scholarly journals Overview of the Use of Sustainable Energies in Agricultural Greenhouses

2016 ◽  
Vol 8 (3) ◽  
pp. 36 ◽  
Author(s):  
John Vourdoubas

<p>Global concern on environmental problems like climate changes has altered our energy patterns promoting non-polluting renewable energies instead of fossil fuels. Technological advances in sustainable energy technologies allow their increasing use in all sectors of everyday life. Agricultural greenhouses utilize energy for heating, cooling and operation of various electric devices. The highest amount of energy used in greenhouses is consumed in heating them. Controlling crops growth conditions including temperature results in higher productivity and in better economic results. Various sustainable energies including renewable energies and high efficiency and low carbon energy technologies have been used in commercial scale and the technical and economic viability of others has been investigated in experimental scale. Among renewable energies solar energy, biomass and geothermal energy can be used in order to cover part or all of the energy requirements for heating, cooling and power generation of greenhouses. Energy efficient and low carbon technologies like co-generation of heat and power, heat pumps, fuel cells but also waste heat can be used also for energy generation in them. Governmental energy incentives for the promotion of sustainable energies like feed-in tariffs or net-metering allow the use of the abovementioned energy technologies for electricity generation in greenhouses offering additional economic benefits to the farmers. Use of the sustainable energies which are mature, reliable and cost effective in greenhouses results in mitigation of climate changes, use of local renewable energy resources instead of fossil fuels and better profitability of the cultivated crop.</p>

2013 ◽  
Vol 12 (4) ◽  
pp. 374-383 ◽  

Global warming is one of the most serious challenges facing humankind as it has the potential to dramatically modify the living conditions of future generations. In order to reduce the emission of greenhouse gases, most countries are implementing regulations aimed at reducing their dependence on fossil fuels, promoting energy efficiency practices and favoring the deployment of low carbon energy technologies, including renewable energy sources. In line with the international commitments assumed as a member of the European Union (EU) and also as a signatory of the Kyoto Protocol, Spain developed a National Plan for Renewable Energies (PER 2005-2010) that forms the basis of the national strategy in this field. Spain has often been cited as an example for the rapid growth in the use of low carbon energy technologies. However, despite significant progress in the last decade, Spain is far from meeting the national objectives set in PER primarily due to slow growth in the demand for biofuels and the limited success of biomass fired power plants. The evolution in other energy technologies has been faster, situating Spain as world a leader in solar and wind energy. However, the contribution of these technologies to the national consumption is very marginal. In the midst of intense regulatory, commercial and R&D activity, this paper analyses the current situation with respect to the production of renewable energies in Spain, focusing primarily on the use of biomass resources. The paper offers a general view of policy and regulatory background, illustrates current progress towards meeting national objectives and provides a brief description of representative projects and market activity in biofuel production and biomass valorization.


2020 ◽  
pp. 89-95
Author(s):  
John Vourdoubas

Mitigation of climate change requires the decrease of greenhouse gas emissions into the atmosphere and the increasing use of renewable energies replacing fossil fuels. Agricultural greenhouses are energy-intensive agricultural systems using mainly fossil fuels. The use of renewable energies during their operation is limited so far. The possibility of using renewable energies for covering their energy needs has been investigated, focused on the Mediterranean region. Various sustainable energy technologies which are reliable, mature, cost-effective and broadly used in various applications are examined. These include solar-PV systems, low enthalpy geothermal energy, solid biomass burning, co-generation systems, high efficiency heat pumps and reuse of rejected industrial heat. Combined use of these systems in greenhouses can cover all their energy requirements in heat, cooling and electricity, reducing or zeroing their net CO2 emissions into the atmosphere due to operational energy use. It is concluded that depending on their local availability in Mediterranean countries, these benign energy technologies can assist greenhouse crop growers in the reduction of their carbon emissions, contributing in the achievement of the universal goal for climate change mitigation.


MRS Bulletin ◽  
2006 ◽  
Vol 31 (3) ◽  
pp. 188-198 ◽  
Author(s):  
Terry M. Tritt ◽  
M. A. Subramanian

AbstractHigh-efficiency thermoelectric (TE) materials are important for power-generation devices that are designed to convert waste heat into electrical energy.They can also be used in solid-state refrigeration devices.The conversion of waste heat into electrical energy may play an important role in our current challenge to develop alternative energy technologies to reduce our dependence on fossil fuels and reduce greenhouse gas emissions.An overview of various TE phenomena and materials is provided in this issue ofMRS Bulletin. Several of the current applications and key parameters are defined and discussed.Novel applications of TE materials include biothermal batteries to power heart pacemakers, enhanced performance of optoelectronics coupled with solid-state TE cooling, and power generation for deep-space probes via radioisotope TE generators.A number of different systems of potential TE materials are currently under investigation by various research groups around the world, and many of these materials are reviewed in the articles in this issue.These range from thin-film superlattice materials to large single-crystal or polycrystalline bulk materials, and from semiconductors and semimetals to ceramic oxides.The phonon-glass/electron-crystal approach to new TE materials is presented, along with the role of solid-state crystal chemistry.Research criteria for developing new materials are highlighted.


SINERGI ◽  
2021 ◽  
Vol 25 (3) ◽  
pp. 329
Author(s):  
Abdeen Mustafa Omer

The increased availability of reliable and efficient energy services stimulates new development alternatives. This article discusses the potential for such integrated systems in the stationary and portable power market in response to the critical need for cleaner energy technology. Several issues relating to renewable energies, environment, and sustainable development are examined from both current and future perspectives throughout the theme. It is concluded that green energies like wind, solar, ground source heat pumps, and biomass must be promoted, implemented, and demonstrated from the economic and/or environmental point of view. Biogas from biomass appears to have potential as an alternative energy source, potentially rich in biomass resources. The current literature is reviewed regarding the ecological, social, cultural and economic impacts of biogas technology. Finally, this article gives an overview of the present and future use of biomass as an industrial feedstock to produce fuels, chemicals and other materials. However, to be truly competitive in an open market situation, higher-value products are required. Results suggest that biogas technology must be encouraged, promoted, invested, implemented, and demonstrated, especially in remote rural areas. Anticipated future energy use patterns and consequent environmental impacts (acid precipitation, ozone depletion, greenhouse effect, or global warming) are discussed in this article. An approach is needed to integrate renewable energies in a way to meet high building performance. However, their ability to match demand is determined by adoption of one of the following two approaches: the utilisation of a capture area greater than that occupied by the community to be supplied, or the reduction of the community’s energy demands to a level commensurate with the locally available renewable resources. Adopting green or sustainable approaches to how society is run is seen as an important strategy in finding a solution to the energy problem. The key factors to reducing and controlling CO2, which is the major contributor to global warming, are the use of alternative approaches to energy generation and the exploration of how these alternatives are used today and may be used in the future as green energy sources.


Author(s):  
Abdeen Mustafa Omer

The move towards a low-carbon world, driven partly by climate science and partly by the business opportunities it offers, will need the promotion of environmentally friendly alternatives, if an acceptable stabilisation level of atmospheric carbon dioxide is to be achieved. This chapter presents a comprehensive review of energy sources, and the development of sustainable technologies to explore these energy sources. It also includes potential renewable energy technologies, efficient energy systems, energy savings techniques and other mitigation measures necessary to reduce climate changes. The chapter concludes with the technical status of the ground source heat pumps (GSHP) technologies. The purpose of this study, however, is to examine the means of reduction of energy consumption in buildings, identify GSHPs as an environmental friendly technology able to provide efficient utilisation of energy in the buildings sector.


Author(s):  
Guenther Haupt ◽  
John S. Joyce ◽  
Konrad Kuenstle

The environmental impact of unfired combined-cycle blocks of the GUD® type is compared with that of equivalent reheat steam boiler/turbine units. The outstandingly high efficiency of GUD blocks not only conserves primary-energy resources, but also commensurately reduces undesirable emissions and unavoidable heat rejection to the surroundings. In addition to conventional gas or oil-fired GUD blocks, integrated coal-gasification combined-cycle (ICG-GUD) blocks are investigated from an ecological point of view so as to cover the whole range of available fossil fuels. For each fuel and corresponding type of GUD power plant the most appropriate conventional steam-generating unit of most modern design is selected for comparison purposes. In each case the relative environmental impact is stated in the form of quantified emissions, effluents and waste heat, as well as of useful byproducts and disposable solid wastes. GUD blocks possess the advantage that they allow primary measures to be taken to minimize the production of NOx and SOx, whereas both have to be removed from the flue gases of conventional steam stations by less effective and desirable, albeit more expensive secondary techniques, e.g. flue-gas desulfurization and DENOX systems. In particular, the comparison of CO2 release reveals a significantly lower contribution by GUD blocks to the greenhouse effect than by other fossil-fired power plants.


2021 ◽  
Vol 48 (2) ◽  
Author(s):  
Carlos Andrés Gallego

The deployment of renewable energy technologies will play a crucial role in the global transition to a low-carbon economy and ultimately in the fight against global warming. However, this transition could face important problems because most of those technologies rely on the steady supply of critical minerals. Colombia, thanks to its hydrological resources, has relied on the hydro­power for electricity generation. However, the government has implemented measures to back-up the energy system in draught periods and, consequently, fossil fuels-based plants have increased the market share and with these, CO2 emissions. This study assesses the mineral demand in Colombia in the period 2020-2050 for the rare earth elements embedded in the deployment of wind power technologies in four different climate policy scenarios in order to establish whether they could face geological bott­lenecks that could ultimately hamper the transition to a low-carbon economy. The Gigawatts (GW) of future capacity additions in the energy system are converted into tons of metal using published metal intensities of use and assumptions of Colombia’s technological pathway. Then, the cumulated mineral demand is compared against current mining production rates and geological reserves to establish geological bottlenecks. The results show that the reserves will not pose any threat to its transition. However, when compared to current mining rates, the mineral demand in 2050 could pose a problem for the supply of minerals. Finally, this study gives some policy recommendations that could be used to mitigate these issues, such as substitution, improved circular economy and sound technological choices.


2021 ◽  
Author(s):  
Hon Chung Lau

Abstract Energies may be described as brown, blue or green. Brown energies are CO2-emitting fossil fuels. Blue energies employ carbon capture and storage (CCS) technologies to remove the emitted CO2 from brown energies. Green energies are zero or low CO2-emitting renewable energies. Likewise, energy carriers such as electricity and hydrogen may be described as brown, blue or green if they are produced from brown, blue or green energy, respectively. The transition from a high carbon intensity to a low carbon intensity economy will require the decarbonization of three major sectors: power, transport and industry. By analyzing the CO2 intensity and levelized cost of energy (LCOE) of energy and energy carriers of different colors, we show that renewable energies are best used in replacing fossil fuels in the power sector where it has the most impact in reducing CO2 emission. This will consume the majority of new additions to renewable energies in the near to medium future. Consequently, the decarbonation of the transport and industry sectors must begin with the use of blue electricity, blue fossil fuels and blue hydrogen. To achieve this, implementation of large-scale CCS projects will be necessary, especially outside of USA and northern Europe. However, this will not happen until significant financial incentives in the form of carbon tax or carbon credit becomes available from national governments. Furthermore, private-public partnership and intergovernmental cooperation will be needed to implement these CCS projects.


Author(s):  
Abdeen Mustafa Omer

The move towards a low-carbon world, driven partly by climate science and partly by the business opportunities it offers, will need the promotion of environmentally friendly alternatives, if an acceptable stabilisation level of atmospheric carbon dioxide is to be achieved. This requires the harnessing and use of natural resources that produce no air pollution or greenhouse gases and provide comfortable coexistence of humans, livestock, and plants. This chapter presents a comprehensive review of energy sources, and the development of sustainable technologies to explore these energy sources. It also includes potential renewable energy technologies, efficient energy systems, energy savings techniques, and other mitigation measures necessary to reduce climate changes. The chapter concludes with the technical status of the Ground Source Heat Pumps (GSHP) technology. The purpose of this chapter, however, is to examine the means of reduction of energy consumption in buildings, identify GSHPs as an environmentally friendly technology able to provide efficient utilisation of energy in the buildings sector, promote using GSHPs applications as an optimum means of heating and cooling, and to present typical applications and recent advances of the DX GSHPs.


Author(s):  
Kathleen Araújo

This chapter outlines the design of the current study. It discusses my underlying logic for scoping energy system change with theory-building in the form of (1) a framework on intervention that operationalizes insights from the previous chapter and (2) conceptual models of structural readiness. A brief review then follows of related, global developments to provide broader context for the cases. The chapter concludes with a preview of the transitions that will be discussed in depth in subsequent chapters. This book draws on my research of four national energy system transitions covering the period since 1970. I selected a timeframe that reflected a common context of international events which preceded as well as followed the oil shocks of 1973 and 1979. Such framing allowed me to trace policy and technology learning over multiple decades for different cases. I completed field work for this project primarily between 2010 and 2012, with updates continuing through to the time this book went to press. I selected cases from more than 100 countries in the International Energy Agency (IEA) databases. The ones that I chose represented countries which demonstrated an increase of 100% or more in domestic production of a specific, low carbon energy and the displacement of at least 15 percentage points in the energy mix by this same, low carbon energy relative to traditional fuels for the country and sector of relevance. I utilized adoption and displacement metrics to consider both absolute and relative changes. Final cases reflect a diversity of energy types and, to some extent, differences in the socio-economic and geographic attributes of the countries. The technologies represent some of the more economically-competitive substitutes for fossil fuels. It’s important to emphasize that the number of cases was neither exhaustive nor fully representative. Instead, the cases reflect an illustrative group of newer, low carbon energy technologies for in depth evaluation. Each of the cases shares certain, basic similarities. These include a national energy system comprised of actors, inputs, and outputs with systemic architecture connecting the constituent parts in a complex network of energy-centered flows over time—including extraction, production, sale, delivery, regulation, and consumption.


Sign in / Sign up

Export Citation Format

Share Document