An electro-chemical energy storage device, but unlike a battery, which stores energy chemically, ultracapacitors store energy through electro-static charge, without making use of any chemical reactions. This means that an ultracapacitor has some characteristics of a traditional capacitor, but also some characteristics of a traditional battery.
Capacitors are energy storage devices that operate by creating a negative charge on one conductive material and a positive charge on another. Electrons are removed from one piece of material and deposited on the other, creating an electrostatic charge in the device which, when connected through a circuit, causes a current to flow. Supercapacitors build on this basic concept using the Electrical Double Layer effect instead of insulating material between the conductive layers to greatly increase energy density and reduce production cost. Ultracapacitors have remarkably high storage capacity, super fast energy release (resulting in higher power availability compared to batteries), quick recharge time, and a lifetime of at least 10,000 charge/discharge cycles. In general, capacitors can deliver energy more quickly than batteries, making them well suited for applications where rapid charging and discharging is required, such as in frequency regulation applications. Ultracapacitors are being examined for a variety of applications including electric vehicle energy storage, utility scale energy storage, renewable energy integration and uninterruptible power supplies. Continued development is aimed at reaching higher energy densities at a lower cost.
Status:
Baseline Description:
While not technically an energy-efficiency technology, this could be an enabling technology for many renewable sources of energy and could therefore at scale be invaluable to energy efficiency and energy security efforts.
"Typical" Savings: 0% Energy Savings Reliability: 2 - Concept validated
Energy savings estimates could be identified by evaluating in the region how many electric light transport trains, electric buses and elevators exist and whether or not they utilize regenerative breaking battery banks or ultra capacitors. In ones that have regenerative capability, the ultra capacitors could be a more energy efficient storage technology to store recovered energy. (Note: elevators with variable frequency drives simply feed recovered energy back into the grid).
Simple payback, new construction (years): N/A
Simple payback, retrofit (years): N/A
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.
Grant Banks, 12/07/2010. Graphene-based supercapacitor hits new energy storage high Gizmag
Jason Lee, 02/01/2012. Ultracapacitor Energy Storage Wind Systems Magazine
Chrissy Coughlin, 06/10/2012. Ultracapacitors: The next big thing in energy storage? GreenBiz.com