DOCUMENT 2 - TENDER SPECIFICATION DOCUMENT
Performance and Cost of Combined Cycle Gas Turbine equipment
for duty cycles with increasing levels of intermittent power
generation
1
Introduction
1.1
This specification sets out the requirements of DECC for tenders to participate
in a study to investigate the impacts of operating combined cycle gas turbine
(CCGT) plant for duty cycles with increasing levels of intermittent power
generation.
1.2
The Department wishes to consult with authorities with Original Equipment
Manufacturing (OEM) experience of large scale (above 300 MWe) CCGT plant
to obtain information about the impact on their proprietary equipment. This
study will include both plant which OEMs anticipate could be procured in the
next few years and beyond 2020.
1.3
The work specified needs to be delivered by 15th March 2013.
2
Background
2.1
The Department of Energy and Climate Change (DECC) was created in
October 2008, to bring together:

energy policy (previously with BERR, which is now BIS – the Department
for Business, Innovation and Skills), and

climate change mitigation policy (previously with Defra – the Department
for Environment, Food and Rural Affairs).
2.2
Climate change is not only a massive threat to the global environment, it is
also perhaps the greatest economic challenge facing us in the twenty-first
century. It demands an urgent and radical response across the developed and
developing world. At the same time, the UK needs to secure clean, safe,
affordable energy to heat and power our homes and businesses.
2.3
DECC exists to take the lead in tackling these challenges. Our Department
reflects the fact that climate change and energy policies are inextricably linked
– two thirds of our emissions come from the energy we use. Decisions in one
field cannot be made without considering the impacts in the other.
2.4
For a significant period of time a number of commentators in industry have
been making claims that conventional least cost planning analysis of power
system development does not fully capture the costs to thermal power plant in
operating much more intermittently. In addition, there is a limited amount of
evidence available as to the overall impact on costs and emissions of running
the GB power system with much higher penetration levels of renewables with
gas generation as the balancing plant, with all studies to date making quite
large simplifying assumptions.
2.5
DECC recently commissioned a study from Imperial College and NERA
Economic Consulting1 which looked at the ‘whole system’ impact of system
balancing, an output of which are some scenarios with different generation
mixes, and a quantification of the degree to which high renewables
penetration increases the need for balancing services.
2.6
The outputs of this work have allowed us to develop ‘typical’ duty cycles which
CCGT plant might need to undertake and use these as the basis for an
analysis of the degree to which the whole life cost and plant emissions might
vary in different operational regimes. It is the Department’s intention to use the
duty cycles developed by the Imperial/NERA study to be used as an input into
this study.
1
Imperial College London & NERA, August 2012,“Understanding the Balancing Challenge”:
http://www.decc.gov.uk/assets/decc/11/meeting-energy-demand/future-elec-network/5767understanding-the-balancing-challenge.pdf
3
Scope
3.1
The Department wishes to understand the impact on performance and cost of
operating CCGT plant for varying degrees of arduous duty cycles. To allow it
to consider different duty cycles, the Department has outlined key components
of a typical duty cycle (start-up, load following, and shutdown), that if known
can be used to model a hypothetical duty cycle.
3.2
The Department wishes to receive information of the following gas turbine,
steam turbine configurations:
i.
ii.
iii.
State-of-the-art, 1 gas turbine, 1 HRSG, and 1 steam turbine
configuration;
State-of-the-art, 2 gas turbines, 1 HRSG and 1 steam turbine
configuration;
Next generation, 1 gas turbine, 1 HRSG, and 1 steam turbine
configuration
All configurations will burn methane and use ambient conditions of 10 °C,
1.013 bar and 60% humidity, with forced draft cooling. A complete list of study
definition can be found in annex A.
3.3
Base load should be considered as 7980 hours at full load, with 3 cold starts,
4 warm starts, 5 hot starts and 2 plant trips.
3.4
For each configuration the following performance and cost information (nonexhaustive) is of interest, see table 1 and 2:
Performance Information:










Net heat rate vs. load (for full load range)
Full load net output
Minimal Stable Generation (MSG)
Standard ramp rate curve
Fastest ramp rate curve
Minimum on time (MOT) and minimum shutdown time
(MST);
No load heat requirement;
Fuel & time for start-up from cold condition to MSG;
Fuel & time for start-up from warm condition to MSG;
Fuel & time for start-up from hot condition to MSG;
Table 1: Performance information





Fuel & time for start-up from cold condition to full load
Fuel & time for start-up from warm condition to full
load;
Fuel & time for start-up from hot condition to full load;
Fuel & time to shutdown from full load;
Fuel & time to shutdown from MSG;
Cost information:
For 4 Duty Cycles compared to Baseload, using the following annual cycle characteristics (to be advised):




No. of Cold Starts
No. of Warm Starts
No. of Hot Starts
No. of Trips




No. of hours at Full Load
No. of hours at 80% Load
No. of hours at 50% Load
No. of hours at MSG

Expected percentage effect on output degradation
over 25 years
Expected percentage effect on heat rate degradation
over 25 years
Expected reduction in asset life
What impact will occur on the following:



Percentage difference in O&M costs
Percentage difference in the average No. of days of
annual planned maintenance
Mid life modification cost as a percentage of CAPEX


For plant that can meet all of the duty cycles, what the percentage difference in CAPEX can be expected
Table 2: Cost information
3.5
The Department will provide information tables to collect the performance and
cost information, see example provided:
3.6
To supplement the information tables the Department wishes to obtain the
following additional information:
a) Please provide a written description of how the plant will be operated
during each of the four duty cycles;
b) Please comment on the difference in performance between the “new plant”
and existing UK CCGTs that may be operated in the same duty cycles and
if necessary any plant modification that would be required to allow the
existing CCGTs to operate in the flexible manner defined in the four duty
cycles;
c) Please describe the effect on non-CO2 emissions associated with
operating CCGT plant over the fluctuating loads described in duty cycles
1-4. Are there loads and times when UK non-CO2 emissions limits cannot
be met? Specific emphasis should be put on the impact of low load factor
operation, start-up, load following and shutdown;
d) Please describe the effect of operating CCGT plant over the fluctuating
loads described in duty cycles 1-4 in regard to life deterioration. Please
include for the full envelope of operation: start-up; ramping; load following
(for example ramping up/down by 5-20% of load); plant trip; emergency
start; and shutdown
e) Please comment on the effect of these duty cycles on start reliability, and
time/cost required following a start failure;
f) Please provide information regarding cost (and timing) of mothballing
CCGT plant and bringing it back into service;
g) Please provide information regarding cost (and timing) of converting
CCGT plant to OCGT;
h) Please feel free to offer any further comments on the approach to this
preliminary start to the study.
4
Period of contract
The contract will be for a study of up to 6 weeks, with the findings delivered by 15th
March 2013 at the latest.
Key timings for the project are listed below:
Project advertised
27th December 2012
Closing date for tender
17.00 25th January 2013
Announcement of successful applicants
31st January 2013
Kick-off meeting (conference call)
1st February 2013
Findings of study by
15th March 2013
5
Contract/service management Requirements
5.1
The successful supplier will be expected to identify one named point of contact
through whom all enquiries can be addressed to.
Annex A
Term
Definition
Base Load
Duty Cycle
Percentage difference in CAPEX (from
base load CCGT) 1
The Base Load Cycle is as described on 'Cycles' tab
The duty cycle are as described on 'Cycles' tab
The estimated percentage CAPEX difference for main power equipment only - Gas Turbine, Heat Recovery
Steam Generator, Steam Turbine Generator and Condenser
Percentage difference in O&M Costs
(from base load CCGT) 1
Percentage Difference in the Average
Number of Days of Annual Planned
Maintenance
(from base load CCGT) 1
Full Load net Output
Net Heat Rate Vs Load Curve
Minimum Stable Load
MSG
Fastest Ramp Rate Curve
Standard Ramp Rate Curve
Minimum on time
Minimum shutdown time
The estimated percentage difference in the average annual O&M costs over a 25 year plant life compared to
experience of existing base load CCGT's
No load heat requirement
Fuel required for typical plant Cold
start-up to full load
Time required for typical plant Cold
start-up to full load
Fuel required for typical plant Warm
start-up to full load
Time required for typical plant Warm
start-up to full load
Fuel input at full speed no load (MWth)
Fuel required for a typical cold start after 48 hours after shutdown from initiation to full load operation of the
CCGT (GJ)
Time required for a typical cold start after 48 hours after shutdown from initiation to full load operation of the
CCGT consistent with above fuel consumption (minutes)
Fuel required for a typical warm start after 12 hours after shutdown from initiation to full load operation of the
CCGT (GJ)
Time required for a typical warm start after 12 hours after shutdown from initiation to full load operation of
the CCGT consistent with above fuel consumption (minutes)
The estimated percentage difference in the average number of days of annual planned maintenance over a 25
year plant life compared to experience of existing base load CCGT's
The 100% load net output at the quoted ambient conditions
The estimated net heat rate at all loads (kJ/kWh)
The minimum load at which a plant would be able to stably operate safely and continuously (%)
Minimum Stable Generation - Net Output at the load defined above (MW)
The OEM's estimated fastest achievable ramp rate (MW/minute)
The OEM's standard ramp rate at which there would not be an equivalent operating hour penalty (MW/minute)
The minimum amount of time from synchronised to de-synchronised (minutes)
The minimum amount of time from de-synchronised to re-synchronised (minutes)
Fuel required for typical plant Hot
start-up to full load
Time required for typical plant Hot
start-up to full load
Fuel required for typical plant Cold
start-up to MSG
Time required for typical plant Cold
start-up to MSG
Fuel required for typical plant Warm
start-up to MSG
Time required for typical plant Warm
start-up to MSG
Fuel required for typical plant Hot
start-up to MSG
Time required for typical plant Hot
start-up to MSG
Fuel required for typical plant shut
down from full load
Time required for typical plant
shutdown from full load
Fuel required for typical plant shut
down from MSG
Time required for typical plant
shutdown from MSG
Mid life modification costs as a
percentage of CAPEX
Expected percentage effect on net
output degradation over 25 years
(from base load CCGT) 1
Expected percentage effect on net
heat rate degradation over 25 years
(from base load CCGT) 1
Fuel required for a typical hot start after 4 hours after shutdown from initiation to full load operation of the
CCGT (GJ)
Time required for a typical hot start after 4 hours after shutdown from initiation to full load operation of the
CCGT consistent with above fuel consumption (minutes)
Fuel required for a typical cold start after 48 hours after shutdown from initiation to MSG of the CCGT (GJ)
Time required for a typical cold start after 48 hours after shutdown from initiation to MSG of the CCGT
consistent with above fuel consumption (minutes)
Fuel required for a typical warm start after 12 hours after shutdown from initiation to MSG of the CCGT (GJ)
Time required for a typical warm start after 12 hours after shutdown from initiation to MSG of the CCGT
consistent with above fuel consumption (minutes)
Fuel required for a typical hot start after 4 hours after shutdown from initiation to MSG of the CCGT (GJ)
Time required for a typical hot start after 4 hours after shutdown from initiation to MSG of the CCGT consistent
with above fuel consumption (minutes)
Fuel required for a typical shutdown from full load to de-synchronisation (GJ)
Time required for a typical shutdown from full load to de-synchronisation consistent with above fuel
consumption (minutes)
Fuel required for a typical shutdown from MSG to de-synchronisation (GJ)
Time required for a typical shutdown from MSG to de-synchronisation consistent with above fuel consumption
(minutes)
Any modifications required to improve performance or maximise plant life for each duty Cycle
An estimated percentage increase/decrease in net output degradation over a 25 year plant life compared to
experience of existing base load CCGT's
An estimated percentage increase/decrease in net heat rate degradation over a 25 year plant life compared to
experience of existing base load CCGT's
Expected reduction in asset life
(compared to base load CCGT) 1
1
Positive = increase, negative =
decrease
An estimated reduction in plant life (i.e. before being required to replace major equipment) compared to
experience in existing base load CCGT's