Co-funded by the Intelligent Energy Europe Programme of the European Union 1 Renewable energy & cogeneration Introduction - Theory - Exercises - Business Case - Summary
Sep 11, 2014
Co-funded by the Intelligent Energy Europe Programme of
the European Union 1
Renewable energy &
cogeneration
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 2
OVERVIEW Introduction
– Cogeneration and renewable energy sources for intelligent energy networks– Renewable energy– Combined Heat and Power (CHP)
Theory– Solar energy– Biomass energy– Wind energy– Geothermal energy– Hydraulic energy– CHP technologies
Exercises Business Case Summary
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 3 Introduction - Theory - Exercises - Business Case - Summary
Introduction
Co-funded by the Intelligent Energy Europe Programme of
the European Union 4
Cogeneration and renewable energy sources for
intelligent energy networks
DG is the core logic of smart cities
DISTRIBUITED GENERATION (DG)
Some renewable energy sources are characterized by large discontinuity:
Storage
Grid
Energy efficiency
UrbanRuralCustomer loads
Industrial
Cogeneration
Renewable sources Local production of energy
ICT
Load balance
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 5 Introduction - Theory - Exercises - Business Case - Summary
Renewable energy sources have a regeneration time of energy smaller than
(or equal to) time of use.
Therefore fossil fuels cannot be considered as renewable ones.
The renewable ones are:
• Solar
• Biomass
• Wind
• Geothermal
• Water
Energy efficiency (is not a source, but reduces the use of sources)
RENEWABLE ENERGY
Co-funded by the Intelligent Energy Europe Programme of
the European Union 6
‘... Integrated system that converts the energy of any primary
energy source in the combined production of electricity and
thermal energy (heat) ...’ [1]
COMBINED HEAT & POWER
Co-funded by the Intelligent Energy Europe Programme of
the European Union 7 Introduction - Theory - Exercises - Business Case - Summary
Theory
Co-funded by the Intelligent Energy Europe Programme of
the European Union
Solar is a source => heat, cool, light and electricity
Great potential: In one hour, the sun provides the energy necessary for
the entire planet for a year[2].
Technologies:
• solar heating
• solar cooling
• photovoltaic
• concentrating solar power
SOLAR ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 9
SOLAR ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Solar heating
100 °C
Tem
pera
ture
150 °C
Production of sanitary hot water
Heating or preheating working fluids (industrial use)
District heating
Co-funded by the Intelligent Energy Europe Programme of
the European Union 10
SOLAR ENERGY
•mature technology
•no local CO2 emissions
•silent
•randomness of production
•storage
•variable environmental impact
Introduction - Theory - Exercises - Business Case - Summary
Solar heating: characteristics
Co-funded by the Intelligent Energy Europe Programme of
the European Union 11
SOLAR ENERGY
Closed-loop systems
• Absorption
• Adsorption
Open-loop systems
• DEC systems(Desiccant & Evaporative Cooling Systems)
Introduction - Theory - Exercises - Business Case - Summary
Solar energy
Solar collector
Deh
umid
ifica
tion
whe
el
Hea
t rec
over
y w
heel
Hum
idifi
erH
umid
ifier
Intake
ExhaustReturn air
Supply air
Solar cooling
Co-funded by the Intelligent Energy Europe Programme of
the European Union 12
•Quite new technology
•High costs for small sizes
•No local CO2 emissions
•Silent
•Randomness of production
•Storage
SOLAR ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Solar cooling: characteristics
Co-funded by the Intelligent Energy Europe Programme of
the European Union 13
SOLAR ENERGY
Direct conversion of solar energy into electricity.
• High cost of electricity
• Concentration
• New organic materials instead silicon
• Energy storage
• Batteries
• Hot water by Joule effect
• Hydrogen production
Introduction - Theory - Exercises - Business Case - Summary
Solar energy
Solar
cells
inverter
End users Grid
Direct current
Alternative current
Photovoltaic
Co-funded by the Intelligent Energy Europe Programme of
the European Union14
• No local CO2 emissions
• Silent
• Distributed
• Low efficiency
• Only electricity production
• Intermitted production
• Environmental impact
• Land use (agricultural use)
SOLAR ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Photovoltaic: characteristics
Co-funded by the Intelligent Energy Europe Programme of
the European Union 15
Concentrate the sun's energy in the unit of intercepting surface
•Linear parabolic
•Tower Systems with central receiver
•Linear Fresnel collectors
•Parabolic dish collectors
SOLAR ENERGY
Source: ENEA Quaderno solare termico a bassa e media temperatura
Introduction - Theory - Exercises - Business Case - Summary
Source: ENEA Quaderno solare termico a bassa e media temperatura
Concentrating Solar Power (CSP)
Electrical use
•Thermodynamic
‐Linear parabolic and Tower Systems
Recent use of molten salts as carrier of thermal energy (high temperature)
Thermal use
Co-funded by the Intelligent Energy Europe Programme of
the European Union 16
SOLAR ENERGY
Introduction - Theory - Exercises - Business Case - Summary
• No local CO2 emissions
• Silent
• Distributed
• Intermitted production
• Environmental impact (especially for tower systems)
• Land use (agricultural use)
• High temperatures achieved (T up to 550° C )
• Improvement of the thermodynamic cycle
• Need to keep the salts at a high temperature even at night
Concentrating Solar Power (CSP): characteristics
Co-funded by the Intelligent Energy Europe Programme of
the European Union 17
• Thermochemical processing
• Biochemical transformation
Biofuels: Converting biomass into liquid fuels for transportation:
• colza oil and sunflower oil (biodiesel),
• sugar cane, beetroot, corn (bioethanol).
Biopower: Burning biomass directly, or converting it into gaseous or liquid fuels
that burn more efficiently, to generate electricity.
Bioproducts: Converting biomass into chemicals for making plastics and other
products that typically are made from petroleum.
BIOMASS ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 18
Biomass
Organic wastes
Forest
Vegetables
Technological
transformation of products- Food
- No food
Agricultural-
Animals-
Vegetables
Energetic coltivations
Aquatic Land
BIOMASS ENERGY
Introduction - Theory - Exercises - Business Case - Summary
[3] Source: Corso di Impatto ambientale Modulo b) Aspetti energetici prof. ing. Francesco Asdrubali Energia dalle Biomasse
Co-funded by the Intelligent Energy Europe Programme of
the European Union 19
MAIN TECHNOLOGIES AVAILABLE FOR USE OF BIOMASS
Biomass
Wood
Oil-bearing crops
Glucose crops
Organic waste
Treatment (mechanics, thermochemical, biochemical)
Mechanics (Cips …)
Gasification
Carbonizzation
Pirolysis
Esterification
Alcoolic fermentation
Anaerobic digestion
Wood
Fuel
Gas
Coal
Oil
Ethanol
Internal Combustion Engine (Otto cycle)
Internal Combustion Engine (diesel cycle)
Gas Turbine Gas Microturbine
Boiler + steam turbine
Technology
BIOMASS ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Pirolysis
Co-funded by the Intelligent Energy Europe Programme of
the European Union 20
• on demand production
• storage
• CHP configuration
• technology in development phase,
• use of weed killer (for intensive crops)
• environmental impact (from very limited to non-negligible)
BIOMASS ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Biomass: characteristics
Co-funded by the Intelligent Energy Europe Programme of
the European Union
Winds are caused by the uneven heating of the atmosphere by the sun, the
irregularities of the earth's surface, and rotation of the earth.
WIND ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Powerup to 8 MW [8]
Localization on shore/off shore
TechnologyHorizontal and vertical axis wind turbines
Rotor
Breaking system
Tower and base
Overgear
Generator
Control system
Nacelle, yaw system
Fonte: ENEA opuscolo l’energia eolica [4]
Co-funded by the Intelligent Energy Europe Programme of
the European Union22
• No local CO2 emissions
• Environmental impact
‐ Noise pollution (sound and sub-sound)
‐ Biodiversity
‐ Visual
• Intermittent production
WIND ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Wind: characteristics
Co-funded by the Intelligent Energy Europe Programme of
the European Union 23
Geothermal energy uses the earth's heat (steam or hot water at various
temperatures.) [5]
•Vapor-dominated hydrothermal systems
•Water-dominated hydrothermal systems
•Hot dry rock systems
•Sands geo-pressurized
Geothermal energy can be classified according to the temperature of the
fluid
GEOTHERMAL ENERGY
Introduction - Theory - Exercises - Business Case - Summary
High enthalpy heat 630 kcal/kg
(dry steam)
Medium-enthalpy heat 100-630 kcal/kg
(a mixture of steam and water)
Low enthalpy heat 100 kcal/kg
(water at 100 ° C)
Co-funded by the Intelligent Energy Europe Programme of
the European Union 24
High enthalpy
•Electric Energy
•Industrial steam use
Low and middle enthalpy
•Balneology and spa resorts
•Greenhouse crops
•Aquaculture
•Industrial use
•Drying products
•Other use
GEOTHERMAL ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 25
Domestic use:
• mature technology• large power range • on demand • reduced environmental impact or negligible • fluid temperature: 12-15 ° C • cooling • heating (with integration by heat pump)
GEOTHERMAL ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Geothermal: characteristics
Co-funded by the Intelligent Energy Europe Programme of
the European Union
Use the potential energy of the water
Different types of turbines as a function of the hydraulic jump
available.
• Pelton,
• Francis,
• Kaplan,
• Cross Flow (Banki)
• Archimedes cochlea
HYDRAULIC ENERGY
Introduction - Theory - Exercises - Business Case - Summary 26
Co-funded by the Intelligent Energy Europe Programme of
the European Union27
• mature technology
• no local CO2 emissions
• on demand
• storage
• high environmental impact,
• ecosystem damage,
• only electricity production
HYDRAULIC ENERGY
Introduction - Theory - Exercises - Business Case - Summary
Hydraulic energy: characteristics
Co-funded by the Intelligent Energy Europe Programme of
the European Union 28
The idea of cogeneration is implicit in the Second Principle of Thermodynamics:
• In really feasible and really used technologies, the portion of discarded heat is, in general, greater than the portion that is converted in mechanical work.
• A generic thermodynamic cycle, addressed to convert heat in mechanical work, has necessary to discharge a part of heat in input to the cycle.
• Thermal energy is a kind of energy largely used in industrial and civil applications.
COMBINED HEAT & POWER
• Cogeneration process leads to a more rational use of primary energy with respect to processes that produces separately the two kinds of energy.
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 29
Plants producing separately electric energy and thermal one can be defined as
Separated Heat & Power (SHP).
A comparison between these two plant engineering solutions can help to
assess the advantages of Combined energy generation (CHP) with respect to
the separated one (SHP)
COMBINED HEAT & POWER VS. SEPARATED HEAT & POWER
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 30
ChemicalEnergy
mcHi
HeatQ
WorkL
Useful WorkLe
Chemical pollution
Thermalpollution
Mechanical losses
UsefulHeat
Electric energy
Thermalenergy
CHP Vs SHP
ηmηtηc
ChemicalEnergy
mcHi
HeatQ
ηtηc
SH
PC
HP
ChemicalEnergy
mcHi
HeatQ
WorkL
Useful workLe
Chemical pollution
Mechanical losses
Electric and
thermal energy
UsefulHeat
ηmηtηc
COMBINED HEAT & POWER
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 31
A) SPLIT PRODUCTION OF ELECTRICITY AND HEAT(All figures are energy units)
= 80/148 = 54%
50
( =80%)
30( =35%)
Losses = 68
THERMAL REQUEST
ELECTRIC REQUEST
+ +
8063
85
148
INPUT
COMBINED HEAT & POWER
Introduction - Theory - Exercises - Business Case - Summary
OUTPUT
Co-funded by the Intelligent Energy Europe Programme of
the European Union 32
B) COMBINED PRODUCTION OF ELECTRICITY AND HEAT
(All figures are energy units)
50
30
IN
Losses = 20
THERMAL REQUEST
ELECTRIC REQUEST
+COGENERATION
PLANT
80 100
= 80/100 = 80%
100
COMBINED HEAT & POWER
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 33
The use of cogeneration systems allows
reducing primary energy consumptions
from 15% to 40%, produced electricity
and heat being equals.
COMBINED HEAT & POWER
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 34
• Economically: thanks to plant better efficiency, the energy content of
the fuel can be used in more efficient way.
Further savings can be realised due to local production of energy.
• Environmentally: lower consumption of fuel implies lower
environmental injurious emissions.
• Financially: cogeneration is considered an energy source comparable
to alternative energy sources (sun, wind and geothermal) and
benefits from the legally prescribed incentives and facilities.
COMBINED HEAT & POWER
Introduction - Theory - Exercises - Business Case - Summary
CHP: characteristics 1/2
Co-funded by the Intelligent Energy Europe Programme of
the European Union 35
• Need for reciprocity between production and demand both for
electric and thermal energy.
• In order that economic convenience could be reached for the
plant, thermal and electric uses have to be near to the
generation system.
• Higher plant costs with respect to traditional systems, due to
cogeneration plant complexity.
COMBINED HEAT & POWER
Introduction - Theory - Exercises - Business Case - Summary
CHP: characteristics 2/2
Co-funded by the Intelligent Energy Europe Programme of
the European Union 36
Saving can be expressed in mathematical terms as follows [1]:
COMBINED HEAT & POWER
Introduction - Theory - Exercises - Business Case - Summary
CTHUCELC
C
/ Q + / W
F 1 =
F
F - F = ndexEfficencyI,,
This Efficiency Index and gives an idea of how much energy can be saved by CHP. It is defined as the ratio between:• Fc-F: difference between primary energy absorbed by the SHP (Fc)and that absorbed by
CHP (F), being equal the output electrical and thermal energy • Fc: primary energy absorbed by the SHP
It can be expressed with the second formula where:• W: is the electric energy in output• Qu: is the thermal energy in output• The two η are, respectively, the efficiency of Electric Generation Plant and of Boiler
Co-funded by the Intelligent Energy Europe Programme of
the European Union 37
Main components
• Engine
• Generator
• Heat exchanger
• Control system
• Distribution system
• Electric connections
• Electric closet (if the company foresee to sell electric energy)
Introduction - Theory - Exercises - Business Case - Summary
COMBINED HEAT & POWER
Co-funded by the Intelligent Energy Europe Programme of
the European Union 38
Combined cycle with heat recovery gas turbine engines Steam backpressure turbine Condensing turbine with steam bleed Gas turbine with heat recovery Internal combustion engine Microturbine Stirling Engine Fuel cell Steam engine Organic Rankine cycles Any other type of technology or combination thereof falling under the
definitions laid down in Article 3.
Plants that can be defined cogeneration ones [6]
COMBINED HEAT & POWER
Source: ENEA Desire – Net Project
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 39
Comparison among efficiency of different generators
COMBINED HEAT & POWER
MCFC
Introduction - Theory - Exercises - Business Case - Summary
LegendSOFC: Solid Oxide Fuel Cell
MCFC: Molten Carbonate Fuel Cells
CCGT: Combined Cycle Gas Turbine
GT: Gas Turbine
ICE: Internal Combustion Engine
PAFC: Phosphoric Acid Fuel Cells
PEM: Polymeric Electrolytic Membrane Fuel Cells
GT: Gas Turbine
MT: Micro Turbine
Co-funded by the Intelligent Energy Europe Programme of
the European Union 40 Introduction - Theory - Exercises - Business Case - Summary
Exercises
Co-funded by the Intelligent Energy Europe Programme of
the European Union 41
Supposing an energy requirement equal to 80 kWh of electric energy and 90
kWh of thermal one, please calculate the consumption variations using a CHP
instead of an SHP.
Data:
• Efficiency of thermoelectric power station equal to 45%.
• Efficiency of thermal power station equal to 95%.
• Cogeneration: electric efficiency equal to 40% and thermal efficiency equal
to 45%
Primary energy saving
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 42
Primary energy saving
SHP
Introduction - Theory - Exercises - Business Case - Summary
Consumption reduction is about 27%
CHP
Electric energy
Thermal energy
Consumed energy (PCI)
80/0,45 = 178 kWh
90/0,95 = 95 kWh
273 kWh
80/0,40 = 200 kWh
90/0,45 = 200 kWh
200 kWh
This has not to be summed, since it refers to simultaneous production of thermal and electric energy
Co-funded by the Intelligent Energy Europe Programme of
the European Union 43 Introduction - Theory - Exercises - Business Case - Summary
HIGH EFFICIENCY ENGINES
Which of the following load profiles is suited for cogeneration?
Chart b
Chart a
Co-funded by the Intelligent Energy Europe Programme of
the European Union 44 Introduction - Theory - Exercises - Business Case - Summary
HIGH EFFICIENCY ENGINES
Which of the following load profiles is suited for cogeneration?
Chart b
Chart a With use of storage systems
Co-funded by the Intelligent Energy Europe Programme of
the European Union 45
Business Case
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 46
Practical example“Hypo Alpe Adria”[7]
Introduction - Theory - Exercises - Business Case - Summary
Trigeneration Plant District Heating and Cooling :
The “Hypo Alpe Adria” trigeneration plant is located in Tavagnacco (UD) in the north-
eastern part of Italy.
In the northern part of the district of Udine, a residential area with several public
and private buildings, including a swimming pool, a hotel, an Italian bank’s
headquarters and other facilities in the service of the community, has been
developed.
The “Hypo Alpe Adria” plant includes a CHP motor engine with 1 MW of electrical
and about 1.3 MW of heat capacity. In addition, two heat boilers with 1.2 and 2.0 MW of
heat capacity have been installed. The cooling plant includes two chillers with 1 MW of
cooling capacity and an absorption chiller with 0.5 MW of cooling capacity.
Co-funded by the Intelligent Energy Europe Programme of
the European Union 47 Introduction - Theory - Exercises - Business Case - Summary
Electrical capacity (total) 1,06 MweHeat capacity (total) 1,27 MWthTechnology Motor engineNo. of units 1Manufacturer JenbacherType of fuel Natural gasElectricity (yearly generation) 2,37 GWhHeat (yearly generation) 2,57 GWhYear of costruction 2006Total investment cost € 2.800.000 Financing Own fundsState support Certificates, tax reductionLocation Tavagnacco,Italy
Co-funded by the Intelligent Energy Europe Programme of
the European Union 48
Summary
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 49
Some renewable sources present strong production discontinuities.
It becomes necessary to adopt energy districts (that are local industrial
zones with local production, exchange and consumption of energy) for
optimizing and using produced energy.
CHP systems represent a way to make efficient use of primary sources
when both electric and thermal energy are needed.
CHP systems can be fed also with renewables sources (biomass).
Repetition
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 50
Readings [1] AEEG (2002) n. 42/02 19 March, 2002 [2] www.roma1.infn.it/rog/pallottino/bacheca/Sole%20e%20rinnovabili.pdf [3] Corso di Impatto ambientale Modulo b) Aspetti energetici prof. ing. Francesco Asdrubali Energia
dalle Biomasse [4] Opuscolo ENEA ENERGIA EOLICA [5] Francesco Zarlenga - ENEA [2011] EAI Energia Ambiente e Innovazione 3/2011 [6] European Parliament [2004] Directive 2004/8/EC on the promotion of cogeneration based on a
useful heat demand in the internal energy market and amending Directive 92/42/EEC [7] CODE PROJECT IEE – Cogeneration Case Studies Handbook [8] http://www.vestas.com/en/products_and_services/turbines/v164-8_0-mw#!at-a-glance
Introduction - Theory - Exercises - Business Case - Summary
Co-funded by the Intelligent Energy Europe Programme of
the European Union 51
Pictures -1 Slide 15 – ENEA Quaderno solare termico a bassa e media temperatura
www.enea.it/it/enea_informa/documenti/quaderni-energia/solare.pdf
Slide 21 – ENEA Opuscolo l’energia eolica
old.enea.it/produzione_scientifica/pdf_op_svil_sost/Op19.pdf
Slide 38 - ENEA Desire – Net Project
www.desire-net.enea.it
Introduction - Theory - Exercises - Business Case - Summary