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hectares, cultivating a verywide diversity of crops, in particular
Citrus fruit, with maize and wheat also widely grown.
Irrigation water for the region is diverted from the
Bembézar dam to the pumping station, operated using
four main pumps of 800 kW backed up by three auxiliary
pumps generating 315 kW, ensuring a service pressure of
30 m at hydrant level.
Energy saving scenarios
In order to arrive an accurate assessment of energy costs,
four management scenarios were proposed to analyze
energy consumption, CO 2 emissions and the energy
costs in the %0, region 7he first scenDrio reSresented the
current operation of the studied irrigation district, while the
remaining three were designed to represent alternative
management strategies.
Scenario One represented the current management of
the pressurized network, organized on-demand, so all
the sectors could be irrigated 24 hours daily. The current
SressXre heDd sitXDted Dt the SXPSing stDtion ZDs fi[ed
to 52 meter cube in order to ensure a minimum pressure
head of 30 meter cube at pumping station level.
Scenario Two represented two independent sectors,
according to two topological dimensionless coordinates,
under semi-arranged demand where farmers were
organized in two irrigation schedules of 12 hours per day,
with the required pressure head at the pumping station
different for each sector.
Scenario Three represented a photovoltaic (PV) system
designed to produce the annual energy required by the
sector with the lowest energy requirements in sector two,
combining sectoring (energy saving strategy) with the use
of renewable energy resources.
Scenario Four was designed to be similar to Scenario
three, although the PV system was designed to supply
energy to the sector with the highest energy requirements
in scenario two. (See Figure Two).
Results
Evaluation of potential energy savings with Scenario
One compared to Scenarios Two, Three and Four
The daily energy requirements in every month for on-
demand operation (Scenario One ) and sectoring operation
(Scenarios Two, Three and Four) are shown in Table One.
The average energy savings when the network operates
in sectors reached 30.8%, with this value found to be
practically constant for all months.
The total annual energy requirements in Scenario One
amounted to 4,319 Megawatt-hours (MWh) annually, while
in Scenarios Two, Three and Four they amounted to 2,985
Figure One: Location of the Bembézar Margen Izquierda irrigation district
Figure Two: Global solar irradiance at selected
Bembézar Margen Izquierda irrigation district during
course of the trial period