WHITE PAPER:

CHALLENGES OF A CHANGING INDUSTRY:
THE TREND OF INCREASING RENEWABLESIMPACT OF RENEWABLES
ON THE GRID
For the first time ever, monthly generation from windand solar exceeded 10 percent of total power generationin the U.S. It happened in March 2017, and it marked atremendous growth from under one percent in 2007
and less than five percent only five years ago, according
to the U.S. Energy Information Administration.
The results in Europe are even more striking. By 2025,
European Network of Transmission System Operators
for Electricity analysts expect that 22 European countries
will have 50 percent hourly load penetration by renewableenergy sources (RES), and eight countries will have
100 percent.
Many Asian countries are experiencing significant
expansion of renewables, tripling their capacity since
2000. Southeast Asia has a rising electricity demandthat’s double the pace of growth of the global average,
and experts from the International Energy Agency believe
50 percent of that increase will come from renewables
due to policy and incentivization efforts.
But this increased RES penetration poses uncertainty
and puts pressure on grid system flexibility and stability.

Coal and nuclear plants are limited in how much they canhelp the grid respond. Energy storage systems such asbatteries can help but are still challenged in capacity andcost. Gas turbine combined cycle (GTCC) power plants,
even those that were designed to run at base load, canprovide support, but partnering with renewable energy
forces these plants to increasingly operate at part load andrequires rapid load changes. Adding to that, regulations onemissions are getting stricter, requiring more stable andefficient combustion during startups, rapid load changes
and part-load operation. Mitsubishi Power acknowledged
this challenge and collaborated with its customers to build
solutions that allow for partnering with renewables.
Based on Mitsubishi Power’s experience, many naturalgas–fired or oil-fired GTCC power plants are already movingfrom the continuous base-load operation seen several years
ago to cycling operation with a reduced number of operating
hours per year. Cycling includes more shutting down andstarting up, rapid load changes and low-load operation
to support grid requirements. These challenges forceequipment designers and power plant operators to explore
new means of flexible, sustainable and environment-friendly
GTCC operation, going beyond the original design basis toallow GTCC plants to remain profitable.

2RENEWABLES
DRIVE DIGITAL
POWER PLANT
SOLUTIONS
In tandem with digital advancements,
Mitsubishi Power collaborated withcustomers and software partners todevelop solutions to address theseand other challenges in an evolving
power industry. This collaboration
created TOMONI®, a suite of intelligent
digital solutions that help thermal
plant operators lower the cost ofelectricity, increase flexibility, improve
efficiency and achieve performancegoals by harnessing big data using
advanced digital technologies.

The need for increased thermal power
plant flexibility drove the creation ofsolutions that improve plant profitability
and performance. They not only
promote lower costs overall but also
increase responsiveness of the plant
throughout the operation cycle.
The challenge for plant operators is
to use advanced data management
and analytics to sift through large
amounts of operational data in realtime to create actionable knowledge
and control the plant with increasedprecision. This will allow plants to run
more flexibly with reduced impact
on hot parts and key component
life, while simultaneously avoiding
unplanned downtime, enhancing
predictive maintenance and enabling
condition-based maintenance.

TOMONI digital solutions help
plant operators achieve more
responsive, reliable andeconomically viable operationin the dynamic market, while
maintaining reliability andavailability comparable tobase-load-operated units.

3

FAST RAMPING RATE

The power output from solar and windfacilities varies from day to day and often on
an hourly or minute scale. In the absence ofwidespread installation of large dedicatedenergy storage systems, thermal power
plants will need to provide most of therequired load support and other ancillary
services, such as frequency control, throughimproved operational response.

FLEXIBLE OPERATION ANDPERFORMANCE IMPROVEMENTLEAD TO HIGHER UTILIZATION
From 2011 to 2017, Mitsubishi Power implemented more than
125 flexibility and performance improvement solutions in GTCC
plants to achieve faster startup and shutdown, lower combined
cycle minimum loads and increased part-load efficiency whilemaintaining performance. These solutions have placed plants ina better position in the market, resulting in higher utilization anddispatch rates in recent years.
Increasing flexible operation while minimizing detrimental effects
on critical components requires detailed data acquisition, expert
analysis and precise control. Among other things, these are
combined to allow operation closer to design limits and reduce
the need for conservative margins used to allow for uncertain
knowledge of actual operating conditions and historical operation.
TOMONI was created using fleetwide learning gathered throughmany years of remote monitoring and diagnostics using the fiveMitsubishi Power Remote Monitoring Centers around the world
as well as its own commercially operated GTCC power plants atT-Point. They provided the data and analysis to validate theseflexibility solutions.
The rapid evolution of the power generation industry is driving
many owners and operators of power plants to shift to more
flexible operation modes while maintaining performance.
Mitsubishi Power developed solutions that provide fast ramping
rate, peak power, reduced minimum load and reduced startup
time for plants to effectively pair with renewables.

TOMONI offers digital solutions that speed
up loading and unloading ramp rates on
existing GTCC plants and can achieve nearly
20 percent of rated load per minute on somenew plants.

REDUCE MINIMUM LOAD

At times of low grid demand, especiallywhen there is high renewable generation,
wholesale power prices are sometimes below
the incremental fuel cost of thermal power
plants. Plants are forced to either take an
expensive shutdown or operate at a loss tostay online and available to sell energy when
the spot market price increases. Being able
to operate as efficiently as possible at thelowest possible load during these periods canimprove plant profitability, and staying online
preserves the ability to take advantage ofupswings in market prices.

TOMONI offers digital solutions that allow
stable operation in a 20 percent load range
and improve part-load efficiency, as well asincreasing turndown by 10 to 15 percent.

4O&M OPTIMIZATION
INCREASINGLY IMPORTANT

REDUCE STARTUP TIME

Cycling operation of today’s power plants demands morevigorous, knowledge-based maintenance practices toprevent unplanned outages and maximize the useful lifeof equipment. A single unplanned unit outage can cause
millions of dollars in lost power generation and repairs.
This makes the increased use of historical and fleetwide
information for predictive maintenance beneficial. TOMONI
solutions use advanced analytics to monitor and forecast thecondition of power plant components and enable plants toimplement a condition-based maintenance strategy, based on
the combined knowledge, experience, data and data analytics
of Mitsubishi Power and the plant owner and operator.

Fast startup will allow response to griddispatch and maximize generation revenue,
while reducing startup fuel cost and emissions.

TOMONI offers digital solutions to reduce GTCC
startup times in existing plants, while some newplants can be near full load in 10 minutes.

PEAK POWERFLEXIBLE
O&M
OPTIMIZATIONOPERATIONSSOLUTIONSCHANGE BRINGSOPPORTUNITYFLEXIBLE
OPERATIONSOPERATIONSSOLUTIONSPERFORMANCEIMPROVEMENTIMPROVEMENTSOLUTIONS
With rapid fluctuations in grid requirements
and wholesale energy market prices, thermalpower plant profitability sometimes relies
more on capacity payments and less onenergy payments. This makes the ability toselect between preprogrammed operating
modes that quickly increase power output
the key to capturing market opportunities.

DATA
FOUNDATIONFOUNDATION& ENABLERS& ENABLERS

As the power market evolves and digital technology advances,the market will demand enhanced reliability, availability andmaintainability for power plants, and the industry will have torespond. Mitsubishi Power is driven to tackle those changes
by developing customized TOMONI solutions that targetcustomer needs and allow thermal power plants to work more
effectively with renewable energy sources, while sustaining orimproving their profitability.

TOMONI offers digital solutions for peak
power that apply increased inlet airflow and/or increased firing temperature.

KNOWLEDGE TO RESPONDDATA FOUNDATION& ENABLERS

O&M
OPTIMIZATIONPERFORMANCEPERFORMANCEIMPROVEMENTIMPROVEMENTSOLUTIONSFLEXIBLE
FLEXIBLE
OPERATIONSOPERATIONSSOLUTIONS 

Immediate response is required to avoid atrip when an alarm occurs, which means
operators need access to real-time information.

TOMONI offers advanced analytics so plant
operators can quickly make informed
decisions and take action.

TOMONI® is a suite of intelligent solutions that accelerates decarbonization with power plant design, O&M and system knowledge, together withstrong customer and partner collaborations. TOMONI leverages advanced controls, artificial intelligence and machine learning with multi-layered
cybersecurity to make energy systems smarter, more profitable and ultimately more autonomous on the road to a sustainable future.

O&M
OPTIMIZATION© Mitsubishi Heavy Industries, Ltd. All rights reserved. TOMONI® is a registered trademark of Mitsubishi Heavy Industries, Ltd.
Mitsubishi Power is a power solutions brand of Mitsubishi Heavy Industries.

Data Foundation & Enablers
O&M Optimization
Performance Improvement
Flexible Operations
METP-11DS06E2-A