68 / 232
68 |
Ten Year Network Development Plan 2015
0
6,000
5,000
4,000
3,000
2,000
1,000
GWh
e
/d
2015
V1 V3 V1 V3 V1 V3 V1 V3 V1 V3
2020
2025
2030
2035
Thermal flexibility
Flexibility from hydro pumped and storage
Figure 4.39:
Split of the daily variability between hydro
pumped storage and thermal sources
1)
0
7,000
6,000
5,000
4,000
3,000
2,000
1,000
GWh/d
2015
V1 V3 V1 V3 V1 V3 V1 V3 V1 V3
2020
2025
2030
2035
Figure 4.40:
Potential variability for Visions 1 and 3 in the daily gas demand (left) and electricity generation from gas (right) as a
consequence of RES variability
2)
0
7,000
6,000
5,000
4,000
3,000
2,000
1,000
GWh
e
/d
2015
V1 V3 V1 V3 V1 V3 V1 V3 V1 V3
2020
2025
2030
2035
Some of the flexibility required to meet the daily variability is provided by hydro
pumped storage, reducing the flexibility required from thermal sources. The hydro
pumped storage installed generation capacities will increase the flexibility provided
by this source by 54% in Vision 1 and by 82% in Vision 3 by 2035. The following
figure shows the split of the daily variability between sources.
Depending on fuel prices and generators’ strategies, the required thermal flexibility
could be provided by either coal or gas. The following figure shows the evolution of
the daily variability of gas demand in electrical and real quantities associated with
variable generation, based on the assumption of a balanced thermal flexibility split
between coal and gas. The flexibility provided by gas is likely to be even greater as
gas fired (CCGT) power stations are inherently more flexible than coal fired ones.
To cope with the expected high gas demand variability, and to compensate for the
unpredictability of variable RES, the gas system will have to have sufficient flexibili-
ty to provide quick and flexible sources of gas. This increased requirement for
system and supply flexibility should drive an increase in both flexible supply sourc-
es and interconnection of markets to ensure the availability of flexibility in the areas
where it is required.
1) As the graph reflects power generation, it is expressed in electrical units.
2) For the conversion to gas demand 50% efficiency has been used.