• Energy Research
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• 7. Clean energy close

Emissions optimization, particularly for complex engines, relies on developing mathematical correlations or 'Response Surface Models' of engine outputs. There is a clear tradeoff between the complexity of the model and its usefulness for a range of optimization tasks. Several current Sl engine management systems use a 'Spark efficiency curve' to elegantly describe the response of engine torque to spark advance using a prescribed characteristic line that is fitted to a spark sweep with only two degrees of freedom. This provides a powerful method of data reduction. A similar technique has been developed to characterize engine emissions data. A single efficiency curve with only two degrees of freedom can be used to accurately describe the response of, say, hydrocarbon emissions to spark over a wide range of engines and operating conditions. The technique offers similar data reduction advantages for engine management system developers and those optimizing engines using high DoF models. The form and application of the efficiency curves is discussed and examples of application to tasks such as engine emission optimization are discussed.

The energy expended to cool the occupied areas by air conditioners represents a substantial share of the total energy exhausted in buildings. Therefore, developing strategies to reduce this energy is crucial. One of the preponderance strategies adopted to depreciate energy consumption in buildings is the occupancy-based strategy. In this research, an innovative model was established to achieve the goal of reducing cooling energy consumed in buildings based on occupancy-based combined with a constant temperature setpoint strategy in two phases, and each phase engrosses in 20 days. Phase one is to identify the extent of cooling energy employed according to the use of room occupants and its costs in consumption was 276.01 kWh after completion of this phase. Sequentially, constructing phase two intended to reduce cooling energy consumption by employing an automatic air-conditioner (AC) control strategy relying on an improved human detection algorithm with a 25℃ as temperature setpoint, resulting in 112.45 kWh of consumption. To complement the motives for elaboration, the human detection measurement using you only look once (YOLO) improved by applying pre-processing algorithms to reach an average human detection enhancement of 21.2%. The proposed model results showed that potential savings associated with the embraced strategy decreases by more than anticipated as the amount of reduced energy reached 59% savings.

Abstract Carbon capture, utilization, and storage (CCUS) is one of several mitigation options that must be implemented in order to reduce anthropogenic CO 2 emissions. The work presented in this paper is a part of the ongoing PRO_CCS project, where the emphasis is on Polish emitters located on or close to the Baltic Sea coast and possible whole chain CCS solutions for these. This paper will focus on the potential use of CO 2 from these sources in CO 2 -EOR projects in the Baltic Sea and/or North Sea. In addition, a number of technical and non-technical CO 2 -EOR related aspects have been identified and discussed. Two oilfields, B8 in the Polish economic sector of the Baltic Sea and Brage on the Norwegian Continental Shelf have been selected. These two fields are matched with suitable emitters in Poland to develop two separate CCUS scenarios. The scenarios will provide a prediction on operations during the CO 2 -EOR project lifetime. These predictions will be based on open information about the oilfields and their current operation, and on available literature on CO 2 -EOR operations. The goal of the project is to assess the economic viability of the two scenarios.

Abstract This paper presented a novel method of dissipating solar photovoltaic heat based on the technology of micro-heat-pipe array and the utilization of photovoltaic-cell waste heat. This novel technology solved the problems of low PV electrical efficiency and thermal failure caused by high cell temperature, greatly increased the comprehensive utilization efficiency of solar energy, and extended the service life of photovoltaic modules. One-year experiments were conducted to investigate the electrical and thermal performance of a forced-circulation, household-type photovoltaic/thermal system based on micro-heat-pipe array in Beijing, China. Test results showed that on the four typical days in different seasons, the average electrical efficiencies were 13.76%, 11.92%, 13.71%, and 14.65%; the average thermal efficiencies were 31.62%, 33.07%, 24.99%, and 17.24%; and the average total efficiencies were 45.38%, 44.99%, 38.70%, 31.89%, respectively. The system met the demand of power supply on sunny days and the demand of hot water between March and November, except in cloudy days. These experimental results can provide basis and reference for practical applications of the system.

In this study, the amount of waste resource that could be recovered was analyzed. The installation and operation costs of waste resource recovery for both single- and multi-regional facility were calculated, and compared with the costs of landfill to investigate the feasibility of them. RDF(Refuse Derived Fuel) process and resource recovery by incineration process were considered as waste resource recovery facility. And, the multi-regions for cost analysis were established on the basis of the proper generation rate of municipal waste with the consideration of combustible ratio. The study results showed that single region facility for both RDF and incineration process has no economic benefit, compared with the landfill method. For the multi-regional facility, RDF process could save a large cost than the landfill method, but the incineration facility couldn`t. Separate from the economic benefits, the waste resource recovery should be importantly considered when considering the depletion of fossil fuel, global warming, environmental toxicity, and the enormous expenses due to social conflict and confuse. When the CDM(Clean Development Mechanism) is vitalized in the near future, the additional economic benefits by CERs(Certified Emission Reductions) could be expected. CERs for RDF facility is corresponding to about 256.5 billion won, and CERs for incineration facility is corresponding to about 54 and 77.4 billion won for single- and multi-regional facility, respectively.

Based in the importance of the Economic Dispatch for operation and planning of power systems, this paper presents the Trelea Particle Swarm Optimization method (Trelea-PSO) applied to this issue. In this paper the ED problem is modeled considering the valve-point effects and multiple fuels, though a non-convex function. Study cases composed of two 10 thermal generators systems are presented to validate the proposed methodology. The results obtained was compared to others presented in literature.

The classical approach to load modeling is to divide the load by customer class and then identify and model the load components corresponding to each customer class. This work explores an alternative way to break down the load using readily available data. Namely, using historical usage data and historical weather data the load can be first divided into temperature-dependent and temperature-independent portions. A simple thermal model of the structure(s) served by the electrical circuit forms the theoretical and mathematical basis of this separation. During summer peaking conditions, the temperature-dependent load is generally composed of air conditioners, which must be modeled properly in order to analyze delayed voltage recovery or other dynamic phenomenon. Once the temperature-dependent fraction of the load has been characterized, the size of compressor, fan, and pump motors can be inferred by the customer class.

The hydraulic balance of heating network is considered as a pre-condition for the implementation of low temperature district heating (LTDH). Its imbalance result into high energy consumption and heat-losses in the network. In this study, a novel hydraulic model is presented which investigates hydraulic imbalance in the LTDH network, using real weather and hourly monitored operational heating data from an existing boiler based building. Analysis of delta t in space-heating system shows that the delta t is maximum when the outside air temperature is lowest and it decreases with increase in outside air temperature. Furthermore, the hydraulic imbalance is analysed for four different control scenarios with the aim to find an optimum scenario with minimum pumping power, energy consumption and heat-losses in the LTDH network. Results show that the hydraulic imbalance is due to the absence of flow-limiters and balancing valves on the return pipe and thermostatic radiator valves (TRVs) alone are unable to maintain hydraulic balance in the space-heating system of buildings. Moreover, the control scenario with variable flow-rate and fixed supply water temperature from the sub-station is found to be optimum. Compared to the constant flow-rate scenario, the pumping power, energy consumption and heat-losses in the LTDH network are reduced by approximately 2%, 63% and 14%, respectively.

Improving access to sustainable energy services and reducing the carbon footprint and deforestation of developing countries presents a substantial challenge to the development industry. This paper aims to critically assess two prevalent business models emerging to meet this challenge: financial institution–technology provider partnerships and the one-stop-shop, pay-as-you-go (PAYG) model. The authors find that collaborations between financial institutions and energy providers need to address grey areas such as product quality standards, marketing, and post-sales services, and incorporate feedback loops to continually evaluate the performance of the partnership. Pay-as-you-go presents an intriguing business case to leapfrog more traditional energy access programmes. However, more robust results from the field need to be reported before the PAYG movement can claim success. Ultimately, collaborative and integrated actions by all stakeholders are needed to achieve universal energy access.