Guest Article by S P Ravi
The share of hydro electricity in the energy mix of state of Kerala has come down sharply over the last three summers. Hydro share that used to be around 25-30 percent in previous summers has come down to well below 15 percent on many days. This is despite a sharp rise in electricity demand since 2023.
Kerala’s historical Hydro domination in Total Power Scene The state used to have a significantly higher share of hydro electricity, compared to the national average. The first hydroelectric project in the state was commissioned across river Periyar, at Pallivasal in Idukki district in 1940. Since then, the state was almost completely dependent on hydro electricity for almost half a century. The state commissioned several hydro projects in the first three decades after independence. The total installed capacity rose to more than 1400 MW after the second phase of Idukki project was commissioned in 1986. The state was actually selling electricity to neighbouring states (at very low rates) after the first phase of Idukki project was commissioned in 1976, as the internal demand was low at that time. The demand started rising in 1980s and by 1990, the state had to buy electricity from outside. By early 2000s, the share of hydro electricity had come down to around 50 percent. With the demand continuing to grow and not much additional hydro capacity being added to the system, the hydro share in the total energy mix came down to about 30 percent by 2020.
Changing Scenario in recent years The last two summers have been extremely severe in Kerala as in other parts of the world. During this time, our electricity consumption has recorded an unprecedented increase. In 2023-24, when the rains failed in summer and in south west monsoon period, the state’s electricity demand increased by about 3200 million units compared to the previous year (From 27740 MU in 2022-23 to 30938 million units in 2023-24); a 11.5 percent increase, against a CAGR of around 3 percent in the previous decade. The highest daily electricity demand till 2022 was 93 million units of electricity, which increased to 103 million units the following year and to 115.95 million units on the 3rd of May, 2024. Similarly, the maximum demand during the evening peak, which was earlier 4400 MW, crossed 5000 MW in 2023 and after setting new records several times in 2024 March and April, it rose to 5797 MW on May 2, 2024.
Fluctuations in Electricity Demand in recent summers Electricity demand in Kerala is becoming more and more dependent on weather, especially during summer. Whereas the seasonal variation in demand is well known with 15-20 percent higher requirement in summer, compared to the Monsoon season, huge variation in daily electricity requirement is witnessed in summer in recent times, depending on the fluctuations in temperature. While such variations are common, with the unique demand pattern in Kerala, where about 55 percent of electricity is consumed by the domestic sector and another 15 percent by the commercial sector, the percentage of variation can be very high. In summer, electricity demand for cooling requirement from these sectors has increased significantly, especially after domestic air conditioner use has grown exponentially over the last few years. This makes it more prone to variations in electricity demand, in tune with the weather conditions.
The variation in demand in line with the temperature was very evident during the 2024 summer. Coming after a deficient monsoon and with the El Nino in force, the summer was expected to be harsh, as it indeed turned out. The mercury began to rise steeply from the second week of March and the electricity demand too started rising substantially. On the 11th of March, 2024, the daily demand crossed 100 MU (Million Units) for the first time in March. Thereafter, the total demand as well as the peak demand kept on rising, making and breaking records on multiple occasions until the second week of May. Even as the demand was steadily rising in April, there was a sudden drop in peak demand on the 12th of April, as several parts of the state received summer showers. Average evening peak demand for the previous three days was about 5400 MW, with a high of 5493 MW on 9/4/24. Against this, the evening peak demand on the 12th was 4769 MW only, a drop of 13 percent! After holidays on the next two days, the peak demand again rose to 5347 MW on the 15 and 5482 MW on the 16April.
The demand remained very high till the summer showers started blessing the state from the 8th of May. Average daily energy requirement in the first week of May was 110.5 MU, with a high of 115.95 MU on the May 3. The peak demand ranged from 5482 MW to 5797 MW with an average of 5663 MW. The corresponding figures for the next week were 94 MU/day and average peak demand of 4641 MW. The reduction in daily demand was 15 percent and that for peak demand was 18 percent. Obviously, such demand variations are challenging for the grid managers. Since the state has got more than 2000 MW hydro capacity, one would expect KSEBL to manage these demand variations with the help of these projects.
Can better forecasts help improve more efficient hydro operations? The state generates an average of over 7000 million units of electricity from its 12 large and several small hydropower projects annually. Projects with large reservoirs, including Idukki and Sabarigiri, limit generation during the rainy season, store maximum water, and generate more electricity in the summer. Plants with small storage capacity utilise the inflow available during the rainy season to the maximum and generate more electricity during that time. Average hydro generation for the entire monsoon period of June to November used to be around 20 MU/day. However, in recent years, hydro generation from June to September has increased significantly. Average daily hydro generation for this period in 2021 and 2022 were 28.5 MU and 31.8 MU respectively. After a very low of only 16.66 MU/day during the failed monsoon of 2023, it again rose to 27.7 MU/day in 2024. In summer, when more electricity is needed, around 20-25 million units were generated from the hydro projects. Surprisingly, there has been a significant decrease in summer electricity generation in the last three years, in spite of huge increase in total as well as peak demand.
Table 1 shows the average daily electricity demand and hydroelectric generation during the summer months since 2020.
Table 1 – Daily average electricity demand and generation from hydro stations in summer (in MU)
| Year | March | April | May | Summer Average | |||||
| Demand | Hydro Gen | Demand | Hydro Gen | Demand | Hydro Gen | Demand | Hydro Gen | Hydro as % | |
| 2020 | 76.7 | 15.29 | 68.32 | 17.7 | 70.71 | 21.62 | 71.91 | 18.2 | 25.3 |
| 2021 | 82.45 | 21.9 | 80.61 | 21.82 | 66.19 | 23.75 | 76.4 | 22.5 | 29.5 |
| 2022 | 84.37 | 26.49 | 82.27 | 27.41 | 76.14 | 20.98 | 80.9 | 25 | 30.9 |
| 2023 | 87.42 | 15.12 | 92 | 19.9 | 91.8 | 23.06 | 90.4 | 19.4 | 21.5 |
| 2024 | 98.61 | 15.96 | 106.37 | 18.99 | 91.82 | 17.45 | 98.9 | 17.5 | 17.7 |
| 2025 | 97.45 | 16.56 | 95.01 | 16.74 | |||||
Source: State Load Dispatch Centre website, KSEBL
The average daily electricity demand in the summer months in 2021 and 2022 were 76.4 MU and 80.9 MU, respectively. The corresponding hydropower generation was 22.5 MU per day in 2021 and 25 MU/day in 2022. 30 percent of the summer electricity demand and 40 percent of the peak demand could be met from hydropower projects on these years. However, in 2023, when the daily electricity demand crossed an average of 90 MU, the hydropower generation decreased to an average of 19. 4 MU. The following year, when the demand rose again to an average of 98.9 MU per day, the hydropower generation decreased further to an average of only 17.5 MU. The situation is similar in 2025; only 16.6 MU per day was generated from hydropower projects in March. It was only 16.74 MU per day in April.
Hydro generation vs water storage The reduction in hydro generation cannot be on account of water shortage. Reservoir storage position (in MU) since 2020 is provided in table 2 below.
Table 2 – Cumulative storage in KSEBL reservoirs (in MU)
| Year | 1st March | 1st April | 31st May |
| 2020 | 1950 | 1812 | 1092 |
| 2021 | 2635 | 2059 | 1483 |
| 2022 | 2751 | 2027 | 1364 |
| 2023 | 2241 | 1876 | 864 |
| 2024 | 2302 | 1885 | 1182 |
| 2025 | 2316 | 1925 | |
| Mean | 2366 | 1931 | 1197 |
Source: State Load Dispatch Centre website, KSEBL
From the table, it can be seen that the water availability at the beginning of summer was less than average in 2020 and above average in 2021 and 2022. The lower hydro generation in 2020 and higher generation in 2021 and 2022 for March, as shown in table 1, is in tune with the water availability. However, by the 1st of April, the storage position on all these years was closer to the mean storage of 1930 MU, with the deviation being less than +/- 7%. While the lower hydro generation in April 2020 can probably be attributed to the lockdown due to covid 19, there is no justification for reduced generation in April over the last three years, especially with huge increase in demand. The storage on the 1st of April in 2023 and 2024 were for 1876 MU and 1885 MU respectively and together with anticipated inflow for two months, total water availability upto the 31st of May was close to 2200 MU. After keeping the required reserve for June, water for generating about 1600 MU would still have been available. With this, it was very much possible to schedule hydro generation of more than 25 MU/day for April and May. However, the actual average hydro generation for April and May was about 21.5 MU/day in 2023 and only 18.2 MU/day in 2024. The figure for 2024 would have been still less, if not for higher hydro generation in the last 10 days of May. Hydro generation from 1st to 21st of May was 290.74 MU at a daily average of 13.84 MU and that in the last 10 days, it was 250 MU!! Interestingly, this increase in generation was made after the total demand had come down sharply from a very high of 110 MU/day in the first week of May to only 79.6 MU/day in the last 10 days of May.
Contingency for below normal monsoon rains The KSEBL is required to keep water for generating 600 MU at the end of May, as a reserve for June, in case of monsoon failure. However, they generally keep a much larger reserve. Table 2 shows that the actual balance as on the 31st of May over the last five years was almost double than what’s required. Needless to say, buying electricity from outside at a high price, ignoring the electricity that can be generated without a single penny of extra cost using the water lying in the reservoirs, creates huge financial burden for the Board.
Apart from the financial loss for the board, reduced hydropower production would mean less water in the rivers downstream, when their water requirement will be highest. This often leads to severe water scarcity at many places. Higher storage at the beginning of water year on June 1 can lead to rapid filling of the dams during the rainy season and increase the risk of floods.
It is likely that the reduced electricity demand may be one of the reasons for lower hydro generation this summer. The board may have planned for a rise in demand this year too, as in the previous two years and may have scheduled for power procurement accordingly. If that is the case, they seem to have failed to read the specific scenario that led to steep rise in demand last summer. Large reduction in summer rains and the El Nino phenomenon literally set Kerala on fire for two months from March last year and this led to a surge in electricity consumption. Also, they don’t seem to have taken into account the fact that the state had received excess summer rains in 2021 and 2022. If the board had factored in the prediction by Indian Meteorological Department in early March that we would receive good summer rains this year, they could have reworked on the demand projection accordingly. It’s high time that the board incorporates multiple layers of weather forecasts into its electricity planning.
Avoidable Financial Burden Financial burden due to excessive demand projection is not a new phenomenon. KSEBL and most other electricity utilities in India generally tend to go for higher demand projection. They often plan and build more projects and/or contract for more procurement than what’s actually required. This often results in under utilisation of available sources and can lead to significant, unnecessary financial burden to the utility. The case of liquid fuel thermal plants that the state built between 1997 and 2001 (5 projects with a total capacity of 771 MW) is a classic example for financial burden due to over projection of demand. These projects produced significant quantity of electricity upto May 2004 only. After that, these stations were kept idle for most of the time. The cost of maintaining these stations that seldom produced electricity was to the tune of Rs.400 – 500 crores annually.
Increasing solar capacity can help in addressing demand variations Since solar PV systems generate more on sunny days and less on cloudy days these systems can actually be of help in managing demand variations due to weather changes. Kerala has been slow in embracing solar power even as many other states were surging ahead. The capacity is now increasing and the state has got about 1500 MW of solar systems. The state is also planning to have some battery energy storage systems (BESS).
Let’s examine the solar generation against demand in the summer of 2024 and during monsoon period in 2023. Generation from only a part of the solar systems is being accounted at the SLDC (State Load Dispatch Cenre) website and table 3 provides data as available at the website.
Table 3 – Comparison of average daily demand and solar generation
| Season | Month | Demand (MU) | Variation (%) | Solar (MU) | Variation (%) |
| Summer 2024 | April | 106.37 | 1.46 | ||
| May | 91.82 | -15.8 | 1.11 | -31.5 | |
| Monsoon 2023 | July | 75.28 | 0.98 | ||
| August | 83.43 | 11 | 1.43 | 46 |
Comparison of the data shows that the demand for May 2024 was 15.8 percent less than that in April 2024. And solar generation for May 2024 was 31.5 percent less. Analysing further, average generation from solar systems in the first week of May 2024 was 1.46 MU/ day when the demand was very high at an average of 110 MU per day. In contrast, solar generation on two rainy days, on the 26th and 28th of May was very low at 0.6 MU and 0.52 MU respectively only against total demand of 72.3 MU and 80 MU.
Kerala faced a deficient monsoon in 2023. While the rain in July was close to normal as can be seen from the inflow into the reservoirs at 1283 MU against anticipated inflow of 1534 MU, August proved a disaster with practically no rains on most days. Inflow into the hydro reservoirs was extremely low at 309.44 MU against anticipated inflow of 1889.15 MU. Table 3 shows that the electricity demand for August was higher by about 11 percent and solar generation was 46 percent higher compared to July. The above discussion makes out a case for a significantly higher share of solar energy, along with facilities to store a part of the generation for managing demand variations in tune with the weather.
2025 situation The current year situation is as follows. Reservoirs had a cumulative storage for generating 2316 million units as on the 1st of March 2025 and for 1925 MU as on the 1st of April. As on the 1st of May, cumulative storage in the reservoirs can generate 1571 MU electricity. Together with the expected inflow for about 230 MU till May 31 the total water availability will be sufficient for generating 1800 MU. Even if 30 million units of electricity is generated from our hydroelectric projects daily till May 31, water for more than 800 million units will remain as a reserve on May 31, which will be 25 percent higher than the required storage for 600 MU.
Idukki, the largest storage project has a live storage of 39 percent (569 Mm3) as on 01/05/2025. Kakki reservoir of the Shabarigiri project also has got similar storage. Unless the KSEBL decides to run Idukki at around 75 percent PLF or more for the remaining part of the summer, the storage as on the 1st of June can be at 25 percent or more.
In Conclusion The state government, KSEBL and State Electricity Regulatory Commission (KSERC) should look into the situation and take necessary steps to increase the production from hydroelectric plants until the 31st of May. The reserve storage on June 1 should be limited to a maximum of 800 million units. It would be advisable for KSERC to prepare necessary guidelines/ protocols to ensure that the storage at the end of water year does not go beyond the upper limit. Provisions for recovery of additional liability on account of excess storage at the end of water year, from the concerned officials may also be part of the guidelines. Weather forecast, especially seasonal and monthly projections and short term forecasts by IMD and other agencies need to be monitored closely by the energy planners and production/ purchase planned accordingly. Increasing solar capacity, along with suitable and optimised energy storage facilities shall be prioritised.
S P Ravi (spravi.18@gmail.com), All Kerala River Protection Council
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Room for
optimality in Kerala Summer Electricity Demand vs Hydro Generation The share of hydro electricity in
the energy mix of state of Kerala has come down sharply over the last three
summers. Hydro share that used to be around 25-30 percent in previous summers
has come down to well below 15 percent on many days. This is despite a sharp
rise in electricity demand since 2023. Kerala’s historical Hydro domination
in Total Power Scene The
state used to have a significantly higher share of hydro electricity, compared
to the national average. The first hydroelectric project in the state was
commissioned across river Periyar, at Pallivasal in Idukki district in 1940.
Since then, the state was almost completely dependent on hydro electricity for
almost half a century. The state commissioned several hydro projects in the
first three decades after independence. The total installed capacity rose to
more than 1400 MW after the second phase of Idukki project was commissioned in
1986. The state was actually selling electricity to neighbouring states (at
very low rates) after the first phase of Idukki project was commissioned in
1976, as the internal demand was low at that time. The demand started rising in
1980s and by 1990, the state had to buy electricity from outside. By early
2000s, the share of hydro electricity had come down to around 50 percent. With
the demand continuing to grow and not much additional hydro capacity being
added to the system, the hydro share in the total energy mix came down to about
30 percent by 2020. Changing Scenario in recent years The last two summers have been extremely
severe in Kerala as in other parts of the world. During this time, our
electricity consumption has recorded an unprecedented increase. In 2023-24,
when the rains failed in summer and in south west monsoon period, the state’s electricity
demand increased by about 3200 million units compared to the previous year (From
27740 MU in 2022-23 to 30938 million units in 2023-24); a 11.5 percent
increase, against a CAGR of around 3 percent in the previous decade. The
highest daily electricity demand till 2022 was 93 million units of electricity,
which increased to 103 million units the following year and to 115.95 million
units on the 3rd of May, 2024. Similarly, the maximum demand during
the evening peak, which was earlier 4400 MW, crossed 5000 MW in 2023 and after
setting new records several times in 2024 March and April, it rose to 5797 MW
on May 2, 2024. Fluctuations
in Electricity Demand in recent summers Electricity demand
in Kerala is becoming more and more dependent on weather, especially during
summer. Whereas the seasonal variation in demand is well known with 15-20
percent higher requirement in summer, compared to the Monsoon season, huge
variation in daily electricity requirement is witnessed in summer in recent
times, depending on the fluctuations in temperature. While such variations are
common, with the unique demand pattern in Kerala, where about 55 percent of
electricity is consumed by the domestic sector and another 15 percent by the
commercial sector, the percentage of variation can be very high. In summer, electricity
demand for cooling requirement from these sectors has increased significantly,
especially after domestic air conditioner use has grown exponentially over the
last few years. This makes it more prone to variations in electricity demand,
in tune with the weather conditions. The
variation in demand in line with the temperature was very evident during the
2024 summer. Coming after a deficient monsoon and with the El Nino in force,
the summer was expected to be harsh, as it indeed turned out. The mercury began
to rise steeply from the second week of March and the electricity demand too started
rising substantially. On the 11th of March, 2024, the daily demand
crossed 100 MU (Million Units) for the first time in March. Thereafter, the
total demand as well as the peak demand kept on rising, making and breaking
records on multiple occasions until the second week of May. Even as the demand
was steadily rising in April, there was a sudden drop in peak demand on the 12th
of April, as several parts of the state received summer showers. Average
evening peak demand for the previous three days was about 5400 MW, with a high
of 5493 MW on 9/4/24. Against this, the evening peak demand on the 12th
was 4769 MW only, a drop of 13 percent! After holidays on the next two days,
the peak demand again rose to 5347 MW on the 15 and 5482 MW on the 16 April.
The
demand remained very high till the summer showers started blessing the state
from the 8th of May. Average daily energy requirement in the first
week of May was 110.5 MU, with a high of 115.95 MU on the May 3. The peak
demand ranged from 5482 MW to 5797 MW with an average of 5663 MW. The
corresponding figures for the next week were 94 MU/day and average peak demand
of 4641 MW. The reduction in daily demand was 15 percent and that for peak
demand was 18 percent. Obviously, such demand variations are challenging for
the grid managers. Since the state has got more than 2000 MW hydro capacity,
one would expect KSEBL to manage these demand variations with the help of these
projects. Can better forecasts help improve
more efficient hydro operations? The
state generates an average of over 7000 million units of electricity from its
12 large and several small hydropower projects annually. Projects with large
reservoirs, including Idukki and Sabarigiri, limit generation during the rainy
season, store maximum water, and generate more electricity in the summer. Plants
with small storage capacity utilise the inflow available during the rainy
season to the maximum and generate more electricity during that time. Average
hydro generation for the entire monsoon period of June to November used to be
around 20 MU/day. However, in recent years, hydro generation from June to
September has increased significantly. Average daily hydro generation for this
period in 2021 and 2022 were 28.5 MU and 31.8 MU respectively. After a very low
of only 16.66 MU/day during the failed monsoon of 2023, it again rose to 27.7
MU/day in 2024. In summer, when more
electricity is needed, around 20-25 million units were generated from the hydro
projects. Surprisingly, there has been a significant decrease in summer
electricity generation in the last three years, in spite of huge increase in
total as well as peak demand. Table 1 shows the average daily
electricity demand and hydroelectric generation during the summer months since
2020. Table 1 – Daily
average electricity demand and generation from hydro stations in summer (in MU)
Year | March | April | May | Summer Average | |||||
Demand | Hydro Gen | Demand | Hydro Gen | Demand | Hydro Gen | Demand | Hydro Gen | Hydro as % | |
2020 | 76.7 | 15.29 | 68.32 | 17.7 | 70.71 | 21.62 | 71.91 | 18.2 | 25.3 |
2021 | 82.45 | 21.9 | 80.61 | 21.82 | 66.19 | 23.75 | 76.4 | 22.5 | 29.5 |
2022 | 84.37 | 26.49 | 82.27 | 27.41 | 76.14 | 20.98 | 80.9 | 25 | 30.9 |
2023 | 87.42 | 15.12 | 92 | 19.9 | 91.8 | 23.06 | 90.4 | 19.4 | 21.5 |
2024 | 98.61 | 15.96 | 106.37 | 18.99 | 91.82 | 17.45 | 98.9 | 17.5 | 17.7 |
2025 | 97.45 | 16.56 | 95.01 | 16.74 |
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Source: State Load Dispatch Centre
website, KSEBLThe average daily electricity demand
in the summer months in 2021 and 2022 were 76.4 MU and 80.9 MU, respectively.
The corresponding hydropower generation was 22.5 MU per day in 2021 and 25 MU/day
in 2022. 30 percent of the summer electricity demand and 40 percent of the peak
demand could be met from hydropower projects on these years. However, in 2023,
when the daily electricity demand crossed an average of 90 MU, the hydropower
generation decreased to an average of 19. 4 MU. The following year, when the
demand rose again to an average of 98.9 MU per day, the hydropower generation
decreased further to an average of only 17.5 MU. The situation is similar in 2025;
only 16.6 MU per day was generated from hydropower projects in March. It was
only 16.74 MU per day in April. Hydro generation vs water storage The reduction in hydro generation
cannot be on account of water shortage. Reservoir storage position (in MU) since
2020 is provided in table 2 below. Table 2 –
Cumulative storage in KSEBL reservoirs (in MU)
Year | 1st March | 1st April | 31st May |
2020 | 1950 | 1812 | 1092 |
2021 | 2635 | 2059 | 1483 |
2022 | 2751 | 2027 | 1364 |
2023 | 2241 | 1876 | 864 |
2024 | 2302 | 1885 | 1182 |
2025 | 2316 | 1925 |
|
Mean | 2366 | 1931 | 1197 |
Source: State Load Dispatch Centre website, KSEBL From the table, it can be seen that
the water availability at the beginning of summer was less than average in 2020
and above average in 2021 and 2022. The lower hydro generation in 2020 and
higher generation in 2021 and 2022 for March, as shown in table 1, is in tune
with the water availability. However, by the 1st of April, the
storage position on all these years was closer to the mean storage of 1930 MU,
with the deviation being less than +/- 7%. While the lower hydro generation in April 2020
can probably be attributed to the lockdown due to covid 19, there is no
justification for reduced generation in April over the last three years,
especially with huge increase in demand. The storage on the 1st of
April in 2023 and 2024 were for 1876 MU and 1885 MU respectively and together
with anticipated inflow for two months, total water availability upto the 31st
of May was close to 2200 MU. After keeping the required reserve for June, water
for generating about 1600 MU would still have been available. With this, it was
very much possible to schedule hydro generation of more than 25 MU/day for
April and May. However, the actual average hydro generation for April and May
was about 21.5 MU/day in 2023 and only 18.2 MU/day in 2024. The figure for 2024
would have been still less, if not for higher hydro generation in the last 10
days of May. Hydro generation from 1st to 21st of May was
290.74 MU at a daily average of 13.84 MU and that in the last 10 days, it was 250
MU!! Interestingly, this increase in generation was made after the total demand
had come down sharply from a very high of 110 MU/day in the first week of May to
only 79.6 MU/day in the last 10 days of May. Contingency for below normal monsoon
rains The KSEBL is required to keep water
for generating 600 MU at the end of May, as a reserve for June, in case of
monsoon failure. However, they generally keep a much larger reserve. Table 2 shows
that the actual balance as on the 31st of May over the last five
years was almost double than what’s required. Needless to say, buying
electricity from outside at a high price, ignoring the electricity that can be
generated without a single penny of extra cost using the water lying in the
reservoirs, creates huge financial burden for the Board. Apart from the financial loss for
the board, reduced hydropower production would mean less water in the rivers
downstream, when their water requirement will be highest. This often leads to
severe water scarcity at many places. Higher storage at the beginning of water
year on June 1 can lead to rapid filling of the dams during the rainy season
and increase the risk of floods. It is likely that the reduced
electricity demand may be one of the reasons for lower hydro generation this
summer. The board may have planned for a
rise in demand this year too, as in the previous two years and may have
scheduled for power procurement accordingly. If that is the case, they seem to
have failed to read the specific scenario that led to steep rise in demand last
summer. Large reduction in summer rains and the El Nino phenomenon literally
set Kerala on fire for two months from March last year and this led to a surge
in electricity consumption. Also, they don’t seem to have taken into account
the fact that the state had received excess summer rains in 2021 and 2022. If
the board had factored in the prediction by Indian Meteorological Department in
early March that we would receive good summer rains this year, they could have reworked
on the demand projection accordingly. It’s high time that the board
incorporates multiple layers of weather forecasts into its electricity
planning. Avoidable Financial Burden Financial burden due to excessive
demand projection is not a new phenomenon. KSEBL and most other electricity
utilities in India generally tend to go for higher demand projection. They
often plan and build more projects and/or contract for more procurement than
what’s actually required. This often results in under utilisation of available
sources and can lead to significant, unnecessary financial burden to the
utility. The case of liquid fuel thermal plants that the state built between
1997 and 2001 (5 projects with a total capacity of 771 MW) is a classic example
for financial burden due to over projection of demand. These projects produced
significant quantity of electricity upto May 2004 only. After that, these
stations were kept idle for most of the time. The cost of maintaining these
stations that seldom produced electricity was to the tune of Rs.400 – 500
crores annually. Increasing
solar capacity can help in addressing demand variations Since solar PV systems generate more
on sunny days and less on cloudy days these systems can actually be of help in
managing demand variations due to weather changes. Kerala has been slow
in embracing solar power even as many other states were surging ahead. The
capacity is now increasing and the state has got about 1500 MW of solar
systems. The state is also planning to have some battery energy storage systems
(BESS). Let’s examine the solar generation against
demand in the summer of 2024 and during monsoon period in 2023. Generation from
only a part of the solar systems is being accounted at the SLDC (State Load Dispatch
Cenre) website and table 3 provides data as available at the website. Table 3 – Comparison of average
daily demand and solar generation
Season | Month | Demand (MU) | Variation (%) | Solar (MU) | Variation (%) |
Summer 2024 | April | 106.37 |
| 1.46 |
|
May | 91.82 | -15.8 | 1.11 | -31.5 | |
Monsoon 2023 | July | 75.28 |
| 0.98 |
|
August | 83.43 | 11 | 1.43 | 46 |
Comparison of the data shows that
the demand for May 2024 was 15.8 percent less than that in April 2024. And solar
generation for May 2024 was 31.5 percent less. Analysing further, average
generation from solar systems in the first week of May 2024 was 1.46 MU/ day
when the demand was very high at an average of 110 MU per day. In contrast,
solar generation on two rainy days, on the 26th and 28th of
May was very low at 0.6 MU and 0.52 MU respectively only against total demand
of 72.3 MU and 80 MU. Kerala faced a deficient monsoon in
2023. While the rain in July was close to normal as can be seen from the inflow
into the reservoirs at 1283 MU against anticipated inflow of 1534 MU, August
proved a disaster with practically no rains on most days. Inflow into the hydro
reservoirs was extremely low at 309.44 MU against anticipated inflow of 1889.15
MU. Table 3 shows that the electricity demand for August was higher by about 11
percent and solar generation was 46 percent higher compared to July. The above discussion
makes out a case for a significantly higher share of solar energy, along with
facilities to store a part of the generation for managing demand variations in
tune with the weather. 2025 situation The current year situation is as
follows. Reservoirs had a cumulative storage for generating 2316 million units as
on the 1st of March 2025 and for 1925 MU as on the 1st of
April. As on the 1st of May, cumulative storage in the reservoirs
can generate 1571 MU electricity. Together with the expected inflow for about 230
MU till May 31 the total water availability will be sufficient for generating 1800
MU. Even if 30 million units of electricity is generated from our hydroelectric
projects daily till May 31, water for more than 800 million units will remain
as a reserve on May 31, which will be 25 percent higher than the required
storage for 600 MU. Idukki, the largest storage project
has a live storage of 39 percent (569 Mm3) as on 01/05/2025. Kakki
reservoir of the Shabarigiri project also has got similar storage. Unless the
KSEBL decides to run Idukki at around 75 percent PLF or more for the remaining
part of the summer, the storage as on the 1st of June can be at 25
percent or more. In Conclusion The state government, KSEBL and State
Electricity Regulatory Commission (KSERC) should look into the situation and take
necessary steps to increase the production from hydroelectric plants until the
31st of May. The reserve storage on June 1 should be limited to a
maximum of 800 million units. It would be advisable for KSERC to prepare
necessary guidelines/ protocols to ensure that the storage at the end of water
year does not go beyond the upper limit. Provisions for recovery of additional
liability on account of excess storage at the end of water year, from the
concerned officials may also be part of the guidelines. Weather forecast,
especially seasonal and monthly projections and short term forecasts by IMD and
other agencies need to be monitored closely by the energy planners and
production/ purchase planned accordingly. Increasing solar capacity, along with
suitable and optimised energy storage facilities shall be prioritised. S P Ravi (spravi.18@gmail.com), All Kerala River
Protection Council
SANDRP 