Dynamic simulations of hybrid energy systems in load sharing application[edit | edit source]
Michele Canellia, Evgueniy Entchev, Maurizio Sasso, Libing Yang, Mohamed Ghorab
The paper focuses on analyzing the energy, environmental and economic performance of two hybrid micro-cogeneration systems in a load sharing application. This is done in order to compare the performance of this two hybrid systems. It even explains that by introducing micro-cogeneration helps in saving energy, it is even economical feasible and better environmental performance i.e low emission of GHG (Green House Gas).
NOTES[edit | edit source]
- Cogeneration (CHP, Combined Heat and Power) means the combined production of electric and/or mechanical and thermal energy from a single energy source.
- The thermal load of residential users typically occurs in the evenings and early mornings, while for commercial it occurs at day time. So single system can be used to provide thermal and cooling demand.
- In this paper several cases are consideredto observe the performance in load sharing approach.
1)conventional case with one boiler and one chiller for each building.
2)conventional case with a common boiler and chiller in load sharing approach.
3)Ground Source Heat Pump (GSHP) systems in load sharing.
4) Hybrid system with GSHP and microcogenerator based on FC in load sharing.
5)Hybrid system with microcogenerator, GSHP and PVT collectors in load sharing.
Simulation inputs and control approach[edit | edit source]
1)Domestic Hot water demand.
2)Electric load Demand: It was considered for three type of days saturday, sunday and weekdays.
3)Equipment Capacity: It is the capacity and nominal characteristics of the main components.
4)Control strategy: Time during which heating is turned on in the house and the office.
Energy, environmental and economic analysis[edit | edit source]
In order to study above cases, energy, environmental and economic analysis are made.
The hybrid microcogeneration systems showed good improvements both in terms of energy and environmental performance. Performance can be further improved by introducing the PVT in the system.
Operational strategy and marginal costs in simple trigeneration systems[edit | edit source]
M.A. Lozano, M. Carvalho, L.M. Serra
This paper analysis the operation of simple trigeneration system. The system is connected to the utility in order to supply electricity and receive excess of electricity. Moreover, thermoeconomic analysis is made depending upon production cost and the best operational strategy as a function of demand for energy services and prices of the fuel. The trigeneration also provide several advantages, energy savings, low GHG emissions and low energy cost.
NOTES[edit | edit source]
- Combining CHP with absorption chillers can fulfill the cooling demand during summers.
- To design an energy system, the following things need to be considered:
(i) the technologies and equipment to install.
(ii) the demands to be satisfied.
(iv) the energy prices.
(v) the optimal operation taking into account the possibility of operating the equipment at variable load.
Simple trigeneration system[edit | edit source]
- Cogeneration system consist of prime mover which converts fuel to shaft power. The alternator is used to convert mechanical energy to electrical energy. The heat recovery unit utilizes the waste heat.
- Trigeneration consists of cogeneration module with absorption chiller.The purpose of the trigeneration system is to attend the demand
of different energy services (electricity heating, and cooling). By using several equations the cost and efficiency of several equipments of the system is calculated.
Conclusions[edit | edit source]
- This paper showed the characteristics of different operation modes of a trigeneration systems.
- The cost of energy demand was reduced by optimal operation mode.
Control strategies and configurations of hybrid distributed generation systems[edit | edit source]
Maria Stefania Carmelia, Francesco Castelli-Dezzab, Marco Maurib, Gabriele Marchegianic, Daniele Rosati
This paper focuses on the main topologies which can be adopted for hybrid system. It also discusses on a hybrid system which combines two different energy sources and explains the power flow for both grid connected and standalone system. It also analyzes on system design aspect and power flow control strategies.
NOTES[edit | edit source]
- The hybrid distributed generator system in thsi paper consists of the CHP unit.
CHP unit: It consists of internal combustion engine(ICE) which is fueled by natural gas, induction machine(IM), Heat exchanger(TRU), gas heat generator group(GHG).
IM: It generates electric power load.
ICE: It generates thermal power which is recovered by TRU, which is stored into the water heat storage unit.
- PV unit: It consists of three arrays each generating electrical power of 3kW. The output of the each PV array is followed but the DC-DC converter and it is connected to a common DC bus which is followed by DC-AC converter.
- Battery bank: The batteries are connected to the Dc bus through a bi-directional chopper(DC-DC converter). This unit is used in order to transfer power in both direction. Normal lead acid batteries in standby condition are used with a constant floating voltage of 2.25V per cell.
- Control and energy management: There are three different control structure involved:
1) Centralized control
2) Distributed control
3) Hybrid centralized and distributed control: It has been adopted for PV-CHP hybrid system. The two main task are:
a) It establishes the power references for PV unit CHP unit and battery bank.
b) It manages heat storage unit and battery bank power flow.
Two operation modes are possible:
Mode I: The power generated by the PV unit is transferred into the grid whereas CHP unit priority is to satisfy the thermal load demand.
Mode II: The hybrid system priority is to satisfy the electric load power and CHP full load operation till possible.
Conclusion[edit | edit source]
This paper has proposed a high level control strategy which allows both standalone and grid connected operation mode.
Optimal Operation Planning of a Photovoltaic-Cogeneration-Battery Hybrid System[edit | edit source]
S. Bando, Member, IEEE, H. Asano, Member, IEEE, T. Tokumoto, Non-member, T. Tsukada, Non-member, and T. Ogata, Non-member
This paper proposes the modelling of optimal planning of hybrid systems and economic dispatch of the hybrid system. This paper also deals with three different objective functions: minimization of cost, reduction of CO2 emission and primary energy consumption.
NOTES[edit | edit source]
- There is a degradation of power quality such as voltage and frequency as the renewable energy sources is fluctuating. To achieve large penetration goal of renewable source, distributed generation is considered.
- The battery capacity can be reduced if gas engines in the hybrid system can follow the cchange in output system of renewable energy.
Micro-grids[edit | edit source]
- In this PV+ gas engine CHP is modeled. Electrical and thermal demand were based on combined data.
- Schematic shown in the paper consist of three gas engines, PV, steam-absorption refrigerator, gas-absorption chiller, gas boiler, and lead acid battery.
- Electricity is supplied by the parallel operation of gas engines, PV and battery.
- The calculation parameters are battery capacity, pv capacity and the number of gas engines.
Mathematical formulation[edit | edit source]
- Mathematical formulation was done in order to minimize the cost to supply electricity.
- In the PV-CHP hybrid system exhaust heat from the gas engines is utilized in order to fulfill thermal demand for the building.
- The capacity of gas absorption chiller and boiler is determined by the maximum thermal demand.
- The capacity of steam absorption refrigerator is determined by the maximum gas engine capacity.
- Several parameters such as gas engines generated efficiences and heat recovery efficiency, PV efficeincy, gas price, CO2 emission coefficient etc are taken into consideration for optimized operation planning of PV-CHP hybrid system.
Conclusion[edit | edit source]
It was seen that the cO2 emission, running cost and primary energy consumption were low compared to conventional energy cost.
A domestic CHP system with hybrid electrical energy storage[edit | edit source]
X.P. Chen, , Y.D. Wang, H.D. Yu, D.W. Wu, Yapeng Li, A.P. Roskilly
This paper focuses on satisfying the the electric and thermal demand using CHP with hybrid electrical energy storage. It also comapares the energy efficiency, capital cost of CHP hybrid system with the conventional system.
NOTES[edit | edit source]
- The CHP unit should satisfy both electrical and heat demand. Heat and domestic demands are quite different from each other. The electrical demand changes drastically within each day, while the heat demand changes very slowly within the day.
The design and implementation of the CHP–EES system for the household[edit | edit source]
- CHP- It consists of generator with heat recovery system. The engine was fueled with bio-diesel and it was used to fulfill electrical demand. The exhaust heat from the engine was stored in the form of hot water in the tank.
- Hybrid Energy storage system(HEES) used to store energy. It consist of battery bank and super capacitor module. The electric energy generated and which was not used during off peak hours was stored in the HEES system. It is then discharged during peak hours in order to meet electric demand. Batteries can store large amount of energy in small amount of volumes. Super- capacitors are used as auxiliary storage device to store electricity. It has very low energy density
and can store limited amount of energy compared to batteries. The super capacitor has long life cycle and it has fast charge and discharge duration.
- The max power calculation for battery is: Pmax =V2oc/4Rb
- The discharge power P� is equal to 0.19 times nominal maximum power Pmax.
- The battery and the super-capacitors are connected in parallel to the DC bus.The DC is then converted to AC using an inverter. This happens when battery is discharging. When the battery is charging AC is converted to DC and fed into the battery.
Operational state transferring diagram[edit | edit source]
In this there are three states and two substates.
- When Pload<Pgen then it goes to state 2(charging state).
- When Pload> Pgen it either supply energy from battery and the CHP unit.
- Sub-states 2–1 and 2–2 stand for two different charging approaches.
Conclusion[edit | edit source]
- The CHP-HEES system can satisfy both electric and heat demand at high efficiency.
- The overall efficiency is increased compared to conventional energy sources.
Microgeneration Model in Energy Hybrid System - Cogeneration and PV Panels[edit | edit source]
J. Galvão*, S. Leitão**, S. Malheiro**, T. Gaio***
This paper proposes the development of a hybrid energy model with solar PV panels and a small CHP (combined heating and power production) system whose primary energy source is the biomass.It also presents the several rules to achieve new energy efficiency levels.
NOTES[edit | edit source]
- The hybrid energy model consists of following processes:
1) Cogeneration process.
2) Thermal process.
3) Electrical process.
4) PV process.
- Cogeneration system uses biomass or ICE as primary energy sources. It provides electrical as well as thermal energy.
- Thermal process includes heating hot water, space heating etc.
- PV solar system is also used to produce electricity.
Energy data consumption[edit | edit source]
- Energy and thermal demand data were considered. The three main energy sources utilized are: Electrical, fuel and gas. Their energy consumption are represented in graphical form in the paper. The most energy source consumed is electricity which contributes to around 55%
- The energy consumption for heating and cooling varies with season. The graph shows the thermal consumption during winter days.
Energy Hybrid Concept and Solar Potential[edit | edit source]
- This system consists of several energy sources combined together. It is used to provide electricity with low cost and low emissions.
- The solar radiation distribution data has been provided in the paper.
- There are two large areas in co-generation system:
1) Handling/storage of biomass.
2) Heat exchangers, filtration of gas engine/ generator.
- If PV cant fulfill the electric demand. The additional electric demand is fulfilled by the CHP unit.
Economic Analysis[edit | edit source]
- The PV process is combined with CHP to supply electricity during peak hours. Excess energy can be stored to electrical net.
- The hybrid system not only fulfills the energy demand but also increases the efficiency.
Conclusion[edit | edit source]
- Efficiency is increased by combining PV with CHP unit.
- This system is eco-friendly i.e it does not emit GHG(Green House Gas).
[Feasibility Study for Self-Sustained Wastewater Treatment Plants—Using Biogas CHP Fuel Cell, Micro-Turbine, PV and Wind Turbine Systems][edit | edit source]
Ahmed Helal, Walid Ghoneim, Ahmed Halaby
This paper focuses on the application of the renewable energy sources. The primary objective is to provide an entirely renewable standalone power system, which satisfies lowest possible emissions with the minimum life cycle cost. This paper also discusses on the hybrid optimization model which was used for simulation of CHP and PV hybrid systems.
NOTES[edit | edit source]
- Combining renewable energy to form a standalone hybrid systems are considered in order to meet the electrical demand of the remote regions. The renewable energy also plays in important role in reducing the green house gas emissions. Using renewable energy resources totally or partially reduces the operating cost of the system.
- Use of biogas for CHP are proved to be quite economic. The solid oxide fuel cell is combined with micro-turbine for maximum electricity generation.
- The gas from the digester is given to the generator in order to generate electricity. Fuel cell and microturbine technology are used to re reduce emissions.
- The selection of the technology For the CHP depends on the application. Microturbine is cost effective and emits less GHG. As low emission is needed fuel cell is used for the CHP unit.
Selection of Fuel Cell Type[edit | edit source]
- They can work with great variety of fuels such as diesel, kerosene, natural gas etc.
- High electrical efficiency.
- Low cleaning demand.
- Low emission.
- High operating temperature.
Micro-Turbines+ fuel cell[edit | edit source]
- In order to raise the electrical output microturbine, the exhaust heat from the fuel cell is utilized by microturbine to convert the gas into electrical energy. combining microturbine with the fuel cell helps to fulfill the electrical demand.
Plant Load Study[edit | edit source]
Electrical Load:
- Energy requirements in waste-water treatment are mainly for pumping, primary treatment, secondary treatment, space heating, and sludge heating and disposal. The average power required by the plant is 201kW and the power generated by microturbine and fuel cell is 166kW. The load coverage energy by biogas is 69%.
Thermal Load:
- Space heating is not required in the plant. As the thermal requirement of the plant is quite low, the CHP unit can fulfill the thermal demand quite efficiently.
System Modeling[edit | edit source]
- The electrical demand is still not satisfied, so other renewable energy resources are connected in order to fulfill remaining electrical demand.
Resources[edit | edit source]
- Biogas from the plant waste in order to operate SOFC.
- Wind and solar are determined by wind speed and solar radiation respectively.
- Optimal system model was designed by modeling all the system depending upon their capital cost, operation and maintanencce cost. Additional required components for modelling were converter and battery bank.
Conclusion[edit | edit source]
- From the simulation results it was cleared that power generation share of the units is as follows:
1) SOFC
2) Wind turbine
3) Solar PV
4) Microturbines.
The cash flow summary share of the units is as follows:
1) SOFC
2) Batteries
3) Wind turbine
4) Solar PV
5) Microturbines.
Modeling and Performance Analysis of an Integrated System: Variable Speed Operated Internal Combustion Engine Combined Heat and Power Unit–Photovoltaic Array[edit | edit source]
Robert Radu1, Diego Micheli, Stefano Alessandrini, Iosto Casula and Bogdan Radu
The paper focuses on modelling of CHP system based on the variable speed internal combustion engine combined with the PV technology.This model was modeled in matlab simulink. This paper focuses on energy saving of hybrid PV+CHP system for different operating conditions and for different PV array size.
NOTES[edit | edit source]
- The CHP system has the capability of reducing the fuel consumption by 20-30% compared to conventional energy consumption.
- Several CHP technologies can be used. But ICE is used due to its several operation advantages like reliability, relatively low costs, fast transients etc. They can be even operated with different type of fuels. So, they are suitable for commercial residential loads.
- The ICE with variable speed was selected, this leads to increase the electrical efficiency of 28% but it is for low loads.
- The advantage of using CHP unit is that, it has low GHG emission. Moreover, combining this with CHP can lead to energy saving. The overall efficiency is increased by using this hybrid system.
System Modeling[edit | edit source]
- It has three subsystem: CHP unit, PV and the load.
- The main input are thermal and electrical load profile. Using this as input the operating parameters for hybrid system is calculated.
- The output are hybrid system efficiencies.
CHP unit model[edit | edit source]
- It has three main blocks ICE and 2 heat exchangers.
- The inputs for the ICE are thermal and electrical priority. At every load block it calculates the exhaust gas, coolant temperature and fuel consumption. The fuel consumption is controlled by PID block.
- The mechanical power and the exhaust gas are calculated at every load condition through which fuel consumption can be calculated.
- Temperatures at the engine and user sides of the cooling water heat exchanger are calculated. Coolant outlet temperature and water outlet temperature are calculated using water flow rate coolant flow rate which is specified in the paper.
- Water inlet temperature is considered as the design parameter.
- The simulation block of exhaust gas heat exchanger is used to calculate the exhaust heat and outlet temperature of both exhaust gas and water.
PV system model[edit | edit source]
- The inputs to the PV system are:
1) The solar irradiation.
2) The ambient temperature.
3) Module characteristics
4) PV array characteristics.
- Using these inputs the module calculates the PV panel output theoretically. The panel electrical output is calculated as the difference between the theoretical output and the sum of temperature, reflection and system losses.
System[edit | edit source]
- The grid connection is done through a power electronics unit composed of a rectifier (AC-DC) followed by the inverter(Dc-AC).
- The output frequency of the CHP is constant 50Hz but the speed of the ICE is variable so it improves the operating efficiency.
- Inverter measures and stores the AC electrical parameters. The DC parameters are connected to the inverter which converts the DC to AC output.
- By coupling CHP with PV we can meet the electrical and thermal demand.
Conclusion[edit | edit source]
- CHP simulation model demonstrates a sufficiently good precision with respect to the electric efficiency.
Optimal sizing of hybrid solar micro-CHP systems for the household sector[edit | edit source]
Caterina Brandonia, Massimiliano Renzib
The paper mainly focuses on the importance of optimal sizing hybrid microgeneration systems. The parameters which should be considered for sizing phase are: energy prices,ambient conditions,energy demand,units' characteristics,electricity grid constraints. This paper also focuses on maximizing the economic and the energy savings compared to conventional generation.
NOTES[edit | edit source]
- Renewable or fossil fuels are used to operate combined heat and power production, providing important results in terms of energy savings and emission reduction.
- Due to the intermittency of the Pv technology the integgration of solar with grid was a problem.This problem was mitigated by introduction of hybrid systems, consisting of coupling solar systems with micro-CHP units fueled by natural gas.
- When dealing with hybrid systems, identifying the optimal sizing of the energy conversion systems is a tough issue due to several parameters that must be taken into account in the analysis, such as electricity and fuel price, energy loads and weather conditions.
Energy system modeling[edit | edit source]
- The system was made up of PV, micro-CHP device (the technologies considered are ICE, Stirling, microturbine and fuel cell), a Thermal Energy Storage (TES), a cooling device (vapour compression chiller or water/LiBr absorption chiller)
- Meteorological Year database for determining the yield of Solar system depending on solar radiation and ambient conditions.
- The hourly values of the following quantities are used: the Direct Normal Irradiation (DNI); the global solar irradiation over a south-oriented 30degree tilted surface; the ambient temperature.
- The efficiency of a PV panel depends on the ambient conditions, the most influential being the available solar radiation and the solar cell temperature figures.
Micro-CHP modeling[edit | edit source]
- All the micro-CHP units were modeled on the basis of electrical efficiency and power to heat ratio.
- The technologies considered in this work are four: ICE, Stirling engine, microturbine and fuel cell. Table is given in paper which shows comparison for all those ways of which fuel cell technique is most efficient as it has power to heat ratio =1. But it has a drawback that is its cost.
- It shows the advantages of using different technologies depending on the application.
Optimal sizing of system[edit | edit source]
- Electrical demand can be satisfied by the (PV),the micro-CHP unit and the electricity bought from the grid (if needed).
- CHP unit is used to fulfill thermal demand such as space heating, hot domestic water etc.
Objective function[edit | edit source]
- The objective is to minimize annual cost derived by implementation of such a hybrid system is given by sum of annualized capital cost of all the devices and annual operating cost of them.
- The capital cost of each device depends on its life time and capacity recovery factor.
- Operating cost depends on fuel cost of running CHP unit, operating and maintenance cost of the CHP unit, Cost of purchasing electric energy from grid if needed, the revenue coming from generating electric energy from solar and CHP unit.
Conclusion[edit | edit source]
- The use of hybrid system is used to minimize the operating cost, overall system efficiency and low GHG emission compared to conventional energy source.
Optimizing design of household scale hybrid solar photovoltaic + combined heat and power systems for Ontario[edit | edit source]
P. Derewonko and J. M. Pearce
This paper focuses on the feasibility of implementing a hybrid solar photovoltaic (PV) + combined heat and power (CHP) and battery bank system for a residential application to generate reliable base load power to the grid. Due to the intermittency of PV technology there is penetration problem into the grid. By installing hybrid system this problem can be mitigated.
NOTES[edit | edit source]
- The CHP unit provides backup for PV arrays, when PV arrays are not able to fulfill thee electric demand.
- The hybrid system also increases the PV penetration level. Thus,implementing a hybrid solar photovoltaic + combined heat and power (CHP) + battery bank system to supply the grid with base load power.
- Due to the intermittent nature of PV technology the penetration level of 5% which can be tracked by the utility. Currently, PV penetration level is <1%. This problems are mainly due to i) diurnal cycle, ii) yearly cycle, and iii) fluctuating weather conditions.
Data Collection and Analysis[edit | edit source]
- A Matlab program was made in order to determine maximum measured irradiance, total amount of measured energy and histogram data for change in PV generation.
- The program gave a bell like shaped showing which determines a maximum solar irradance value and at what time they took place. The area under this curve gives information of the solar irradiance at every cloudless day in a month. Using this data Solar energy Lost due to cloud cover was determined.
Hybrid PV+CHP+Battery design for a residential system[edit | edit source]
- The CHP system which produced electric energy same as the electric power generated by the solar PV.
- During hours of high solar flux, the instantaneous PV energy is the primary energy source, and the CHP unit is turned off. However, the CHP unit runs continuously during the non-solar hours of the day and during an additional specified overlap time with the low irradiance hours of the day (morning and evening), generating a base load of 1.2 kW using natural gas as a fuel.
- The heat generated during this process can be used for heating space or water or even can be used by absorption chiller(cooling).
- The excess electrical energy generated by can be stored in the battery. This energy stored in battery can be utilized when the PV is not able to meet electric load requirements and CHP unit is off.
Results[edit | edit source]
- From the data for the average electric energy generated by the PV over an year (monthly data).
Modelling the Italian household sector at the municipal scale: Micro-CHP, renewables and energy efficiency[edit | edit source]
Gabriele Comodia, , , , Luca Cioccolantia, Massimiliano Renzi
This purpose of this paper is to reduce household energy consumption. The study also investigates the effects of tourist flows on town's energy consumption by modelling. Cogeneration and renewables (PV) were proven to be valuable solutions to reduce the energetic and environmental burden.
NOTES[edit | edit source]
- The hybrid system was installed in order to reduce energy consumption and reduction of GHG emission.
Micro-CHP unit[edit | edit source]
- CHP are used for space heating using heat exchangers.
- There are several CHP technologies like MGT (micro-gas turbine),ICE(Internal combustion engine) ,FC (Fuel cell) and stirling engines.
- Techno-economical parameters considered are efficiency, investment cost,cogeneration ratio and life cycle of the devices.
Solar Panel unit[edit | edit source]
- Techno-economical parameters considered are Efficiency, life time and AF (availability factor), indicates the percent working hours over the year.
- Techno-economical parameters to be considered are AF data reflect the overall yearly production of the PVs in the town, investment cost, cost for M&O, life time, efficiency.
Results[edit | edit source]
- Overall efficiency was reduced.
- GHG emission was reduced.
- Consumption of energy was minimized.
Micro combined heat and power (MCHP) technologies and applications[edit | edit source]
Maryam Mohammadi Maghankia, Barat Ghobadiana, Gholamhassan Najafia, Reza Janzadeh Galogah
The purpose of this paper is reduction of energy demand of the residential sector for space heating, domestic hot water heating,and electricity by using cogeneration hybrid system.The reduced green house gas emissions and reduced reliance by installing hybrid system. The comparison has been made between the MCHP technology and the other ones such as primemover, electrical and thermal power,efficiency and emissions.
NOTES[edit | edit source]
- Prime mover for CHP technology can be ICE,SE,MGT,MRC.
- The output of prime-mover is electricity which is if generated in excess can be fed into grid. If the electricity demand is not fulfilled the excess required can be taken from grid.
The CHP unit[edit | edit source]
- The CHP unit consists of a heat exchanger, auxiliary boiler and thermal storage unit. This is used in order to meet thermal demand such as space heating and hot domestic water. If the heat so generated is in excess by CHP then it is stored in the thermal storage unit.
- The efficiency of the CHP unit varies depending on the technology being used and also the fuel/gas source employed.
- It reduces the fuel consumptions by 76.5%.
CHP Technologies[edit | edit source]
- The overall efficiency of a CHP unit is combined of thermal and electrical efficiency. The overall efficiency varies from technology used in CHP.
- ICE internal combustion engine provides efficiency up to 90%. MRC Micro rankine cycle provides efficiency of more than 90%. The efficiency varies with technologies.
Conclusion[edit | edit source]
- It provides really high efficiency.
- Less fuel consumption.
- Low GHG emission compared to conventional source.
- CHP unit is able to fulfill 80% of thermal demand and approximately 85% of electrical demand.
MODELLING AND SIMULATION OF THE COMBINED HEAT AND POWER PLANT OF A REAL INDUSTRIAL SYSTEM[edit | edit source]
Semra Öztürk, Mehlika Şengül, Nuran Yörükeren
This paper proposes a mathematical model of a Combined Heat and Power (CHP) plant. In this study, operating of CHP which produce electricity and heat in order to fulfill electrical and thermal demand. Cogeneration system are connected to auxiliary devices such as boiler, compressor, combustion chamber, gas turbine etc.
NOTES[edit | edit source]
COGENERATION SYSTEMS AND THEIR OPERATING[edit | edit source]
- In this CHP generates both electricity and heat simultaneously which is utilized by industries.
- In conventional energy heat needed is obtained from the boiler which utilizes fuel. But by using CHP the waste heat produced is utilized for heating purpose, which leads to saving fuel and increasing efficiency.
- In industries un-interrupted power supply and heating and cooling process is essential. Even outage for short period of time can cause very large lose. So using CHP along with the conventional energy can minimize the outages to a great extend.
- By using CHP for water heating the thermal efficiency is too high. Thermal efficiency is upto 85% with fuel oil and 90% with gas applications.
- When generating heat and electricity from the CHP only a small portion of cooling water heat can be recovered.
- The volume of outlet power as electricity, exhaust gas temperature, steam pressure and steam quantity can be observed by this model.
Conclusion[edit | edit source]
- Cogeneration with gas turbine provides high efficiency.
- Low gas emission.
- Mathematical model for control strategy was used in order to operate CHP efficiently.
The effect of installation of nextgeneration home energy systems in Japan[edit | edit source]
This paper demonstrates the simulation model for PV, CHP and batteries in order to reduce energy bill, fuel used and reduction in CO2 emission. The paper focuses on several condition in order to achieve zero energy consumption.
NOTES[edit | edit source]
- Net zero energy houses require not only high levels of insulation and high efficiency appliances, but also some kind of distributed home energy system, such as a combined heat and power (CHP) system and a photovoltaic generation (PV) system.
- The combination of PV and CHP is called double power generation. The fuel cell power efficiency is decreased during partial load. It can be energy efficient by charging the battery when demand is low.
Simulation conditions[edit | edit source]
The simulation is done on the basis of:
1) Energy cost, primary energy consumption and reduction of GHG emission.
2)Hourly data for a week in each month.
3) Heat loss of storage tank.
The simulation is done on three forms of combination:
- Fuel cell system:
When the electricity demand is less than the minimum rated value of the fuel cell. The heater in the CHP runs and is heated energy is stored in the tank.
- Photovoltaic System(PV):
PV is connected to the grid. The surplus energy is fed into the grid.
- Battery:
The purpose of using battery is that the fuel cell can be operated at as high a load as possible. This improves the power generation efficiency.
- Photovoltaic (PV) generation:
Hourly meteorological data about one week per month is selected.
Conclusion[edit | edit source]
- By using CHP system with PV and battery can reduce the energy cost, primary energy consumption and Co2 emission by 84%, 54% and 73% respectively compared to conventional system with no PV and no batteries.
The present and future of residential refrigeration, power generation and energy storage[edit | edit source]
R.Z. Wang, X. Yu, T.S. Ge, T.X. Li
This paper focuses on summarizing the current status and possible developments related to residential refrigeration, power generation and energy storage. Based upon the fast development of energy efficiency, energy safety and use of renewable and sustainable energy, various energy systems related to residential refrigeration, power generation and storage have been developing. In this paper the current status of such various integrated system are summarized.
NOTES[edit | edit source]
Solar PV+CHP[edit | edit source]
- PV+CHP system is very efficient compared to conventional energy system because conventional energy uses primary fuel for generating electricity and CHP can use natural gas for generating heat and electricity. The exhausted can be used by absorption chiller for cooling. This system is called CCHP.
- The exhausted can be used by absorption chiller for cooling. This system is called CCHP. Adding an absorption chiller unit in the circuit will increase the efficiency more of the system. Such an arrangement is called PV+CCHP model.
Wind energy and solar energy power generation[edit | edit source]
- The stand-alone wind energy and a solar energy has drawback of generating unpredictable electric output, since the output power depends on intermittent weather conditions. A conventional stand-alone wind-solar hybrid system topology, which contains: a wind turbine, a permanent magnet generator, a diode bridge rectifier, a solar cell, three direct current (DC)/DC converters, a DC/alternating current (AC) converter, a storage battery, a control unit, sample circuits, a DC load and an AC load.
- The efficient power should be DC power as it has no AC losses and can be obtained directly from solar PVs. The DC can be converted to AC using inverter.
Energy storage[edit | edit source]
It helps in increasing the energy consumption efficiency. The energy storage is an effective method in meeting the energy demand during peak periods, and storing during off peak time.
Conclusion[edit | edit source]
- High efficiency can be achieved using hybrid systems.
