pre planning submission op05 derryduff ... - Organic Power

The filling of the lakes to an operational level will take 15-24 weeks depending on the precipitation levels.
2.4 Operations
2.4.1 Overview
The proposed Cappanabrick-Derryduff PHES project will be commissioned to supply electric power from a
hydroelectric pump-turbine, to be produced by pumping 280,000 meters cubed water to a gravitational head of
210 meters using 49MW of electric power sourced from the grid during off peak hours of electricity demand, and
drawing down this head while producing 45MW of power from the turbine which power is delivered to the grid
during peak hours. All of the input electric power will be sourced from grid connected wind energy projects.
The process will transform unpredictable and variable windpower to reliable, dispatchable clean energy
delivered to the grid.
Electric Energy
The PHES scheme will deliver power 4 hours per day, corresponding to peak demand from 0600-0800 and 1700-
1900. The scheme will accept energy off peak for from 4 up to 20 hours per day depending on the available
wind energy. Energy is lost in the process through resistance and less than 100% efficiency in the pump and
turbine. These losses are more than compensated both in value and power quality, by the fact that intermittent
and unpredictable power is delivered via PHES as a predictable quality product in time and volume. The amount
of wind energy capacity that will need to be available to supply the scheme is approximately 30MW installed
capacity of wind turbines, assuming that the wind turbines are on average 35% efficient, and that the PHES
requires a minimum of 196MW hours per day over 20 hours.
2.5 Employment
When operational, the plant will require 1 part time supervisor, and the equivalent of 1.5 full time technical staff
for maintenance and management. The total full time job creation will be 2.
Fig. 6 Powerhouse (Indicative Only)
2.6 Decommissioning
It is current practice to re-commission PHES plants once the technical life of its components is over, due to the
increasing penetration of wind power into power grids. For example, many schemes in mainland Europe which
were built in the 1930s are now being re-tooled and upgraded after 70 years of operation (i.e. Waldeck 1 PHES,
Hessen, Germany, owned and operated by EON).
However, in the event that decommissioning is warranted for unforeseen superseding of the technology by
advances elsewhere in power systems, the following will be undertaken as decommissioning:
• All roads and structures will remain in place for future re-use
• The top reservoir be maintained empty
• The bottom reservoir will be maintained full to act as a semi-natural lake, and fish life encouraged
through the introduction of aquatic flora and soil to anchor them.
• Security fence around bottom reservoir will be removed to allow access for recreational purposes.
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