• Energy Research

Renewable distributed energy generation (DEG) system plays an important role in future power developments and is one of the options to reduce energy consumption. It is envisaged that energy efficiency of DEG systems can be improved via load shifting (LS). This study proposed a heuristic-based numerical approach to perform LS analysis on renewable stand-alone DEG systems. The technique is an extension from a method known as the Electric System Cascade Analysis (ESCA). The new technique, which focuses on efficient electricity utilisation is able to determine the optimal: (i) load profiles, (ii) capacity of power generator, (iii) capacity and power of energy storage (ES) and (iv) charging/discharging schedule of ES. The stage-wise technique allows user to compare and determine the optimal design in a flexible way while having a better understanding of the selection of options. The application of ESCA-LS on a case study revealed that after incorporation of direct LS (load manipulation) in addition to LS by ES (supply manipulation), the power generators and ES capacity can be further reduced. While reduction of 3.1 % for solar-PV installation area and 3.9 % for biomass power generator is recorded, ES power-related capacity and energy-related capacity managed a higher reduction of up to 19.0 and 13.2 % for the main case study

Integrated biomass solar town concept is a concept which encourages local community to utilize biomass waste comprehensively with strong ties between community and local stakeholders. This paper discusses about an Integrated Biomass Solar Town for eco village with and without load shifting (LS). On the other hand, the energy storage (ES) is also incorporated which could help cut electricity demand during peak periods and smoothing variations in power generation by variable solar power. A substantial technical and economic benefit was achieved through the implementation of integrated (LS) and ES. In this study, LS is used mainly to increase demand during periods of high supply and also shift the load to interval with low demand hence reduce the size of ES significantly. The concept is one of the great initiatives to spur economic growth and environmental protection through energy efficiency improvement and deployment of low-carbon technologies.

Wastewater has typically been regarded as an environmental problem and a source of health hazard. Converting wastewater into value-added products such as energy production, and various products recovery have become more attractive. Industrial wastewater sludge has become viable resource of many products such as fertilisers, soil conditioner and artificial aggregate or cement-like materials. The objective of this study is to develop a model to select the appropriate wastewater treatment units that could maximise resources recovery via a simple and cost effective technology while complying the environmental discharge limit. A superstructure of potential treatment technologies is proposed in this work. Ideal networks that consist of interconnections between few treatment technologies to remove contaminants and recover valuable products are obtained by maximising the Net Present Value (NPV) for the plant. The model recommends the connection between anaerobic digester (AD), sludge pump (SP) and bio solid utilisation (BS) to reduce the final concentration in the effluent and at the same time generate the maximum amount of bio solid (soil conditioner) for agricultural purposes. Results of the proposed network yields an optimal network selected by the model that gives a positive NPV of USD 4,035, 506.

Electric System Cascade Analysis (ESCA), an optimisation technique for the design and scheduling of a distributed energy generation (DEG) system based on Pinch Analysis concept is developed with the basis to ensure maximal thermal efficiency of the power generators. By assuming that the power generator will operate at full load at all time, the optimal capacity of the power generator and the energy storage (ES) device including the optimal schedule of the system is revealed. While the generator operates at maximum thermal efficiency, it may results in higher energy losses due to extensive inversion of current, and storage of energy. It also may lead to the needs of larger ES which could be expensive. In this article, the trade-of between generator thermal efficiency and ES-related losses is studied upon. A new set of heuristic is also introduced to discuss on the flexibility of operating the power generator. It is revealed that indeed by increasing the capacity of the generator and allowing flexibility to its operation, the overall efficiency of the DEG system will be higher. As for the economics, the cost of the system increases with increasing capacity of the power generator despite decreasing capacity of ES.

AbstractPalm oil mill is rich with biomass and biogas resources. Thus the resources can be utilised to power a green DEG energy system for an eco-community comprising of the POM itself as well as a local residential community in Iskandar Malaysia. Solar energy systems are also integrated to the DEG system to supply additional energy to ensure the system is fully RE operated, to drive the realisation of a low carbon society in Iskandar Malaysia. Thus in this work, a model that incorporates load shifting feature is developed, with the aim to design an optimal biomass and biogas power generation system, solar energy system, and energy storage system, with consideration of the variation of electricity and thermal energy requirement due to weekday/weekend profiles and operation status of palm oil mill.

AbstractMalaysia is considered as a major palm oil producer in the world. Therefore, it is vital to utilize an environmentally friendly and inexpensive method to treat palm oil mill effluent (POME) in Malaysia. Nowadays, the use of microalgae to remove pollutants from POME has gained a lot of attention. The main objective of this research was to investigate the effect of POME as a nutrient on the microalgae growth and analyze the removal rate of pollution. In this study, a pure culture Chlamydomonas incerta was aseptically transferred to an Erlenmeyer flask containing POME. The effect of POME as a high nutritional substrate, different cultivation scales, carbon total nitrogen (C:TN) ratio, and the lipid productivity of microalgae C. incerta were assessed. C. incerta was grown at room temperature under continuous illumination with the intensity of ± 15 (μmol/m2/s) for 28 days, followed by the measurement of chemical oxygen demand (COD) reduction at different substrate concentrations. The results of this study demonstrated that organic carbon was removed by C. incerta for the ratio of 100:7, 100:13, and 100:31 respectively within the second day of cultivation. Fast growth of microalgae was observed in organic and inorganic substrates for adoption within the second day of experiment. The optimum achievement rate of nutrient removal with C. incerta was about 67.35% of COD for 250mg/L of POME concentrations in 28 days. The significance of this study is regarding the introduction of a new microalgae strain with a high ability to remove nutrients from POME, which can contribute to the effort in finding an efficient and economic technology for improving our environment.

Abstract Palm oil mill effluent (POME) is recognised as one of the biggest sources of pollution due to its eutrophying nature and methane emitting treatment. Although biogas recovery and utilisation are promoted through government initiatives, the motivation and support from mills still reported low in Malaysia. This paper aims to discuss the benefits and drawbacks of POME utilisation in the palm oil supply chain based on environmental, social and economic concerns to review the favourability of POME elimination. A zero effluent approach is introduced based on POME evaporation technique, undiluted clarification practice and water recycling strategy as an alternative for conventional POME management approaches. An integrated palm oil complex concept is proposed which includes new palm oil processing approach that eliminates POME and provides industrial symbiosis possibilities within palm oil upstream and downstream sectors to promote sustainability of palm oil industry with balanced economic and environmental advantages. A comparative study between POME utilisation (Case 1 and 2) and POME elimination (Case 3) in different perspectives is included in this work. In the economic view, the payback period of Case 3 is shorter (4 y) compared to Case 1 and 2 (4.3–8.3 y). In comparison, POME elimination technology is more environmentally friendly due to smaller water and land footprint, zero methane emission and minimum waste generation. Approximately 0.3% improvement in oil extraction rate can be potentially achieved by the proposed mill configuration in Case 3. One of the challenges in POME elimination implementation is the additional 0.25 kg steam requirement associated with evaporation of 1 kg water. The study provides insights on the feasibility of the proposed sustainable concept in Malaysia with consideration of government policies and programmes. The suggested POME elimination-based complex provides alternative option to mill owners who are uninterested to invest in biogas capturing facilities.