Wind Energy Storage OptionsGREG BELL

WARRINGTON EGGLESTON

SARAH HARDING

Background Information

Unlike coal or other energy sources, the amount of energy produced by wind cannot be controlled.

A large wind farm’s generating capacity can drop from gigawatts to zero watts in just seconds.

Electrical energy cannot be stored directly, so supply must meet demand and this balance has cost implications.

If a turbine’s energy is moved directly to the grid, energy in excess of the grid’s demand must be dumped.

Storage Options

Pumped Hydroelectric Storage (PHS) [Gravitational Potential Energy]

Battery Storage (Chemical Energy)

Compressed Air Energy Storage (Potential Energy)

Flywheels (Kinetic Energy)

Must be efficient in storage and provide power in a timely manner to meet demand.

Pumped Hydroelectric Storage Most mature and most used form of

storage (127 GW worldwide storage capacity).

Electricity is used to pump water uphill where it is stored as gravitational potential energy.

Low energy density – large area required.

Constrained by elevation and water availability.

Pumped hydro systems round trip efficiency is between 75 and 78 percent.

Compressed Air Energy Storage(CAES)

Use electricity to power an air compressor

The energy is converted back to electricity by mixing pressurized air with fuel and using it to power a combustion engine

Efficiency estimates vary significantly depending on the specific CAES technology and geologic features, but is usually between 73 and 89 percent

Risk of explosion

Flywheel Energy Storage(FES)

Converts electricity to kinetic energy in the form of rotational momentum of a mass

Converted back into electricity by letting the spinning mass power a motor

About an hour of stored energy, but can be released instantaneously

Constrained by rotor material strength, weight, and cost, as well as motor-generator size and technology

Can cause noise pollution

Electrochemical Batteries

Lead acid Very low cost, low specific energy and power, short life cycle, high

maintenance requirements and toxicity

Nickel cadmium Relative low cost, high energy density, high power delivery

capabilities, hardiness, reliability, high life expectancy and toxicity

Lithium Ion High cost, high energy density, are less mature, low standby losses

and cycling tolerance, low expected lifetime at full discharge, used in consumer electronics

Comparison of Options

Comparison of Options

Comparison of Options

Installed Revenue Opportunity

Comparison of Options

Comparison of Options

Works Cited

http://www.purdue.edu/discoverypark/energy/assets/pdfs/SUFG/publications/SUFG%20Energy%20Storage%20Report.pdf

http://spectrum.ieee.org/energywise/energy/renewables/an-energystoring-wind-turbine-would-provide-power-247

https://upcommons.upc.edu/e-prints/bitstream/2117/11473/1/Mu%C3%B1oz4.pdf

https://www.wind-watch.org/faq-electricity.php

http://www.mpoweruk.com/electricity_demand.htm