Technological change is not only continuous but operating simultaneously across a wide range of fields. Here is a summary of some of the most promising areas of innovation with implications for the electricity sector.
Solar PV becoming more economic
Photovoltaics are coming close to a commercial breakthrough, says Nadav Enbar, a research manager with Energy Insights, a division of research and consulting firm IDC. Thin film manufacturer First Solar has begun producing cadmium telluride photovoltaic modules at a cost of under a dollar (93 cents) per kilowatt-hour. While crystalline silicon has provided the first wave of photovoltaic generation, it’s expensive to make. Increasing efficiencies and decreasing costs of newer thin-film PV technologies – cadmium telluride, copper-indium-gallium, dye-sensitized and multilayer cells able to capture energy from several wavelengths of light – will be the next wave, many believe.
Among manufacturers, Solyndra Inc. in Fremont, California has recently secured a federal loan guarantee of $US 530 million, which it will use to expand its manufacturing capacity. Solyndra, which only began commercial production in July of 2008, says it is currently shipping its cylindrical systems to fulfill more than $1.2 billion of multi-year contracts with customers in Europe and the United States.
Among others, Fort Collins, Colorado-based Abound Solar announced the April 14 opening of its first full-scale production facility, also thin-film, in Longmont, Colo. The plant will produce 200 MW of modules a year by 2010. Helio Volt in Austin, Texas is another, founded in 2001 but just ramping up production this year.
Meanwhile, a number of utilities – Southern California Edison and Pacific Gas & Electric, on the west coast, and style='color:black'>Public Service Enterprise Group in New Jersey, to name three – are planning genuinely massive investments in rooftop-mounted PV. Together, SCE and PG&E intend to own or PPA 750 MW in the next five years, , and potentially another 250 MW in the five years after that. PSE&G isn’t much behind, planning installation of 120 MW worth on utility poles, street lights, and the like.
Installed prices aren’t yet at competitive levels, the utilities say, but they’re getting closer. SoCalEd is targeting installed costs about $3.50/watt; its initial installations managed a cost of about $4.30 per watt, beating its own target of $5/W for that stage of the program. PG&E is presently targeting an installed cost of $4.28/W, and PSE&G is targeting $6.40 – all better than the current national average installed cost of $7 - $7.50/W.
At the distribution level, Arizona Public Service and National Grid, to name two, have announced they will be using rooftop solar as part of smart grid operation or to defer more expensive grid investment to deal with occasional local bottlenecks.
All of this represents a potential game changer, Enbar says.
Storage
Advanced storage technologies are emerging as potential game-changers capable of participating in ancillary services markets to, for example, provide frequency and voltage regulation, and also enable the greater grid integration of variable renewable resources. A number of technologies have been advancing on this front, including sodium-sulfur and lithium-ion batteries, flywheels, and ultracapacitors that are showing promise to provide storage options suited to specific short-term power and longer-term energy applications. Where geologic formations permit, underground compressed-air storage (CAES) is also an option, as several projects are demonstrating.
Relatively small energy storage facilities are becoming increasingly economic. Though still have a ways to go, their advancing technical possibilities have tremendous upside. For example, one game-changing concept is to distribute 25-50 kWh lithium-ion battery systems throughout neighborhoods to provide greater grid reliability. What if distributed energy storage units, installed by customers for their own purposes, could be automatically accessed by grid operators and other customers to provide high-value ancillary services? The utility doesn’t have to build as much backup capacity itself, and the customer who does invest in storage capacity gets a pretty attractive revenue stream to help pay off his investment. The ability to switch seamlessly between providing internal and external services based on momentary changes in relative value could bring more exotic technologies into the realm of the practical.
Advanced Batteries
Two major battery technologies are being explored by several companies: sodium-sulfur and lithium ion. Sodium-sulfur (NaS) batteries operate at temperatures high enough (300 to 350 °C) to keep the two poles, elemental sodium and sulfur, in a molten state. They have high energy density, high efficiency of charge/discharge (89—92%) and long cycle life. Because of the corrosive and potentially explosive nature of their components, their use is restricted to stationary power installations. To date, they are currently only manufactured by NGK Insulators in Japan, in the NGK/TEPCO consortium.

One recent installation of an advanced sodium sulfur battery energy storage system (BESS) is at the Metropolitan Transportation Authority in New York City. Designed for storing electricity to reduce refueling costs for the Authority’s fleet of more than 220 natural gas-powered buses, the system is saving about $246,500 a year: $26,500 in utility bills and an additional $220,000 annual savings in labor costs. The system powers the electric motors for three compressors used to refuel the buses. It is also virtually noiseless, produces no emissions and requires minimal maintenance.
"This advanced battery application, a first of its kind, will show the way to many more such facilities throughout the U.S. and will help pave the way toward a greener and more resilient electrical grid," said Dr. Imre Gyuk, Program Manager, Energy Storage Research, U.S. Department of Energy, at the official inauguration.
The pilot project has a long list of partners, including Natural Resources Canada and Hydro One.
Lithium ion batteries will be much more familiar to readers, as the power pack in their laptops, as well as the power source for the next generation of electric vehicles. They are also starting to be used in stationary grid applications. A recent installation was by 123Systems, a developer and manufacturer of advanced Nanophosphate™ lithium-ion batteries and battery systems. 123Systems delivered its first Hybrid Ancillary Power Units (H-APU) with AES Energy Storage, LLC, a subsidiary of The AES Corporation, in Watertown, Mass.
The system can serve two functions. First, A123’s H-APU will absorb (charge) energy from the grid during times when the frequency or voltage is too high and inject (discharge) that energy back to the grid when it is too low. A123’s H-APU is expected to allow greater use of variable sources of energy such as wind and solar by rapidly absorbing or injecting energy as these sources vary. The H-APU is expected to provide variable service much faster than existing power plants responding in seconds rather than minutes. And, because it is recycling energy already in the system, it will provide these services without additional emissions.
Second, the units are designed to provide backup services by storing energy until it is needed by the grid in the event of a power plant or other asset failure. In some markets, the portion of thermal power plant capacity normally reserved for ancillary services to provide reserve capacity and frequency regulation services can be freed up with such installations, allowing them to operate at a higher capacity and produce more electricity and associated revenue.
"We believe fast-responding, high-efficiency energy storage systems, such as A123’s H-APU, will make power systems more efficient and responsive. This technology gives Independent System Operators’ (ISOs) a powerful new tool to balance varying load with the increasingly varying supply created by renewable sources. They also create an efficient, low-cost way for plants to meet reserve requirements,” said Chris Shelton, President of AES Energy Storage, LLC.
A123 is under contract to provide multiple Hybrid Ancillary Power Units in 2008 and 2009 for use in grid stabilization applications in several AES facilities across the world. The initial unit, installed at one of AES’s Southern California power plants, is capable of delivering 2 MW of power at close to 90% efficiency.
Development of lithium-based battery technologies continues. Altair Nanotechnologies Inc., a provider of energy storage systems for power and energy management, and Amperex Technology Ltd., a designer and manufacturer of lithium-ion battery cells for mobile devices, announced a joint development agreement May 18 to accelerate the commercialization of a next generation of high-performance lithium-titanate battery cells.
American Electric Power, which in the past has been criticized in Ontario for sulfur dioxide emissions that waft across the border from its coal-fired power plants, has committed to creating upwards of a gigawatt of energy storage in its service territory over the next decade. At present it has seven MW of NaS batteries at four installations, serving a variety of purposes: enhancing reliability, providing support for weak sub-transmission systems and avoid equipment overload, deferral of grid investment by providing power during specific times of day when an area is constrained.
Michael G. Morris, AEP´s Chairman, President and Chief Executive Officer, said in 2007, “Our near-term goal is to have at least 25 megawatts of NAS battery capacity in place by the end of this decade. But this is just a start. Our longer-term goal is to add another 1,000 megawatts of advanced storage technology to our system in the next decade. We will look at the full spectrum of technologies – flow batteries, pumped hydro, plug-in hybrid vehicles and various other technologies in early stages of development today – to determine their feasibility and potential for commercial application.”
It’s also worth noting that AEP’s batteries constitute a type of distributed storage, located as they are in residential areas. Community energy storage thus becomes a cousin to distributed generation. Ali Nourai, AEP's manager of distributed energy resources, has called the company’s storage program a potential "game changer" for the utility industry. See below for a note on community energy storage.
Another US utility, Xcel Energy, is also testing out NaS batteries, with a recently-commissioned 7 megawatt-hour battery connected directly to a wind turbine at the MinnWind wind farm in southwest Minnesota. The installation will store wind energy and return it to the grid – and in fact will operate as a test to “straightline” output from a single wind turbine for daytime baseload power. The location was also chosen for its climate, to evaluate the battery in extreme cold weather. The unit has several functions, including frequency regulation, the object to try using a single unit for several functions, each with a potentially different commercial value, and thereby to generate several revenue streams. That installation cost $3000 per kilowatt, and while costs will inevitably come down as the technology matures, the operation will benefit from exploiting high-value niche markets as well as more dependable bulk power.
Electric vehicles
Discussion of lithium ion batteries leads naturally to an application that Nadav Enbar says is anticipated to become mainstream: distributed storage in the form of plug-in electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs). Machines that can take power off the grid during periods of low demand – doing so under the control of smart applications that can read the price of power, for example – and delivering it back to the grid when demand is high – are under development. Some beta models and one-off conversion units are being tested in small pilot demonstration projects. It can often provide this service while the vehicle is sitting in its parking space and the car’s operator is sleeping or working at his or her desk. The difference here is that now the parking spot has a power connector, making the vehicle part of a distributed power storage system that makes a smart grid run better.
The February issue of IPPSO FACTO covered one innovator in the field, Better Place, that is steaming ahead with pilots in Israel and Denmark and plans elsewhere. But Better Place is not the only one. Coulomb Technologies, also headquartered in California, provides a similar system of interconnected charging stations through a network of distributors, with vehicle energy paid for through smart cards and subscriptions to a smart charging network. The company has the beginnings of a system in San Jose, and plans for San Francisco, Chicago, Amsterdam and points in Belgium.
Elektromotive in the UK has developed an extensive EV recharging network, with already 21 charging stations in seven boroughs in London, more across the country, and more to come.
Xcel Energy is also putting electric vehicles together with smart grid management technology, with a recent announcement describing how it is testing six Ford Escape Hybrids with vehicle-to-grid technology, which will allow them to charge from and discharge energy to the grid, in one of the nation’s first field tests of the emerging technology. That project will help prove the significant environmental benefits associated with the dual value (transportation and electric energy storage) inherent in PHEVs, Xcel says, by demonstrating to what degree the variable nature of renewable sources can be eliminated by utilizing massive amounts of storage devices connected to the grid and available to be dispatched. “This project will move us closer,” the company says, “to better understanding the energy security benefit of PHEVs by helping quantify the percentage of the vehicle fuel market that potentially can be moved to domestic electric energy sources. In addition, it serves as a testing and validation opportunity for other types of distributed generation, related to how they can be managed and how the energy from distributed generation can be put back onto the grid when needed.”
Xcel describes its Smart Grid City, which it is testing in Boulder, Colorado, as consisting of “converting existing metering infrastructure to true two-way architecture integrated with outage management and customer information systems. In addition, we will convert substations to ‘smart’ substations; provide/install 10,000 in-home control devices and the necessary infrastructure to fully automate home energy use; and integrate 1,000 dispatchable distributed generation technologies (PHEVs, battery systems, vertical wind turbines, and solar panels) designed to minimize our carbon footprint by eliminating the inherent variable nature of renewable energy sources.”
Nadav Enbar cautions that full development of such a system, with all the control systems and billing models, will take decades.
Ultracapacitors
There is a certain amount of noise around ultracapacitors these days, much of it in connection again with electric vehicles. They also point to the potential for EVs to support the grid in distributed storage applications.
Capacitors have the ability to respond to demand very quickly, but conventional designs, in existence since the Leyden jar was invented in the 16th century, have little ability to deliver steady current for prolonged periods of time. New materials, experiencing a surge of development through, for example, nanotechnology, promise the ability to deliver far higher power output. Graphene Energy, a startup based in Austin, Texas, is working on ultracapacitors with electrodes made of graphene — sheets of carbon just an atom thick, a product of nanoengineering. The storage capacity of an ultracapacitor is limited only by the surface area of its electrodes, and graphene offers a way to greatly increase the area available.
Ultracapacitors are used for a number of commercial applications already in electronic devices and regenerative braking where high speed charging and discharging are important. The expected number of charge-discharge cycles in the lifetime of an ultracapacitor is huge – probably three orders of magnitude higher than that of conventional rechargeable batteries. The ultracapacitor market, which currently appears to be in the in the hundreds of millions of dollars per year, is expected to grow, partly because the devices can be used to condition power and significantly extend battery life when used in combination with more conventional power storage.
Another ultracapacitor maker, EEStor, has been making claims of a product with high energy density across a broad range of operating temperatures, and Toronto-based electric vehicle maker Zenn Motor announced May 21 that it plans to increase its investment in EEStor, with a view to replacing its current low-speed electric vehicles with vehicles powered by EEStor’s technology by fall 2009.
“Our engineering team has been working hard in preparation for the integration of EEStor’s technology into our planned range of electric vehicle offerings,” Michael Bergeron, VP of Engineering at Zenn, said in a news release. “The permittivity results provide a great incentive for us to further increase our investment in this regard.”
Recent test results of EEStor’s latest designs indicate the ability to achieve higher energy density at the same voltage—an important step in commercializing electric vehicles.
Energy Management Hubs
Smart energy management systems form another field of technology likely to encourage intelligent use of the grid. Time has not permitted a detailed exploration of this aspect, but as reported in the February issue of IPPSO FACTO, an Energy Hub Management System is being developed out of the University of Waterloo to allow real-time management of a consumer’s energy demand, production, storage and resulting import or export of energy. Project leader Professor Ian Rowlands notes that a central core at the consumer’s location will collect information from two-way sensor controls placed on energy-consuming devices, as well as information from the external environment (for example, local electricity conditions, electricity market prices and weather forecasts). The system will be able to make decisions that can be expected to manage local energy consumption and production effectively. A third component, a web-based portal, plus state-of-the-art wireless communication devices, will allow the system’s managers to oversee both energy consumption and energy production – such as embedded cogeneration – locally or remotely.
Technology will be developed that will integrate these systems, developing models and decision rules to determine whether the combined heat and power unit should be operated, or whether energy should instead be imported, to determine whether excess energy should be sourced (through generation and/or import) and stored in order to be used later, and to determine whether manufacturing operations should be curtailed in order to take advantage of demand response programs being offered (for example, interruptible load tariffs). To do this effectively, the hub’s control technologies will be embedded within the ‘bigger picture’ (markets and grids) and will also be reactive to the demands of the individuals (workers and immediate neighbours) who work and/or live within the hub. Development involves both specialized hardware for the hub, plus the software to run the system. It will be able to communicate with the various devices already available on the market to control individual pieces of equipment.
Superflywheels
Another highly-efficient, emission-free storage technology with rapid response capability, good for regulating grid power characteristics, is high-speed flywheels. style='mso-bidi-font-weight:bold'>See “Large scale flywheels,” elsewhere this issue.