Combined Heat And Power System Research Articles

Techno-economic assessment of integrated spectral-beam-splitting photovoltaic-thermal (PV-T) and organic Rankine cycle (ORC) systems

Promising solar-based combined heating and power (CHP) systems are attracting increasing attention thanks to the favourable characteristics and flexible operation. For the first time, this study explores the potential of integrating a novel spectral-beam-splitting (SBS), hybrid photovoltaic-thermal (PVT) collector and organic Rankine cycle (ORC) technologies to maximise solar energy utilisation for electricity generation, while also providing hot water/space heating to buildings. In the proposed collector design, a parabolic trough concentrator (PTC) directs light to a SBS filter. The filter reflects long wavelengths to an evacuated tube absorber (ETA), which is thermally decoupled from the cells in the PVT tube, subsequently enabling a high-temperature fluid stream to be provided by the ETA to an ORC sub-system for secondary power generation. The SBS filter’s optical properties are a key determinant of the system’s performance, with maximum electricity generation attained when the filter transmits wavelengths between 485 and 860 nm onto the PVT tube, while the light outside this range is reflected onto the ETA. The effect of key design parameters and system capacity on techno-economic performance is investigated, considering Spain (Sevilla), the UK (London) and Oman (Muscat) as locations to capture climate and economic impacts. When operated for maximum electricity generation, the combined system achieves a ratio of heat to power of ∼1.3, which is comparable to conventional CHP systems. Of the total incident solar energy, 24% and 31% is respectively converted to useful electricity and heat, with 54% of the electricity being generated by the PV cells. In Spain, the UK and Oman, respective electricity generation of 1.8, 0.9 and 2.1 kWhel/day per m2 of PTC area is achieved. Energy prices are found to be pivotal for ensuring viable payback times, with attractive payback times as low as 4–5 years obtained in the case of Spain at system capacities over 2.7kWel. Integrating the ORC sub-system with the concentrating SBS-PVT collector design reduced the levelised cost of electricity (LCOEel). A LCOEel of 0.10 £/kWh is attained in Spain at an electrical capacity of only 4 kWel, demonstrating the significant potential of exploiting the proposed systems in practical applications, as highly competitive with established combustion-based CHP systems.

Technical, economic and environmental analysis of a hybrid CHP system with a 5 kW PEMFC, photovoltaic panels and batteries in the Brazilian scenario

This work focuses on the numerical simulation of an on-grid hybrid combined heat and power (CHP) system to meet small residential demands, using natural gas and solar energy. The system includes a natural gas reformer, a proton exchange membrane fuel cell (FC), photovoltaic panels (PV) and batteries connected to the grid by a bidirectional inverter. The impact of four parameters in the economic viability are investigated: number of consumers, electric and natural gas tariffs evolution, reverse metering factor and configuration of the system (energy sources, with or without storage). The results showed that the system can feed up to 4 consumers without significantly purchasing energy from the grid. Also, the electric tariffs exert more influence than natural gas tariffs over the performance of the system in terms of net present value. Dealing with configuration aspect, the FC + PV configuration provided earlier payback predictions, since fewer equipment substitutions were required. Reverse metering factor impact on system’s final profit and payback estimation was verified just slight. As results of environmental analysis conducted for the operation of the system, it was shown that emissions as low as 276.5 gCO2eq/kWh are achievable for the FC + PV configuration with cogeneration, meaning a 61.5% reduction in comparison with gas microturbines technology.

Integrated unit commitment and economic dispatch of combined heat and power system considering heat-power decoupling retrofit of CHP unit

Low-carbon development of a power system is realised via the flexibility retrofit of thermal power units with heat-power decoupling (HPD) of combined heat and power (CHP) units providing the necessary transformation pathway. First, this study examined the primary measures of HPD of CHP units and their impact on unit flexibility. Thereafter, aiming to realise flexibility retrofit of thermal power units, a detailed HPD model on the power side was proposed. In addition, the heat delay and heat loss in the process of heat transmission were also considered, followed by the establishment of a simulation method for unit commitment and economic dispatch (UCED) of CHP system considering HPD. Subsequently, based on IEEE RTS-79 test system, the effectiveness of the model and method proposed in this study was proven. Moreover, the proposed UCED method was applied to systematically analyse the comprehensive benefits achieved via the use of the HPD retrofit of the CHP units. The results showed that HPD retrofit has significant benefits in reducing dispatch costs, enhancing units' flexibility, and promoting wind and solar energy consumption. Finally, combined with the actual power supply and heating in Zhangjiakou, China, the HPD effect in the area was analysed to provide guidance and suggestions for the flexibility retrofit of local thermal power plants.

Thermodynamic analysis of operating strategies for waste heat recovery of combined heating and power systems

The multi-generation system often operates under off-design conditions due to the highly dynamic energy demand. Improving its off-design performance is crucial for energy conservation and emission reductions. To this end, this paper proposed a novel control strategy for the gas turbine cycle applied in combined heating and power (CHP) system, which effectively combines turbine inlet temperature control (TITC) and inlet air throttling control (IATC) methods, to improve system off-design performance and avoid discharging low-temperature gas. The hybrid control strategy can improve system efficiency by 3.70% on average over the traditional TITC method during the entire load range. Moreover, the maximum efficiency difference between these two methods reached 5.15% at the 30%-load factor conditions. To further showcase the effectiveness of the IAT-TITC method, the CHP system is integrated with an electric chiller and thermal refrigeration, respectively, forming four combined cooling, heating, and power (CCHP) system scenarios to supply the energy for a hotel building. Not only did the CCHP system scenarios with the IAT-TITC method show better performance, but also considering an electric chiller as an extra cooling supply machine can reduce primary energy consumption by 30.73%, 28.32%, and 11.56% in summer, transition season, and winter typical days, respectively, compared with separation system.

Study on thermal performance of solar methanol reforming MCFC-GT-ST-CHP system

In recent years, fuel cells have begun to attract the attention of many countries in the world. Based on Aspen Plus, this paper constructs a distributed energy system about solar assisted Methanol reforming-Molten Carbonate Fuel Cell (MR-MCFC), which is combined with GT-ST power generation system and heating system. The results show that the MCFC efficiency, total electrical efficiency and total thermal efficiency of the system are 44.12%, 58.62% and 90.36%, respectively. The research results will provide a theoretical basis for exploring a new method of highly complementary utilization of solar energy and chemical energy. By analyzing the variable working conditions of the system, the complementary utilization affinity characteristics of the solar MR-MCFC and the integrated system are revealed. We will continue to innovate and optimize the system in order to provide reference for the further development of the CHP (Combined Heat and Power) system.

CHP systems optimal allocation in the interconnected heat and electricity distribution network based on minimizing electrical and heat transfer losses

Combined heat and power (CHP) systems are employed to supply electrical and thermal loads of distribution networks (DNs). However, the heat loss can significantly hinder the heat transfer through pipelines from CHP systems to consumers Therefore, the optimal placement and sizing of CHP systems to reduce losses, including electrical and thermal losses, are very crucial. To minimize electrical loss, many methods have been proposed for optimal resource allocation. In this paper, a new approach for the optimal allocation of CHP systems to minimize electrical loss and heat transfer loss (HTL) is presented. Accurate modeling of HTL through the pipeline is performed. The proposed method is applied to 33-bus, 69-bus, and 84-bus test systems. According to the simulation results, it is concluded that considering HTL in the resources optimization problem leads to major changes in the selection of CHP systems' optimal size and location. To solve the optimization problem, a new enhanced imperialist competitive algorithm (E-ICA) is presented. The proposed algorithm enhances the performance and efficiency of the ICA algorithm by improving exploitation and exploration to prevent getting trapped in local optimums. Comparison of CHP systems allocation results confirms the superiority of the E-ICA algorithm over other methods.

Improved performance of a residential combined heat and power system by integrating compact fuel processor and proton exchange membrane fuel cell

AbstractA combined heat and power (CHP) system, which consists of a proton exchange membrane fuel cell and an integrated fuel processor is developed based on solving the energy balance between endothermic and exothermic hydrogen production reactions. The developed system simplifies the traditional complex fuel processing, and only three reactor units are needed—catalytic combustion, new integrated hydrogen production reactor and CO removal. In the novel CHP system, the H2‐rich reformate production from methanol and water is approximately 8 Nm3 h−1 with an H2 concentration of 53%–55% and CO less than 30 ppm. The CHP system was run continuously for more than 1100 h. The power demand was observed to be about 2–9 kW corresponding to the usual load of a residential unit. To increase the whole system efficiency, anode off‐gas (AOG) from fuel cell was returned to the fuel processor and utilized in the catalytic combustion reactor to improve the energy efficiency of the whole system. The average system efficiency can be increased from 60.3% to 67% by utilization of the energy from AOG catalytic combustion.

Opportunity Analysis of Cogeneration and Trigeneration Solutions: An Application in the Case of a Drug Factory

Increasing the energy efficiency of a drug factory is the main purpose of this paper. Different configurations of cogeneration systems are analyzed to meet most of the heat demand and to flatten the heat load duration curve. Due to the variable nature of heat demand, there is a need for heat storage, but there is also a need for the fragmentation of power into two units of cogeneration to increase the operational flexibility in these plants. When the heat produced by the combined heat and power (CHP) unit is insufficient to meet the heat load, the heat stored can then be used to meet that demand. Heat storage plays a significant role in managing the heat supply and demand profiles in the CHP system, and in reducing its capacity and size. Trigeneration and heat storage are used as options to increase the operating time of cogeneration units and, implicitly, the amounts of heat and electricity generated in cogeneration. The results of this study demonstrate the economic and technical viability of the cogeneration and trigeneration solutions proposed. For the values of electricity and natural gas prices at the time of the analysis (2021), Scenario 4 is characterized as the optimal economical and technical option for the current rate of consumption, as it ensures the highest values of heat and electricity production and the shortest investment payback period (5.06 years). Compared with separate heat and power generation, we highlight a primary energy saving of 25.35% and a reduction in CO2 emissions of 241,138 kg CO2/year.

A Multiobjective Fractional Programming for a CHP System Operation Optimization Based on Energy Intensity

The objective of this research is to establish a multiobjective fractional programming (MOFP) model for supporting the operational management of a combined heat and power (CHP) system. Compared with the traditional operational optimization model of the CHP system, the importance of the energy intensity (i.e., the ratio of energy consumption and energy production) was emphasized in the MOFP model, which is considered as the system objective for replacing the common objective of minimizing the economic cost. This innovative transformation effectively reduces excessive energy consumption, accompanied by improvement in the system revenue. The CHP system of an industrial park in the City of Jinan, China, was used as a study case for demonstration. The obtained results reflected that the combination of two gas turbines (GTs) ensured safe, efficient, and stable output for meeting daily power requirements in various seasons. As for the steam load, during the summer, two heat recovery steam generators (HRSGs) play a major role, where the insufficient part is supplemented by two gas-fired boilers (SBs); conversely, the steam load in winter is mainly satisfied by the aid of two SBs. The successful application of the MOFP model in the park could provide a good demonstration for CHP management in many other districts and cities.

Optimal Dispatching of Combined Heat and Power System Considering the Power Demand Elasticity of Hydrogen Storage Active Load

With the wide application of hydrogen storage technology in the integrated energy system, the advantages of multienergy complementation on the load side are becoming obvious. In order to fully explore the elasticity of multienergy complementation to optimize system operation, this article incorporates hydrogen storage active load (HS-AL) into the combined heat and power system (CHPS) and analyzes its optimal operation mechanism. By analyzing the operating characteristics of hydrogen storage and the integrated demand response of terminal electric and thermal loads, the external demand elastic space of HS-AL is extracted. Then, the optimal dispatching model considering the power demand elasticity of HS-AL is established. Finally, the simulation validates the effectiveness of the proposed model. The results also show that the elasticity of HS-AL can be fully utilized to promote wind power accommodation and effectively reduce the deep regulation pressure of coal-fired power units at night. This research will provide a theoretical reference for the bidirectional coordinated optimization between HS-AL and CHPS.

Numerical Simulation of an on-Grid Natural Gas PEMFC - Solar Photovoltaic Micro CHP Unit: Analysis of the Energy, Economic and Environmental Impacts for Residential and Industrial Applications

As global natural resources depletion and concern on emission of greenhouse gases intensify, the interest for low emission technologies and the use of renewable energy increased in the world. In this context, this paper aims to present an hybrid energy system for on-grid micro residential and industrial applications. The system is composed of a micro combined heat and power (CHP) unit, including a natural gas (NG) reformer coupled with proton-exchange membrane fuel cell (PEMFC), solar photovoltaic modules (PV) and a bank of batteries (B), connected to the grid through a bidirectional inverter. Different system configurations (PEMFC + PV + B, PEMFC + B, PEMFC + PV), with or without cogeneration of the heat from the CHP system, were investigated to calculate the required NG and electricity flows and assess the economic cost during 10 years of operation in an 2020–2040 horizon. The impact of fuel cell sizing and two electricity tariffs was also assessed for both applications. Afterwards, the cash flow in terms of net present value of a 20 years operation period was simulated within the Brazilian context, yielding estimated paybacks between 7 and 19 years for the simulated cases. Finally, an environmental impact analysis was carried out to investigate the total GHG emissions for some cases of interest in this work. The proposed system could reduce total emissions up to 31% when compared to the complete power and thermal supply by the Brazilian Electricity grid and natural gas heater The results showed that the proposed system were economically viable, relatively low-polluting and more efficient than traditional PV systems.

Off-design modeling of a microturbine combined heat & power system

There is increasing interest in decision support software tools that evaluate the techno-economic potential of distributed energy system technologies for deployment in combined heat and power (CHP) applications, such as commercial buildings, microgrids, and connected communities. This trend is particularly evident among end-users looking to integrate renewable resources with more traditional CHP technologies for on-site generation and enhanced resiliency. However, many of these software tools do not account for part-load and off-design characteristics of prime mover and heat recovery equipment, resulting in lower accuracy for both the optimal selection and sizing and the economic value proposition of integrated hybrid renewable energy-CHP systems. Microturbine technology is an attractive distributed energy resource whose performance is sensitive to both part-load and off-design (i.e., excursions of ambient conditions away from the design point temperature and pressure) operating conditions but is widely unreported. In the present work, we address this deficiency by developing a detailed, thermodynamic model of a commercial 200 kW microturbine CHP system and paramaterizing results for incorporation into the Renewable Energy Optimization (REopt) tool developed by the National Renewable Energy Laboratory. The details of the microturbine model, including model benchmarking and validation, are presented. Microturbine off-design modeling includes part-load analysis, assessment of ambient sensitivities, and mapping heat recovery heat exchanger response to hot water grade requirements. The model is then exercised in several illustrative examples to depict the numerous factors which alter electric power, electric efficiency, and hot water recovery. Model results show, for example, predictions of a 4 percentage point electric efficiency range occurring between intake air temperatures of -18 to 50 °C. Likewise, the model closely predicts the 25 % loss in heat recovery while at -18 °C and the 8 % gain in heat recovery while at 35 °C. An additional case shows how heat recovery may increase or decrease by 9.5 % of the design value when changing the return water temperature plus-or-minus 22 °C. In particular, the impact of ambient conditions on best-possible microturbine performance is conveyed through hourly simulations of the system subjected to the weather of different geographic locations within the United States. • A model of a 200 kW microturbine configured for hot water recovery is developed. • Part-load modeling approach and simulation results for both electric efficiency and waste heat recovery are detailed. • Off-design performance as functions of ambient temperature and pressure is explored. • Heat recovery performance maps as functions of return and supply hot water temperatures are developed.

Performance evaluation of a solid oxide fuel cell multi-stack combined heat and power system with two power distribution strategies

Solid oxide fuel cell (SOFC) combined heat and power (CHP) system is a promising candidate for future energy conversion systems. Large power SOFC-CHP system needs multi-stack fuel cell (MFC) to solve the problems of thermal stress and system stability because MFC systems can achieve better performances for maximum power output and average efficiency than single stack fuel cell systems. This study develops an energy management strategy (EMS) for a SOFC multi-stack CHP system coupled with a methane reformer. SOFC multi-stacks are connected in parallel and verified by the published results. The effect of pressure and temperature on the overall multi-stack CHP system electrical efficiency and heat power is investigated with chain and adaptive EMS. The results show that as temperature and pressure increase, the system power increases. The temperature is more effective for the multi-stack system peak efficiency. Up to 11% of electrical system efficiency can be improved when the temperature rises from 700 °C (973 K) to 900 °C (1173 K). However, higher pressure reduces the peak efficiency by 1.5%. Both temperature and pressure can enlarge the output power range. The proposed model can serve as an effective solution for optimizing the SOFC multi-stack CHP system running on methane.

Design and Feasibility Study of Biomass-Driven Combined Heat and Power Systems for Rural Communities

Abstract Meeting energy demands at crucial times can often be jeopardized by an unreliable power supply from the grid. Local, onsite power generation, such as combined heat and power (CHP) systems, may safeguard against grid fluctuations and outages. CHP systems can provide a more reliable and resilient energy supply to buildings and communities while it can also provide energy-efficient, cost-effective, and environmentally sustainable solutions compared to centralized power systems. With a recent increased focus on biomass as an alternative fuel source, biomass-driven CHP systems have been recognized as a potential technology to bring increased efficiency of fuel utilization and environmentally sustainable solutions. Biomass as an energy source is already created through agricultural and forestry by-products and may thus be efficient and convenient to be transported to remote rural communities. This paper presents a design and feasibility analysis of biomass-driven CHP systems for rural communities. The viability of wood pellets as a suitable fuel source is explored by comparing it to a conventional grid-connected system. To measure viability, three performance parameters—operational cost (OC), primary energy consumption (PEC), and carbon dioxide emission (CDE)—are considered in the analysis. The results demonstrate that under the right conditions wood pellet-fueled CHP systems create economic and environmental advantages over traditional systems. The main factors in increasing the viability of biomass-driven CHP (bCHP) systems are the appropriate sizing and operational strategies of the system and the purchase price of biomass with respect to the price of traditional fuels.

Integrated dispatch for combined heat and power with thermal energy storage considering heat transfer delay

Installing thermal energy storage (TES) devices and utilizing the TES characteristic of heating networks are effective means of improving the flexibility of combined heat and power (CHP) systems. However, to truly take advantage of these, many factors such as the heat transfer (HT) processes, heat exchanger (HE) internal structure, HT area, mass flow rate, the HT delay are essential to be considered. These vital factors are not discussed in sufficient detail simultaneously and may lead to inaccurate modelling and underutilisation of thermal inertia. Thus, this paper investigates the HT process and thermal time-lag issues by analysing the structure and working characteristics of HE. A novel dispatch model considering HT delays is first established based on detailed HT processes. The developed model poses a strongly non-linear problem that is difficult to solve. Then, a decomposition-coordination method is proposed to deal with it. Furthermore, the sensitivity of different factors affecting HT delays is analysed so that the operator is able to configure parameters more clearly. Simulation results prove the necessity of considering the HT delay in CHP systems and the effectiveness of the proposed model. Further analyses also demonstrate that the proposed method offers higher accuracy than a solver and fitting method.

Analysis of economy, energy efficiency, environment: A case study of the CHP system with both civil and industrial heat users

Integrated energy supply via the high-capacity combined heat and power (CHP) system is an effective way to achieve “win-win cooperation” for regional carbon reduction. A case study of the CHP system with both civil and industrial heat users is conducted to analysis the mixed impact of integrated energy supply on CHP systems. The steam-water equations and the off-design calculation model are developed to analyze the heat-power coupling mechanism of the CHP system. The linear-calculating diagram is obtained, which provides operational guidance for CHP system with simultaneous power, civil heat and industrial loads. Further, the analysis of economy, energy efficiency and environment within the operation region is performed. The results show that for a constant main steam flow rate, the industrial heat load is more profitable than the civil heat load. Moreover, the energy efficiency of the CHP unit can be further improved by undertaking the industrial heat load, despite at the expense of part capacity to supply civil heat. The average value of CO2 emissions per unit profit is reduced by approximately 7.69% overall after the stable industrial heat load of 100 MW, which means about 1.64 tons of CO2 can be reduced per 1000 USD profit.

Solution of Combined Heat and Power Economic Dispatch Problem Using Direct Optimization Algorithm

This paper presents the solution to the combined heat and power economic dispatch problem using a direct solution algorithm for constrained optimization problems. With the potential of Combined Heat and Power (CHP) production to increase the efficiency of power and heat generation simultaneously having been researched and established, the increasing penetration of CHP systems, and determination of economic dispatch of power and heat assumes higher relevance. The Combined Heat and Power Economic Dispatch (CHPED) problem is a demanding optimization problem as both constraints and objective functions can be non-linear and non-convex. This paper presents an explicit formula developed for computing the system-wide incremental costs corresponding with optimal dispatch. The circumvention of the use of iterative search schemes for this crucial step is the innovation inherent in the proposed dispatch procedure. The feasible operating region of the CHP unit three is taken into account in the proposed CHPED problem model, whereas the optimal dispatch of power/heat outputs of CHP unit is determined using the direct Lagrange multiplier solution algorithm. The proposed algorithm is applied to a test system with four units and results are provided.

Assessing the Effects of Uncertain Energy and Carbon Prices on the Operational Patterns and Economic Results of CHP Systems

In the power and heat sectors, the uncertainty of energy and carbon prices plays a decisive role in the rationale for decommissioning/repurposing coal-fired CHP (combined heat and power) systems and on investment decisions of energy storage units. Therefore, there is a growing need for advanced methods that incorporate the stochastic disturbances of energy and carbon emission prices into the optimization process of an energy system. In this context, this paper proposes an integrated method for investigating the effects of uncertain energy and carbon prices on the operational patterns and financial results of CHP systems with thermal energy storage units. The approach combines mathematical programming and Monte Carlo simulation. The computational process generates feasible solutions for profit maximization considering the technical constraints of the CHP system and the variation of energy and carbon emission prices. Four scenarios are established to compare the operational patterns and economic performance of a CHP system in 2020 and 2030. Results show that in 2020, there is an 80% probability that the system’s annual profit will be less than or equal to €30.98 M. However, at the same probability level, the annual profit in 2030 could fall below €11.88 M. Furthermore, the scenarios indicate that the incorporation of a thermal energy storage unit leads to higher expected profits (€0.74 M in 2020 and €0.71 M in 2030). This research shows that coal-fired CHP plant operators will face costly risks and potentially greater challenges in the upcoming years with the increasing regulatory and financial pressure on CO2 emissions and the EU’s plan of phasing out fossil fuels from electricity and heat generation.

Optimization of a 30 kW SOFC combined heat and power system with different cycles and hydrocarbon fuels

Solid oxide fuel cells (SOFCs) could generate power cleanly and efficiently by using a wide range of fuels. Through the recovery and utilization of the energy in the SOFC tail gas, SOFC combined heat and power (CHP) systems achieve efficient cascade utilization of fuels. In this article, an efficient 30 kW SOFC CHP system with multiple cycles is designed based on a commercial kw-level SOFC device. The energy and substances could be recycled at multiple levels in this system, which makes the system do not need external water supply anymore during working. Meanwhile, the performance, fuel applicability, flexibility and reliability of the system are investigated. Finally, an optimized operating condition is confirmed, in which the electrical efficiency is 54.0%, and the thermoelectric efficiency could reach 88.8% by using methanol as fuel.

Synthesize a Sustainable Supply Chain of Biomass to Electricity via Mathematical Approach

The huge amount of biomass waste and palm oil mill effluent (POME) generated during oil extraction has prompted the need for a more sustainable framework in waste management. Since oil palm biomass waste is rich in lignocellulosic content, it can be potential to be converted into green energy such as bioelectricity via different pathway of processes such as the thermal conversion pathway and biochemical conversion pathway. This study proposes a mathematical approach to synthesise a sustainable supply chain of biomass to electricity by implementing the combined heat and power (CHP) system in palm oil mill. The optimum pathway of supply chain based on the technical, economical, and environmental aspects is generated. The purpose of this approach is to assists the industry players or owners to make decision in choosing the location of the pre-treatment technology, transportation method, location of power plant and configuration of CHP. A generic superstructure is first developed to achieve the objective. Then, a series of generic mathematical equations will then be formulated based on the pathways demonstrated in the generic superstructure. The mathematical equations involve general mass and energy balance, cost computation and carbon emission. The fuzzy optimisation concept will be adopted in this research to trade-off the conflicting objectives (maximize profit and minimize carbon footprint) in order to generate the optimum pathway. A palm oil-based bioelectricity supply chain case study in Selangor, Malaysia is solved to illustrate the presented approach. According to the optimised result in this case study, a total of 3,753.36 MW of bioelectricity can be generated per year. The result proved that the optimum pathway is feasible by comparing with the existing oil palm biomass-based power plant in Sarawak, where only 375 MW of electricity is generated by oil palm biomass. On the other hand, RM 7.25 million per year of net profit is estimated with a payback period of 2.81 years. Moreover, the CHP system is able to achieve 570 million kg CO2 per year.