To meet climate change and decarbonisation, the electricity sector is going through a transition phase towards a more sustainable energy system, while trying to remain reliable and affordable. This means that the system has renewable energy sources like wind, solar, biomass, hydro, etc. as a major part of the generation process. Some of these sources are also intermittent in nature, thus making the generation process variable and very dependent on the weather pattern. The ways in which electricity is consumed has also changed due to weather changes. The evolving power landscape is most apparent to independent system operators (ISOs), the entities tasked with managing the electric grid.

1. Mainstreaming Renewables:
Forecasting, Scheduling and Dispatching of RE
Towards A Net Zero Energy Power Sector
04th March 2020

2. GUJ, MAH & MP
KAR,
TAM
& AP
RAJ
SLDC
India Power Structure Integration with
RE Rich State phenomenon

3. Green Energy Corridor

4. Category
Anticipated Capacity
(MW)
Existing Capacity
(MW)
Requirement (MW)
Wind 60000 37608 (63%) 22392 (37%)
Solar 99533 34036 (34%) 65497 (66%)
SHP 5000 4677 323
Biomass 10000 9861 139
Total 174533 86181 (49%) 88352 (51%)
GoI RE target by 2022
Targeted RE Capacity to be added by 2022
RE target of 450 MW by 2030.
 RE Rich State: Issues
• Solar Generation is highly varies during morning & evening and extremely
varies during cloud cover and monsoon.
• Wind Generation variation @ 1000 to 1500 MW is common now in a days.
• Demand variation @ 2000 to 3000MW is common now in a days.

5. RE Forecasting & Scheduling Challenges
RE F & S

6. RE Forecasting Challenges
RE Forecasting Tool
o REMC (at 11 places (1 NLDC, 3 RLDC & 7 RE Rich State)) is implemented /
under final stage.
o However, most important, error between forecast and actual data are
measured with Normalised root mean square error, which cannot be justified
with current Deviation mechanism.
o Also, need to be developed accurate forecast mechanism, where Day ahead
forecast value should be nearer to the real value.
Issues with Forecasting of RE
o Forecasting of each Forecaster is having different value, due to
o having its own model to forecast.
o sources of weather data are also differ.

7. RE Scheduling Challenges
RE Scheduling Tool
o Concept of unique regulation on RE frame work at central and State.
o Accurate forecasting by QCA and provision for cluster wise forecast can be
considered.
o Forecasting fees structure for QCA.
o Provision of participation of each RE generators and strong involvement and
role of State Energy Development Agency for RE generators which are not
participating.
Issues with Scheduling of RE
o Each RE rich State is having its own RE regulation.
o RE PS wise scheduling exist, group wise scheduling in some of States.
o In case of wind mills, 51% de-pooled criteria, leads other generators towards
the majority generators, without its willingness.
o Even resilient steps towards RE generators for non-adhering RE regulation,
lots RE generators are still silent.
o Error / penalty formula.

8. RE Dispatching of Power Challenges
Issues with Dispatching of RE
o Adequate grid infrastructure is required to transmit the RE power to the load
centre.
o Long transmission line causes constraints in the grid parameters in the form
of over voltage & voltage fluctuations.
o Transmission network developed for RE plants remains unutilized during low
RE generation / off-peak condition resulting high voltage in system.
o Very high or low RE generation resulting in over / under loading in
associated transmission elements.

9. RE Dispatching of Power Challenges
Requirement for smooth Dispatching of RE Power
o The connectivity / injection should be approved at higher level voltage i.e. 66
KV & above
o The developer is need to be asked to construct required capacity
transmission line up to CTU/STU grid substation.
o Necessary upward transmission strengthening is need to be carried out as
required, by CTU/STU.
o Permission of injection in the grid is to be granted on
o Approval of permission of Injection into the Grid
o Verification of ABT meter installation and data availability at control
centre
o Verification of real time data availability at control centre

10. RE Dispatching of Power Challenges
Requirement for smooth Dispatching of RE Power
o Support from Developer & IPP
o To adhere CEA (Technical Standards for Connectivity to the Grid)
Amendment Regulations, 2013. -Measurement of harmonic content, DC
injection and flicker shall be done at least once in a year in presence of the
parties concerned.
o LVRT / HVRT installation & Operation and intimation of all static and
operation data to SLDC.
o Single window communication from Developer.

11. RE (23 %)
Variable, intermittent &
uncertain energy
Coal Generation
(56 %)
Not Effective
Nuclear
Generation
(2 %)
Must Run
Hydro Generation
(12 %)
Not available in RE
Rich State & as per
need
Gas Generation
(7 %)
Costlier & not
easily available
Thermal capacity is the backbone
of balancing RE as it is available
in large quantities.
Gas plant may ramp up / down quickly.
Must Run Status
Hydro plants can quick
response.
Balancing of Power System Challenges

12. Coal / Tech Minimum issues
– Old Machine: Slow response in pick up / back down
– Design of machine:
» Limited ability to back-down the generation as per machine design
» Not permit to run machine below CM / TM
– Oil Support after certain minimum level:
» Heat rate increases due to running of generator below TM / CM -
costlier generation
– Seasonal efficiency constrain:
» Thermal - summer &
» Gas - winter
Thermal capacity is the backbone of balancing RE as it is available in
large quantities.
Further, gas is costlier and hydro is negligible amount in India,
particularly in RE rich State.
Mainstreaming Renewables: Challenges

13. Coal / Tech Minimum concerns
60 to 70 % Technical Minimum in India (50 to 60 % TM / CM in new plants,
having advance technology)
Ramp up / ramp down Issues
Low Flexibility of thermal plant to pick up & back-down frequently
To keep costly gas base generation on bar to handle RE variation leads merit
order violation resulting uneconomical system operation
Ramp up / ramp down concerns
Coal - 1MW to 5MW per minute ramp (5MW to 10MW per minute ramp in
new plants, having advance technology)
Gas - 3MW to 7MW per minute ramp (7MW to 15MW per minute ramp in new
plants, having advance technology)
Mainstreaming Renewables: Challenges

14. Practical problem with
Coal plant:
– How long RE generation prevail (High or low wind gen trend) ?
– Can conventional plant put on RSD ?
– Are power plant again on bar on time after shut down ?
– Hot Start Issue: may synchronized in short duration
– Cold Start Issue: takes long time to synchronization
Gas plant:
– How long high / low RE generation prevail in a day ?
– Can gas based generation carry on bar with OC or CC ?
– Availability of Gas
– Penalty for non utilization
– Advance confirmation for next days
Mainstreaming Renewables: Challenges

15. Hydro plants can well balance the RE generation variation due to its quick
response with high ramping of 5MW to 15MW per minute.
• Most of hydro generation available in monsoon season during low load
scenario
• Cannot be utilised as balancing every time
• In general, hydro station running with irrigation programme also
• Availability of water level
Mainstreaming Renewables: Challenges

16. o Constrain in managing DSM (Deviation Settlement Limit)
o Change in ISGS schedule effective from 4th time block
o Tighten band of deviation +/- 250MW at State boundary
o DSM (Fifth Amendment effective from 3rd June 2019)
o Up to 31.03.2020, the sustained deviation from schedule continues for
12th time blocks, shall attract an additional charge of 10% on the time
block DSM payable / receivable as the case may be.
o From 01.04.2020, the sustained deviation from schedule continues for
6th time blocks, shall attract an additional Charge of 3%, 5% & 10%
on daily base DSM payable / receivable as the case may be. (3% from
1st to 5th , 5% from 6th to 10th & 10% from 11th violation onwards).
Mainstreaming Renewables: DSM

17. Additional Charge on account of violation of deviation in sign change as per 4th Amendment
Week
Additional
Charge
in
Crore
Additional Charge on account of violation of deviation in sign change as per 5th Amendment
0
100,000
200,000
300,000
400,000
500,000
600,000
10
(03.06.19
to
…
11
12
13
14
15
16
17
18
19
20
(12.08.19
to
…
Additional
Charge
in
Lacs
0
10,000,000
20,000,000
30,000,000
40,000,000
50,000,000
60,000,000
40
(01.01.19
to
…
41
42
43
44
45
46
47
48
49
50
51
52
1
2
3
4
5
6
7
8
9
(27.05.19
to
…
Week
Case Study GJ
Mainstreaming Renewables: DSM

18. Current - Technological Approach
o Accurate forecasting by State & RE developer
o Special APM gas allocation to RE rich State
o Two shift operation of conventional plant
o Ancillary service at Intra-State level
o Enhance O/D & U/D limit for RE rich State
o Operative hydro stations - pooled at national level
o Operative Pump mode - pooled at national level
o Energy Banking between States
Next - Technological Approach
o Increases Technical Minimum of conventional plant (up to 30%)
o Adoption of Battery Storage & Other storage – Suitable for Micro grid
o Made Operative of Pump mode hydro power station
o Research to convert conventional hydro into Pump mode
Solution

19. 19
Thanking you !!!