Available Renewable Energy Resources Research Articles

Renewable energy and power: a review of the power sector reform and renewable energy law and policy nexus in Ghana

ABSTRACTThe Ghanaian government initiated its policy on power sector reform in 1995 to engender both structural and regulatory changes in the electricity market. Due to attainment of certain objective of the sector reform, some restructuring in the electricity market has been observed since the reform years. Other goals underpinning the sector reform such as the 100% national access to electricity are yet to be realized. About 30% of the Ghanaian population still lack access to electricity. This is despite the availability of renewable energy resources in Ghana and its potential for substantially increasing electricity generation capacity, which in turn, would help secure the supply of electricity. This paper examines the role of renewable energy in the power sector reform of Ghana and how the power sector reform of 1995 has contributed to the development of renewable energy law and policy in the country. Regulatory and structural changes that resulted from the power sector reform has contributed to the development of renewable energy law and policy in Ghana even though the potential for generating electricity from renewable energy resource in Ghana was overlooked during the power sector reform period.

Robust Optimization for Electricity Generation

We consider a robust optimization problem in an electric power system under uncertain demand and availability of renewable energy resources. Solving the deterministic alternating current (AC) optimal power flow (ACOPF) problem has been considered challenging since the 1960s due to its nonconvexity. Linear approximation of the AC power flow system sees pervasive use, but does not guarantee a physically feasible system configuration. In recent years, various convex relaxation schemes for the ACOPF problem have been investigated, and under some assumptions, a physically feasible solution can be recovered. Based on these convex relaxations, we construct a robust convex optimization problem with recourse to solve for optimal controllable injections (fossil fuel, nuclear, etc.) in electric power systems under uncertainty (renewable energy generation, demand fluctuation, etc.). We propose a cutting-plane method to solve this robust optimization problem, and we establish convergence and other desirable properties. Experimental results indicate that our robust convex relaxation of the ACOPF problem can provide a tight lower bound.

A hybrid energy system based on renewable energy for the electrification of low-income rural communities

Electrification of low-income rural areas that have a limited connection or no access to electrical grids is one of the most demanding challenges in developing countries such as Peru. The international commitment to stop global warming and the reduction in the cost of renewable sources of energy have reduced the prices of fossil fuels in some cases. This has opened the way to the current research which proposes a hybrid energy system (HES) based on the use of renewable sources of energy. Therefore, a renewable electricity system (HRES) was set up at the village of Monte-Catache in the Cajamarca region, which is one of the poorest areas of Peru. Surveys and field studies were used to evaluate the socioeconomic characteristics, availability of renewable energy resources, and energy demand of this region. Potential energy sources were evaluated, and isolated photovoltaic systems with a battery bank were found to be the most appropriate according to the results obtained in the simulation with HOMER. This proposal constitutes an interesting contribution for future energy solutions in isolated and low-income rural areas.

Intelligent Residential Energy Management System for Dynamic Demand Response in Smart Buildings

The advancements in renewable energy technologies direct the power sector to focus on power generation from renewable energy resources (RER) as an alternative solution for meeting the future demand. Nowadays residential buildings are becoming smarter with wide use of smart appliances, integration of information and communication technology, and in-house power generation using RER. In this paper, an intelligent residential energy management system (IREMS) for prosumers of smart residential buildings is proposed, and its benefits are demonstrated through a case study. The primary objective of IREMS is reduction in electricity bills while maintaining the power demand under the maximum demand limit subjected to the various constraints governing the operation of household loads and RER. The IREMS achieves the objective by scheduling the schedulable loads during low pricing intervals while considering the operational dynamics of nonschedulable loads and availability of RER. IREMS also manages the battery energy storage in such a way so as to reduce the power dissipated through the dump load when excess power is available from RER due to the utility-defined power export limit to grid. Further, an optimal resources sizing algorithm is used to choose the size of RER and battery storage for the effective utilization of available renewable energy.

Design of Stand-Alone Hybrid Power Generation System at Brumbun Beach Tulungagung East Java

Indonesian government insists to optimize the use of renewable energy resources in electricity generation. One of the efforts is launching Independent Energy Village plan. This program aims to fulfill the need of electricity for isolated or remote villages in Indonesia. In order to support the penetration of renewable energy resources in electricity generation, a hybrid power generation system is developed. The simulation in this research is based on the availability of renewable energy resources in Brumbun beach, Tulungagung, East Java. Initially, the electricity was supplied through stand-alone electricity generations which are installed at each house. Hence, the use of electricity between 5 p.m. – 9 p.m. requires high operational costs. Based on the problem above, this research is conducted to design a stand-alone hybrid electricity generation system, which may consist of diesel, wind, and photovoltaic. The design is done by using HOMER software to optimize the use of electricity from renewable resources and to reduce the operation of diesel generation. The combination of renewable energy resources in electricity generation resulted in NPC of $ 44.680, COE of $ 0,268, and CO2 emissions of 0,038 % much lower than the use of diesel generator only.

Availability of Renewable Energy Resources in India: An Exemplary Resolution to Energy Crisis & its Future Prospective for Rural Areas

Availability of Renewable Energy Resources in India: An Exemplary Resolution to Energy Crisis & its Future Prospective for Rural Areas

LEAPFROGGING TO RENEWABLE ENERGY: THE OPPORTUNITY FOR UNMET ELECTRICITY MARKETS

Electricity plays a crucial role in the socio-economic development of any country. Developing countries, however, unlike their developed counterparts, do not have electricity markets that are fully satisfied, nor are they ‘laden’ with large-scale infrastructure that could create inertia about making the transition. The objective of this paper is to identify the potential trajectories for unmet electricity markets in sub-Saharan Africa to leapfrog to renewable energy as they strive to accelerate access to electricity. The following key drivers of renewable energy leapfrogging in unmet electricity markets were identified from the review: the need to achieve sustainability targets; the availability of renewable energy resources on a sufficient scale; growing investment in renewable energy; maturing niche renewable technologies; a weakening renewable energy cost hypothesis; and a growing population and increasing urbanisation. The paper further conceptualised three potential transition paradigms: revolutionary, scattered , and coned pathways. These paradigms were defined by the pace and magnitude of the transition that can be observed, and depend on the intensity of the identified drivers in a specific unmet electricity market. The paper argues that the largely unmet electricity market in sub-Saharan Africa provides an opportunity to leapfrog the fossil-intensive energy regime to adopt a renewable energy regime.

Exergy as Measure of Sustainability of Energy System

Exergy is a measure of energy quality. The amount of exergy in energy carriers is very different. Normally the price includes only the value of quantity and not the quality of energy. Exergy is the only part of energy available to do work. For different purposes we need energy with different amounts of exergy: for heating and cooling the energy mixture between small amount of the exergy and large part anergy is needed. Transition to sustainable energy system, without GHG emissions, based on RE, open the questions how to evaluate exergy from solar energy. Solar energy in all form (irradiation, water flows, wind, and biomass) consists of nearly 100% of exergy. Solar energy is free, conversion systems are not. To exploit at maximum the solar exergy we need a sustainable energy system using in great amount the present infrastructure and existing or new developed energy conversion technologies. There is common agreement that we need four main presently used energy carriers: electricity, gaseous, liquid and solid fuels. Our vision is the new Sustainable Energy System (SES) based on the use of solar and planetary energy for production of renewable electricity as a base for production of hydrogen. Hydrogen is a raw material for carbon recycling from biomass, making synthetic methane and methanol. The proposed SES is based on the existing infrastructure and known chemical processes. With regard to availability of renewable energy resources (RES) it is unrestricted and harmless in comparison to present fossil fuels use. The proposed SES consists of the three main exergy carriers: solar electricity, synthetic methane (CH4) and synthetic methanol (CH3OH).

Assessing the value of forecast-based dispatch in the operation of off-grid rural microgrids

Hybrid microgrids are expected to play an important role in the expansion of access to electricity in developing countries. While most of these systems are operated with dispatch strategies which do not make use of predictions about the load or about the availability of renewable energy resources, forecast-based strategies have recently gained attention as an alternative to bring down operation costs. In this work, we develop a framework to assess this potential under a range of assumptions about the quality of load and photovoltaic generation forecasts. The application of the methodology to a village of 600 households reveals cost savings ranging between 2% and 7% depending on the forecast quality and the composition of the microgrid. We also show that sizing microgrid components under the assumption of a predictive operation strategy results in a design with a higher share of intermittent generation.

Predictive control of residential HVAC and its impact on the grid. Part II: simulation studies of residential HVAC as a supply following resource

This paper introduces a methodology, using model predictive control, for shaping the electric demand of residential distribution feeder. The methods are designed to result in a paradigm shift from generation that follows load to load that follows supply. First, a reference demand curve, obtained from “smoothing” a base case demand profile, is proposed. Then, in order to better match the availability of renewable energy resources, the reference demand curve is modified to consider residential rooftop photovoltaic systems and utility scale wind generation. A simulation framework introduced in a companion paper is employed. Simulation results suggest that the active load shaping methodology is very effective at providing demand flexibility at time scales shorter than two or three hours. At longer time scales, flexibility is limited by the thermal storage effectiveness of the residential building envelope, and to a large extent, the amount of load being shifted relative to total active cooling demand.

Sustainable multi-period electricity planning for Iskandar Malaysia

This paper presents the current situation and projected planning of the electricity generation sector for Iskandar Malaysia by implementing a model to optimise the cost, utilise the usage of available renewable energy sources, and achieve carbon dioxide reduction targets. This Mixed Integer Linear Programming model was developed with the main objective of minimising the total cost of electricity generation, taking into consideration energy demand, reserve margin, electricity generation, peak and base generation, resource availability, and CO2 emission. Data for the year 2013 were forecasted until 2025 to illustrate the analysis for this study, and are represented via four scenarios. This optimal model is capable of balancing types of fuel and switching coal plants to natural gas power plants. It also enhances the use of renewable energy (RE) to meet CO2 emission targets. The model is further integrated with several other considerations related to energy systems, such as suitability of power plants as peak or base plants, RE resource availability, intermittency of solar power, losses during transmission, fuel selection for biomass, decision to retrofit existing coal power plant to NG power plant, and construction lead time of power plants. The results for this study determined that the optimal scenario is Scenario 3 (CS3). This research proves that Iskandar Malaysia can reduce CO2 emission by 2025 via utilisation of RE. This model is generic and can be applied to any case study, which would be useful for assisting government policy-making.

Feasibility assessment of Anchor-Business-Community model for off-grid rural electrification in India

The concept of “micro-grids” as self-sustained power systems is driven largely by business models, which have to be developed by considering the perspectives of all the stakeholders. This study tests the feasibility of the Anchor-Business-Community model of off-grid electrification in a cluster of two Hamlets in Uttar Pradesh, from the perspective of a Renewable Energy Service Company. Telecom towers, Flour Mills and rural communities have been considered as the Anchor, Business and community customers respectively. Primary surveys have been carried out to assess socio-economic characteristics, renewable energy resource availability and energy demand. Cost savings has been assumed to be the primary incentive for the customers to switch to clean energy. Cash flow analysis has been done to estimate the level of profitability of the project with and without the current level of subsidy. Solar Photovoltaic systems, Biomass gasification systems and Solar-Biomass hybrid systems have been modelled using HOMER. The model for Solar PV system with subsidy was found to be the most robust out of all three models in the scenario analysis. Solar-Biomass hybrid systems and Biomass Standalone systems are found to have the potential to offer a healthy level of returns under the best case and most likely scenarios.

Renewable Energy in Ghana and the Lessons from the EU: An Examination of the Regulatory Support Schemes

Ghana has realised the need to develop its renewable energy (RE) potential given the enormous availability of RE resources. To this end, the Ghanaian authorities established a national strategic policy target to achieve 10% penetration of renewable energy sources (RES) into the country's energy mix by the year 2020. In line with the strategic policy direction, the Renewable Energy Act, 2011 (RE Act) was adopted with the objective of, inter alia, attracting investment, promoting the use of RES for the production of electricity and to safeguard energy security. This article examines whether the support schemes provided under the RE Act create the necessary environment for attaining those goals. It argues that, for the Ghanaian RE Act to create the enabling environment it would have to establish clear and concrete support schemes that will cater to the concerns of lack of investment into the RE sector of the country. The support systems established under the RE Act must also provide stability for long-term return on investment. It further suggests some lessons that will be relevant to the Ghanaian authorities by highlighting some regulatory issues from the EU experience.

Solar Photovoltaic Energy Production Forecast Using Neural Networks

The management of renewable energy resources plays an important role in the availability, stability and energy quality in the modern power systems. A key role of the energy management policies is played by the primary resource availability adjustment to the required consumption. As the renewable energy resources are variable in time their forecast represents an important issue. In this paper is explored how the use of consecrated artificial intelligence techniques such as feed-forward and Elman neural networks are suitable for such energy production forecasting. The main reason is that artificial intelligence techniques offers a viable solution to correct the behavior of these systems while operating by learning the changes that occur as a result of power systems external and internal factors evolution. In this case the back-propagation learning algorithm was tested in different configurations of the neural networks to find an adequate solution for the specific datasets of solar photovoltaic renewable energy resource availability.

Spatial Modelling of Solar Energy Potential in Kenya

Solar energy is one of the readily available renewable energy resources in the developing countries within the tropical region. Kenya is one of the countries which receive an average of approximately 6.5 sunshine hours in a single day throughout the year. However, there is slow adoption of solar energy resources in the country due to limited information on the spatial variability solar energy potential. This study aims at assessing the potential of photovoltaic solar energy in Kenya. The factors that influence incident solar radiation which were considered in this task included atmospheric transmissivity and topography. The influence of atmospheric transmissivity was factored in by modelling monthly transmissivity factors from a combination of cloud cover, diffuse ratios and the effect of altitude. The contribution of topography was included by applying hemispherical viewshed analysis to determine the amount of incident global radiation on the surface based on the orientation of the terrain. GIS concepts were used to integrate the spatial datasets from different themes. The results showed that, about 70% of the land area in Kenya has the potential of receiving approximately 5kWh/m 2 /day throughout the year. In outline, this work successfully assessed the spatio-temporal variability in the characteristics of solar energy potential in Kenya and can be used as a basis for policy support in the country.

Optimal Planning of a Smart Microgrid Including Demand Response and Intermittent Renewable Energy Resources

Heating/cooling systems have played an important role in building energy and comfort management. There have been intensive discussions about the integration of heating/cooling systems into the smart grid infrastructure over the past decade, yet controlling the operation of heating/cooling systems in a smart grid with high penetration of renewable resources has not been addressed clearly. This study has investigated the suitability of a novel active controller applied to heating/cooling systems in the context of smart grid with high penetration of renewable energies. The proposed controller operates by responding to a combination of internal set points and external signals (e.g. the availability of renewable energy resources and welfare of customers) from a single local controller. The heating/cooling systems management minimizes the overall cost of the simulated smart microgrid, the size of smart microgrid units, and the imported energy from the distribution grid through an optimization process. It also at the same time maximizes the reliability of the smart microgrid. Demonstrated results confirm the capability of the proposed heating/cooling system controller on the planning of a smart microgrid.

Renewable Power Generation Management: Case Study – Nakhonratchasima Province, Thailand

Electricity is a pre-requisite for technological progress and economy growth. Thailand has been facing an electric energy crisis in inadequate electricity generation capacity compared with the demand. It is essential to replace the conventional energy (e.g. fossil fuels) with renewable energy resources, particularly biomass that can play a major role to meet the electricity demand. A modified deming PDCA management has been proposed for power generation. The objective of this study is to evaluate the future electricity consumption as well as to explore the current state of renewable energy potential in Nakhonratchasima Province, Thailand. The results show an electricity energy potential of from agricultural residues, livestock manure and solar energy resources. It is indicated that each these resources can supply the electricity demand excesses. The selection of renewable power generation is mainly driven by the installation cost and the availability of renewable energy resources. The power plant from livestock manures resources is found to be the most promising because its power plant installation requires lower investment in this study.

Natural Resources, Renewable Energy Sources, GHG-emission and Demographic Profiles in United States: A Broad Analysis for Developing Sustainable Low-Carbon Energy Sector

Renewable energy production is a priority policy agenda in US. The natural and renewable energy resource availability, energy use trends and demographic profiles are all critical components for correctly gearing the proper and sustainable development of this sector. Co-assessment of the natural and renewable energy resources in US is a must for renewable energy industry growth without dramatic environmental detrimental effects. For analyzing the natural and renewable energy resources and its developmental potential, this concept paper divides US into seven different regions (R-1: Northeast; R-2: Southeast; R-3: Midwest; R-4: Southcentral; R-5: Northwest; R-6: Southwest; R-7: Alaska & Hawaii). Based on parameters such as land availability, water resource availability, demographic patterns, and renewable energy sources, natural resource index (NRI), renewable energy index (REI) and development potential index (DPI) were defined and calculated for these various regions. Our analysis showed that R-6 had high NRI (6) and REI (14). Therefore it had the highest DPI (20). There were also marked differences in various regions with respect to energy use and GHG-emissions. The R-3, R-4 and R-5 regions had high-energy use and GHG-emissions. In light of these broader trends, the implications and the need for regional prioritization, resource coupling, investment allocation, and future policy directions for optimal and sustainable renewable energy production were discussed.

Optimization of Renewable Energy Hybrid System for Grid Connected Application

ABSTRACT. Hybrid energy systems are pollution free, takes low cost and less gestation period, user and social friendly. Such systems are important sources of energy for shops, schools, and clinics in village communities especially in remote areas. Hybrid systems can provide electricity at a comparatively economic price in many remote areas. This paper presents a method to jointly determine the sizing and operation control of hybrid energy systems. The model, PV wind hydro and biomass hybrid system connects to grid. The system configuration of the hybrid is derived based on a theoretical domestic load at a typical location and local solar radiation, wind and water flow rate data and biomass availability. The hybrid energy system is proposed for 10 of teacher’s houses of Industrial Training Institute, Mersing. It is predicted 10 kW load consumption per house. The hybrid energy system consists of wind, solar, biomass, hydro, and grid power. Approximately energy consumption is 860 kWh/day with a 105 kW peak demand load. The proposed hybrid renewable consists of solar photovoltaic (PV) panels, wind turbine, hydro turbine and biomass. Battery and inverter are included as part of back-up and storage system. It provides the economic sensitivity of hybridization and the economic and environmental benefits of using a blend of technologies. It also presents the trade off that is involved in optimizing a hybrid energy system to harness and utilize the available renewable energy resources efficiently.

A photovoltaic proposed generation promotion policy—The case of Jordan

Jordan has scarce petroleum resources and hence depends to a large extent on imported crude oil, and natural gas to cover its energy needs and to generate electricity in order to cope with the growing demand. The escalating fuel prices associated with the global economic crisis have negative impacts on the economy of Jordan. However, the availability of renewable energy resources (mainly solar, and wind) supported by well-designed and ambitious incentive schemes that runs in parallel with an energy efficiency program, can contribute positively in solving the current problems. This may result in a dramatic reduction in energy bill cost for both short and long terms. Moreover, it shall result in a better and cleaner environment. In this paper an incentive policy is proposed by the Electricity Regulatory Commission (ERC) based on supporting the installation of PV generating units. ERC plays a major role in this effort which aids decision makers to adopt the proper policies in the electricity sector. It is anticipated that the implementation of this proposed policy will result in a win–win situation for both consumers and government, and will lead to increasing the energy security level in general, and electricity security in particular, within Jordan.