Renewables

Energy ◽  
2012 ◽  
Author(s):  
José Goldemberg
Keyword(s):  
Fossil Fuels ◽  
Wind Waves ◽  
Solar Thermal ◽  
The Sun

What are renewables? Renewables, by definition, are forms of energy that are not exhaustible, as are fossil fuels. All renewables originate in the Sun and will last as long as the Sun itself. Most of them, such as wind, waves, hydroelectric, solar thermal, and...

Introduction

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Fossil Fuels ◽  
Standard Of Living ◽  
The Sun ◽  
Fundamental Physics ◽  
Atomic Nuclei

Our standard of living depends on transforming energy locked up in fossil fuels, atomic nuclei or provided free of charge by the sun and wind into a form that we can use. That transformation of energy is governed by fundamental physics and chemistry. This book is for those who want to understand more about where the energy we use comes from, and how it gets used. It lays out the simple physics behind our use of energy....

Design, Development and Performance Test of Two-Axis Solar Tracker System

2014 ◽  
Vol 704 ◽  
pp. 350-354
Author(s):  
Muhammad Ikram Mohd Rashid ◽  
Nik Fadhil bin Nik Mohammed ◽  
Suliana binti Ab Ghani ◽  
Noor Asiah Mohamad
Keyword(s):  
Tilt Angle ◽  
Solar Collector ◽  
Performance Test ◽  
Tracking System ◽  
Electrical Power ◽  
Solar Thermal ◽  
The Sun ◽  
Solar Pv ◽  
Design Development ◽  
Solar Tracking

The energy extracted from photovoltaic (PV) or solar thermal depends on solar insolation. For the extraction of maximum energy from the sun, the plane of the solar collector should always be normal to the incident radiation. Sun trackers move the solar collector to follow the sun trajectories and keep the orientation of the solar collector at an optimal tilt angle. Energy efficiency of solar PV or solar thermal can be substantially improved using solar tracking system. In this paper, an automatic solar tracking system has been designed and developed using DC motor on a mechanical structure with gear arrangement. The movements of two-axis solar trackers for the elevation and azimuth angles are programmed according to the mathematical calculation by using the Borland C++ Builder. Performance of the proposed system over the important parameter like solar radiation received on the collector, maximum hourly electrical power has been evaluated and compared with those for fixed tilt angle solar collector.

scholarly journals Solar Tracker

2020 ◽  
Vol 2 (1) ◽  
pp. 59-65
Author(s):  
Irfan Danial Hashim ◽  
Ammar Asyraf Ismail ◽  
Muhammad Arief Azizi
Keyword(s):  
Fossil Fuels ◽  
Electrical Energy ◽  
Maximum Amount ◽  
Solar Panel ◽  
Angle Of Incidence ◽  
The Sun ◽  
Continuous Change ◽  
The Earth ◽  
Solar Tracker ◽  
Rotation Of The Earth

Solar Tracker The generation of power from the reduction of fossil fuels is the biggest challenge for the next half century. The idea of converting solar energy into electrical energy using photovoltaic panels holds its place in the front row compared to other renewable sources. But the continuous change in the relative angle of the sun with reference to the earth reduces the watts delivered by solar panel. Conventional solar panel, fixed with a certain angle, limits their area of exposure from the sun due to rotation of the earth. Output of the solar cells depends on the intensity of the sun and the angle of incidence. To solve this problem, an automatic solar cell is needed, where the Solar Tracker will track the motion of the sun across the sky to ensure that the maximum amount of sunlight strikes the panels throughout the day. By using Light Dependent Resistors, it will navigate the solar panel to get the best angle of exposure of light from the sun.

PRODUCTION OF DOMESTIC HOT WATER IN A SUSTAINABLE WAY BY USING A COMBINED SOLAR - TLUD SYSTEM

2020 ◽  
Author(s):  
Radu Radoi ◽  
Ioan Pavel ◽  
Corneliu Cristescu ◽  
Liliana Dumitrescu
Keyword(s):  
Climate Change ◽  
Fossil Fuels ◽  
Heat Waves ◽  
Hot Water ◽  
Experimental Results ◽  
Solar Thermal ◽  
Extreme Weather Events ◽  
Automation System ◽  
Low Carbon ◽  
Domestic Hot Water

Fossil fuels are an exhaustible resource on Earth, and their use pollutes the environment massively. The population of the planet has grown a lot, and for the production of domestic hot water, to ensure a decent standard of living, it is necessary to consume increasing quantities of fossil fuels. The very high level of greenhouse gases released into the atmosphere leads to an increase in average of annual temperature and climate change. Climate change is manifested by the melting of the ice caps, which has the consequence of increasing the level of the seas and oceans. Climate change also leads to extreme weather events such as floods, heat waves or the appearance of arid areas. Risks to human health have increased through deaths caused by heat or by changing the way some diseases are spread. Risks also exist for flora and wildlife due to rapid climate change.Many species of animals migrate, and other species of animals and plants are likely to disappear. Climate change also leads to costs for society and the economy due to damage to property and infrastructure, which have been more than 90 billion euros in the last 30 years, just because of the floods. In order to reduce the effects of environmental pollution, ecological energy production solutions need to be expanded. The article presents the creation of an experimental stand of a Solar - TLUD stove combined system for the production of domestic hot water in a sustainable way. TLUD is the acronym for "Top-Lit UpDraft". The advantage of the combined heat system is that it can provide thermal energy both during the day and at night. If the atmospheric conditions are unfavorable (clouds, fog) and do not allow the water to be heated only with the solar panel, TLUD gas stove can be used to supplement the energy. The TLUD stove has low Carbon Monoxide (CO) and Particulate Matter (PM) emissions. After gasification, about 10% of the carbon contained in the biomass is thermally stabilized and can be used as a "biochar" in agriculture or it can be burnt completely, resulting in very little ash. The stand is composed of a solar thermal panel, a TLUD stove, a boiler for hot water storage and an automation system with circulation pumps and temperature sensors. To record the experimental results, a data acquisition board was used, with which data were recorded from a series of temperature and flow transducers located in the installation. Experimental results include diagrams for temperature variation, available energy and heat accumulated in the boiler. Keywords: combined thermal system, TLUD stove, domestic hot water, solar thermal panel, data aquisition system

The Siren Song of Renewable Energy

2014 ◽  
Author(s):  
Michael H. Fox
Keyword(s):  
Renewable Energy ◽  
Nuclear Power ◽  
Fossil Fuels ◽  
Rocky Mountain ◽  
Electricity Production ◽  
The Sun ◽  
Solar Panels ◽  
Water Heater ◽  
Pv System ◽  
Energy Needs

Renewable energy from the sun—which includes solar, wind, and water energy— can meet all of our energy needs and will allow us to eliminate our dependence on fossil fuels for electricity production. At least, that is the “Siren song” that seduces many people. Amory Lovins, the head of the Rocky Mountain Institute, has been one of the strongest proponents of getting all of our energy from renewable sources (what he calls “soft energy paths”) (1) and one of the most vociferous opponents of nuclear power. A recent article in Scientific American proposes that the entire world’s needs for power can be supplied by wind, solar, and water (2). Is this truly the nirvana of unlimited and pollution-free energy? Can we have our cake and eat it, too? Let’s take a critical look at the issues surrounding solar and wind power. Let me be clear that I am a proponent of solar energy. I built a mountain cabin a few years ago that is entirely off the grid. All of the electricity comes from solar photovoltaic (PV) panels with battery storage. The 24 volt DC is converted to AC with an inverter and is fed into a conventional electrical panel. It provides enough energy to power the lights, run a 240 volt, three-quarter horsepower water pump 320 feet deep in the well, and electrical appliances such as a coffee pot, toaster, and vacuum cleaner. But I am not implying that all of my energy needs come from solar. The big energy hogs—kitchen range, hot water heater, and a stove in the bedroom—are all powered with propane. Solar is not adequate to power these appliances. In 2010 I also had a 2.5 kW solar PV system installed on my house that ties into the utility grid. When the sun is shining, I use the electricity from the solar panels, and if I use less than I generate, it goes out on the grid to other users. If it does not produce enough for my needs, then I buy electricity from the grid.

scholarly journals The revival of thermal utilization from the Sun: interfacial solar vapor generation

2019 ◽  
Vol 6 (3) ◽  
pp. 562-578 ◽  
Author(s):  
Lin Zhou ◽  
Xiuqiang Li ◽  
George W Ni ◽  
Shining Zhu ◽  
Jia Zhu
Keyword(s):  
Thermal Management ◽  
Energy Resource ◽  
Thermal Conversion ◽  
Energy Utilization ◽  
Solar Thermal ◽  
The Sun ◽  
Vapor Generation ◽  
Figures Of Merit ◽  
Designed Materials ◽  
Significant Attention

Abstract Since solar energy is the ultimate energy resource and a significant amount of global energy utilization goes through heat, there have been persistent efforts for centuries to develop devices and systems for solar–thermal conversion. Most recently, interfacial solar vapor generation, as an emerging concept of solar–thermal conversion, has gained significant attention for its great potentials in various fields such as desalination, sterilization, catalysis, etc. With the advances of rationally designed materials and structures and photon and thermal management at the nanoscale, interfacial solar vapor generation has demonstrated both thermodynamic and kinetical advantages over conventional strategies. In this review, we aim to illustrate the definition, mechanism and figures of merit of interfacial solar vapor generation, and to summarize the development progress of relevant materials and applications, as well as to provide a prospective view of the future.

scholarly journals Evaluating the Environmental Performance of Solar Energy Systems Through a Combined Life Cycle Assessment and Cost Analysis

2019 ◽  
Vol 11 (9) ◽  
pp. 2539 ◽  
Author(s):  
Maria Milousi ◽  
Manolis Souliotis ◽  
George Arampatzis ◽  
Spiros Papaefthimiou
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Large Scale ◽  
Fossil Fuels ◽  
Energy Systems ◽  
Economic Assessment ◽  
Raw Material ◽  
Solar Thermal ◽  
Multiple Perspectives ◽  
Environmental Implications

The paper presents a holistic evaluation of the energy and environmental profile of two renewable energy technologies: Photovoltaics (thin-film and crystalline) and solar thermal collectors (flat plate and vacuum tube). The selected renewable systems exhibit size scalability (i.e., photovoltaics can vary from small to large scale applications) and can easily fit to residential applications (i.e., solar thermal systems). Various technical variations were considered for each of the studied technologies. The environmental implications were assessed through detailed life cycle assessment (LCA), implemented from raw material extraction through manufacture, use, and end of life of the selected energy systems. The methodological order followed comprises two steps: i. LCA and uncertainty analysis (conducted via SimaPro), and ii. techno-economic assessment (conducted via RETScreen). All studied technologies exhibit environmental impacts during their production phase and through their operation they manage to mitigate significant amounts of emitted greenhouse gases due to the avoided use of fossil fuels. The life cycle carbon footprint was calculated for the studied solar systems and was compared to other energy production technologies (either renewables or fossil-fuel based) and the results fall within the range defined by the global literature. The study showed that the implementation of photovoltaics and solar thermal projects in areas with high average insolation (i.e., Crete, Southern Greece) can be financially viable even in the case of low feed-in-tariffs. The results of the combined evaluation provide insight on choosing the most appropriate technologies from multiple perspectives, including financial and environmental.

scholarly journals Consumption and Emissions Analysis in Domestic Hot Water Hotels. Case Study: Canary Islands

2019 ◽  
Vol 11 (3) ◽  
pp. 599 ◽  
Author(s):  
Francisco Díaz Pérez ◽  
Ricardo Díaz Martín ◽  
Francisco Pérez Trujillo ◽  
Moises Díaz ◽  
Adib Mouhaffel
Keyword(s):  
High Temperature ◽  
Carbon Footprint ◽  
Canary Islands ◽  
Fossil Fuels ◽  
Heat Pumps ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Panels ◽  
Domestic Hot Water ◽  
Temperature Heat

We analyze the energy consumption of domestic hot water (DHW) in the hotels of the archipelago of the Canary Islands (Spain). Currently, systems use fossil fuels of propane and gas oil. However, this paper analyzes several alternative systems which focus on renewable and mixed energies, such as biomass, solar thermal and heat pumps systems associated with an electric generation with photovoltaic solar panels for self-consumption. The carbon footprint generated is calculated for each method of generation of DHW. In our analysis, we demonstrate that by using a high-temperature heat pump with an average coefficient of performance (COP) equal to or greater than 4.4 associated with photovoltaic solar panels, a zero-emission domestic hot water system can be achieved, when the installation area of the photovoltaic solar panels is equal to that of the solar thermal system. The importance of DHW’s carbon footprint is proven, as is the efficiency of using high-temperature heat pumps associated with photovoltaic solar panels. As such, such mixed system suggests that the generation of DHW would have zero emissions with maximum annual savings according to hotel occupancy, between 112,417 and 137,644 tons of carbon dioxide (CO2), compared to current boilers based on fossil fuels.

Solar thermal technologies as a bridge from fossil fuels to renewables

2015 ◽  
Vol 5 (11) ◽  
pp. 1007-1013 ◽  
Author(s):  
Vishwanath Haily Dalvi ◽  
Sudhir V. Panse ◽  
Jyeshtharaj B. Joshi
Keyword(s):  
Fossil Fuels ◽  
Solar Thermal

Evaluation of the Prospects of Using Solar Thermal Air-Conditioning Systems in Saudi Arabia

2014 ◽  
Vol 554 ◽  
pp. 271-275 ◽  
Author(s):  
Islam Mazharul ◽  
Ruhul Amin Muhammad ◽  
Farid Nasir Ani
Keyword(s):  
Saudi Arabia ◽  
Solar Energy ◽  
Air Conditioning ◽  
Renewable Energy Sources ◽  
Solar Thermal ◽  
Solar Irradiation ◽  
The Sun ◽  
Space Cooling ◽  
Power Capability ◽  
Air Conditioning Systems

Saudi Arabia is endowed with abundant solar energy which is readily available from the sun. Solar energy is one of main renewable energy sources and it can be harnessed for an array of applications including heating, cooling and generation of electricity. Due to its hot climate and relatively high purchasing power capability of the general population, Saudi Arabia has a huge demand for air-conditioning (cooling) appliances. Currently these appliances are mainly powered by electricity generated by conventional sources using fossil fuels. Solar air-conditioning system is an emerging technology which relies on the sun for meeting the energy demand. One attractive feature of this system is that the high demand for space cooling by air-conditioning equipment coincides with the abundant availability of solar irradiation during the long summer months. Currently there are several types of solar air-conditioning systems, including the absorption, adsorption and desiccant systems. Each system has its merits and demerits. In this paper, the prospects of using absorption solar thermal air-conditioning systems for space cooling in Saudi Arabia are given.

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