Recent advancements in energy storage are growing the technology’s potential as a ubiquitous sustainable energy tool. Today, storage is considered to be a component of Smart Grid. And it is being applied to a number of types of applications.

Larry Dickerman, KEMA VP of T&D smart grid integration, provided an overview of the current status of energy storage at the 2009 Commonwealth of Virginia Energy Symposium (COVES). Focusing on “The New Energy Future” the event was held in Lexington, VA on October 7, 2009 (www.vmi.edu/coves). Here’s what Larry had to say about storage:

Why storage now.
The answer lies in how you look at what are we really trying to accomplish for our energy and utility future:

• Advanced metering infrastructure (AMI) deployment? – AMI is essentially the customer touch point on the smart grid, includes the smart meters on the customer property and the meter-utility data communications.  
• Smart grid? – This goes beyond AMI to encompass distribution automation and volt-VAR, automating the “mid-grid” distribution system from the substation through to the customer loads.   
• Integrated sustainable utility? – This expands on AMI deployment and distribution automation by integrating distributed generation, energy storage, hierarchy of control, renewables, EVs/PHEVs and beyond.

Old energy storage concept is new again.
Ultimately catalyzing the energy transition and building the utility of the future rests on integrating technical solutions to create sustainable environmental and economic outcomes. Energy storage is an “old” concept that has new applications in the emerging multi-directional energy system with an increasing renewable and distributed generation portfolio.

Storage concepts have been around for a number of years. Pumped hydro is the most common form of storage technology. But geographic limitations make it difficult to be placed where needed most and there’s the issue of seasonal unpredictability.

Recently, advancements in emerging storage technologies provide the potential of making storage a ubiquitous sustainable energy tool. Advancements have occurred in battery, flywheel storage technologies, and “above ground” compressed air. The types of improvements include fast response, multiple cycles, and transportability. And the technologies are NOT all the same. They perform differently but all have their place.

An integral part of future smart grids
Storage is now considered a tool and component of Smart Grid. It is being applied to a number of types of applications. Storage is part of integrating renewables into the grid—it can help maintain grid operations with large percentages of wind on the grid, which has ramping and diurnal challenges. It also offers benefits as Ancillary Services–fast response capabilities allow devices to perform better than current devices especially with the increased need for regulation. And storage can help addressing the convergence of electric and automotives industries being driven by emerging prospects for EVs and PHEVs.

Here’s a snap-shot look at the various storage applications:

• Renewables – decoupling and demand source availability, control and integration
• Transmission and distribution – asset management, VAR control, power quality, grid stability
• Trading / generation – control / load following, energy management, peak generation, load leveling
• System operators – frequency control, spinning reserve, balancing
• End user / industry – UPS / ride through / shut down, peak shaving, optimization of energy purchase by load shifting, reactive power

Advancing storage technology and applications: examples

Energy Island – an innovative plan for large-scale energy storage, a KEMA-Lievense study has examine the optimal size of energy storage in The Netherlands and the costs and cost-savings (value) of energy storage systems.

Community distributed storage – The concept being discussed today by AEP, examining 15-30kWh devices that can provide power and reliability for 4-6 homes or small commercial establishments. The benefits range from reliability to peak shaving.

The concept was first advanced as large scale devices, but now smaller, distributed concepts are being advanced as well. The application will not have the “cycling” stress that accompanies applications such as frequency regulation.

Currently, this application is being demonstrated with new storage technologies and equipment, such as NaS batteries–flow batteries may also fit well. Cost is a factor for “new” equipment being proposed for this application. Recycled vehicle batteries can be an excellent resource to provide a “low cost” storage device for application–EV lifecycles map into application needs quite well.

PHEVs and EVs – Technology is pushing out fuel economy and fuel cost savings. PHEV could eliminate 2 out of 3 gallons of gasoline used and EV’s eliminate 100% of gasoline. From an energy independence and security perspective, according to the DOE, the US imports 60% of its oil—two-thirds of which is for vehicle fuel. EVs use domestic fossil fuels, nuclear and renewables. And the environmental benefits include a net reduction in CO2 emissions and a reduction or elimination in tail pipe emissions. The technology poses challenges—from supporting purchasers to an increased demand on electric utilities.