Graphene Could Kill Lithium-Ion Batteries

December 29th, 2014 by Tina Casey

Don’t break out the widow’s weeds just yet, but it looks like momentum is building for energy storage to move past the lithium-ion phase and get into the more powerful territory of lithium-sulfur technology. In the latest development, a multinational research team has figured out how to overcome a major obstacle in the path of lithium-sulfur energy storage, by using graphene as a “bridge” between different components.

In theory, lithium sulfur (Li-S) batteries possess far greater energy density than the familiar lithium-ion (Li-ion), so breaking the technology out of the lab and into commercial development could have huge clean tech implications for EV battery range and energy storage for solar and wind sources, among other applications.

Schematic of 3-D hierarchically structured graphene-sulfur/carbonZIF8-D composite ( by K.Xi/Cambridge viaalphagalileo.org).

Lithium-Sulfur Energy Storage

Sulfur is super-cheap, which is mainly why researchers are interested in developing energy storage devices incorporating the material.

Sulfur also has some bonus attributes compared to conventional Li-ion battery technology, such as a high tolerance for overcharging, relatively light weight, and low toxicity.

The economics of residential battery storage in Australia

By Giles Parkinson on 14 August 2014

Wednesday’s story about the rapidly approaching status of socket parity for solar and battery storage sparked a lot of interest, and a bunch of email requests asking for more information.

That story pointed out that if Brisbane-based Redflow could increase the number of cycles in its zinc-bromine flow batteries, it could be cost competitive with the grid within a few years.

Here’s some more information from the report from Australian broking house Morgans. The table below is instructive because it includes the estimated capital cost of the storage system, plus the integrated systems manager. It notes that at its current cycles capability of just 1,000, the technology costs $1.29/kWh – effectively pricing it out of the market.

But that cost is lowered by half if the number of cycles is doubled. If the cycles can be increased to 3,500, and the kWh of storage increased from 8 to 10, then the cost of the technology falls to just 29c/kWh.

That, says Morgans, is very possible. And it means that the technology will be competitive with the grid.

“If Solar currently costs 10-12c (unsubsidised) then Australian energy storage will not be competitive with average grid prices any time soon. However with storage costs of ~30c there could still be a commercial case for peak shifting,” Morgans notes.

Without that increase in cycles, and peak pricing, the short term the economics of using a ZBM in conjunction with renewables at a household level in Australia doesn’t look compelling.

“For ethically or environmentally motivated individuals the ZBM is still an option, just don’t do the maths. The other alternatives that looks more likely over time is for the use of ZBM’s for peak shaving (i.e. versus expensive peak rates rather than average grid rates) and for off-grid or remote locations.”

Grid Battery Storage: Four Reasons to Invest

The emerging battery storage market will present new opportunities for investors.

Richard Heap, A Word About Wind 
July 31, 2014  

Think of a product — chances are that Hawaii has to import it. From food and cars to electronics and building materials, there are few areas where the U.S. state is self-sufficient — and energy is no different.

Hawaii is in the middle of the Pacific Ocean and about 2,400 miles from California, its closest neighbouring U.S. state, so it clearly cannot link to a grid on the U.S. mainland. But it is still reliant on the mainland for the imported oil and petroleum from which it generates almost 90 percent of its energy. 

Hawaii is now looking to change that. It has spent the last six years embracing renewable energy to reduce its reliance on imported fuels. Its efforts are an interesting case study on how nations are set to use energy storage to cope with fluctuating production from sources such as wind farms.

It also highlights some important reasons why investors in wind and solar should be interested in storage, particularly battery storage.

Here are four reasons why you should take this technology seriously:

1. Opening Remote Regions

The situation in Hawaii shows us the problems for islands if they develop renewable sources but can’t store the energy. Storage is now a vital part of the island’s ambitious attempts to go green.

In January 2008, the state of Hawaii and the U.S. Department of Energy launched the Hawaii Clean Energy Initiative so business leaders, policy makers and citizens could find a way for the island to become energy independent. This set a goal of 70 percent of energy from renewable sources by 2030.

Big Batteries Are Starting to Boost the Electric Grid - MyArkLaMiss.com - KTVE NBC 10 - KARD FOX 14 - Your homepage for the latest News, Weather and Sports in the ArkLaMiss!

Big Batteries Are Starting to Boost the Electric Grid - MyArkLaMiss.com -

(PGE VIA PNNL / NBC)

(NBC News) -- Long hailed as a game changer that will allow unlimited amounts of wind and solar energy onto the electric power grid, big rechargeable batteries are beginning to move out of research labs and find a home amid the real-world tangle of smokestacks, turbines and power lines. Today, the reality falls short of the hype about fossil-fuel-free electricity — but experts say that future could be in store.

For the foreseeable future, electric utilities will rely on coal, gas and nuclear power plants to provide a steady base of power, according to Paul Denholm, a senior analyst at the National Renewable Energy Laboratory in Golden, Colorado. But batteries can help balance the flow of electricity as demand ramps up and down throughout the day.

"That is where the hot applications are right now for energy storage," he told NBC News.

Traditionally, utilities maintain a little "wiggle room" on their system, he explained. For example, they might run power plants at 90 percent capacity, so that extra juice can be made available when a dark cloud passes overhead and thousands of people flick on their lights.

Operating power plants that way is hard on a system. It's inefficient, and expensive. Batteries, which can add extra juice nearly instantaneously, are a more cost-efficient way to keep the grid humming. What's more, this load leveling usually only requires 15 to 30 minutes' worth of energy. "You can have a relatively small storage device and make a decent amount of money on it," Denholm said.

While the market for this type of battery usage is limited, it is an entry point for a technology in need of experience on the grid, he explained.

Load leveling is precisely what Avista Corp. in the Pacific Northwest plans to do with the 3.6-megawatt capacity vanadium flow battery it is purchasing for its grid in Pullman, Washington, with the help of a $3.2 million matching grant it received in July from Washington state to advance energy storage technology.

In theory, the battery from Mukilteo, Wash.,-based UniEnergy Technologies could be installed next to a wind farm to store excess generated electricity, for occasions when wind speeds go so high that turbines are shut down to prevent damage, or when the wind suddenly dies out.

"But that carries with it a lot of cost [for] a single purpose … and you still have to send it across the transmission lines to get it to the load," Curt Kirkeby, a senior electrical engineer and technical strategist with Avista in Spokane, Washington, told NBC News.

Rows of battery racks are arrayed at Portland General Electric’s Salem Smart Power Center in Salem, Ore. PGE is a participant in the Pacific Northwest Smart Grid Demonstration Project, which is using the center’s 5-megawatt energy storage system to test smart-grid strategies.

Sodium-β batteries could transform wind and solar into baseload generators : Renew Economy

The cost of generating wind and solar power has been sinking like a stone, but the cost of storing all that energy for a rainy day has remained stubbornly high. With that in mind let’s take a look at a new advanced energy storage development announced by our friends over at Pacific Northwest National Laboratory.

PNNL has been working on bringing down the cost of sodium-β batteries (that’s β for beta). Sodium-β batteries are widely perceived to be the key to advanced energy storage for utility scale wind and solar energy power, but their relatively high cost has been an obstacle to widespread adoption.

New liquid metal alloy improves sodium-β batteries (courtesy of PNNL).

Sodium-β Batteries For Advanced Energy Storage

Sodium-β refers to a class of rechargeable metallic batteries, in which the two electrodes are separated by a ceramic membrane made of beta alumina. Initially used to construct industrial furnaces, by the 1960′s beta alumina was rediscovered as a conductive material with applications for advanced energy storage.

According to the Energy Department, there are two promising materials for the positive electrodes, sodium-sulfur or sodium-nickel-chloride (the later is the ZEBRA battery, for those of you familiar with the topic).

In terms of performance potential, sodium-β batteries could far outstrip lithium-ion batteries, the current gold standard. In addition to advanced energy storage for utility operations, sodium-β batteries could also play a role in mobile energy storage for electric vehicles.

The main problem is that under current technology, the molten state of the sodium-β electrode materials is maintained by a high operating temperature, up in the 350 C range. The high temperature is the main driver of expense for the batteries. It contributes to a relatively short lifespan, and it also requires the use of more expensive materials.

Pumped hydro – the forgotten storage solution : Renew Economy

By Tim Forcey and Dylan McConnell on 2 July 2014

Storage is in the energy news now, in more places than can be listed.

To pick a few, here is recent news from Europe,Tesla, and Queensland.  Everyone is looking to the day when battery technology can economically partner with the popular yet variable renewables: solar PV and wind.

But what if today there was a proven way to store vast amounts of energy at capital costs lower than what battery technologists hope they might achieve in 20 years time? A technology with high round-trip efficiency and one heck of a lifespan: 85 years and counting!

If you have read this article’s title, then you know where we are going with this: pumped hydro.

You may know, in energy terms, pumped hydro can be enormous (the Bath County Virginia facility with 3 GW of generation capacity and 30 GWh of stored energy is said to be the “world’s largest battery”), or niche (the 11 MW El Hierro pumped hydro facility, partnered with wind, now makes that Canary Island 100% renewable).

Possibly you already know that pumped hydro – with 140 GW of generation capacity installed globally – dwarfs all other forms of frequently and deeply cycled, on-purpose energy-storage technologies such as batteries, compressed air, flywheels, molten-salt-thermal storage, or synthetic chemicals created to store energy, combined!

Why? Because for so long pumped hydro has been the cheapest. At the University of Melbourne Energy Institute (MEI) we surveyed literature costs for pumped hydro projects globally and found capital costs as low as $100 to $200 capital per kWh of useable energy stored. Chemical battery makers are aiming for costs in the range of $200 to $500 capital per kwh (useable) to be on the market in 2025.

Due to this technology-cost gap and other factors such as the growing penetration of renewables, you may know pumped hydro is resurging globally: in China and Europe, and it is again being considered in Japan, Canada, and the US (California, Hawaii, North Carolina, and even in the desert state of Arizona.)

You may know Australia already has three large-scale pumped hydro facilities in Queensland and New South Wales, operating for more than 30 years: Shoalhaven (240 MW), Wivenhoe (500 MW), and Tumut 3 (600 MW).

New York to Install Battery Storage for Subway and Bus System Operator

Jim Polson, Bloomberg 
April 23, 2014  

NEW YORK -- American Vanadium Corp., owner of the only known U.S. deposit of the metal, agreed to install an energy storage system designed to reduce power costs for the agency that operates New York’s subways and buses.

The $1.2 million project will feature three vanadium-flow batteries at a Metropolitan Transportation Authority building in downtown Manhattan, the Vancouver-based company said today in a statement.

Watch Charlie Thurston talk with American Vanadium about the company's entry into the North American market at Intersolar North America 2013.

The system is expected to validate the company’s technology as a way to cut utility bills. The MTA plans to charge the batteries at night when power is cheap and discharge them when energy is more expensive, said Bill Radvak, American Vanadium’s chief executive officer.

“The MTA wants it there as they are big believers in energy storage,” Radvak said in an interview. “This is a very high profile site that will stimulate the market.” American Vanadium is paying about $700,000 and the New York State Energy Research and Development Authority will pay another $500,000.

Demand for power storage is growing, driven in part by wider use of battery systems to complement rooftop solar-power projects and electric vehicles. Tesla Motors Inc. on Feb. 26 announced plans for a $5 billion factory to cut the cost and increase the supply of batteries for both homes and its electric cars. California regulators in October ordered the state’s utilities to buy 1,325 megawatts of energy storage by 2020.

Vanadium Batteries

The batteries are capable of storing 130 kilowatt-hours each. They are produced by DMG Mori Seiki AG’s Gildemeister unit, which has installed 50 of the systems under the brand name CellCube, Radvak said.

The CellCube batteries use vanadium dissolved in sulfuric acid. Unlike standard lead-acid batteries or the lithium-ion units used by Tesla, they can be recharged and discharged indefinitely and may last as long as 20 years, Radvak said.

“The system excels at multiple hours of energy for long- duration requirements,” he said. “It’s also very safe. It can’t light on fire. The difficulty has been commercializing it.”

From the Editor: Energy Storage Gives Us The Power of Flexibility

Jennifer Runyon 
March 28, 2014  

When we consider the rapid rise of energy storage technology that we are witnessing all across the globe, it is key that we remember all of the reasons that this technology is and/or will be a key component in the grid of the future.  Today’s energy storage is not just about having a battery backup for a solar PV system (although consumers are using batteries this way in record numbers).  No, the rapid increase in energy storage technology is being driven by engineers all along the electricity spectrum from transmission operators who are deploying large-scale grid-connected energy storage to generate electricity when the grid is compromised through to distribution engineers who are using energy storage as a grid management tool to smooth out ramp events that are caused by rapid increases or decreases in electricity produced by solar PV or wind turbines. Further down the line, we find commercial electricity users installing energy storage on their buildings to lower their demand charges and finally there are homeowners who are examining how energy storage technologies might lessen their dependence on the grid or give them greater control over how and when they use grid electricity.  

Energy storage is therefore a cost-saving mechanism; a transmission asset; a micro-grid enabler; an efficiency driver and more.  That’s why there is so much interest in energy storage today and that’s why this technology is a major component in the grid of the future.

(This Letter from the Editor sets the stage for our March/April 2014 issue, one of our best yet.  If you haven't checked it out yet, why not subscribe today? You can view our 100 percent digital issue on your tablet or computer. Who needs the Sunday Papers when you can sit back and relax with a cup of coffee or tea and Renewable Energy World Magazine? Plus, you can read more about the Nice Grid Project on pp. 36-42.)

Energy Storage: Bank On It

Jane Weissman 
April 04, 2014  

Storage is cool.  It's so ingrained in our daily lives that it's invisible.  From the pantry closet and fridge storing our food to fuel tanks in our homes and cars, storage gives us the advantage to have something when we need it.  It's there waiting to be used.

So, doesn't it make a lot of sense to store excess power from photovoltaics and other distributed generation resources to provide backup during outages?  And, wouldn't storage change the intermittent nature of PV on cloudy days and at night into a more dispatchable resource? Couldn’t it also provide other grid services to help maintain power quality and reliability?

What's holding distributed storage back?  Why can't a home with a solar roof keep its lights on during the storm that puts the rest of the street in the dark?

To get a handle on some of the issues on the table, I tapped the expertise of two very smart colleagues, Chris Cook and Sky Stanfield.

Chris, who is on IREC's Board of Directors and (in full disclosure) the president and general counsel of Solar Grid Storage, says that "much like the debate that occurred with early solar incentive programs, the question once again arises with storage as to whether utilities should own those facilities."  The debate also continues on whether battery storage supporting solar should be co-located with distributed solar installations (at the customer site) or aggregated into larger community storage facilities that might be located at a utility substation.

Chris makes the point that if it is backup power that is the driver, a substation-based storage system does little in the way of providing backup power to the customer – storage at customer PV sites would be vastly preferable. "Contrast that with making solar PV dispatchable,” Chris explains. “If that is the desired outcome, then substation or even central storage is a fine solution and one doesn't have to address the added cost and complexity of customer-sited storage."

Sky, one of the lawyers who represents IREC, continued this thread at a recent Regulatory Advisory Board meeting by discussing that there are many types of storage technologies under development, and a variety of different locations in which storage can be deployed. "Where storage is deployed affects the types of functions it may serve and to whom those services are most directly provided,"  Sky said.

Tesla “giga” factory to boost rooftop solar’s storage needs

By Eric Wesoff on 21 February 2014

Greentech Media

V pioneer Tesla Motors announced its fourth quarter and 2013 results after market close today. Most recently, share price is up 14 percent after hours to $220. The shareholder letter is here.

Tesla Motors (TSLA) beat analyst profit estimates but fell short of revenue forecasts.

• The electric car pioneer had Q3 revenues of $615 million. This quarter’s revenue did not include any ZEV credit sales but did include $15 million in regulatory credits.
• The automaker sold a record 6,892 Model S vehicles during the period and expects to ship 35,000 Model S units in 2014.
• Tesla’s gross margin of 25.2 percent is in line with expectations. By the end of this year, the automotive supplier expects gross margin closer to 28 percent.
• The supercharger network has been built across most of the U.S. and northwest Europe.
• GAAP losses of $16 million for the quarter on revenue of $615 million
• Expecting over 55 percent vehicle delivery growth in 2014 and 28 percent automotive gross margin by Q4

Highlights from the investor letter

• The Model S was the top-selling vehicle in North America among comparably priced cars.
• Toward the end of the year, Tesla expects sales in Europe and Asia combined to be almost twice that of North America.
• Tesla believes an automotive gross margin of 28 percent, excluding ZEV credit sales, is “a reasonable target for Q4 2014.”
• Tesla claims that 80 percent of its customers are using their Model S as their primary vehicle.

2014 Expectations

• Tesla expects to deliver over 35,000 Model S vehicles in 2014, representing more than 55 percent growth over 2013. Production is expected to increase from 600 cars/week presently to about 1,000 cars/week by end of the year as Tesla expands its factory capacity and addresses supplier bottlenecks. Battery cell supply will continue to constrain production in the first half of the year, but will improve significantly in the second half of 2014.
• First-quarter production is expected to be about 7,400 vehicles.

The Giga factory

Musk in the shareholder letter:

Solar storage from used EV batteries set for testing in Japan

By Sophie Vorrath on 10 February 2014

The world’s first large-scale solar power storage system to incorporate used batteries from electric vehicles has been built in Japan.

The commercial-scale energy storage system has been developed and deployed at a 10MW solar farm in south western Japan, having been selected by Japan’s Ministry of Environment as a ‘model project’ to test the use of battery storage in conjunction with renewable energy.

The Hikari-no-Mori (‘Forest of Light’) solar farm was built by Sumitomo Corporation and six associate companies, when their mega-solar proposal won the city of Osaka’s 2010 public tender for ideas on a new use for a landfill site located on Yume-Shima Island, Osaka.

Sumitomo then created a joint venture company with Nissan Motors – 4R Energy Corporation – to investigate the re-purposing of used EV batteries. This led to the development and installation of a 600kw/400kWh prototype system, using sixteen used lithium-ion batteries from Nissan’s Leaf model EV.

The idea that the used battery from a hybrid or electrical car can be re-used for such purposes as the storage of renewable energy is an exciting one for the industry, with the potential to lower one of the biggest hurdles to energy storage proliferation – that of cost.

Battery makers such as BYD have pondered the deployment of used EV batteries in home storage applications, a development they say could reduce the cost of storage substantially.

In the Netherlands, grid operator Liander is working with the University of Applied Sciences of Arnhem & Nijmegen and the University of Technology in Eindhoven, to test the possibilities of giving batteries from hybrid or fully electrically-powered cars a second life, using two expertly dismantled Volkswagen Golfs.

“Once the operating radius has fallen by 20-30 per cent, batteries for … (EV use) are disposed of,” said Jos Blom, Innovation and Strategy Consultant at Liander. But for other (stationary) applications, he adds, there may be untapped potential.

These applications, says Blom, could include household energy storage, as well as backup for a diesel generator in combination with solar PV in remote and rural ares. But for grid operators like Liander, he says, “it is important that we already start investigating such possibilities with a view to changes in customer demand.”

In Japan, the Osaka solar storage system – which is due to begin operating this month – will be trialled for three years to test the suitability of the batteries to smooth fluctuating output from the 10MW solar farm, Sumitomo said in a statement. It will also test the suitability of used EV batteries for large-scale storage applications.

“We are pleased to be a part of such an important verification project that can both utilize used EV batteries, and provide a large-scale power storage facility, which are important issues that need to be addressed for the future of renewable energy,” said battery business development department General Manager, Norihiko Nonaka.

Biggest solar tower storage plant starts commissioning

By Giles Parkinson on 14 February 2014

As Ivanpah, the world’s biggest solar tower power plant comes on line, commissioning has begun on Crescent Dunes, the world’s biggest solar tower power plant that incorporates storage.

The 110MW Crescent Dunes project near Tonopah. Nevada, is 5 times bigger that other pilot and demonstration projects that have tested molten salt technology, and the first at what is regarded as “utility scale.”

The plant has been built by California-based Solar Reserve, which recently opened an office in Western Australia, and the storage capability means that it will have twice the output per MW of other solar technologies.

It also means that it can deliver electricity when needed. It has a contract to deliver electricity to Las Vegas between the hours of noon and midnight. As this graph shows, it can deliver its output in blocks, if needed, rather than the variable curves featured of solar technologies without storage.

The storage technology also eliminates the need for any backup fossil fuels, such as natural gas.

Solar Reserve says the commissioning is the initial stage of bringing the project into operations and includes system-by-system verification and startup, as well as equipment calibration and testing.

This includes “energization” of the utility interconnection system and other electrical systems, and testing and calibration of the heliostat field, which comprises more than 10,000 “billboard-sized” mirrors that track the sun and total more than 1 million square meters of glass.

Commissioning also includes systems unique to Crescent Dunes such as a Heliostat Field Control System that will control and concentrate the sun’s energy and also the Molten Salt System that will harness, store and transform the sun’s energy into superheated steam, making this the most advanced solar power plant in the world.

The facility also includes a dry cooled condenser in a hybrid configuration to minimize water use to levels well below that of conventional power plants.

“Start of commissioning of the Crescent Dunes solar power plant marks a critical milestone for the project as well as the solar industry,” CEO Kevin Smith said in a statement. “We are now able to build utility-scale power plants, fueled only by the sun, which operate on-demand, day and night, just like traditional fossil fuel or nuclear power plants.

SolarReserve’s industry-leading solar thermal energy storage technology solves the intermittency issue that limits the use of other renewable energy projects and thus enables firm, reliable delivery of electricity whether or not the sun is shining or the wind is blowing.”

Abengoa is also looking to build a 110MW solar tower plant with 17 hours of storage in Chile.

New Battery Technology Could Help Unlock Solar, Wind Power Potential

By Roxanne Palmer

on January 08 2014 4:13 PM

The new flow battery design from a Harvard team uses organic (carbon-based) materials instead of a rare metal. Eliza Grinnell/ Harvard School of Engineering and Applied Sciences

A new kind of battery designed by Harvard University scientists and engineers could unlock the potential of renewable energy sources like wind and solar.

One of the problems with solar and wind power is that the flow of electricity can’t be constant – the sun sets or goes behind clouds, and the wind dies or picks up. This can cause problems if these systems are wired into the electric grid, which has trouble handling sudden massive surges and dips in demand (Hawaii and Germany are two areas where this problem has already begun to butt up against widespread solar panel adoption). Having a reliable, cheaper way of storing massive amounts of electricity would be a big step towards wider reliance on these alternative energy sources.

In a paper published in the journal Nature on Wednesday, Harvard chemist Roy Gordon and colleagues described their design for a special kind of battery that might fit the bill. The team’s current model is just a laboratory experiment for now, but they think it could be scaled up to store large amounts of energy, providing the buffer that the grid needs to handle excess energy pouring in from solar panels and wind turbines. And the central ingredient of the battery is relatively cheap, which means it may move to market quicker.

Catching solar energy with salt balls 

IVAN PENN

The New York Times News Service

Published Monday, Nov. 11 2013, 11:57 AM EST

Last updated Monday, Nov. 11 2013, 11:57 AM EST

To Florida’s big utilities, the Sunshine State isn’t as bright as its nickname indicates.

Too cloudy. Too hazy. Too much darkness. It just doesn’t have the pounding rays of, say, Arizona or parts of California.

As such, the reasoning goes, the Sort of Sunny State isn’t great for solar energy – unless someone develops storage technology to overcome those limitations.

His solution: salt-filled ceramic balls that can turn water into steam for hours after the sun disappears. The steam powers turbines that produce electricity, in much the same way as burning coal.Enter Yogi Goswami, an internationally renowned mechanical engineer at the University of South Florida.

Dr. Goswami, 65, isn’t the only researcher to develop a solar thermal storage technology for renewable energies. And he’s not the only one to use salt as a main component.

But he has devised a way to concentrate the energy storage into golf ball-size capsules that even at high volumes take up little space, reduce costs and last longer than other technologies so far.

“We think that this has a bright future,” Dr. Goswami says. “For solar, in my view, [storage] is essential.”

Storing power

In the renewable energy world, building a cost-effective, utility-scale system that can store solar power for hours at a time is a Holy Grail of sorts.

“That will be a game changer,” Duke Energy Florida president R. Alexander “Alex” Glenn told state lawmakers last spring. “Storage is going to be critical.”

A race is on to develop the best technology. A few systems are already in use or being tested.

Duke Energy for instance operates one of the nation’s largest storage technologies at its Notrees Battery Storage Project that uses lead-acid battery blocks at a wind farm in Texas.

Arizona’s Solana Generating Station already uses a salt-based storage system that powers two 140-megawatt turbines that generate electricity for as long as six hours after sunset. The system produces enough power for 70,000 Arizona Public Service customers.

Vanderbilt Proposes Building Energy Storage Into Solar Cells

Chris Meehan 
November 11, 2013  

Imagine a photovoltaic cell or module that actually produces and stores energy, acting as a battery and producing power even after dark. New research into silicon-based supercapacitors at Vanderbilt University shows that it’s possible. 

Supercapacitors have long been looked at as a potential alternative to batteries for energy storage, but they remain bulky and expensive with low storage density. However, they offer some significant advantages over conventional batteries. For instance, they can charge and discharge energy rapidly. They also promise lighter weight and much longer lifespans than batteries do because of the way supercapacitors store energy. 

Whereas a battery stores energy in a chemical reaction, supercapacitors store energy in ions on the surface of a porous material — usually activated carbon, Vanderbilt explains. So, as their energy density capacity increases, they become more attractive. Graphene and nanostructuring with silicon may prove the panacea for such devices. 

Researchers at the university published their findings in the Oct. 22 issue of the journal Scientific Reports. They propose making a supercapacitor out of silicon — a first — and that such devices can be built into a silicon chip along with the microelectronic circuitry that it powers. “It should be possible to construct these power cells out of the excess silicon that exists in the current generation of solar cells, sensors, mobile phones and a variety of other electromechanical devices, providing a considerable cost savings,” the university says.

“If you ask experts about making a supercapacitor out of silicon, they will tell you it is a crazy idea,” says Cary Pint, the assistant professor of mechanical engineering who headed the development. “But we’ve found an easy way to do it,” he added.

Renewable energy storage device developed 

at Muskegon's GVSU business incubator  

MUSKEGON, MI – Grand Valley State University’s Michigan Alternative and Renewable Energy Center has launched a number of upstart businesses, but breakthrough products have been few and far between.
Energy Partners LLC founder and GVSU professor emeritus Jim Wolter thinks he and partner Ed Brandel have come upon an energy storage device that could be a game changer.

Solar 24 combines a large solar energy panel with a battery pack and electronic circuits to provide a steady stream of energy whether the sun is shining or not.Dave Alexander | Muskegon Chronicle

Energy Partners – a three-year research and development venture that has made the MAREC business incubator its home – introduced Solar 24 at the Solar Power International Conference in Chicago at the end of October.
The energy storage device allows for the steady discharge of electricity created by solar panels over the course of a day even during nighttime hours, Wolter said. Besides technical support from MAREC, Solar 24 received funding from the Michigan-based Business Accelerator Fund.
“This is breakthrough technology,” said Arn Boezaart, director of the Muskegon-based MAREC. “It’s the first of its kind that I’ve seen in the renewable energy industry and addresses the often-cited intermittent nature of solar energy. This kind of innovation is the reason MAREC’s business incubator program provides the resources and space to develop new products and concepts.”
The “secret sauce” is in the electronic circuits that Brandel brought to Energy Partners, Wolter said, adding that patents are pending. The Muskegon native is a Texas Tech University engineering graduate who worked for Texas Instruments in Lubbuck, Texas as an electrical engineer.
Brandel worked in the areas of consumer products, semi-conductors and microprocessors before returning to Muskegon, he said. Wolter and Brandel have been working together on the Solar 24 for the past year and a half.
“The circuitry controls how much power you take out of the device,” explained Wolter, a retired professor of both engineering and marketing who has specialized in bringing new technologies to market.