Optimization of a Sawmill-Based Polygeneration Plant

Author(s):  
Marianne Salomón ◽  
María F. Gómez ◽  
James Spelling ◽  
Andrew Martin

Biomass-based fuels have attracted worldwide interest due to their plentiful supply and their environmentally friendly characteristics. In many cases they are still considered waste but for most industries in Sweden, biomass has changed from being simply a disposal problem to become an important part of the energy supply, thanks to the long-term efforts made by the government, researchers and industry, where energy policies have played an important role. However, the amount of power that could be generated from biomass resources is much greater than that which is currently used. To effectively capture this resource requires a new generation of biomass power plants and their effective integration into already existing industrial processes. The implementation of an integrated polygeneration scheme requires the simultaneous consideration of technical, economic and environmental factors to find optimum solutions. With this in mind, a unified modeling approach that takes into account thermodynamic as well as economic and environmental aspects was used. The analysis was done using ASPEN Utilities and the MATLAB optimization toolbox. A specific case of a sawmill in Sweden, with an annual capacity of 130’000 m3 of sawn wood, has been analyzed and different options for generating electricity and process heat (for the sawmill and for a district heating network) as well as densified biofuels was analyzed. Optimization was then applied for different configurations and operational parameters. The results show that the sawmill has the capability to not only supply its own energy needs, but also to export from 0.4 to 1MW of electricity to the grid, contribute 5 to 6 MWth of district heating and 20 000 ton/y of biomass pellets. The production of pellets helps to maintain the electricity production throughout the year when the district heating demand is lower. However, the levelized electricity cost is higher than the usual electricity price in the Nordic electricity market and may have difficulty to competing with low-cost electricity sources, such as nuclear energy and hydropower. In spite of this, polygeneration remains attractive for covering the energy demands of the sawmill and pelletization plant.

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2576
Author(s):  
Cristina Moliner ◽  
Elisabetta Arato ◽  
Filippo Marchelli

This work analyses and discusses data on thermochemical plants in Southern Italy that are fed with solid biomass. The analysis takes into account the biomass availability and potential together with the cost-benefit analysis using technology development and economic indicators (LCOE). A total of 63,762 units have been categorised according to the employed technology and produced energy: power plants for electricity production or cogeneration plants for combined heat and electricity production (53 plants) and thermal units for heat production (63,709 units). The eight regions of the area have noteworthy differences. In terms of electricity generated from solid biomass Calabria is by far the largest producer, followed by Apulia. Sicily, Sardinia and Molise provide lower amounts while Abruzzo, Basilicata and Campania generate almost negligible amounts. Regarding thermal production, Campania and Calabria are the largest producers, but Basilicata, Molise and Abruzzo generate the highest amount per capita. The area is far from fully exploiting its biomass potential, and there are also no district heating grids. Bioenergy can be remarkably competitive, provided that capital costs are relatively low and low-cost biomass is available, as it is the case of Italy. New applications and markets for sub-products (i.e., char, ash) would help in lowering the still not competitive economic indicators (LCOE).


Mechanika ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 242-251
Author(s):  
M. AMANI ◽  
A. SMAILI ◽  
A. GHENAIET

The aim of this study is the thermo-economic assessments of an integrated solar combined cycle (ISCC) system, in terms of thermal efficiency, electricity production and levelized electricity cost (LCOE). During the day light the power plant operates as an ISCC and operates as a conventional combined cycle (CC) during the night or cloudy days. In one hand the obtained results show that at the design point the solar electricity ratio may reach about 17 % and the global thermal efficiency 63 %, leading to lower fuel consumption and carbon emission. On the other hand, the economic assessment depicts that LCOE may reach 0.0222 $/kWh, which is about 28 % higher than that of (CC) power plants. Furthermore, by introducing the environmental effect LCOE becomes equal to 0.0272 $/kWh which is higher. Therefore, the annual solar contribution relatively to this ISCC installation site will allow about 18.45 million $ of fuel saving, avoiding emission of 0.89 million ton of CO2 over 30 years operation.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4134 ◽  
Author(s):  
Katharina Koch ◽  
Bastian Alt ◽  
Matthias Gaderer

The targets of global CO2 reduction outline the importance of decarbonizing the heating and cooling sector, which consume half of the final energy in the European Union (EU). Consequently, heating network operators must adapt to growing requirements for carbon neutrality. Energy system modeling allows the simulation of individual network compositions and regulations, while considering electricity market signals for a more efficient plant operation. The district heating model, programmed for this work, covers a measured heat demand with peak load boiler, biomass-fired combined heat and power (CHP) plant, and biomass heating plant supply. The CHP plant reacts to electricity prices of the European Power Exchange market and uses a long-term heat storage to decouple heat and electricity production. This paper presents the results of three annual simulation scenarios aimed at carbon neutrality for the analyzed heating network. Two scenarios achieve a climate-neutral system by replacing the peak load boiler generation. The exclusive storage capacity expansion in the first scenario does not lead to the intended decarbonization. The second scenario increases the output of the CHP plant, while the third simulation uses the biomass heating plant supply. This additional heat producer enables a significant reduction in storage capacity and a higher CHP plant participation in the considered electricity market.


2018 ◽  
Vol 20 (04) ◽  
pp. 1850008 ◽  
Author(s):  
Ryle S. Perera

We study how a government can manage a policy of environmental sustainability in a competitive electricity market. We assume that the government plays a Stackelberg game as leader, to study the evolutionary stable equilibria of the problem under this game theory paradigm. We then analyze a bimatrix coordination game to have many equilibria when no single power plant has incentives to deviate when the others reduce carbon emissions. In fact for power plants the adapted behavior is to avoid heavy tariffs, preserve the market share and minimize the environmental impact. We use the notion of quantal response equilibrium (QRE) in the case of bounded rationality to obtain a unique Nash equilibrium known as the centroid-dominant equilibrium of the game. This proposed quantitative framework can be applied by policy makers to determine incentives and tariffs to meet the environmental obligations in the electricity market.


The increase reliance on competitive electricity market has led to widespread research to reallocate energy sources and minimize the price of energy and the services related to it. The main issues that faces the design of any energy market, is thehigh cost of generation and the high shadow pricesthat highly impacts the consumers.Also,achieving the supply-demand balance and minimization of the transmission congestion is a vital goal while planning. In this paper, a transparent and open competitive market is attained. In order to control the electricity market and reduce the market clearing price, this study proposed introducing renewable energy power plants which has lower electricity generation cost in comparison with the conventional power plants.Minimization of the shadow price is achieved by dividing the electricity grid into multiple regions. Every region has a different shadow price depending on the load demand and the power plants available to supply the demand at this region. Where,the market clearing price of each region is set as the price of generation of the highest power plant sharing in supplying the load demand at this region. This methodology is applied on the Egyptian unified power network.Sizing and allocation of the renewable energy power plantsis studied carefully from the technical and economical point of view to maximize the benefit and minimize the overall cost function and shadow price


2022 ◽  
Vol 9 ◽  
Author(s):  
Houyin Long ◽  
Hong Zeng ◽  
Xinyi Lin

The Chinese government has adopted many policies to save energy and electricity in the chemical industry by improving technology and reforming its electricity market. The improved electricity efficiency and the electricity reform may indirectly reduce expected energy and electricity savings by decreasing the effective electricity price and the marginal cost of electricity services. To analyze the above issues, this paper employs the Morishima Elasticity of Substitution of the electricity cost share equation which is estimated by the DOLS method. The results show that: 1) There exists a rebound effect in the Chinese chemical industry, but it is quite large because the electricity price is being controlled by the government; 2) the reform of the electricity market reduces the rebound effect to 73.85%, as electricity price begins to reflect cost information to some extent; 3) there is still a lot of space for the reform to improve, and the rebound effect could be reduced further once the electricity price is adjusted to transfer the market information more correctly. In order to succeed in saving electricity and decreasing the rebound effect in the chemical industry, the policy implications are provided from perspectives of the improved energy efficiency and electricity pricing mechanism.


Author(s):  
Robert Pitz-Paal ◽  
Ju¨rgen Dersch ◽  
Barbara Milow ◽  
Fe´lix Te´llez ◽  
Alain Ferriere ◽  
...  

Beside continuous implementation of concentrating solar power plants (CSP) in Europe, which stipulate cost reduction by mass production effects, further R&D activities are necessary to achieve the cost competitiveness to fossil power generation. Therefore the cost range of 15–20 cents€/kWh for the currently planned CSP systems in Europe has to be decreased by a factor of 2–4. The European Concentrated Solar Thermal Roadmap (ECOSTAR) study that is conducted by leading CSP research institutes in Europe intends to stipulate the direction for R&D activities in the context of cost reduction. It uses a common methodology approach, based on an annual performance model to identify the most essential technical innovations that will reduce the cost of seven different CSP system concepts, which are currently under promotion world wide. The potential of innovative concepts for solar light weight concentrators, low-cost thermal energy storage concepts, solar receivers/absorbers and power cycles are in the main focus of interest. The results of the study include a description of the value of CSP power, the sensitivity of the electricity cost information, a list of innovations that have been investigated and recommendations for the focus of further R&D work.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1930 ◽  
Author(s):  
Anahita Farsaei ◽  
Sanna Syri ◽  
Ville Olkkonen ◽  
Ali Khosravi

Finland has adopted a high profile in climate change mitigation. A national target of achieving carbon neutrality by 2035 has been declared. As a part of this, the use of coal for energy purposes has been banned from May 2029 onwards. The Nordic electricity market was a world fore-runner in creating a liberalized, multi-national electricity market in the 1990s. At present, the electricity systems of Finland, Sweden, and Norway are already very low-carbon. The Baltic countries Estonia, Latvia, and Lithuania joined the Nordic market about a decade ago. Estonian electricity production is the most carbon-intensive of all the EU countries due to the extensive use of domestic oil shale. Especially Lithuania still suffers from capacity deficit created by the closure of the Soviet time nuclear reactor Ignalina in Lithuania. This paper presents the ambitions of the EU and national level energy and climate policies and models the multi-national impacts of Finland’s forthcoming closure of coal-fired generation. We also take into account Sweden’s planned decrease in nuclear generation. We find that these national-level policies have an impact on the Baltic countries as reduced import possibilities and increasing electricity prices, and the expected rise of the EU CO2 allowance prices amplifies these. We further find that the abandonment of coal and nuclear power plants increases the net import and increases CO2 emissions in neighboring regions.


Author(s):  
Clifford K. Ho ◽  
M. Michael Hightower ◽  
Ronald C. Pate ◽  
Wayne Einfeld ◽  
Christopher P. Cameron ◽  
...  

Energy and water are critical resources that are inextricably and reciprocally linked. The production of energy requires large volumes of water, and the treatment and distribution of water depends upon readily available, low-cost energy. For example, electricity production from thermoelectric power plants can use ∼140,000 million gallons of water per day for cooling—accounting for 39% of all freshwater withdrawals in the nation, second only to agriculture in the United States (Figure 1). Significant amounts of water are also needed for hydropower, extraction/refining of minerals for energy, and bio-fuel production. Electrical energy, on the other hand, is needed for water treatment (e.g., desalination, wastewater), pumping, and distribution. The amount of electricity used in water and wastewater industries is equivalent to the amount used in chemical, petroleum refining, and paper industries. These interdependencies, coupled with increasing demands for energy and diminishing availability of freshwater supplies, pose significant challenges to ensure the sustainability of these two critical resources. Examples of the interrelationships between energy and water use are shown in Figure 2.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Cyprien Nsengimana ◽  
Xin Tong Han ◽  
Ling-ling Li

Photovoltaic microgrids provide free renewable energy solutions for Rwandans. Although solar technology keeps on its advancement, hydropower remains the principal power source in Rwanda. Other renewable power sources include wind and geothermal energies that are not yet fully exploited. Nonrenewable sources in Rwanda including methane, peat, thermal, and fuels are also used for providing energy solutions for the citizens. Rwanda Energy Group (REG) sets the energy strategic plan since 2015 for achieving the minimum of 512 MW of energy production in 2024/2025 to meet the total energy demand. The plan predicted 52% for grid-connected and 48% for off-grid (standalone) connections. The literature survey and data analysis collected on site were used to evaluate and determine the best cheaper microgrid model from the three comparison case studies for the household in Rwanda. The study focused on the economic power generation model mainly based on solar resources to minimize the electricity cost and provide income for the excess energy produced. Moreover, the study resulted in a low-cost (four times cheaper), reliable, and affordable grid-connected PV and battery microgrid model for a residential home with a minimum daily load of 5.467 kWh. The simulation results based on economic comparison analysis found the levelized cost of energy (LCOE) and net present cost (NPC) for each power-generated model by using Hybrid Optimization Model for Electric Renewable (Homer) pro software. The results show that the LCOE for electricity production by each of the Grid connected-PV-Battery system, Diesel GenSet-PV-Batteries, and PV-Batteries systems was 0.0645 US$/1 kWh, 1.38 US$/1 kWh and 1.82 US$/1 kWh, respectively, compared with 0.2621 US$/1 kWh, the current residential electricity price (2020) for Rwanda.


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