utilities can spend months negotiating the terms of a power purchase agreement for a combined solar and battery project and still not realize that they have mismatched expectations and assumptions about what the battery needs to do, the battery’s operating parameters (and its limitations) and who controls its use. Too often, a battery is seen as simply another line item in a budget that can be priced like another piece of equipment added to a generating facility. But it’s much more than that.

Adding a battery to a solar project can appear deceptively simple. And it’s true that for developers, adding a battery (especially to a utility-scale development) is not a particularly burdensome step in a greenfield solar project. Solar site selection, resource assessments, environmental reviews, engineering studies/economic modeling and interconnection studies can all require more time, planning and due diligence.

By contrast, adding a battery to a solar project usually does not require additional permitting. And because they have a relatively small footprint, additional land acquisition is usually not required, nor is an additional environmental impact review required.

To be sure, there are some important operational questions that must be addressed around where to connect a battery to the electrical system. Should the solar energy be transmitted to the battery and then to the grid? Or, should the solar energy be allowed to flow directly to the grid or to the battery? Answers to these questions can have a significant impact on the cost of the project as well as significant tax implications that go beyond the scope of this article.

CleanTechnica met up with Generac’s Chief Marketing Officer and president of its new clean energy business, Russ Minick at SPI 2019, to talk about the company’s big pivot into energy storage products to learn more about where that strategy came from.

At SPI2019, Generac and its team of Patagonia vest clad associates rolled out a new home energy storage system based largely on the units designed by Pika Energy, which Generac acquired earlier this year. The company injected the brain of the solution, the PWRcell inverter, with intelligence from another acquisition, Neurio Technologies, adding home energy usage monitoring and much more through its new PWRview tool.

The addition of Neurio’s intelligent energy management and monitoring tech also enabled integration with another renewables star: residential solar systems. The ability to not only harness energy in the battery for later use, but to enable homeowners to run off of that power for hours or days in the event of a grid outage resonated with Generac’s core customer base.

Customers looking to add a generator to keep their home and refrigerator running through a power outage caused by a storm were thrilled at the prospect of a system that taps into the unlimited resource of the sun without the need for any additional fuel. Sharing the PWRcell inverter slashes the cost of having to purchase a second inverter for the home solar system and makes the combined solar-plus-storage that much more affordable.

Exploring the potential of rooftop solar integration led Generac to not only allow for a direct connection of a rooftop solar system to its PWRcell inverter, but to develop a suite of products that intelligently integrate an on-site solar installation with the overall home energy system.

After the solar modules themselves, the first point of connection for a single inverter solar system is typically to a dedicated DC optimizer for each panel. Generac took the idea one step further with its PV Link Substring Optimizer (diagram above) that can control up to nine PV modules per unit. That cuts the number of connections required for installers and minimizes the potential points of failure in a rooftop solar system.

Working our way down the rooftop solar trunk cable that connects all the modules together, current NEC code requires a rapid shutdown device to be installed within a few feet of each solar array. These are typically dedicated devices that require their own enclosure. That equates to more cost and more space in the home that must be dedicated to the solar system. For example, in our Tesla Solar Roof installation, we have ~10 of these rapid shutdown devices, each enclosed in a dedicated ~12″ x 12″ x 4″ enclosure in our attic space.

These are great ways to play solar energy.

Over the next seven years, Bank of America estimates energy storage costs will decrease by 50%, ushering in the next phase of the global transition to renewable energy. The firm estimates the energy storage market could grow 16% annually from 2020 to 2031 and continue to expand to $58 billion by 2040. Those projections may seem aggressive, but solar energy costs alone are on track to drop 70% from 2010 to 2020. Here are seven renewables, batteries and electrification stocks to buy to play the coming energy storage boom, according to Bank of America.

Sunrun (ticker: RUN)

Sunrun finances, installs and services U.S. residential solar installations. The majority of its installations are leased by customers. Analyst Julien Dumoulin-Smith says Sunrun has limited downside given its fundamental valuation, even based on conservative estimates for costs and deployments. Dumoulin-Smith says refinancing opportunities and preventative electrical outages in California during wildfire season could drive further market penetration. Sunrun recently reaffirmed its full-year 2019 guidance for between 16% and 18% deployment growth and net present value of $1.15 per watt. Bank of America has a “buy” rating and $25.50 price target for RUN stock.

Vivint Solar (VSLR)

Vivint is another U.S. leader in residential solar installations, leasing the majority of its panels to customers. Vivint shares recently traded below $6.60 even though Dumoulin-Smith says Vivint’s PowerCo assets alone are worth about $7.30. He says Vivint shares are not pricing in long-term, attractive-margin growth prospects and a favorable low interest rate environment. Dumoulin-Smith says Vivint is well-positioned to capitalize on the next solar upgrade cycle triggered by a spike in electricity demand, potentially driven by electric vehicles. Bank of America has a “buy” rating and $14 price target for VSLR stock.

Worldwide demand for battery energy storage will jump to 400,000Mwh in 2025, compared with 100,000 in 2015.

That’s according to independent market assessments commissioned by the Consortium for Battery Innovation (CBI), which suggests while electric vehicles will increase lithium batteries’ share of the market, demand for all battery technologies will continue to rise as the world increasingly adopts renewables and electrifies its infrastructure.

It notes electricity grids and renewables drive demand for longer-lasting, safe, and reliable high-performance batteries – the CBI aims to achieve this more economically than previously possible, as well as increase the cycle life of advanced lead batteries by up to five times.

It suggests improved battery cycle life would help to significantly reduce operating costs, which it claims are “a key parameter for utility and renewable energy installations”.

As a result, CBI says a greater number of clean energy storage projects would be able to be installed, providing reliable and affordable electricity.

Dr Alistair Davidson, Director of the CBI, said: “We’re in the midst of a revolution in battery technologies as governments look to accelerate their move to low carbon energy sources. We need a range of high-performance batteries for different products and applications to meet this growing trend.

“Our technology innovation plan looms at a short-term boost in battery performance. But we’re also focusing on the next big leap in advanced batteries over the next decade as new forms of lead battery technology come to market.”

I’ll be honest. When a company known for installing more than 2 million backup generators for homes reached out to me for a meeting at Solar Power International 2019 last week, I was not excited. Was the company making the move to green its image, to woo new investors, or to gauge customer interest? We have seen too many legacy companies over the years dabble in clean tech with most of those roads leading to dead ends, but I figured what the heck. Let’s give it a shot. Boy was I wrong.

Walking up to the booth, the show floor around the Generac booth was abuzz over the new home energy storage product it was working on. Earlier this year, Generac acquired the residential energy storage company Pika Energy, who we first talked to at SPI last year at the Panasonic booth. Stacking onto the excitement, Generac aqui-hired the team of energy storage intelligence experts at Neurio Technology Inc. The news was exciting, but with the residential energy storage market moving as quickly as it is today, it was anyone’s guess whether Generac would be able to integrate the two new companies into the fold and translate their disparate technologies into a single set of customer-facing products quickly enough for it to matter.

We connected with Generac’s Chief Marketing Officer and president of its new clean energy business, Russ Minick, at SPI 2019, to talk about its big pivot into energy storage products to learn more about where that strategy came from. Right off the bat, Russ said that Generac had been eyeing the residential energy storage market for quite some time, but until recently, felt that, “it wasn’t worth the diversion of focus.”

“We’ve had our eye on solar and storage for some time,” but the company was really trying to hit the sweet spot in the market. “If you go in too soon, the market isn’t mature enough…if you go in too late, the leaders will already be entrenched.” In early 2019, it started dabbling with the technology, assembling a team of engineers well-versed in residential backup power solutions. After 2 or 3 months, it became clear that they were working outside their core competency and the company instead pivoted towards the prospect of an acquisition. “The ability to get a really competent product to market…would have taken too long,” Russ said.

The early efforts quickly bore fruit as Generac honed its search, performed its due diligence, and decided to acquire the energy storage intelligence experts at Neurio, and just a few weeks later, the energy storage builders at Pika Energy. “We put the teams together,” Russ said. “They’re 3,100 miles apart. One’s in Vancouver, one is in Portland, Maine. We closed, put them in a room and I got out of the way because I’m from Iowa and just let the magic happen.”

GE Renewable Energy recently announced it is has been selected by Convergent Energy + Power for the supply of battery energy storage systems for three projects in California for a total capacity of 100 MWh. GE’s scope of work includes a long-term service agreement and augmentation guarantees.

With this project, GE will reach a total of 495 MWh in operations or construction in the battery energy storage space. It is GE’s largest energy storage project in the United States to date, showing the clear demand for energy storage solutions in the United States and around the world.

The energy storage systems support two primary goals. First, they provide targeted local capacity to enhance grid reliability during peak periods. Second, as fast-acting stabilization devices, the battery energy storage systems can charge and discharge rapidly to regulate frequency and contribute to grid stability, helping to balance and facilitate the ever-growing penetration of variable renewable energy. Assets such as these will assist with making California’s state targets of 33% renewable energy penetration by 2020 and 100% by 2050 a reality.

Frank Genova, COO and CFO of Convergent, said, “Convergent has a track-record of developing trailblazing energy storage assets that advance the energy storage sector; we’re proud to partner with GE to provide for local area reliability and support the growth of renewable energy in California.”

Prakash Chandra, renewable hybrids CEO, GE, said, “Energy Storage is going to be a major component in the energy transition to more renewable generation and our collaboration with Convergent in California is a stepping stone in demonstrating the industry’s commitment to deliver more reliable and dispatchable renewable energy.”

Iowa is betting on big batteries to help it unlock more wind energy potential as a lack of grid capacity begins to constrain development in parts of the state.

The Iowa Economic Development Authority for the past couple of years has been funding and encouraging research into various forms of battery storage. In July, it gave Steve Martin, a materials science and engineering professor at Iowa State University, a $480,000 grant to continue work aimed at making a battery based on solid sodium.

Should Martin succeed in devising a feasible way to store large amounts of power in a solid-state sodium battery, it could be “a game-changer,” said Brian Selinger, who directs the Economic Development Authority’s energy office. Sodium, one of the two ingredients in table salt, is the seventh most common mineral and would be easy and cheap to acquire compared to the relatively rare lithium used in most batteries.

The award was the largest of 10 energy grants issued this summer and the only one for work on storage technology. The authority sees great economic development potential in energy storage and has raised its profile in keeping with the recommendations of the 2016 Iowa Energy Plan.

Batteries today typically use liquid lithium or sulfuric acid to shuttle ions back and forth between the battery’s positive and negative poles. A few use a liquid form of sodium. Although lithium-ion is the prevalent technology in cell phones and electric vehicles, it has important limitations, according to Martin.

In its liquid form, lithium is volatile and vulnerable to exploding when heated. Also, it is a fairly expensive soft metal whose cost Martin predicts will “skyrocket” as the demand for battery storage escalates. That would make it a pricey technology to pair with the grid in general and wind energy in particular.

He and a few others around the world are working to solve technical issues so that sodium batteries can come to market and provide storage on a massive scale.

“This is a very large problem,” Martin said. “If you’re going to build gigawatts of batteries for storing wind energy, it takes tons and tons and tons of sodium.”

Work is underway to devise ways to stash large amounts of energy in vanadium redox flow batteries, molten salt, and compressed or liquid air, according to Jason Burwen, vice president for policy at the Energy Storage Association.