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Technobit Solutions India Pvt. Ltd Powered By Docstoc
					Technobit Solutions India Pvt. Ltd

               And

Qingdao Wuxiao Group Co., Limited

         Presents in India


  VRB Batteries
                              Introduction
The VRB battery, which stands for vanadium redox battery, is a technology which is being
described by many as "showing some real promise in stabilizing energy distribution in
renewable systems" (well sphere.com). This battery, which is not what we typically think of
when we hear the word, will help store and deliver power to the energy grid.
Right now, many of the problems being faced by those who would prefer a switch to renewable
power sources includes storage of the collected energy especially for the peak times, or those
times when the demand is at its highest. Solar power is collected during the day, but without a
way to store it, it is not of any use at night when we need our lights to see or want to relax in
front of the television for the evening.

Other methods of storing or creating energy have been used, including hydroelectric energy
where water is used to create electricity and then pumped back uphill and into reservoirs during
off peak periods. "Another method that has gained some recognition in the past is with
compressed air." (well sphere 2008) While these methods may be good ideas, building a huge
hydroelectric facility is not going to be cost effective in every area of the country. Batteries as
energy storage will still remain in the forefront as the most widely accepted and probably the
most cost effective method that is in development up to this point.
            Introduction contd........

The element vanadium, which was discovered in the 19th century and named for the
Norse goddess Vanadis (goddess of youth, love, and beauty), was first used in a project
with NASA and flow batteries. The flow battery is a simple concept with complex
formulations: liquid electrolytes are pumped from external tanks to a cell stack. Each cell
stack contains a different elemental form of vanadium/sulfuric acid. Ions are exchanged
through the charge/discharge cycle after traveling through a hydrogen-ion polymer
membrane. (Wellsphere.org 2008)

In simple English: a flow battery has outer tanks and an inner cell. The flow of the
solution (in this case vanadium and sulfuric acid) travels into the cell and interacts with
what is there. Ions switch from positive to negative or negative to positive and energy is
then produced or stored until needed, as in during peak times.

Reference: http://www.wellsphere.com/green-living-article/vanadium-battery-technology.
Retrieved on August 16, 2009.
                                  Overview

The VRB-ESS can economically store and supply large amounts of electricity on
demand and is focused on stationary applications. It is a long life, cost effective, low
maintenance, efficient technology that allows for the scalability of power and storage
capacity independently. The VRB-ESS is particularly beneficial to renewable energy
providers, utilities and end users through its ability to “inventory” electricity, allowing for
the optimal match of supply and demand.

The VRB-ESS is well suited for a variety of applications. Enabling the provision of
“firm” capacity from intermittent renewable generation such as wind and solar; more
cost effective and efficient generation of electricity in remote areas; capital deferral for
utilities; and load levelling (peak shaving) applications. The VRB-ESS is also capable
of providing backup power solutions including applications for utility sub-stations and
telecommunication sites
Overview contd..........
             Overview contd............
The VRB-ESS is characterized by having the lowest ecological impact of all energy
storage technologies and is unlike most other conventional energy storage systems that
rely on substances such as lead or cadmium.
Power supply in remote areas
                  Remote Area Power
                    Supply(RAPS)
In remote communities such as those off the grid on islands, diesel engines are
generally the source of power. These diesel engines operate for the most part
inefficiently as the load reduces to a fraction of maximum rating. The fuel efficiency can
vary by as much as 30%.

The integration of VRB-ESS reduces diesel consumption, O&M, emissions and
extends diesel life.

As wind and PV penetration rises on grids, there is a point at which the variation of
power generation begins to curse instability in the local grid. In RAPS networks this
figure is about 30% of the diesel nameplate. The additional of any wind or PV power is
then limited.

However by adding a VRB-ESS, the penetration level can approach 100% and project
paybacks as short as 2 years can be achieved. As fuel costs rise, the economics
improv
                             Product Diagram
Layouts & Footprint

Shown are some layouts for a VRB-ESS (500kW x 8hour) showing Cell Stacks, Electrolyte Storage
tanks and the housing of power electronics, controls and conditioning equipment.




                         .
.




Due to the flexibility in design layout, each system will be engineered for the chosen site. In
addition if it is indicated that a possible relocation is desired, single larger storage tanks will be
used.
                           Capital Deferral
A small amount of storage can be used to avoid a large capital investment and as a result,
increase utility asset utilization, reduce financial risks associated with large lump sum
investments whose capacity may never be used, conserve capital for other critical projects
and most importantly, reduce overall cost to end users. Other important benefits of storage
located at critical points in the distribution system include:

Enhanced service reliability and power quality using active VAR compensation and voltage
stabilization.

Load shifting, using low cost off-peak electricity for resale when electricity prices are higher,
thus reducing market risk exposure to volatile on-peak prices and controlling high cost energy
imbalance charges.

I2R losses avoided by serving peaks with local supply and actively correcting power factor
and maintaining system voltages.

Relieve congestion and provide a "ride-through" for pre-positioned energy sources at
bottlenecks - constraint relief and capital deferment.

Provision of spinning reserves, reactive power, flicker compensation and black start
capabilities.

Base-load units can achieve additional off-peak power operating hours at higher utilization
rates, raising the value of these assets - Load Levelling (Peak Shaving) - capacity extension.
                          How it Works
The VRB Energy Storage System (VRB-ESS) is an electrical energy storage system
based on the patented vanadium-based redox regenerative fuel cell that converts
chemical energy into electrical energy. Energy is stored chemically in different ionic
forms of vanadium in a dilute sulphuric acid electrolyte. The electrolyte is pumped
from separate plastic storage tanks into flow cells across a proton exchange
membrane (PEM) where one form of electrolyte is electrochemically oxidized and the
other is electrochemically reduced. This creates a current that is collected by
electrodes and made available to an external circuit. The reaction is reversible
allowing the battery to be charged, discharged and recharged.

The principle of the VRB is shown in more detail in Figure 1 - it consists of two
electrolyte tanks, containing active vanadium species in different oxidation states
(positive: V(IV)/V(V) redox couple, negative: V(II)/(III) redox couple). These energy-
bearing liquids are circulated through the cell stack by pumps. The stack consists of
many cells, each of which contains two half-cells that are separated by a membrane.
In the half-cells the electrochemical reactions take place on inert carbon felt polymer
composite electrodes from which current may be used to charge or discharge the
battery.
              How it works contd......


The VRB-ESS employs vanadium ions in both half-cell electrolytes. Therefore, cross-
contamination of ions through the membrane separator has no permanent effect on the
battery capacity, as is the case in redox flow batteries employing different metal species in
the positive and negative half-cells. The vanadium half-cell solutions can even be remixed
bringing the system back to its original state.

The open circuit cell voltage at a concentration of 2 mole per liter for each vanadium
species is 1.6 V when fully charged. The relatively fast kinetics of the vanadium redox
couples allows high Coulombic and voltage efficiencies to be achieved without costly
catalysts. The same current is passed through all of the cells as they are arranged in
series. Such systems have many admirable properties including high efficiency, long cycle
life, ease of scalability and negligible environmental impact.
                              Advantages

1. Layout
Rapid design and construction including environmental permitting - typically 8 months, since
no appreciable air, waste or sound emissions are produced.

Existing systems can be readily upgraded - additional storage capacity can be added (at low
incremental costs) by increasing the volume of electrolyte (litres) and/or output power can be
increased by adding additional cell stacks.
            Advantages contd.........

2. Operations & Maintenance
Low operating temperatures and less sensitivity to ambient temperature variations.

SCADA interface is Internet enabled or via dial up modem. Modbus interfaces are
available for interconnection to auxiliary systems.

Power Electronics and Controls. Use of advanced multi-quadrant power flow control
allowing phase control of outputs, voltage sag/dip compensation, low harmonic
distortion, reactive power function compensation (PFC), high short term and
instantaneous overload capacity - ideal for stability enhancement. Multi-layer,
encrypted password access to the control PLC.

Designed for unattended (remote) operation with very low maintenance costs (Rs.
0.4/kWh for the VRB-ESS).
                Advantages contd.......

3. Performance
Availability of greater than 99%.

The VRB-ESS can be discharged and charged greater than 100,000 times or 10 years
without material deterioration in system efficiencies.

The VRB-ESS has system round-trip AC to AC efficiencies of 65 - 75% depending on use
and location.

A theorical charge/discharge window of 1.7:1 (option of 1:1) - allowing off-peak charging
for on-peak dispatch - a fraction of the time required by other battery systems and ideal for
wind generation applications.
           Advantages contd...........


4. Electrolyte
For the VRB-ESS, cross mixing of electrolytes does not lead to the contamination of
electrolytes.

Indefinite life of electrolyte (no disposal or contamination issues).

Once charged, the electrolyte remains fully charged with low self-discharge.
                         Components


1. Control System
The VRB-ESS is controlled by a Programmable Logic Controller (PLC) and a Human
Machine Interface (HMI). One of the key functions of the PLC system is to control the
times and rates of charging the VRB-ESS. For example the PLC can be fed real time
data on prices and based upon the allowable maximum demand, state of charge and
price of off-peak versus peak energy, it will decide how quickly to re-charge the VRB-
ESS, when and for how long. This can be dynamic and can be optimized based upon
the situation. It is integrated with the rest of system through standardized
communications inputs, control signals and power supplies. It may be dialed up or
accessed through the Internet. It has multiple security layers to limit access to its
various functions and provides a tailored reporting and alarming function for remote
control and monitoring.
             Components contd.......

2. Power Conversion System (PCS)
The PCS role is to charge and discharge the battery and to provide enhanced power
quality, voltage support and frequency control to the local grid. It has a sophisticated,
fast acting (DSP), multi-quadrant, dynamic controller with proprietary control
algorithms, which is capable of switching the output the full range of the device i.e.
from absorbing full power to exporting full power within cycles. It does the same on a
reactive power basis and in any combination of the real and reactive power
requirements. The intelligence within the Inverter is integrated with the overall control
system. It is therefore capable of being easily reprogrammed (on site or remotely), to
adjust for any changes in site requirements, or settings that the operator requires
adjusted. The PCS is connected either in a series (isolated load) mode or in a shunt
configuration with static transfer switch option for UPS functionality.
             Components contd.......


3. Electrolyte & Storage Tanks
Energy is stored by chemical changes to a working fluid called the electrolyte. In redox
flow batteries the fluids contain dissolved species that can be electrochemically
oxidized or reduced to store the energy. The electrolyte in the VRB-ESS is known as
an "Aqueous Solution of Sulphates of Vanadium". It is made up of Sulphuric Acid, and
emulsified vanadium particles.

Storage tanks are used to contain the positive and negative electrolyte. The tanks are
typically a double-wall, self-supporting, fiberglass type with an internal PVC lining. They
are easily transported and supported on site. Each tank provides its own secondary
containment for the purposes of achieving "best-practice" design for spill management
and regulatory compliance. Tanks are a sub-assembly item factory assembled and
transported to site.
            Components contd........



4. Cell Stacks
The Cell Stacks are self-contained sealed devices that consist of many cells, each of
which contains two half-cells that are separated by a membrane. In the half-cells, the
electrochemical reactions take place on inert carbon felt, polymer composite,
electrodes from which current may be used to charge or discharge the battery.

When charged electrolyte solution is allowed to flow through the stack, ionic transfer
between the different forms of vanadium ions across a separating membrane will result
in a balancing electron flow into an external circuit (DC current) and so complete the
electrochemical path for discharge. Forcing current into the stack from an external
source reverses the process and recharges electrolyte in the stack, which is then
pumped back into the reservoirs.
       Components Contd.............



5. Balance of Plant
The balance of components required for the installation of a VRB-ESS consists of PVC
pipes for connection between the electrolyte storage tanks and the Cells Stacks, and
pumps to circulate the electrolyte through the system. Where required, HVAC units to
ensure electrical equipment is not exposed to extreme ambient temperatures and heat
exchangers to maintain the operating temperature of the electrolyte are included. In
cold climates the heat exchangers are not required.
                 Modular and Scalable

A primary advantage of the VRB-ESS is in its modularity - the separation of the power
component and the storage component of the system. A specified power rating is
determined by the number of cell stacks maintained in the system while the amount of
energy storage capacity required is determined by the amount of electrolyte in litres. If
a plant is determined to require a higher power rating, or additional storage capacity is
required, simply add additional cell stacks and/or tanks and electrolyte to the system.
  Load Levelling / Peak Shaving

The VRB-ESS can reduce the peak of a customer's energy load as seen by the
distribution system. This improves utilization of assets on the electrical grid and
rescues customer energy demand. The utility load factor is improved. The diagram
shows that by selectively releasing power during periods of high demand, significant
energy saving can be achieved.
Tomammae wind storage project
    operated by J-Power


In 2005 NEDO founded the first large scale wind energy storage project in the world. The
system was sized at 4MW nominal with a 6MW pulse and 1.5 hours of energy storage. It
was operated and ran for 3 years proving the capability of energy storage to smooth the
intermittent output of a wind farm. The wind farm consisted of 32MW of Vestas wind
turbines and was operated on Hokkaido Island by the utility J-Power. The system was
cycled over 270,000 times over the course of 3 years and several control algorithms
were developed to control the SOC of the VRB system. This validated the uniqueness of
the VRB as a battery capable of having its SOC measured under load at all times. This
reduces the sizing as compared with ALL other batteries and also ensures safety of
operation by avoiding any overcharging.
  Tomammae wind storage project
      operated by J-Power
Japan VRB technology installations
Place             Application                 Specifications Start of Operation

Utility Company   Peak Shaving         200kW x 8h                   1996
Utility Company   Peak Shaving         450kW x 2 hours              1996
Office building   Peak Shaving         100kW x 8h                   2000
LCD Factory       1) UPS
                  2) Peak Shaving        3000kW x 1.5 sec
                                         1500kW x 1h                2001
Laboratory        Wind Turbine Stabilization 170kW x 6 hours        2001
Golf Course       Photovoltaic hybrid 30kW x 8h                     2001
University        Peak Shaving           500kW x 10h                2001
Industries        Stabilization of wind turbine output 4MW x 1.5h   2005
Product display 1
Product Display 2
Product Display 3
Product display 4
Product Display 5
                       Product Display 6

Cathode V(Ⅱ)Solution   Cathode V(Ⅲ)Solution Anode V(Ⅳ)Solution   Anode V(Ⅴ)Solution
        0.5—3M                      0.5—3M                       0.5—3M
        0.5--3M
    Thank You



End of the slide show

				
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