Canadian rebirth for wind power (vanadium batteries)

http://www.canada.com/nationalpost/financialpost/printedition/story.html?id=11afe88f-f605-448b-ab7d-91af8a3fc6e4

VANCOUVER - Inside an unremarkable office building on the outskirts of Vancouver, a small team of engineers and marketers is building a technology that will tame the wind.

It is a high-tech battery that looks like a pair of hot-water tanks linked by a twisting network of plastic piping. Each tank is filled with vanadium, an element named after a Norse fertility goddess that could give birth to new possibilities in alternative energy by making wind turbines nearly as reliable as coal-fired electric plants.

First designed by NASA and developed by Vancouver-based VRB Power Systems Inc., the vanadium battery took a major step toward commercial success yesterday after the Irish government released a study showing it could substantially boost profitability at wind farms when the Emerald Isle is looking to inject some of its famous green into its power supply.

"It's definitely going to give us a lot of credibility," said Simon Clarke, VRB executive vice-president. "There's never been a fully commercial, large-scale storage project with wind, and this study gives us a blueprint for our technology, which we can use in Ireland, Europe and worldwide."

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Hmm. I could do a terawatt-hour for $170 billion. (bet that contract would make their nipples hard). They said their membranes last 10 years. Wonder what the replacement cost is? They didn't break that out.

Still seems like a better bargain to use that $170billion to build 85 gigawatt nuclear reactors. (or 170 reactors, if I buy them from India?) That gets me the actual energy, with no need for storage since it's baseload.

Not to worry...

n/t

1. What is the Vanadium Redox Battery Energy Storage System (“VRB-ESS™”)?

The VRB-ESS is a device that is capable of storing energy in multi megawatt ranges and for durations of hours or days - from any available input source such as the Grid, Renewable Resources or diesel generator. The stored energy can then be provided back into the Grid or supplied to a load as required and directed. It is uniquely capable of being charged as quickly as it was discharged and is able to respond to all forms of power quality variations so it can be operated in an Uninterruptible Power Supply (UPS) mode as well. For loads which require reactive energy, the VRB-ESS is fully rated to provide VARS at nameplate on a continuous basis either when charging or discharging.
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2. What are the Ranges of VRB-ESS Sizes Available?

VRB Power is the only provider of a full range of Energy Storage products for use by end users and utilities. This comprises four product lines:

1. The VRB-ESS for small systems sized for telecom applications intended to replace lead acid battery backup systems from 2.5kW's to 10kW's (multiple hours)
2. The VRB-ESS for small systems designed for Utility and Remote Area Power Supply systems - less than 25kW's (multiple hours).
3. The VRB-ESS for larger applications from 25kW's to 10MW's (multiple hours).

Units greater than 25kW's are available in 50kW increments with any specified hours of storage. You can specify storage requirements separately from power rating.
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3. What is the Energy Density of the Electrolyte (Wh/litre?)?

This is a function of the application requirement and can range from 15Wh/litre to 25Wh/litre as measured on a round trip charge/discharge cycle. These are actual measured and delivered values and should not be confused with ideal theoretical values which could be as high as 28 to 43Wh/litre. Other energy storage systems often quote theoretical values.
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4. What is the Power Density (W/kg)?

This is a function of the system cell stacks and electrolyte. For large systems this is 100-150 Watts/kg and for the small systems about 80 Watts/kg.
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5. Does the Electrolyte Self-Discharge?

Once charged the Electrolyte has very low self discharge as it is circulated through the cell stacks. If charged and stored separately it can remain charged indefinitely.
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6. How Many Hours are Required to Charge for Each Hour of Discharge?

You can charge the system as quickly as you discharge it. The system provides a roundtrip efficiency of 65 - 75%. Therefore with the input of 25 -35% additional power to cover the losses, you can get 1 hour of discharge for every hour of charge. A practical charge discharge ratio for optimal performance is about 1.8 to 1.
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7. How Fast Can it Respond to Short-Term Events?

Transient response to millisecond events such as voltage sags or motor starts is a standard capability of the system. Its use as an UPS is thus possible. In a DC application it is always "on" so instantaneous response is provided. There is no need for any bridging device as fuel cells require.
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8. What is the Footprint? What are the Weights of the System Components?

A unique factor of the VRB-ESS is that you can sore the electrolyte separately of the Cell stacks and Power electronics. This allows you to design the system footprint to fit virtually any space. The largest area required is for the electrolyte storage tanks. This can be determined form the energy density in Wh/liter. You can then chose the shape of the tanks and hence footprint of the system. For example a 1 MW 8Hour storage system will require 1MWx 1,000,000 x 8hours / 15 Wh/liter = 540,000liters of electrolyte. If square, 2meter high tanks are chosen then the footprint for the tanks will be 200square metres. The cell stacks and Power conversion systems will add a further 10 to 15% to the space.

The electrolyte weights about 1.4kg/liter and is usually over 90% of the total weight.
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9. What is the Life Cycle of the VRB-ESS?

The VRB-ESS can be discharged and charged greater than 10,000 times (20% to 80% SOC) and suffers minimal to no degradation from repeated deep charges and discharges. The anticipated life of the system is over 10 years, and could be extended by replacing the membranes in the cell stacks. The electrolyte will retain a residual value close to its original cost as it is completely reusable.
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10. What is the Time Required to Complete an Installation?

For multi-megawatt systems, delivery is approximately 8 months from order to energisation, including environmental permitting. Small systems can be delivered in approximately 3 months or from inventory.
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11. What is the Cost per kW? What is the Incremental Cost of Additional Storage Capacity?

The cost is quoted in $/kWh or $/MWh since the VRB-ESS is an "Energy Storage System" and should not be considered a UPS or even a generator. Although the VRB-ESS provides the full UPS capability, its primary use is for energy storage for long periods, which UPS and conventional technologies cannot provide. As an approximate cost, systems are priced between $350-$600 per kWh, sizes ranging from a few hundred kW's to MW size systems. As the size of the system in kWh increases, the cost per unit decreases significantly. The incremental cost of storage for large systems is approximately $170 per kWh.
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12. What are the O&M Costs Associated with the VRB-ESS?

There are only two moving parts in the VRB-ESS. These are low maintenance long life pumps, which require replacement every 5 to 7 years. All other operations and maintenance costs are limited to possibly two visits per year to check on overall status of the system. Detailed on line data is available to determine if any unplanned maintenance is required. Operations are automatic and programmed into the system controller. We estimate an O&M cost of $0.008/kWh is required. Reliability is thus very high.
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13. What Size is Required for Wind Farm Applications?

When sizing a VRB-ESS and wind farm the rule of thumb is that you need between 15 to 20% of the wind farm nameplate size in storage to achieve a 90% smooth output. The duration of storage is determined by tariffs, cost of undelivered energy, periods of low wind (wind regimen) and economics. The VRB can provide PULSE output up to 100% of its rating short term and longer term at 50% of rating allowing it to capture spikes of wind and to smooth volatility very well. No other technology can do this! The VRB-ESS is also supplied with a PCS capable of continuous reactive energy/VAR support (+ and -) so removes the need for static Var compensation.
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14. Is it possible to couple to SOLAR (PV) applications?

Yes the flexibility of the system allows the direct connection to the solar DC bus via a charge controller. The DC bus for the VRB-ESS varies from 900Vdc to 650Vdc. We can either supply the power for charging and discharging via a rectifier/inverter combination (PCS), or a DC/DC chopper and have the solar inverter convert to AC thus cutting costs and improving efficiency. In most situations the VRB-ESS output is AC stepped up from LV to MV so 400/480/690V to 13/11kV at 50 or 60Hz. The system also provides full reactive energy compensation if required for voltage control and removal of static capacitor banks.

When the market for V-batteries scales-up to GW/year (to keep up with the multi-GW/yr growth in wind power) the costs will come down....

The cost of the membrane "stacks" will come down with manufacturing. But that's not what drives the cost per kwh, only the cost of the rate of power you can shove into and out of it. The energy cost is just big giant tanks of vanadium solution, and that's about what they will cost, because that's about what that mineral costs -- once you get past a certain point the economy of scale on large hermetically sealed vats runs into the diminishing returns wall and you're left with the raw materials cost as the dominant factor.

$170 per KWh is actually rather good. Compare to lead acid which is still the price king: http://www.solarbuzz.com/Batteryprices.htm

The upshot though is that systems which aim to store/provide power for very long periods of time will be cheaper per kWh, which is the neat and unique thing about flow batteries.

...or gells if we got some extra bucks.

the non-USA part of the world does not seem interested
for other applications