Renewable energy policy development in the Caribbean

The Caribbean region is endowed with renewable energy resources which remain largely untapped. With an average insolation of 15-20 MJ m⁻² day⁻¹, investment in some renewable energy technologies is feasible. The major problem confronting the region is lack of financial resources. Petroleum imports continue to dominate the energy scenario except for Trinidad and Tobago and Barbados. However, increased awareness of sustainable development issues throughout the region is a major factor in support of renewable energy implementation and is a driving force for energy policy decision-making. With the necessary joint-venture partnerships and government fiscal incentives, photovoltaic technologies, wind energy and solar energy industries are poised to expand thus reducing the dependency on fossil fuel imports while preserving the environment.     

Condition and development of the cogeneration facilities based on autoproduction investment model in Turkey

Turkey, with its young population and growing energy demand per person, its fast growing urbanization, and its economic development, has been one of the fast growing power markets of the world for the last 20 years. It is expected that the demand for electric energy in Turkey will be 294 billion kWh by the year 2010 and 556 billion kWh by the year 2020. Turkey’s electric energy demand is growing 7% yearly. Because a substantial amount of Turkey’s energy need has been met by cogeneration facilities in recent years. Cogeneration facilities have an important role in Turkey’s energy strategy. While there were only four cogeneration facilities and the total capacity of them was 30 MW_e in 1994, in 1999, 10.6% of total electric production was produced by these facilities. In accordance with the governmental decree numbered 85/9799, cogeneration is the technology which produces electricity and heat synchronously and autoproduction is the name of the firm which was founded for the purpose of producing electricity and heat. In this study, the development of autoproduction facilities in Turkey, which are the most convenient legal investment model for cogeneration investors, has been investigated.     

Applying resource efficiency principles to the analysis of EU-27 bioenergy options by 2020 – Findings from a recent study for the European Environment Agency

The Renewable Energy Directive sets a target for the European Union (EU) to consume 20% of its final energy from renewable sources by 2020 and further targets are under discussion. EU renewable energy targets will lead to a substantial increase in the demand for bioenergy. As for other sectors, it is important, therefore, to apply the principles of the EU Resource efficiency roadmap to bioenergy production: producing more output with less material input and minimising adverse environmental impacts during the entire production life cycle. This paper uses that concept to analyse the most resource efficient ways for reaching the 2020 bioenergy targets (as set out in National Renewable Energy Action Plans).Scenario analysis with three different storylines is used to model environmental and land use implications plus total bioenergy potential and GHG reductions in 2020 from the agricultural, forest, and waste sectors. These storylines vary in environmental ambition level and economic and political assumptions and explore plausible bioenergy development paths. They show substantial variance in terms of environmental impact and the GHG efficiency between different bioenergy pathways.The modelling shows that under Storyline 1 bioenergy targets of the National Renewable Energy Action Plans would be achieved with CO₂ eq emissions of 44 kg GJ⁻¹, i.e. 62% less GHG emission than if the energy were generated using fossil fuels. In contrast, stricter environmental constraints in Storyline 3 lead to a substantially lower CO₂ eq burden of 25 kg GJ⁻¹, which represents an 80% reduction compared to fossil fuels.     

Mitigation of greenhouse gas emissions by adopting anaerobic digestion technology on dairy,sow and pig farms in Finland

The impact of anaerobic digestion (AD) technology on mitigating greenhouse gas (GHG) emissions from manure management on typical dairy, sow and pig farms in Finland was compared. Firstly, the total annual GHG emissions from the farms were calculated using IPCC guidelines for a similar slurry type manure management system. Secondly, laboratory-scale experiments were conducted to estimate methane (CH₄) potentials and process parameters for semi-continuous digestion of manures. Finally, the obtained experimental data were used to evaluate the potential renewable energy production and subsequently, the possible GHG emissions that could be avoided through adoption of AD technology on the studied farms. Results showed that enteric fermentation (CH₄) and manure management (CH₄ and N₂O) accounted for 231.3, 32.3 and 18.3 Mg of CO₂ eq. yr^?1 on dairy, sow and pig farms, respectively. With the existing farm data and experimental methane yields, an estimated renewable energy of 115.2, 36.3 and 79.5 MWh of heat yr^?1 and 62.8, 21.8 and 47.7 MWh of electricity yr^?1 could be generated in a CHP plant on these farms respectively. The total GHG emissions that could be offset on the studied dairy cow, sow and pig farms were 177, 87.7 and 125.6 Mg of CO₂ eq. yr^?1, respectively. The impact of AD technology on mitigating GHG emissions was mainly through replaced fossil fuel consumption followed by reduced emissions due to reduced fertilizer use and production, and from manure management.     

Fed-batch operation for bio-H2 production by Rhodopseudomonas palustris (strain 42OL)

Interest in renewable and clean energies such as hydrogen has increased because of the high level of polluting emissions, increasing costs associated with petroleum and the escalating problems of global climate change. In the presence of a light source, a microbial photosynthetic process provides a system for the conversion of some organic compounds into biomass and hydrogen. Using Rhodopseudomonas palustris as a cell-factory, hydrogen photo-evolution was investigated in a photobioreactor (PBR) irradiated either from one or two opposite sides. Irradiating the photobioreactor from only one side, in the presence of malic acid, a reactor hydrogen production of 2.786 l(H₂) PBR⁻¹ was achieved. When the PBR was irradiated from two opposite sides, hydrogen photo-evolution increased to 3.162 l(H₂) PBR⁻¹. Experiments were carried out using inoculum from either the retardation or the exponential growth phases. Using the latter, the highest hydrogen photo-evolution rate based on the bacteriochlorophyll (Bchl) concentration was achieved (3295 μl(H₂) mg (Bchl⁻¹ h⁻¹). The hydrogen to biomass ratio (r_g) was 1.91 l g⁻¹ in the medium containing malic acid and 1.07 l g⁻¹ in that containing acetic acid. It was found that the hydrogen production rate was higher with malic than with acetic acid. Although photobiological hydrogen production cannot furnish alone the greater and greater world requirements of clean renewable energy, it is desirable that photobiological hydrogen technology will grow, in the near future, because photobioreactors for bio-hydrogen production can be positioned in fringe areas without competition with agricultural lands.     

Solar chemical reactor technology for industrial production of lime

We developed the solar chemical reactor technology to effect the endothermic calcination reaction CaCO₃(s) → CaO(s) + CO₂(g) at 1200–1400 K. The indirect heating 10 kW_th multi-tube rotary kiln prototype processed 1–5 mm limestone particles, producing high purity lime that is not contaminated with combustion by-products. The quality of the solar produced quicklime meets highest industrial standards in terms of reactivity (low, medium, and high) and degree of calcination (exceeding 98%). The reactor’s efficiency, defined as the enthalpy of the calcination reaction at ambient temperature (3184 kJ kg⁻¹) divided by the solar energy input, reached 30–35% for quicklime production rates up to 4 kg h⁻¹. The solar lime reactor prototype operated reliably for more than 100 h at solar flux inputs of about 2000 kW m⁻², withstanding the thermal shocks that occur in solar high temperature applications. By substituting concentrated solar energy for fossil fuels as the source of process heat, one can reduce by 20% the CO₂ emissions in a state-of-the-art lime plant and by 40% in a conventional cement plant. The cost of solar lime produced in a 20 MW_th industrial solar calcination plant is estimated in the range 131–158 $/t, i.e. about 2–3 times the current selling price of conventional lime.     

CO2 emission from China's energy sector and strategy for its control

This paper identifies the main features of CO₂ emission from fossil energy combustion in China. Then it estimates China's future energy requirements and projects its CO₂ emission from 2010 to 2020 based on the scenario analysis approach. China's rate of carbon productivity growth is estimated to be 5.4% in the period 2005–2020, while the CO₂ intensity of GDP will reduce by about 50% but CO₂ emission in 2020 will still be about 40% higher than prevailing in 2005 because of rapid growth of GDP. This estimation is based on the assumption that China will implement a sustainable development strategy in consideration of climate change issues. The main objectives of the strategy are to implement an “energy conservation first” strategy, to develop renewable energy and advanced nuclear technology actively, to readjust the country's economic structure, and to formulate and legislate laws and regulations, and to build institutions for energy conservation and development of renewable energy. It concludes that international measures to mitigate CO₂ emission will limit world fossil fuel consumption. China is not placed to replicate the modernization model adopted by developed countries and has to coordinate economic development and carbon dioxide emission control while still in the process of industrialization and modernization. China has to evolve a low carbon industrialization model. This is the key to the success of sustainable development initiatives in China.     

Fossil fuel reduction potential in Germany's transport sector by wind-to-hydrogen

Wind-to-hydrogen (WH) is a promising option for reducing greenhouse gas emissions in the transport sector. Therefore, the reduction potential of fossil fuels by WH was estimated taking meteorological, geographical, and technical constraints into account. The wind resource estimation is based on the application of the high-resolution (200 m × 200 m) wind speed-wind shear model (WSWS). Together with the power curves of the six most frequently installed wind turbines in 2017, WSWS was used to assess Germany's technical wind energy potential. The WH and fossil fuel reduction potentials were calculated based on proton exchange membrane electrolysis. Results from the wind resource assessment demonstrate that in addition to the currently realized wind energy (89 TWh/yr in 2017), which is directly used for electricity generation, Germany's technical onshore potential for WH is 780 TWh/yr. This amount of renewable energy available for WH could replace 80.1% of the fossil fuels currently used in the transport sector.     

Renewable energy policy in Turkey with the new legal regulations

Since the energy crises in the 1970’s, public and private decision makers are considering how to achieve a sustainable transition from fossil fuel based energy to sustainable and clean energies - namely renewable energies. Combined with the improvement of energy efficiency and the rational use of energy, renewable energy can provide everything fossil fuels currently offer in terms of heating and cooling, electricity generation and transportation. Renewable energy technologies posses many long term benefits including energy security, job creation, business opportunities, sustainable development and prevention of global warming.Turkey’s population is growing at an annual rate of 1.04%. If Turkey uses only traditional energy sources, it simply will not have enough energy capacity for its population. Renewable energy sources have the potential to make a large contribution to Turkey’s sustainable and independent energy future.Turkey aims to utilize its energy potential, including from renewable sources in a cost-effective manner. Turkey targets the share of renewable resources in electricity generation to be at least 30% by 2023 has in its 2009 Electricity Market and Security of Supply Strategy. Positive achievements have been obtained in renewable energy development and manufacturing in Turkey over the past decade. The renewable energy related legislation has been intensified. To meet its 30% target, the current promotion mechanism for renewable sources of electricity relies on feed-in tariffs for different renewable energy sources. Large hydropower is already competitive to conventional fossil-based electricity, so feed-in tariffs in the new RE Law are set to facilitate expanding the deployment of other, less mature renewable energy technologies.     

Bio-methanization of energy crops through mono-digestion for continuous production of renewable biogas

The aim of this laboratory-scale study was to investigate the long-term anaerobic fermentation of an extremely sour substrate, an energy crop, for continuous production of methane (CH₄) as a source of renewable energy. The sugar beet silage was used as the mono-substrate, which had a low pH of around 3.3–3.4, without the addition of manure. The mesophilic biogas digester was operated in a hydraulic retention time (HRT) range between 15 and 9.5 days, and an organic loading rate (OLR) range of between 6.33 and 10 g VS l⁻¹ d⁻¹. The highest specific gas production rate (spec. GPR) and CH₄ content were 0.67 l g VS⁻¹ d⁻¹ and 74%, respectively, obtained at an HRT of 9.5 days and OLR of 6.35 g VS l⁻¹ d⁻¹. The digester worked within the neutral pH range as well. Since this substrate lacked the availability of macro and micro nutrients, and the buffering capacity as well, external supplementation was definitely required to provide a stable and efficient operation, as provided using NH₄Cl and KHCO₃ in this case. The findings of this ongoing long-term fermentation of an extremely acidic biomass substrate without manure addition have reflected crucial information about how to appropriately maintain the operational and particularly the environmental parameters in an agricultural biogas plant.     

Economical analysis and relation between energy inputs and yield of greenhouse cucumber production in Iran

This paper studies the energy balance between the input and the output per unit area for greenhouse cucumber production. For this purpose, the data on 43 cucumber production greenhouses in the Tehran province, Iran, were collected and analyzed. The results indicated that a total energy input of 148836.76 MJ ha⁻¹ was consumed for cucumber production. Diesel fuel (with 41.94%) and chemical fertilizers (with 19.69%) were amongst the highest energy inputs for cucumber production. The energy productivity was estimated as 0.80 kg MJ⁻¹. The ratio of energy output to energy input was approximately 0.64. Results indicate 10.93% and 89.07% of total energy input was in renewable and non-renewable forms, respectively. The regression results revealed that the contribution of energy inputs on crop yield (except for fertilizers and seeds energies) was significant. The human labour energy had the highest impact (0.35) among the other inputs in greenhouse cucumber production. Econometric analysis indicated that the total cost of production for one hectare of cucumber production was around 33425.70 $. Accordingly, the benefit–cost ratio was estimated as 2.58.     

A statistical analysis of wind power density based on the Weibull and Rayleigh models at the southern region of Turkey

The electric generating capacity of Turkey must be tripled by 2010 to meet Turkey’s electric power consumption, if the annual 8% growth in electric power consumption continues. Turkey has to make use of its renewable energy resources, such as wind and solar, not only to meet the increasing energy demand, but also for environmental reasons. Studies show that Iskenderun (36°35′N; 36°10′E) located on the Mediterranean coast of Turkey is amongst the possible wind energy generation regions. In the present study, the wind energy potential of the region is statistically analyzed based on 1-year measured hourly time-series wind speed data. The probability density distributions are derived from time-series data and distributional parameters are identified. Two probability density functions are fitted to the measured probability distributions on a monthly basis. The wind energy potential of the location is studied based on the Weibull and the Rayleigh models.     

Overview analysis of bioenergy from livestock manure management in Taiwan

The emissions of greenhouse gases (GHGs) from the livestock manure are becoming significant energy and environmental issues in Taiwan. However, the waste management (i.e., anaerobic digestion) can produce the biogas associated with its composition mostly consisting of methane (CH₄), which is now considered as a renewable energy with emphasis on electricity generation and other energy uses. The objective of this paper was to present an overview analysis of biogas-to-bioenergy in Taiwan, which included five elements: current status of biogas sources and their energy utilizations, potential of biogas (methane) generation from livestock manure management, governmental regulations and policies for promoting biogas, benefits of GHGs (i.e., methane) emission reduction, and research and development status of utilizing livestock manure for biofuel production. In the study, using the livestock population data surveyed by the Council of Agriculture (Taiwan) and the emission factors recommended by the Intergovernmental Panel on Climate Change (IPCC), the potential of methane generation from livestock manure management in Taiwan during the period of 1995–2007 has been estimated to range from 36 to 56 Gg year⁻¹, indicating that the biogas (methane) from swine and dairy cattle is abundant. Based on the characteristics of swine manure, the maximum potential of methane generation could reach to around 400 Gg year⁻¹. With a practical basis of the total swine population (around 4300 thousand heads) from the farm scale of over 1000 heads, a preliminary analysis showed the following benefits: methane reduction of 21.5 Gg year⁻¹, electricity generation of 7.2 × 10⁷ kW-h year⁻¹, equivalent electricity charge saving of 7.2 × 10⁶ US$ year⁻¹, and equivalent carbon dioxide mitigation of 500 Gg year⁻¹.     

Life cycle assessment of electricity generation in Mexico

This paper presents for the first time a Life Cycle Assessment (LCA) study of electricity generation in Mexico. The electricity mix in Mexico is dominated by fossil fuels, which contribute around 79% to the total primary energy; renewable energies contribute 16.5% (hydropower 13.5%, geothermal 3% and wind 0.02%) and the remaining 4.8% is from nuclear power. The LCA results show that 225 TWh of electricity generate about 129 million tonnes of CO₂ eq. per year, of which the majority (87%) is due to the combustion of fossil fuels. The renewables and nuclear contribute only 1.1% to the total CO₂ eq. Most of the other LCA impacts are also attributed to the fossil fuel options. The results have been compared with values reported for other countries with similar electricity mix, including Italy, Portugal and the UK, showing good agreement.     

Reevaluation of Turkey's hydropower potential and electric energy demand

This paper deals with Turkey's hydropower potential and its long-term electric energy demand predictions. In the paper, at first, Turkey's energy sources are briefly reviewed. Then, hydropower potential is analyzed and it has been concluded that Turkey's annual economically feasible hydropower potential is about 188 TWh, nearly 47% greater than the previous estimation figures of 128 TWh. A review on previous prediction models for Turkey's long-term electric energy demand is presented. In order to predict the future demand, new increment ratio scenarios, which depend on both observed data and future predictions of population, energy consumption per capita and total energy consumption, are developed. The results of 11 prediction models are compared and analyzed. It is concluded that Turkey's annual electric energy demand predictions in 2010, 2015 and 2020 vary between 222 and 242 (average 233) TWh; 302 and 356 (average 334) TWh; and 440 and 514 (average 476) TWh, respectively. A discussion on the role of hydropower in meeting long-term demand is also included in the paper and it has been predicted that hydropower can meet 25–35% of Turkey's electric energy demand in 2020.     

Net energy balance of molasses based ethanol: The case of Nepal

This paper evaluates life cycle energy analysis of molasses based ethanol (MOE) in Nepal. Net energy value (NEV), net renewable energy value (NREV) and energy yield ratio are used to evaluate the energy balance of MOE in Nepal. Total energy requirements in sugarcane farming, cane milling and ethanol conversion processes are estimated and energy allocation is made between co-products (molasses and sugar) as per their market prices. The result shows negative NEV (−13.05 MJ/L), positive NREV (18.36 MJ/L) and energy yield ratio (7.47). The higher positive value of NREV and energy yield ratio reveal that a low amount of fossil fuels are required to produce 1 L of MOE. However, negative NEV reveals that the total energy consumption (both fossil and renewables) to produce the ethanol is higher than its final energy content. Nevertheless, the renewable energy contribution amounts to 91.7% of total energy requirements. The effect of the increased price of molasses and reduced energy consumption in the sugarcane milling and ethanol conversion are found to be significant in determining the energy values and yield ratio of MOE. In addition, there are clear measures that can be taken to improve efficiency along the production chain. Finally, energy security, scarcity of hard currency for importing fossil fuels and opportunities for regional development are also strong reasons for considering local renewable energy options in developing countries.     

The prospective of coal power in China: Will it reach a plateau in the coming decade?

Coal power holds the king position in China's generation mix and has resulted in ever-increasing ecological and environmental issues; hence, the development of the electric power sector is confronted with a series of new challenges. China has recently adopted a new economic principle of the “new economic normal,” which has a large effect on the projection electricity demand and power generation planning through 2020. This paper measures electricity demand based upon China's social and economic structure. The 2020 roadmap presents China's developing targets for allocating energy resources to meet new demands, and the 2030 roadmap is compiled based upon an ambitious expansion of clean energy sources. Results show that electricity demand is expected to reach 7500 TWh in 2020 and 9730 TWh in 2030. Coal power is expected to reach its peak in 2020 at around 970 GW, and will then enter a plateau, even with a pathway of active electricity substitution in place.     

An analysis of hydrogen production from renewable electricity sources

Three aspects of producing hydrogen via renewable electricity sources are analyzed to determine the potential for solar and wind hydrogen production pathways: a renewable hydrogen resource assessment, a cost analysis of hydrogen production via electrolysis, and the annual energy requirements of producing hydrogen for refueling. The results indicate that ample resources exist to produce transportation fuel from wind and solar power. However, hydrogen prices are highly dependent on electricity prices. For renewables to produce hydrogen at $2 kg⁻¹, using electrolyzers available in 2004, electricity prices would have to be less than $0.01 kWh⁻¹. Additionally, energy requirements for hydrogen refueling stations are in excess of 20 GWh/year. It may be challenging for dedicated renewable systems at the filling station to meet such requirements. Therefore, while plentiful resources exist to provide clean electricity for the production of hydrogen for transportation fuel, challenges remain to identify optimum economic and technical configurations to provide renewable energy to distributed hydrogen refueling stations.     

Markets for energy efficiency: Exploring the implications of an EU-wide ‘Tradable White Certificate’ scheme

Recent developments in European energy policy reveal an increasing interest in implementing the so-called ‘Tradable White Certificate’ (TWC) schemes to improve energy efficiency. Based on three evaluation criteria (cost-effectiveness, environmental effectiveness and distributional equity) this paper analyses the implications of implementing a European-wide TWC scheme targeting the household and commercial sectors. Using a bottom-up model, quantitative results show significant cost-effective potentials for improvements (ca. 1400 TWh in cumulative energy savings by 2020), with the household sector, gas and space heating representing most of the TWC supply in terms of eligible sector, fuel and energy service demand, respectively. If a single market price of negative externalities is considered, a societal cost-effective potential of energy savings above 30% (compared to the baseline) is observed. In environmental terms, the resulting greenhouse gas emission reductions are around 200 Mt CO_2-eq by 2010, representing nearly 60% of the EU-Kyoto-target. From the qualitative perspective, several embedded ancillary benefits are identified (e.g. employment generation, improved comfort level, reduced ‘fuel poverty’, security of energy supply). Whereas an EU-wide TWC increases liquidity and reduces the risks of market power, autarky compliance strategies may be expected in order to capture co-benefits nationally. Cross subsidies could occur due to investment recovery mechanisms and there is a risk that effects may be regressive for low-income households. Assumptions undertaken by the modelling approach strongly indicate that high effectiveness of other policy instruments is needed for an EU-wide TWC scheme to be cost-effective.     

Promotional policy and perspectives of usage renewable energy in Lithuania

The article outlines renewable energy (RE) sources according to the energy efficiency policy in Lithuania as well as practical experience of implementation of RE projects within the framework of the government policy to promote RES use due to the requirement of the European Union. The main goal of the country is to reduce the import of fossil fuel, to improve environment conditions and to reduce the climate change impact. Analysis of implemented RE projects and forecasts for the future projects are also presented. Most of the efforts in Lithuania were aimed at drafting the biomass (wood chips, wood waste, straw, biogas) and small hydro projects and their subsequent implementation. At present the total capacity of wood-chip-fuelled boilers reached above 251 MW. No serious obstacles can be seen for the extension of wood fuel use. At present, new demonstrational projects have been started covering geothermal energy, solar energy, biogas, biofuels for transport and other. In this time, the RE sources comprise 7.69% of national energy balance. Taking into account feasible resources of RE (it is more than 19.85 TWh/year) and the ongoing implementation of projects it is clear that the share of RE sources will constitute 12–13% of national energy balance in 2010 year. The main factor limiting further growth is high investment costs. The electricity production from local and RE sources in Lithuania is mainly based on hydro energy. At this time the wind energy is not used for this purpose. The electricity production from local and renewable energy sources is about 3.22% of the total consumption.