सौर ऊर्जा ; कैलिफोर्निया के अनुभव से भारत क्या सीख सकता है : The California Duck Curve – lessons for renewables in India?
भारत सौर ऊर्जा मैं व्यापक निवेश कर ने वाला है . परन्तु जैसे उद्योगों से पर्यावरण की समस्या को किसी ने नहीं सोचा था इसी तरह आज विश्व मैं सौर ऊर्जा के संभावित दुश परिणामों से कोई सचेत नहीं है. अमरीका के कैफ़ोर्निआ राज्य ने २०२० तक तेतीस प्रतिशत व् २०३० तक पचास प्रतिशत ऊर्जा का उत्पादन सौर ऊर्जा से करने का लक्ष्य रखा था .परन्तु वहां कुछ समस्याएं आयीं . एक तो सौर ऊर्जा का उत्पादन दिन मैं होता है जब की बिजली की मांग कम होती ई . भारत भी २०२० तक १७५ गीगा वात पॉवर सौर ऊर्जा से बनाने की सोच रहा है .यह भारत के लिए इतना लागू नहीं है क्योंकि यहाँ तो दिन मैं बिजली की मांग ज्यादा होती है . कोयले की बिजली हर समय बनायी जा सकती है . वायु टरबाइन से बिजली हवाकी स्पीड पर निर्भर करती है . पानी से बिजली हर समय बनाने के लिए दंस की आवश्यकता होती है . इन सब के समन्वय मैं कई तकनीकी समस्याएं आती हैं .
आदित्य गाँधी की इस लेख से भारत को बहुत सीखने को मिल सकता है .
5/25/2017 The California Duck Curve – lessons for renewables in India? – Opinion by Aditya Gandhi | ET EnergyWorld
http://energy.economictimes.indiatimes.com/energy-speak/the-california-duck-curve-lessons-for-renewables-in-india/2368 1/9
Aditya Gandhi
Director, Sapient Global Markets
The California Duck Curve – lessons for renewables in India?
The intermittency in renewable power generation creates a huge need for flexibility
in the grid. The “duck chart” suggests that flexible, non-solar energy resources will
increasingly be called upon to compensate for the sudden drop in solar power when
the sun goes down.
May 22, 2017, 01.08 PM IST
The California state in USA has been on the fore front of power sector transformation. In
2015, California lawmakers had passed a climate-change bill making it mandatory that the
Golden State should get 33% of its electricity from renewable sources by 2020 and
increase the production to 50% by the year 2030. The aim was to increase use of solar
photovoltaic cells significantly especially in the residential area. The plan seems to be
largely working. They seem to be well on track to meet their 2020 target and have already
achieved 27% of their electricity in the form of renewable energy.
But there is a hitch. According to a report by GE, California’s famous sunshine helps
produce lots of solar electricity, but only during the day—when the demand is typically
low. The report states that power demand peaks in the morning as people get ready for
work or school. This usage drops while they are away during the day, that’s when
maximum power is generated. Later, in the evening when they return home, the demands
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5/25/2017 The California Duck Curve – lessons for renewables in India? – Opinion by Aditya Gandhi | ET EnergyWorld
http://energy.economictimes.indiatimes.com/energy-speak/the-california-duck-curve-lessons-for-renewables-in-india/2368 2/9
peak again as ACs, TVs etc are switched back on typically between 7 to 9 p.m.
To explain why it is called the “Duck Curve”, let us simplify this with the help of a graph
given below. The blue line represents a typical electricity load pattern. The Grey line
represents solar production on an average day. The difference between the two is the net
load (represented by the orange line) that needs to be met by conventional sources. As
solar production is increasing the net load curve is taking the shape of a duck’s
belly).When the sun goes down, the demand for power from conventional power plants
needs to quickly ramp up. In a span of 3 hrs in the evening the conventional sources
need to ramp up production by almost 10 GW.
In fact the California grid operator expects this problem to continue to worsen over next
few years. See the graph below that shows how the ramp is becoming steeper year over
year.
5/25/2017 The California Duck Curve – lessons for renewables in India? – Opinion by Aditya Gandhi | ET EnergyWorld
http://energy.economictimes.indiatimes.com/energy-speak/the-california-duck-curve-lessons-for-renewables-in-india/2368 3/9
This is a practical problem as renewables become more widespread and their
intermittency creates new challenges for effective management of the grid. India has set
itself an admiral target of 175 GW of Renewable energy by 2022. The target will
principally comprise of 40 GW Rooftop and 60 GW through Large and Medium Scale
Grid Connected Solar Power Projects. With this ambitious target, India will become one of
the largest Green Energy producers in the world, surpassing several developed countries.
As is clear, generation output from solar before sunrise and after sunset is 0 MW.
The power system works by doing real time balancing of supply and demand. The
intermittency in renewable power generation creates a huge need for flexibility in the grid.
The change in the net load needs be nullified by increasing output of other power plants,
discharging energy stored in batteries or other storages etc. The “duck chart” suggests
that flexible, non-solar energy resources will increasingly be called upon to compensate
5/25/2017 The California Duck Curve – lessons for renewables in India? – Opinion by Aditya Gandhi | ET EnergyWorld
http://energy.economictimes.indiatimes.com/energy-speak/the-california-duck-curve-lessons-for-renewables-in-india/2368 4/9
for the sudden drop in solar power when the sun goes down. An expected all India duck
curve is provided below, extrapolated with just 20 GW of Solar generation connected to
the grid.
Today, most of the electricity is produced from coal based power plants in India. They
have a low ramp-up / ramp-down rate. This means that the Indian Grid will need to adapt
to meet this flexibility challenge. It will need to look at a number of alternates to handle this
challenge. On the supply side the biggest change needs to be recognition of ramp-up /
flexible / ancillary resources as special and to have a separate pricing model for them.
Hydro resources can very quickly ramp-up production and will need to be used more
judiciously. Gas based power plants can also act as great peaking or ramp-up resources
and will need to be priced and deployed appropriately. More supercritical coal thermal
power plants will need to be built which can better handle lower base capacity and sustain
higher number of starts/ stops and ramp rates. Grids will need to deploy more automate
generator control units to be able to quickly respond to changes in an automated fashion.
Also grid storage solutions like pumped hydro and newer means like battery storage etc.
will need to be researched and invested in.
On the demand side, time of use pricing should help flatten the peaks to some extent and
provide price signals for some of these peaking resources. This should be accompanied
by products like Demand response where customers are incented to move their demand
5/25/2017 The California Duck Curve – lessons for renewables in India? – Opinion by Aditya Gandhi | ET EnergyWorld
http://energy.economictimes.indiatimes.com/energy-speak/the-california-duck-curve-lessons-for-renewables-in-india/2368 5/9
to times of day when power is cheaper helping reduce peak demand and therefore the
ramp rate needed. This will also mean more detailed planning for generation, demand and
transmission and to keep sufficient contingency for unexpected variations.
All of this will require state of art grid management with increased real time supply
demand balancing, monitoring and ability to control and react to changes. Our clients in
North America are actively looking at solutions to handle this better and are reaching out
to us to help evolve their market processes and systems to better prepare them for the
future.
DISCLAIMER: The views expressed are solely of the author and ETEnergyworld.com does not
necessarily subscribe to it. ETEnergyworld.com shall not be responsible for any damage caused to any
person/organisation directly or indirectly.
About Aditya Gandhi
Aditya Gandhi works as a Service Delivery Lead for Sapient Global Markets based in Gurgaon.
He has worked with companies in the oil & gas and power space apart from mutual funds and
hedge funds in trading, risk management and physical portfolio optimization. In his previous
roles he has also worked in the Capital and Commodities markets. Aditya is a Bachelor of
Technology from IIT Delhi.
