Synergies between Renewable Energies
and Combined Heat and PowerMihail Ketov, June 12th 2018, Bucharest
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
Climate Policy Targets lead to Energy Transition
Introduction 1
Emerging Usage of Renewable Energy Sources (RES)
German target: 50% share of RES in electricity consumption in 2030
Especially intermitted sources like wind and solar
➔ Increasing feed-in from RES must be integrated into electricity markets
0
50
100
150
200
250
300
Reference A B C B
nuclear lignite hard coal natural gasmineral oil pump storage misc. conventional wind on-shorewind off-shore solar biomass hydromisc. RES peak load
GW
Electricity System Development Scenarios
(by German Transmission System Operators)
2012 2030 2035
Source: network development plan 2017
Source: IAEW
windsolar
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
Costs of Renewables on Downward Trend
Introduction 2
German RES capacity auctions (mandatory up from 750 kW)
Pay-as-bid principle based on merit order of bids (subsidy level and capacity)
Bids with lowest subsidy level will be granted until the total capacity reached
Total capacity based on expansion targets for each technology
Take place three times a year since 2015
➔ RES close to economic break even and thus subsidies not necessary
9,28,5
8,07,4 7,3 6,9 6,6
5,74,9
5,7
4,33,4
0
2
4
6
ct/kWh
10
Average Solar PV and Wind Onshore Auction Results in Germany
Solar PV Wind onshore auctions2015 2016 2017
Source: TenneT Market Review 2017
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
Compare German RES feed-in 2015 and 2030 – Exemplary Week
In future RES feed-in will
1. exceed demand temporarily
2. nearly completely missing for up to two weeks
➔ Volatile and random RES generation needs to be compensated
➔ Flexible and secure generation capacity crucial in order to cover volatile
difference between demand and RES feed-in (residual load)
0
20
40
60
80
Intermittent Renewable Generation requires Flexibility
Introduction 3
0
20
40
60
80
Windenergie Photovoltaik Nachfrage
GW
feed-in / load
2015
GW
2030
demand
MO TU WE TH FR SA SU MO TU WE TH FR SA SU
wind solar
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
Flexibility Option: Combined Heat and Power (CHP)
CHP plants provide thermal and electric power simultaneously
➔ High total efficiency due to usage of both energy types (up to 90 %)
Decreasing competitiveness of thermal plants
due to high RES share with low marginal costs
Increasing efficiency by using heat
Additional revenue due to heat sales
Target of German government:
25% of thermal generation with CHP
➔ CHP will coexist with RES during transition
0%
5%
10%
15%
20%
25%
German CHP Electricity Generation Share of
Thermal Power Plants
Combined Heat and Power as Efficient Generation
Introduction 4
Input and Output
CHPelectric power
thermal power
fuel
Source: Eurostat and BMWi
futu
re t
arg
et
high
efficiency
0%
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
Installed CHP
Thermal and electric output
increased in Germany
➔ CHP increase parallel to RES
CHP by countries in Europe
Widely used technology
Installed for utility services as district
heating as well as for industrial applications
➔ Germany with most absolute CHP generation in Europe
CHP in Germany and Europe
Analysis 5
0
20
40
60
80Electric CHP Generation (2015)
Source: EurostatTWhel
a
40
50
60
70
80
90
100
22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
the
rma
l
electric
Development of CHP Capacity in Germany
2009
20102011 2012
2013
GWel
GWth
Source: Eurostat
0
0
2014
2015
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
CHP process heating applications
Steam processes up to 500 °C
Hot water processes
Cooling
➔ Primarily used in chemical, paper
and food production
➔ Various technologies available depending
upon application
CHP Industry Applications in Germany
Analysis 6
0
10
20
30
40
50
CHP Applications in German Industry (2011)
CHP (own generation)heat network
TWhth
a
Source: Bundesverband Kraft-Wärme-Kopplung e.V.
010203040506070
0,001 0,01 0,1 1 10 100 1000
Brennstoffzellen (BZ) Gasmotoren (GM)
Mikrogasturbinen (MGT) Gasturbinen (GT)
Dampfturbinen (DT) Gas- und Dampfturbinen (GUD)
Technologies Available
eff
icie
ncy e
lectr
ic
power electric
%
MW
extraction condensing
heat recovery
backpressure
fuel cell (FC)
micro gas turbine (MGT)
steam turbine (ST)
gas engine (GE)
gas turbine (GT)
combined cycle gas turbine (CCGT)
GT
CCGT
STFC
MGTGE
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
Heat Demand
Depending on connected heat consumers,
temperature and time
➔ Heat demands needs to be covered at all times
Heat Supply
CHP units provide heat and electric energy
simultaneously
Power-to-Heat (PtH) as heat generation for
peak load through electric consumption
Heat storages for equalizing demand
➔ Heat generation portfolio provides a
degree of freedom in unit commitment
➔ Flexibility given in electric generation (CHP)
and electric consumption (PtH)
CHP as a Part of Heat Generation Portfolios
Analysis 7
hydro/thermal electric load
heat
storage
heat only thermal
load
heat portfolio
. . .
. . .
. . .
CHP
. . .
PtH
. . .
RES
Coupled Electricity
and Heat Sector
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
Industrial heating
Temperature independent process heat
Large-scale consumption
➔ High utilization and secure supply due
alternative generation units
District heating
Mainly in urban areas
Consumers mostly small scale businesses
and private households
➔ Volatile demand leads to lower utilization
and back-up capacities
➔ Both types can provide flexibility
Heat Portfolios in Germany
Analysis 8
Large Scale Heat Portfolios
industry district heating ~31 PJth/a
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
RES Integration and Market Incentives
CHP and PtH used to cover thermal demand
RES feed-in exceeds demand
→ PtH uses RES overproduction
→ Capacity for positive and negative residual load
→ Flexibility demand will result in corresponding incentives at the electricity market
➔ Integration of RES by using flexible CHP and PtH
➔ CHP and RES complement each other
Coverage of Residual Load with CHP and PtH
Flexibility 9
RES Overproduction
el.
ge
ne
rati
on
demand RES PtH
RES Missing
el.
ge
ne
rati
on
demand RES CHP
RES feed-in is missing
→ CHP fills electric demand gap
Synergies between Renewable Energies and Combined Heat and Power | 12.06.2018 | Mihail Ketov
Introduction
Intermitted and random feed-in from RES results in flexibility demand
Analysis
CHP with high total efficiency due utilization of thermal and electric output
Efficiency up to 90 %
Germany with the largest CHP generation in Europe
CHP will coexist with RES
CHP for heat provision used in chemical, paper and food production
Diversity of technologies for different production applications
Flexibility given by CHP in electric generation and PtH in consumption
Flexibility
Electricity market will reflect flexibility demand by price incentives
CHP and RES complement each other
Key Take Away
Summary 10
Institute for Power Systems and Power Economics (IAEW)RWTH Aachen University
Mihail Ketov, M.Sc.Mobile: +49 (0)162 80 252 88Mail: [email protected] Web: www.iaew.rwth-aachen.de
Director of IAEWUniv.-Prof. Dr.-Ing. Albert Moser
Any further questions?
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