Solar Combined Cooling, Heating And Power Research Articles

Strategic integration of residential electricity: An optimisation model for solar energy utilisation and carbon reduction

The Solar Combined Cooling, Heating, and Power (S-CCHP) system, distinct from traditional centralised generation, provides clean energy solutions by installing user-side renewable energy capture facilities like solar panels to address the energy crisis and mitigate global warming. Previous research on the design of S-CCHP for buildings has often emphasised self-sufficiency, with less focus on the role of these systems as energy suppliers on the market. However, it is feasible to install scaled-up solar facilities that generate enough power to export to the grid, reducing grid pressure and enhancing the renewable energy mix. This study analyses the optimal design deployment for electricity within the S-CCHP system, based on the Renewable Energy System for Residential Building Heating and Electricity Production (RESHeat) system installed in Limanowa. It aims to optimise owner energy deployment by strategically integrating electricity generation, hybrid storage, and the electricity market to maximise owner benefits. A Life Cycle Assessment is also conducted to explore greenhouse gas emissions across scenarios with different storage facilities and reuse rates. Results show that the optimal deployment of 264 PV panels, each with a rated power of 440 W, generates 105 MWh annually, resulting in the surplus of 90.18 MWh with a selling price of 115 EUR/MWh. Vanadium redox flow batteries offer the highest revenue (4922.01 EUR) with the lowest storage costs, while lithium-ion batteries have the lowest carbon emissions (1.22 t CO2 eq/y). Sensitivity analysis and revenue break-even analysis are further conducted to assess the robustness and financial viability.

Chance-constrained optimization of hybrid solar combined cooling, heating and power system considering energetic, economic, environmental, and flexible performances

Uncertain parameters and factors substantially impact the operational performances of combined cooling, heating, and power (CCHP) systems. This paper constructs a chance-constrained programming model for system design and energy dispatch management of a hybrid solar CCHP system under the uncertainties of solar energy and building loads. The uncertain scenarios with probability distributions are generated in the Latin hypercube sampling and clustering methods. The chance-constrained model transforms stochastic optimization into deterministic optimization based on these scenarios. Then, the multi-objective optimization model of CCHP system considering the performances of economic, energy, emission, and flexibility is established, and the modified ε-constraint method is employed to obtain Pareto solutions. A case study validates the proposed model. The capacities and operational strategies of components in the hybrid CCHP system are optimized, and the impacts of the confidence level of probability distributions of uncertain factors on the optimization results are discussed. The results indicate that the photovoltaic capacity in the hybrid CCHP system declines by 87.5% when the confidence level increases from 0.50 to 0.99. But other components’ capacities are raised, and the gas turbine capacity as the key component rises by 10.49%. The energetic and environmental performances of the CCHP system rise with the confidence level, and the operation safety is improved.

Photovoltaic-Thermal (PV-T) Systems for Combined Cooling, Heating and Power in Buildings: A Review

Heating and cooling (H/C) represent the largest share of energy consumption worldwide. Buildings are the main consumers of H/C, while the share of renewable energy for H/C provision still represents a low percentage, 22.0% in 2019. Hybrid photovoltaic-thermal (PV-T) systems are gaining increasing attention both in research and in applications, as they generate both electricity and useful heat simultaneously. The relevance and potential of PV-T collectors and their integration into wider systems are evident, but there is still a lack of review articles that address the potential of these systems in building applications in a comprehensive way. This work aims to review the state-of-the-art of PV-T collectors for building applications, as well as the corresponding PV-T systems for solar combined cooling, heating and power (S-CCHP) provision. The novelties of this work involve the comparison of these systems with conventional solar H/C technologies, the review of the market of H/C technologies, a summary of the challenges for the wider integration of S-CCHP systems and proposal lines of work to improve the cost-competitiveness of these systems. The first section summarises the focus and findings of previous reviews, followed by an overview of the current development status of the main types of PV-T collectors. Then, PV-T-based S-CCHP systems are reviewed, and the potential of PV-T systems’ penetration in the built environment is evaluated and discussed.

Life Cycle Assessment of solar energy systems for the provision of heating, cooling and electricity in buildings: A comparative analysis

A detailed Life Cycle Assessment (LCA) “from cradle to grave” is performed to a solar combined cooling, heating and power (S-CCHP) system that provides space heating, cooling, domestic hot water and electricity, following two different methodologies (the ReCiPe 2016 Endpoint (H/A) v1.03 and the carbon footprint IPCC 2013 100 years). The innovative S-CCHP system is currently in operation in an industrial building located in Zaragoza (Spain), and the transient model developed to estimate the annual energy outputs has been validated. The system consists of hybrid photovoltaic-thermal (PV-T) collectors integrated via two parallel thermal storage tanks with an air-to-water reversible heat pump (rev-HP). Another contribution is that the detailed LCA analysis is also performed to a conventional PV-system and a grid-based system, viz building electricity consumption supplied from the grid (baseline configuration). The results show that the proposed S-CCHP system has half of the environmental impact of the grid-based system, according to the ReCiPe 2016 Endpoint (H/A) and the IPCC GWP 100a methods (4.48 kPts vs 8.87 kPts, and 82.4 tons of CO2 eqvs 166.9 tons of CO2 eq, respectively). The PV-system has 30% less environmental impact than the grid-based system. Another novelty and contribution are the sensitivity analyses performed to assess the influence of the system lifetime, the solar irradiance and the power generation mix (also known as the electricity mix) on the LCA results. The results show that the proposed S-CCHP system appears as an up-and-coming alternative to reduce the environmental impacts of buildings in all the considered solar irradiance levels and electricity mix scenarios, even in climates with low irradiance levels or in countries with a highly decarbonised electricity supply.

Optimization of Solar CCHP Systems with Collector Enhanced by Porous Media and Nanofluid

The low efficiency of solar collectors can be mentioned as one of the problems in solar combined cooling, heating, and power (CCHP) cycles. For improving solar systems, nanofluid and porous media are used in solar collectors. One of the advantages of using porous media and nanoparticles is to absorb more energy under the same conditions. In this research, a solar combined cooling, heating, and power (SCCHP) system has been optimized by porous media and nanofluid for generating electricity, cooling, and heating of a 600 m2 building in a warm and dry region with average solar radiation of Ib = 820 w/m2 in Iran. In this paper, the optimal amount of nanofluid in porous materials has been calculated to the extent that no sediment is formed. In this study, solar collectors were enhanced with copper porous media (95% porosity) and CuO and Al2O3 nanofluids. 0.1%–0.6% of the nanofluids were added to water as working fluids; it is found that 0.5% of the nanofluids lead to the highest energy and exergy efficiency enhancement in solar collectors and SCCHP systems. Maximum energy and exergy efficiency of parabolic thermal collector (PTC) riches in this study are 74.19% and 32.6%, respectively. Figure 1 can be mentioned as a graphical abstract for accurately describing the cycle of solar CCHP.

Operation Strategy Analysis and Configuration Optimization of Solar CCHP System

This paper proposed a new type of combined cooling heating and power (CCHP) system, including the parabolic trough solar thermal (PTST) power generation and gas turbine power generation. The thermal energy storage subsystem in the PTST unit provides both thermal energy and electrical energy. Based on the life cycle method, the configuration optimization under eight operation strategies is studied with the economy, energy, and environment indicators. The eight operation strategies include FEL, FEL-EC, FEL-TES, FEL-TES&EC, FTL, FTL-EC, FTL-TES, and FTL-TES&EC. The feasibility of each strategy is verified by taking a residential building cluster as an example. The indicators under the optimal configuration of each strategy are compared with that of the separate production (SP) system. The results showed that the PTST-CCHP system improves the environment and energy performance by changing the ratio of thermal energy and electric energy. The environment and energy indicators of FEL-TES&EC are superior to those of FTL-TES&EC in summer, and the results are just the opposite in winter. The initial annual investment of the PTST-CCHP system is higher than that of the SP system, but its economic performance is better than that of the SP system with the increase of life-cycle.

Thermodynamic analysis of a novel solar trigeneration system

Loop heat pipes (LHPs) are high efficiency devices which can be used in solar systems. The main objectives of this research are to propose a novel solar combined cooling heating and power (SCCHP) system based on loop heat pipe (LHP) evaporator, and to present thermodynamic analyses to effectively improve the utilization of loop heat pipes for distributed renewable energy sources. Also a parametric analysis is carried out to investigate the effect of the key variable parameters on the system performance for three operation modes (solar mode, solar and storage mode and storage mode). The results showed that, for the solar and solar and storage operation modes, the main source of the exergy destruction is the solar loop heat pipe evaporator while for the storage operation mode, the main source of the exergy destruction is the hot storage tank. The energy efficiency of the proposed system is 70.52% for the solar mode, 72.09% for the solar and storage mode, and 64.77% for the storage mode and the exergy efficiency of the proposed system is 12.36% for the solar mode, 14.78% for the solar and storage mode, and 47.45% for the storage mode.

Solar combined cooling, heating and power systems based on hybrid PVT, PV or solar-thermal collectors for building applications

A modelling methodology is developed and used to investigate the technoeconomic performance of solar combined cooling, heating and power (S-CCHP) systems based on hybrid PVT collectors. The building energy demands are inputs to a transient system model, which couples PVT solar collectors via thermal store to commercial absorption chillers. The real energy demands of the University Campus of Bari, investment costs, relevant electricity and gas prices are used to estimate payback times. The results are compared to: evacuated tube collectors (ETCs) for heating and cooling provision; and a PV-system for electricity provision. A 1.68-MWp S-CCHP system can cover 20.9%, 55.1% and 16.3% of the space-heating, cooling and electrical demands of the Campus, respectively, with roof-space availability being a major limiting factor. The payback time is 16.7 years, 2.7 times higher than that of a PV system. The lack of electricity generation by the ETC-based system limits its profitability, and leads to 2.3 times longer payback time. The environmental benefits arising from the system’s operation are evaluated. The S-CCHP system can displace 911 tons CO2/year (16% and 1.4 × times more than the PV-system and the ETC-based system, respectively). The influence of utility prices on the systems’ economics is analysed. It is found that the sensitivity to these prices is significant.

The study of a seasonal solar CCHP system based on evacuated flat-plate collectors and organic Rankine cycle

The demands of cooling, heating and electricity in residential buildings are varied with seasons. This article presented a seasonal solar combined cooling heating and power (CCHP) system based on evacuated flat-plate collectors and organic Rankine cycle. The heat collected by evacuated flat-plate collectors is used to drive the organic Rankine cycle unit in spring, autumn and winter, and drive the double-effect lithium bromide absorption chiller in summer. The organic Rankine cycle condensation heat is used to yield hot water in spring and autumn, whereas supply heating in winter. The system thermodynamic performance was analyzed. The results show that the system thermal efficiency in spring, autumn and winter, ?sys,I, increases as organic Rankine cycle evaporation temperature, T6, and evacuated flat-plate collectors outlet temperature, T2, decrease. The maximum ?sys,I of 67.0% is achieved when T6 = 80?C and T2 =100?C. In summer, the system thermal efficiency, ?sys,II, increases first and then decreases with the increment of T2. The maximum ?sys,II of 69.9% is obtained at T2 =136?C. The system output performance in Beijing and Lanzhou is better than that in Hefei. The average output power, heating capacity, hot water and cooling capacity are 50-72 kWh per day, 989-1514 kWh per day, 49-57 ton per day and 1812-2311 kWh per day, respectively. The system exergy efficiency increases from 17.8-40.8% after integrating the organic Rankine cycle unit.