Research by Seamus Garvey, Professor of Dynamics at the University of Nottingham, led to the invention of WindTP - a new type of power transmission system for wind turbines that enables enables large quantitites of energy to be stored at low marginal costs and high effective turnaround efficiencies. Energy storage capacities in the order of 25-100 hours of rated turbine output are easily achievable with turnaround efficiencies above 80% and marginal costs below £10/kWh of (output) energy storage capacity.

Conventional power transmission arrangements for wind turbines simply enable the turbine to make electricity when the wind blows. With WindTP, energy is collected when the wind blows but energy is dispatched as electricity when required.

How it works

The WindTP system can be operated in any of the modes summarised below:

a) As a pure power-transmission system – using collected wind power directly to make electricity.
b) Transforming some wind power into electricity but putting most (60%) into storage.
c) Generating electricity where most of the energy comes out of storage and a small amount (40%) from wind.
d) Taking power from the grid and charging the store (no wind power used).
e) Recovering energy from storage (no wind power used).
f) A mix of (b) and (d) where all wind power gathered goes into storage.
g) A mix of (c) and (e) where any available wind power contributes some generation.

In all operating modes, gas circulates in the closed circuit - being compressed from 20bar up to 500bar and expanded again back down from 500bar to 20bar.

Why use it

By using this system a wind farm can become a flexible generation facility - generating electricity predominantly when demand is high. In effect, a windfarm incorporating WindTP transmissions achieves exactly the same functionality as a windfarm with a very large battery alongside, but the energy storage provided has longer lifespan and much lower cost than a traditional battery system.

Find out more about WindTP