Batteries: The Other Half of Hawaii’s Energy Future

Batteries are old. In a sense, the last major development in battery technology was the invention of the lead-acid battery in 1859 by the French physicist Gaston Plante. Earlier batteries had short lives, quickly losing their charge as their electrodes dissolved, but Plante’s battery could be recharged by simply running electricity through it in reverse. That changed everything. Suddenly, the battery went from being an arcane tool of the laboratory to a critical device of daily life.

Remarkably, battery technology hasn’t changed much since then. Over the last 157 years, innovators have fiddled with its chemistry and rejiggered its architecture, but the battery under the hood of your car (unless it’s an electric or hybrid vehicle) isn’t terribly different from the lead-acid battery invented by Plante. Yet, this humble device and its (slightly) more sophisticated heirs have become instrumental to the future of energy. Whatever the future holds for the grid, it almost certainly will depend on the chemical energy stored in batteries.

Nowhere is the importance of battery technology more obvious than Hawaii. By passing the Clean Energy Initiative in 2008, the state committed itself not just to renewable energy, like solar and wind power, but, inevitably, to the storage technology that make those types of power practical. Unlike the fossil-fuel-powered generators they’re supposed to replace, solar and wind power are intermittent. We need some way to save the excess energy they produce for the times when the sun doesn’t shine and the wind doesn’t blow. For the foreseeable future, that’s likely to be batteries.

There are, of course, other ways to store energy. Pumped hydro is one: using renewable energy, when it’s available, to pump water from a low elevation to a high one, then allowing that water to run downhill, through a pipe, to spin a turbine and produce electricity at night or when the wind isn’t blowing. The technology works, but calls for massive infrastructural investment and the right topography to be practical.

“Whatever the future holds for the grid, it almost certainly will depend on the chemical energy stored in batteries.”

A more indirect form of storage is to use excess renewable energy to convert water into hydrogen gas. Hydrogen is interesting because it can be used in fuel cells for the direct production of electricity, and as a transitional fuel in the millions of internal-combustion engines that power our existing cars, generators and power equipment. Because of this versatility, and the ubiquity of hydrogen, energy analysts have long predicted the imminent arrival of the “hydrogen economy.” But, despite its inherent advantages, hydrogen remains a long-term option. At least in the short term, that leaves batteries as the medium for our renewable-energy future.

Lead in the Grid

Incredibly, lead-acid batteries are still a key component of our energy present. Until recently, this market has been dominated by Xtreme Energy, a grid-scale battery manufacturer that went bankrupt in 2014. (Its assets were acquired by the German battery company Younicos.) Many of the largest, grid-scale renewable-energy installations in the state are still backed up by Xtreme Energy’s massive battery systems. The Kaheawa Wind farm on Maui has two: a 1.5 megawatt battery capable of holding 1 megawatt-hour of electricity, and a 10 megawatt battery with 20 megawatt-hours of storage. On Lanai, David Murdock backed up his La Ola PV project with a 1.125 megawatt battery with 0.5 megawatt-hours of storage. And First Wind’s Kahuku wind farm on Oahu was initially backed by a giant 15 megawatt, 10 megawatt-hour battery. Unfortunately, it was destroyed in a catastrophic fire and not replaced.

But the company that depends most on lead-acid batteries is probably Kauai’s power company, the Kauai Island Utility Cooperative, which integrated Xtreme Energy batteries into its early solar farms.

“We currently have 10.5 megawatts of battery energy storage on the grid,” says KIUC communications manager Jim Kelly, “4.5 megawatts for the Port Allen and Koloa solar projects, and 6 megawatts that just came online at Anahola.” All of these systems, he points out, are designed to provide “frequency support” – to level out the voltage in the system despite the inherent fluctuations of solar power. The newer Anahola project uses the latest lithium-ion-nickel-cobalt-aluminum batteries, made by the French manufacturer Saft; but the Port Allen and Koloa projects rely on Xtreme Energy lead-acid batteries. So far, this storage arrangement hasn’t suffered any catastrophic failure – like the fire that destroyed the Kahuku facility – but KIUC’s batteries still suffer from the well-known weaknesses of lead-acid technology, Kelly says.

“The Xtreme batteries saved our bacon literally dozens of times in the first couple of years by covering a frequency drop long enough so we could bring additional generation online to prevent an outage. And those events weren’t just with solar. There were instances where we lost a generator and the batteries helped prevent a small outage from turning into a big event.”

But the performance of lead-acid batteries suffers when they’re exposed to the workload it takes to buffer the grid, Kelly says. “The downside is that cycling the batteries like that really wears them out fast and so their useful life is shorter than we had hoped. That’s a big reason we’re switching to lithium-ion technology, which has proven to be much more durable.”

KIUC’s experience with Xtreme highlights one principal risk of the move to grid-scale storage: The industry is still new and volatile. Many of the most innovative battery companies are startups, with all the attendant risks of young companies. The industry is littered with promising technologies that succumbed to bankruptcies or garage-sale mergers. As Kelly points out, Xtreme Energy was one of the industry’s stars, yet it still failed.

“The failure of Xtreme illustrates how the battery business is still in its formative years, very capital and research intensive. But doing utility-scale solar without batteries doesn’t work, so we’ve had to be an early adopter and acknowledge the risks and learning curve that goes along with that. KIUC bought its first Xtreme battery in 2010. Five years is like centuries ago in the evolution of the battery business.”

Lead in the Home

Lead-acid batteries aren’t restricted to utility-scale projects. Until recently, they were also the dominant storage technology for residential systems. Neighbor Island solar companies that specialize in off-grid customers have been installing lead-acid batteries for years. Only recently have some of these companies, like Haleakala Solar, gone over to later technologies, such as lithium ion or Aquilon’s saltwater battery. That’s because lead acid was a proven technology and the cheapest alternative for customers that were either too remote, or didn’t have the money, to connect to the grid.

Even on Oahu, where nearly all homes are connected to the grid, lead acid has been the main option for storage. For example, the solar installation company Island Pacific Energy began offering clients storage solutions as far back as 2013. Nevertheless, they’ve only installed a handful of systems. The reason, says CEO and founder Joe Saturnia, is batteries are still too expensive.

“We’ve been using lead-acid batteries, which have been around for decades. The technology has been proven all over the world. If you have solar or wind power with storage, you can go off grid if you like. But, if you compare the cost of that to purchasing energy from the grid, it’s still a little too expensive.”

He notes other battery types, which often have technological advantages over lead acid, are even more expensive. Lithium-ion batteries, for example, can go through many more charging cycles than lead-acid batteries before they need to be replaced. That makes their life-cycle cost comparatively low. They can also be fully discharged, while lead-acid batteries shouldn’t be run down past a 50 percent charge, which means you have to buy a battery twice as large as you need. Maybe most important, lithium-ion batteries pack a lot of power in a compact size. This is why they’re the preferred battery where weight is important, as in laptops, cell phones and electric vehicles. (See sidebar on the difference between energy and power on page 81.) But, on a kilowatt-hour to kilowatt-hour basis, the initial cost of lithium-ion batteries is more than twice as high as lead acid.

That could be about to change, though. One reason may be because of advances in battery manufacturing technology. Although battery technology itself has only improved incrementally, many new battery companies focus on how those batteries are made. In part, this is because of the popularity of electric and hybrid cars. Battery manufacturers are rushing to lower costs and improve the performance of these vehicles, and that innovation has bled into other technologies. The most famous example is the much-ballyhooed entrance of Tesla, the electric car manufacturer, into the home-storage market.

Until recently, Tesla’s cars have been high-end toys for the affluent. But the company’s planned Model 3 sedan is aimed at mid-market buyers. Because the batteries account for nearly a quarter of the price of an electric car, those costs will have to come down for the Model 3 to sell. Tesla CEO Elon Musk believes the only way to do that is to create massive economies of scale. The result is the “Gigafactory,” a 10-million-square-foot factory going up in the desert outside Reno, Nevada. To support the scale for this plant, Tesla has jumped into the home-storage market in a big way, offering two models of wall-mounted batteries: a 7-kilowatt-hour battery the company says is designed to be discharged daily, and a 10-kilowatt-hour battery designed to be discharged weekly.

“If electricity was so phenomenally cheap … The amount of money that we freed up in the economy to do other things would be like a repeat of the Industrial Revolution.”

— Joe Saturnia, CEO, Island Pacific Energy

These new products, and their effect on the price of storage generally, may make batteries more affordable for the wind and solar communities that make up Hawaii’s distributed generation. But it’s worth remembering that Tesla is an electric car company, not a battery manufacturer. In fact, the batteries used in Tesla’s cars and being sold for home storage are actually manufactured by its partner, Panasonic, which will occupy much of the real estate in the Gigafactory. It remains to be seen if “scale” is enough to lower the price of batteries far enough to be affordable for the home, let alone grid storage.

Policy Connection

The cost-effectiveness of batteries is also driven by policies and regulations. By way of analogy, Saturnia cites the recent decision by the Public Utilities Commission to end the current net-energy metering system. Under NEM, residential customers with rooftop solar could sell their excess electricity to the utility at retail rates. In effect, these customers used little of their own power. During the day, they sold most of the energy produced by their PV system to the utility; at night, they bought power from the grid at the same price. If they were lucky, at the end of the month, their buying and selling netted out to zero and all they had to pay was a small connection fee. This was a big part of why installing rooftop solar made sense. For residential customers, the savings on their electric bill often paid for the cost of the system within five years. For commercial customers, Saturnia says, the payback was sometimes 18 months or less.

The end of NEM changes those calculations. Under the new system, customers can go one of two routes: grid-supply or self-supply. Customers installing self-supply systems will no longer have to get interconnection approval from the utility, but they also won’t be able to export power into the grid. Grid-supply customers will still be able to sell their excess production back to the utility, but at only 15 cents a kilowatt-hour compared to about 26 cents for Oahu customers before. For customers considering installing PV systems, that extends the payback period. In addition, the PUC decision only requires the utility to accept a limited amount of so-called grid supply, and only requires the utility to pay for feedback power for two years. That further complicates the calculus for potential PV customers. How do you figure out the payback period on your investment with so many unanswered variables?

“I’ve heard that grid supply is 50 percent committed already,” Saturnia says. “I don’t know if that’s true or not, but the PUC’s decision and order said the utility was going to allocate 25 megawatts to grid supply. When that’s over, it’s done.”

On its face, he says, self-supply is more straightforward.

“Say you’re a homeowner and you’re on a circuit that HECO is saying is ‘at capacity,’ but you really want to put PV in. How do you do it? The answer is: You put PV on the roof, and you put in an energy-management system with a storage component. Then, instead of constantly sending power back and forth to the grid, what you’re doing is sending power back and forth to your batteries, and you’re using the power from your roof to charge your batteries. Only when you’ve run out of power do you start to pull from the grid.”

“The initial problem with the flow battery was that it required about seven hours to fully charge.”

— Henk Rogers, co-founder of Blue Planet Energy Systems

Does that mean the end of NEM will create a booming market for battery suppliers? Maybe.

“What I can tell you,” Saturnia says, “is that, ever since we’ve seen the end of NEM and, now, with this new self-supply/non-export thing, our phone has been ringing daily with technology firms, mostly from the mainland, who want to introduce PV/battery-storage type of products to Hawaii, in a variety of different technologies and configurations.”

That’s a positive sign for innovation and the development of distributed storage to go with the state’s already blooming network of distributed generation. But it doesn’t stop Saturnia – and many of his peers in the battery-storage market – from worrying the utilities or regulators will still find a way to mess things up. He cites the example of the slowdown in PV installations.

      “The primary cause for that slowdown has been the time it takes for HECO to approve an interconnection. If HECO didn’t have to approve the interconnect, we’d probably have twice as much PV on the Island as we do today. I’m not making any judgment call on that; I’m just putting the fact out there. What would concern me would be if the PUC, either by its own action, or by allowing HECO, through its action, somehow slowed down independent storage that really has no operational or mechanical impact on the grid.

“For example, when HECO started to shut circuits, PV companies began advertising non-export model PV systems. They said, ‘Hey, we’re going to put PV on your home and, as long as you don’t export power, you don’t need an interconnect agreement.’ And, by the strict reading of the NEM, you didn’t. Well, the PUC asked HECO – or HECO asked the PUC to ask them – to address this situation, and very quickly an addendum to the NEM came out stating that, if you have any storage component to your system, you needed an interconnect agreement.”

Saturnia notes this addendum was quickly removed when people complained, but says it highlights a key vulnerability in the system. If regulators or the utility have the means to interfere, there likely will be unforeseen complications. More effective, he says, would be to use incentives to get people to do what you want them to do. Time-of-use rates, like the ones Hawaiian Electric recently proposed, are a good example: Charge people more for electricity at peak hours when it’s expensive to supply, and less late at night or in the middle of the day, when there’s much less demand. That will get people to change their behavior (and buy batteries to store energy to use during those expensive peak times).

Commercial Breaks

Ted Peck, the former energy administrator for the state, agrees. “That’s the point for policymakers to take,” he says. “Get out of the way of consumer forces. Consumer forces are far better influences than regulation. Regulation gets you into docket hell. Consumer forces are what make boardrooms quiver.”

Peck is now the CEO of Holu Energy, a Honolulu-based energy consulting company. Holu has partnered with EnSync, a well-known national battery manufacturer, to provide commercial and industrial customers with an advanced storage option. These commercial customers have an added incentive compared to residential customers. In addition to their bill for total kilowatt-hours used, commercial customers pay a fee based on their highest level of demand during the billing period. These so-called demand charges can add up to as much as a quarter of their total electric bill. On Oahu, demand charges come to about $12 per kilowatt per month. Large customers pay even more. For the 500 or so largest customers, the charge might be more like $20 per kilowatt. (Some mainland customers see even higher demand charges, as much as $40 a kilowatt for San Diego Gas and Light customers.) That means a company on Oahu with a peak demand of 100 kilowatts, for example, would pay an additional $1,200 in demand charges on its monthly bill.

A graph showing a customer’s electric usage isn’t typically a straight line. It’s a range of peaks and valleys. For commercial customers, it’s the peaks that determine those demand charges. The reason businesses are more interested in storage isn’t because they want to go off grid; it’s because they want to reduce the height of those peaks, and thereby reduce their demand charges. This “peak shaving” is the main reason commercial customers are embracing storage. By running batteries during peak hours, they can reduce their bill as much as 10 percent to 15 percent, more than enough to justify the investment.

But the EnSync system goes beyond peak shaving. It re-envisions the relationship between large customers and the utility, and it starts with a battery. The EnSync battery is unusual: It’s a hybrid, pairing a lithium-ion battery with EnSync’s patented zinc-bromide flow battery. The lithium battery satisfies the customer’s power needs, while the flow battery provides a highly flexible energy-storage system. These flow batteries work differently than most other batteries. Instead of storing energy in the electrodes, a flow battery stores its charge in fluids. If you need more energy storage, you can simply enlarge the tanks.

“There are a number of advantages to that,” says Ensync VP Dan Nordloh. “For example, you can deploy a flow battery as a 20-year asset. So, in terms of cost of ownership, they are superior to other types of batteries that are out there. With a flow battery, when the efficiency isn’t quite fit for the purpose, rather than replace the entire battery, you simply replace some of the stacks within the battery. So, it’s much less costly to own that for a 20-year period. With a lithium-ion, when it has served its efficiency purpose, you have to replace the entire battery.”

EnSync’s approach is to take advantage of each kind of battery’s strengths. Another way to look at the hybrid battery system, though, is as an admission that neither battery type is adequate alone. Both have faults and strengths. And until battery technology improves, this kind of jury-rigged system may be unavoidable.

“The perfect battery does not exist,” says Nordloh. “And I don’t foresee it on the marketplace anytime soon, because no battery can provide both power and energy in a cost-effective manner, and in a way that will be advantageous for the lifespan of that battery. But most applications, especially in the commercial and industrial space, require both power and energy. So, if you only put one kind of storage in, you’re going to be asking it to do things that it’s not designed to do very effectively.”

But battery technology isn’t really what Holu and EnSync are selling. Their most advanced product is an energy-management system called Matrix that’s designed to maximize the effectiveness of those batteries. This is the clearest trend in distributed storage: While the improvements in battery technology may be only incremental, the computerized power-management technology that goes with it is advancing quickly.

As Peck explains, Matrix coordinates the functions of EnSync’s two battery types.

“The flow battery and the lithium-ion are integrated so you have different devices actually meeting different needs simultaneously,” Peck says. “You might have one of the batteries discharging, and the other charging at the same time to meet different requirements. That’s actually a patented technology. Really, it acts like a power filter.”

He says the system is sophisticated enough to handle multiple inputs – not just PV, but wind, generators and even small-scale geothermal. As clients install new power sources, the system can grow to accommodate them. Matrix may also provide a glimpse of the future grid, one that fully embraces both distributed generation and distributed storage.

“We’re moving toward a network of networks,” Peck says, “where EnSync’s management system gives visibility to the utility so it really does become an Internet of energy, providing them visibility behind the meter. Behind the meter is the customer’s side of things, so there obviously needs to be some protections there. But it really provides a way for the 21st-century grid to come to life. We’re there now. The technology is there to do that.”

In other words, by combining its storage and power management technologies, EnSync not only allows customers to benefit from peak shaving, it may also provide services directly to the grid. It’s easy to imagine a scenario where storage companies like EnSync become independent power suppliers, reducing the utility’s need to fire up that extra generator at peak times, and perhaps eliminating the need to build new power plants as more and more renewables come on line.

Grid Ready

EnSync isn’t the only company thinking this way. Stem, a small energy company in California, has begun a pilot project, in partnership with HECO on Oahu, to create a network of commercial customers with battery storage that can be accessed by the utility. In California, Stem uses its network of batteries to sell power on the spot market for electricity. Here, much like EnSync, its plan is to serve as a sort of independent power provider to the utility, says Tad Gaulthier, Stem’s VP for development.

“Right now, we’re only installed and fully operational at one site, but we should have another five sites, maybe more, by the end of 2015. We will have 25 to 30 sites within six months. That’s the scope of this first effort. Each battery in our system is 18 kilowatts, but you can scale them up. You can have one or two or more units. The largest site, the Wet ’n’ Wild Hawaii waterpark, is going to have six. In all, we’re going to have 56 of these battery towers divided up across 25 to 30 locations. In all, that comes to 1 megawatt of power.”

Stem’s commercial customers will benefit from the batteries’ peak shaving capability, but the most interesting part is what happens at the grid level. As Gaulthier points out, the key to this approach isn’t the battery technology (they’re using high-quality, but fairly typical lithium-ion batteries manufactured by the Korean giant LG Chem). It’s the 24/7, cloud-based power management program that makes the system work. By monitoring every battery at every location, Stem can optimize their use. The idea is to create benefits for both the customer and the utility.

“Doing utility-scale solar without batteries doesn’t work, so we’ve had to be an early adopter and acknowledge the risks and learning curve that goes along with that.”

— Jim Kelly, Communications manager, Kauai Island Utility Cooperative

“In a practical sense,” Gaulthier says, “the way it works is that, when the batteries are needed by the commercial customer, they’re going to discharge for the commercial customer. They’re going to do that peak shaving that we talked about. But, when they’re not in use, what Stem does as an aggregator is we kind of simplify the world for the utility. We’ve got these batteries spread out over the grid on Oahu, but the utility doesn’t want to deal with that complexity – which ones are being used right now and where they are – so we’ll just show them one single number and say, ‘Here’s your fleet capability, right now. Here’s what we have to offer you as a single resource.’ We’re not asking them to manage each one of those individually.”

This is a model the utility can understand. In fact, it’s not that different from demand response, a common utility strategy to deal with spikes in demand. With demand response, instead of firing up a peaking plant, which is very expensive, the utility has the ability to temporarily turn off some of the equipment of customers enrolled in the program. For example, in exchange for a slight reduction in their bill, customers may agree to allow their hot water heater to quietly cycle on and off during peak periods. These customers are often aggregated, and the relevant equipment installed, by independent contractors.

“We’re kind of the same model,” Gaulthier says. “We’re seen as a kind of aggregator by the utility, but we’re an aggregator of fast-responding storage. They don’t really have a precedent for this, so we don’t want to be thrown in with old-style demand response, and we don’t want to be seen as a generator. We want to be seen as a new kind of asset.”

Bringing it Home

By installing their batteries at the sites of commercial and industrial customers, companies like Stem and EnSync may actually be strengthening the grid, making it more resilient, and better able to deal with the intermittency of renewables, like solar and wind power. On the residential side, the opposite may be happening. Especially with the end of NEM, residential customers with battery storage have little stake in the success of the utility. The trend for these customers and these batteries is to go off grid. And technology is making that less and less costly (though still not affordable for most). The best example is Blue Ion, the Sony battery and power-management system being sold by Blue Planet Energy Systems, the newest company of Tetris mogul Henk Rogers (Hawaii Business magazine’s 2015 CEO of the Year.)

Rogers and his Blue Planet Energy co-founders,

V. Paul Ponthieux and Alex Velhner, began researching battery storage several years ago at Puu WaaWaa Ranch, Rogers’ Big Island home. The goal was to take the ranch off-grid. To start with, they chose a flow battery.

“We started with 80 kilowatt-hours of energy,” Ponthieux says. “That required four fairly large tanks – about 400 gallon tanks – and two of the cell stacks. This gave us 10 kilowatts of power. At that time, we were running half the ranch on that. We wanted to test it and see if it worked before we took the entire ranch off grid. The initial problem with the flow battery was that it required about seven hours to fully charge. That’s because the efficiency of flow-battery technology is only about 70 percent. But we didn’t get seven hours of sun every day to charge it. We’re in a microclimate where we only average about 3.8 hours of good sun a day throughout the year. We know that from a two-year study we did, in conjunction with UH. Also, the flow battery started failing and degrading after only about 12 months. It pretty much completely failed in about 18 months. The company was called Prudent Energy, but they weren’t very prudent with their warranty. They were basically bought up by a Chinese company and moved their operations to China and we never got warranty support. So, we learned the hard way.”

Next, they looked at lithium-ion batteries. “Lithium-ion” is actually an umbrella term for a variety of different chemistries. For example, the battery that Panasonic makes for Tesla’s home storage system is a lithium-nickel-manganese-cobalt-aluminum battery. The Sony battery that Blue Planet Energy Systems sells uses lithium-iron-phosphate technology. Comparing the two is a quick primer in the pros and cons of different battery chemistries.

“The big difference between the Sony batteries and the Tesla batteries,” Rogers says, “is that the Sony batteries, in their present form, are meant to be primary storage. In other words, you can take your house or your business or whatever it is and use these as primary storage. The Tesla batteries basically aren’t set up that way. The one you see advertised, the one that looks like a turtle you hang on the wall, that’s meant for peak shaving. It only stores seven kilowatt-hours. That would work if you live in a tent, maybe. But at my house, for example, I use 60 kilowatt-hours a day. The average house uses 25 kilowatt-hours. So, seven kilowatt-hours doesn’t even touch the usage at the average house.”

That brings up what Rogers describes as the main drawback of Tesla’s lithium cobalt batteries: They’re hot. This exacerbates the issue of the batteries’ storage capacity. “You can put in more than one,” Rogers says, “but each one is a heater. One, you could maybe put in your garage, but two or three, you’re going to want to put them outside. If I leave my garage door closed while I charge my car, which is a Tesla, then it produces a lot of heat, so I always try to leave the door open.”

As a consequence of the heating problems, the Tesla batteries incorporate loud cooling systems. In contrast, Sony’s lithium-iron-phosphate batteries need no cooling and run quietly. And, because they’re cooler, they don’t pose the fire hazard lithium-cobalt sometimes does. So, why do Tesla’s batteries get so much more press than lithium-iron-phosphate batteries? Partly because they’re the superior technology for what they were designed to do: power an electric car. Lithium-iron-phosphate batteries are both heavier and more bulky. But the main reason for the popularity of the Tesla battery is the Tesla mystique.

“Someone once asked me who my hero was,” Rogers says, “and I said Elon Musk. They asked me why, and I said, ‘Because he’s got planet-sized dreams and the planet-sized balls to carry them out with.’ ”

“The perfect battery does not exist. And I don’t foresee it on the marketplace anytime soon, because no battery can provide both power and energy in a cost-effective manner, and in a way that will be advantageous for the lifespan of that battery.”

— Dan Nordloh, VP, EnSync Energy Systems

Nevertheless, Blue Planet Energy Systems went with Sony’s lithium-iron-phosphate batteries.

“They performed even better than what Sony claimed,” Ponthieux says. He says some of the first Sony batteries they acquired were eventually installed in the Mars Habitat. “They’re up on Mauna Loa, where they’ve been running the longest of any of our installations. And they get pushed very hard. We figured if there was any way to break them, that would be the way – put them in a very extreme environment and cycle them to death.”

Now, of course, Blue Planet Energy Systems sells the Blue Ion system. And, while the batteries may end up proving popular with commercial customers, too, residential buyers are likely to use them to get off the grid. That could be disastrous for HELCO and the other utilities in the state. If everyone who can afford to goes off grid, those left behind will have to pay for keeping the creaky grid functioning. That, too, may be part of the price of battery storage.

A New Era?

Not surprisingly, the battery people are more optimistic. To Saturnia, the combination of distributed generation and distributed storage is nothing less than an energy revolution.

“There’s a whole, larger economic issue to this,” he says. “Imagine a world where the cost of electricity was nominal. Think of all the things that we don’t do today because it’s expensive. You don’t air condition your house 24/7 because it costs too much money. You may not drive to the North Shore every day because you can’t afford the gas. If you lived in the Northeast, instead of hiring someone to shovel the snow off your driveway, you could just press a button and melt the snow. If electricity was so phenomenally cheap, we could do all those things we can’t even imagine doing. The amount of money that we freed up in the economy to do other things would be like a repeat of the Industrial Revolution.”