A survey of tourist attitudes to renewable energy supply in Australian hotel accommodation

The results of a survey are presented describing the attitudes of Australian tourists to micro-generation renewable energy supply (RES) for hotel accommodation. The average positive response rate to all questions was above 50%, implying a desire by tourists for environmentally friendly accommodation and renewable energy supply. Tourists indicated that they perceived RES to be reliable and expressed a willingness to cooperate with RES initiatives and possible resultant inconveniences. However, there were mixed opinions with regard to consumer willingness to pay for the product. Of the 49% of respondents who were willing to pay extra for RES, 92% replied they would pay between 1% and 5%. Analysis of the variation in response due to accommodation type revealed a ‘city’ hotel versus ‘eco-resort’ difference. Likewise, a breakdown of responses according to country of origin indicated that Australians had a more positive attitude to RES than overseas visitors, including Japanese and Americans. While no variation in response was detected according to gender, age had a measurable bearing on response, with older guests returning a higher positive response rate. Visual queue questions querying aesthetic opinions and ‘not-in-my-backyard’ (NIMBY) attitude to RES revealed that there was virtually no opposition to photovoltaics. Opinions regarding wind energy conversion systems (WECS) varied with type and location, with rooftop WECS receiving more acceptance than stand-alone varieties. A high level of visual acceptance was shown by respondents for onshore wind farms located close to a tourist accommodation centre, with less enthusiasm for offshore farms. A strong NIMBY attitude to WECS was not observed among Australian or local respondents.     

Feasibility analysis of stand-alone renewable energy supply options for a large hotel

This paper provides a feasibility analysis of renewable energy supply (RES) for a stand-alone supply large-scale tourist operation (with over 100 beds). The analysis utilises the power load data from a hotel located in a subtropical coastal area of Queensland, Australia. The assessment criteria of the analysis are net present cost, renewable factor and payback time. Due to the limited number of RES case studies in tourist operations and the absence of studies for large resorts, requiring facilities with a higher degree of comfort such as air-conditioning, it is not possible to establish with confidence the viability of RES in this industry. The specific operational characteristics of the tourism accommodation sector, such as 24-h operation, comfort provision and low tolerance for failure necessitates a separate assessment of RES viability for this sector, rather than relying on similar assessments from other commercial sectors. This study uses RES assessment software tools, HOMER (National Renewable Energy Laboratory, US) and HYBRIDS (Solaris Homes, Queensland, Australia), in order to compare diesel generator-only, RES-only and RES/diesel hybrid technologies. HOMER uses hourly load data, whilst HYBRIDS uses average daily energy demand for each month. The modelling results demonstrate that RES, in principle, has the potential to adequately and reliably meet power demand for a stand-alone large-scale tourist accommodation. Optimisation modelling demonstrates that 100% of power demand can be supplied by a RES-only configuration. A hybrid diesel/RES configuration provides the lowest NPC result with a resultant RF of 76%. In comparison to the diesel generator-only configuration, NPC is reduced by 50% and Greenhouse Gas (GHG) emissions by 65%. The payback time of the hybrid RES scenario is 4.3 years. Results indicate that wind energy conversion systems (WECS), rather than photovoltaics, are the most economically viable RES for large-scale operations. Large-scale WECS (over 1000 kW) are more efficient and economical than multiple small-scale WECS (0.1–100 kW). Both modelling tools produced similar results, with HYBRIDS producing on average slightly higher NPC results than HOMER. The modelling and resulting data from the analysis indicate that RES is technically feasible and economically viable as a replacement for conventional thermal energy supply for large-scale tourist operations dependent on stand-alone power supplies.     

Case study feasibility analysis of renewable energy supply options for small to medium-sized tourist accommodations

This paper outlines a feasibility analysis of renewable energy supply (RES) for small to medium-scale tourist operations (less than 100 beds) dependent on stand-alone supplies. The analysis utilised the power load data from three accommodation case studies that had RES/hybrids already installed. The accommodation sites, chosen from diverse locations within Australia, varied in both climatic and geographic characteristics. The assessment criteria for the analysis were net present cost (NPC), renewable factor (RF) and payback time. The specific operational characteristics of the tourism accommodation sector, such as 24-h operation, comfort provision and low tolerance for failure, necessitates a separate assessment of RES viability for this sector, rather than relying on similar assessments from other commercial and domestic sectors, which may not be representative. This study utilised RES assessment software, HOMER (National Renewable Energy Laboratory, US) in order to compare the present RES/hybrid configuration to diesel generator-only (genset-only), RES-only and optimised RES/hybrid configurations. Analysis of both actual data and modeling results demonstrated that RES can adequately and reliably meet the power demand for stand-alone small to medium-scale tourist accommodations. Optimisation, achieved by further addition of RES to the existing configurations, reduced NPC in the majority of cases, with the added benefit of increased RF. Furthermore, NPC for these optimised RES/hybrid configurations were comparable to the optimised genset-only configurations. Modeling of conversions to RES-only configurations demonstrated this option as uneconomical unless existing RF was already high. Results indicated that wind energy conversion systems (WECS), rather than photovoltaics, were the most economical RES for sampled hybrid systems. For example, the payback time of the WECS/hybrids was approximately 3–4 years compared to PV/hybrids at 6–7 years. Hydrogen fuel cells and storage systems, whilst technically feasible, were not economically viable for the case studies due to the present high cost of components, especially compared to gensets. Modeling future potential increase in diesel fuel prices and implementation of carbon taxes shows a significant increase in NPC for genset-only configurations compared to RES/hybrid configurations in the sample. Carbon taxes of $50/ton increases NPC by 10% for genset-only systems but increases NPC less than half that amount for RES/hybrid systems. The data and subsequent modeling demonstrate that RES is both technically feasible and economically viable compared to diesel energy supply, for the small to medium-scale tourist operations sampled, dependent on stand-alone power supplies.     

Feasibility analysis of renewable energy supply options for a grid-connected large hotel

This study presents an analysis of the technical and financial viability of grid-only, RES-only and grid/RES hybrid power supply configurations for a large-scale grid-connected hotel (over 100 beds). Assessment criteria comprised net present cost (NPC), renewable fraction (RF) and payback time. The RES software HOMER (National Renewable Energy Laboratory, US) was utilised as the assessment tool with modeling performed with hourly load data input from a hotel located in a subtropical coastal area of Queensland, Australia. The results demonstrate that RES, in principle, has the potential to supply significant power for a large-scale tourist accommodation, in conjunction with the grid-electricity supply. Optimisation modeling demonstrated that, at 2004 prices, the NPC of the grid/RES hybrid configuration is comparable with the grid-only supply and resulted in a RF of 73%, a payback time of 14 years and a reduction in greenhouse gas emissions of 65%. Optimisation modeling also showed that whilst a RES-only configuration can potentially supply 100% of power demand, such a configuration is presently uneconomical given current electricity costs. Results indicate that wind energy conversion systems (WECS), rather than photovoltaics, are the most economically viable RES technology for large-scale grid-connected operations. Specifically, large-scale WECS (over 1000 kW) are more efficient and more economical than multiple small-scale WECS (0.1–100 kW). Hydrogen fuel cells and storage are presently uneconomical in grid-connected configurations. Sensitivity analysis demonstrated that operations that rely on grid-only supply are more economically susceptible to escalations in electricity costs and the imposition of carbon taxes, in comparison to grid/RES hybrids. Indeed, at present electricity prices, which have nearly quadrupled since 2004, the grid/RES hybrid is more economical over a 20-year span than the grid-only system, with a NPC which is 50% lower, and a payback time of 4.5 years. The analysis demonstrates that RES is both technically feasible and economically viable as an addition to grid-connected supply for large-scale tourist operations, and should become more attractive as costs of conventional supplies increase.     

Evaluating energy conservation outreach programs: A case study in Minnesota

The Minnesota Energy Agency and the Department of Administration sponsored workshops for boiler operators in 1979. The workshops, attended by engineers from state-owned facilities and from private buisnesses, dealt with improvements to fuel/air ratios for large gas and oil-fired boilers.

The process and costs of developing and running these workshops are documented. Two different surveys of workshop attendees were conducted, one directly after the workshops and the second two months later. The first survey asked attendees about their reactions to the course (instructor, manual, and visuals) and their intentions to make the fuel/air ratio changes that were discussed during the workshops. The responses were remarkably positive, with 82% of the attendees rating the probability of making these changes as either excellent or good.

The followup telephone survey sought to determine how many attendees had actually made these changes in the two months following the workshops. Again, the results were quite positive: 79% of the respondents said that they had made the adjustments to some or all of their boilers. Altogether 60% of the boilers operated by these respondents had been adjusted.

If these responses accurately reflect the changes made because of the workshops, then the State of Minnesota saved $88,000 in fuel bills during 1979. This is three times the cost of running the two March workshops (including the value of the attendees' time). This suggests that this workshop—and by implication, others like it—are an effective use of State resources.     

Adoption of innovative heating systems—needs and attitudes of Swedish homeowners

Questionnaire surveys of Swedish homeowners of detached houses were carried out in 2004 and 2007 to understand their needs and attitudes towards attributes of innovative heating systems (IHSs) comprised of a bedrock heat pump, district heating, or a wood pellet boiler. In each occasion 1,500 homeowners were randomly selected. The response rate was 42% in 2004 and 48% in 2007. Results showed that the majority of the respondents were satisfied with their existing heating system and did not intend to install new systems. Economic factors and functional reliability were the most important factors in the respondents’ choices of heating system, while environmental factors were of lower importance. Among the IHSs, respondents had the most favorable attitude towards bedrock heat pumps followed by district heating and pellet boilers. But the attitude was more favorable towards electric boilers than for pellet boilers. The least favorable attitude was towards oil boilers. Between 2004 and 2007, there was a positive change in respondents’ attitude towards IHSs and electric boilers, and a negative change in attitude towards resistance heaters and oil boilers.     

Are fundamentals enough? Explaining price variations in the German day-ahead and intraday power market

European electricity market participants are encouraged to balance intraday deviations from their day-ahead schedules via trades in the intraday market. Together with the increasing production of variable renewable energy sources (RES), the intraday market is gaining importance. We investigate the explanatory power of a fundamental modeling approach explicitly accounting for must-run operations of combined heat and power plants (CHP) and intraday peculiarities such as a shortened intraday supply stack. The fundamental equilibria between every hour's supply stack and aggregated demand in 2012 and 2013 are modeled to yield hourly price estimates. The major benefits of a fundamental modeling approach are the ability to account for non-linearities in the supply stack and the ability to combine time-varying information consistently. The empirical results show that fundamental modeling explains a considerable share of spot price variance. However, differences between the fundamental and actual prices persist and are explored using regression models. The main differences can be attributed to (avoided) start up-costs, market states and trading behavior.     

Large-scale integration of optimal combinations of PV, wind and wave power into the electricity supply

This article presents the results of analyses of large-scale integration of wind power, photo voltaic (PV) and wave power into a Danish reference energy system. The possibility of integrating Renewable Energy Sources (RES) into the electricity supply is expressed in terms of the ability to avoid excess electricity production. The different sources are analysed in the range of an electricity production from 0 to 100% of the electricity demand. The excess production is found from detailed energy system analyses on the computer model EnergyPLAN. The analyses have taken into account that certain ancillary services are needed in order to secure the electricity supply system.The idea is to benefit from the different patterns in the fluctuations of different renewable sources. And the purpose is to identify optimal mixtures from a technical point of view. The optimal mixture seems to be when onshore wind power produces approximately 50% of the total electricity production from RES. Meanwhile, the mixture between PV and wave power seems to depend on the total amount of electricity production from RES. When the total RES input is below 20% of demand, PV should cover 40% and wave power only 10%. When the total input is above 80% of demand, PV should cover 20% and wave power 30%. Meanwhile the combination of different sources is alone far from a solution to large-scale integration of fluctuating resources. This measure is to be seen in combination with other measures such as investment in flexible energy supply and demand systems and the integration of the transport sector.     

How to achieve a 100% RES electricity supply for Portugal?

Portugal is a country with an energy system highly dependent on oil and gas imports. Imports of oil and gas accounted for 85% of the country’s requirements in 2005 and 86% in 2006. Meanwhile, the share of renewable energy sources (RES) in the total primary energy consumption was only 14% in 2006. When focusing only on electricity production, the situation is somewhat better. The share of RES in gross electricity production varies between 20% and 35% and is dependent on the hydropower production in wet and dry years. This paper presents, on a national scale, Portugal’s energy system planning and technical solutions for achieving 100% RES electricity production. Planning was based on hourly energy balance and use of H₂RES software. The H₂RES model provides the ability to integrate various types of storages into energy systems in order to increase penetration of the intermittent renewable energy sources or to achieve a 100% renewable island, region or country. The paper also represents a stepping-stone for studies offering wider possibilities in matching and satisfying electricity supply in Portugal with potential renewable energy sources. Special attention has been given to intermittent sources such as wind, solar and ocean waves that can be coupled to appropriate energy storage systems charged with surplus amounts of produced electricity. The storage systems also decrease installed power requirements for generating units. Consequently, these storages will assist in avoiding unnecessary rejection of renewable potential and reaching a sufficient security of energy supply.     

Comparative analyses of seven technologies to facilitate the integration of fluctuating renewable energy sources

An analysis of seven different technologies is presented. The technologies integrate fluctuating renewable energy sources (RES) such as wind power production into the electricity supply, and the Danish energy system is used as a case. Comprehensive hour-by-hour energy system analyses are conducted of a complete system meeting electricity, heat and transport demands, and including RES, power plants, and combined heat and power production (CHP) for district heating and transport technologies. In conclusion, the most fuel-efficient and least-cost technologies are identified through energy system and feasibility analyses. Large-scale heat pumps prove to be especially promising as they efficiently reduce the production of excess electricity. Flexible electricity demand and electric boilers are low-cost solutions, but their improvement of fuel efficiency is rather limited. Battery electric vehicles constitute the most promising transport integration technology compared with hydrogen fuel cell vehicles (HFCVs). The costs of integrating RES with electrolysers for HFCVs, CHP and micro fuel cell CHP are reduced significantly with more than 50% of RES.     

An energy management approach for renewable energy integration with power generation and water desalination

The share of the renewable energy sources (RES) in the global electricity market is substantially increasing as a result of the commitment of many countries to increase the contribution of the RES to their energy mix. However, the integration of RES in the electricity grid increases the complexity of the grid management due to the variability and the intermittent nature of these energy sources. Energy storage solutions such as batteries offer either short-term storage that is not sufficient or longer period storage that is significantly expensive. This paper introduces an energy management approach which can be applied in the case of power and desalinated water generation. The approach is based on mathematical optimization model which accounts for random variations in demands and energy supply. The approach allows using desalination plants as a deferrable load to mitigate for the variability of the renewable energy supply and water and/or electricity demands. A mathematical linear programming model is developed to show the applicability of this idea and its effectiveness in reducing the impact of the uncertainty in the environment. The model is solved for the real world case of Saudi Arabia. The optimal solution accounts for random variations in the renewable energy supply and water and/or electricity demands while minimizing the total costs for generating water and power.     

Medium-term demand for European cross-border electricity transmission capacity

The aim of this paper is to discuss the needs for investment in electricity interconnectors in Europe by 2025. We evaluate the impact of cross-border transmission capacity on dispatch costs, curtailment needs for renewable energy sources (RES), on CO₂ emissions, on hydro storage utilisation and on security of supply (in terms of energy not served). The analysis is performed with EUPowerDispatch, a minimum-cost dispatch model. For the evolution of the electricity generation portfolio and electricity consumption we use the latest Scenario Outlook and Adequacy Forecast of the European Network of Transmission System Operators for Electricity (ENTSO-E). The model results show that the planned additional cross-border transmission capacity between 2010 and 2025 will reduce annual dispatch costs, will have limited impact on the security of supply and will not be a significant cause of variable RES curtailment. However, in case of more RES, it will reduce dispatch costs to a larger extent and will considerably reduce RES curtailment needs, and, if demand grows at the historical rate of 2%, it will be needed to maintain the current level of security of supply. Moreover, our study shows that hydro pumping and storage and cross-border transmission are partly complementary technologies.     

The role of pumped storage systems towards the large scale wind integration in the Greek power supply system

In the recent years, the debate on the necessity of pumped storage systems in the Greek power supply system has started. In the current decade, the Greek power system will gradually try higher RES penetration, mainly due to wind energy and photovoltaics integration. Variability of wind and PV generation and the current structure of the Greek power system introduce technical constraints, which should be taken into consideration in the forthcoming large scale RES integration. This paper examines the ability of the Greek power system to absorb renewable power and the necessity of pumped storage systems. The feasibility of pumped storage systems is discussed in three different scenarios of wind–photovoltaics integration. Results show that for the gradual increase of variable output RES, pumped storage systems are required, but the feasibility of pumped storage systems is not proved in the intermediate scenarios of RES integration.     

Energy constraints and organizational change in US production

There is still considerable uncertainty about the way in which energy supply constraints affect industrial thinking and activity. Yet this is an important issue in determining the effectiveness of conservation programmes and in formulating energy policy. In 1978 S. Mehra and A.G. Kefalas conducted a survey of US business attitudes and responses to energy constraints. Some of their findings were published in the September 1979 Energy Policy. In the article below they present the results of further analysis of their survey. In particular they examine correlations between perceived causes and preferred solutions of energy problems, organizational adjustments to energy constraints in energy intensive industries and the ways in which production operations have changed in response to supply problems.     

Wood-energy market impact on competition, procurement practices, and profitability of landowners and forest products industry in the U.S. south

Recent emphasis on producing energy from woody biomass has raised questions about the impact of a wood-energy market on the U.S. South’s wood supply chain. We surveyed wood-energy facilities, fibermills, sawmills, private landowners, and government landholders to investigate the expected impact of a vibrant wood-energy market on the southern wood supply chain. Specifically, our study was designed to document potential competition for resources, wood supply chain profitability, and landowner willingness to sell timber to energy facilities. Results indicate that wood-energy facilities and traditional mills were not competing for raw material on a large scale at the time of the study, but competition is expected over the next decade. Almost 90% of fibermills reported that traditional forest industry mills should enter the wood-energy market, but most were skeptical that the new market would improve profitability. Ninety percent of responding landowners reported a willingness to sell to energy facilities if the right price is offered and all of those who had already sold timber to an energy facility were satisfied with the experience. Only 3.5% of respondents were unwilling to sell timber to an energy company, and only one of these respondents listed timber production as a primary objective, which indicates those who would not harvest timber for energy, may be unlikely to harvest timber for other purposes also. This study suggests that the southern wood supply chain is in position to profit from a wood-energy market; however, concerns remain about the coexistence of the forest products and wood-energy industries.     

Power-to-Gas integration in the Transition towards Future Urban Energy Systems

Temperature levels play a key role in the thermal energy demand of urban contexts affecting their associated primary energy consumption and Renewable Energy Fraction. A Smart Heating strategy accounts for those supply features requiring new solutions to be effectively renewable and to solve the RES capacity firming. Power-to-Gas (P2G) is the way to decarbonize the energy supply chain as fraction of Hybrid fuels, combination of fossil ones and Renewable Hydrogen, as immediate responsive storage solution. While, Power-To-Heat is conceived as the strategy to modernize the high and medium temperature heating systems by electricity-driven machines to switch from Fuel-to-Heat to Electricity-to-Heat solutions. The authors investigated on different urban energy scenarios at RES share increase from 25% up to 50% in the energy mix to highlight strengths and weaknesses of the P2G applications. Primary Energy Consumption was chosen as the objective function. Three Reference Cities were chosen as reference scenarios. Moreover, the analytical models of P2G was designed and implemented in the reference energy system. The results of the twelve scenarios, four for each Reference City were evaluated in terms of amount of Renewable Heat delivered. Finally, the interaction between P2G and renewable heat production was evaluated.     

Benchmarking energy use and greenhouse gas emissions in Singapore’s hotel industry

Hotel buildings are reported in many countries as one of the most energy intensive building sectors. Besides the pressure posed on energy supply, they also have adverse impact on the environment through greenhouse gas emissions, wastewater discharge and so on. This study was intended to shed some light on the energy and environment related issues in hotel industry. Energy consumption data and relevant information collected from hotels were subjected to rigorous statistical analysis. A regression-based benchmarking model was established, which takes into account, the difference in functional and operational features when hotels are compared with regard to their energy performance. In addition, CO₂ emissions from the surveyed hotels were estimated based on a standard procedure for corporate GHG emission accounting. It was found that a hotel’s carbon intensity ranking is rather sensitive to the normalizing denominator chosen. Therefore, carbon intensity estimated for the hotels must not be interpreted arbitrarily, and industry specific normalizing denominator should be sought in future studies.     

Applications of thermostatically controlled loads for demand response with the proliferation of variable renewable energy

More flexibility is desirable with the proliferation of variable renewable resources for balancing supply and demand in power systems.Thermostatically controlled loads (TCLs) attract tremendous attentions because of their specific thermal inertia capability in demand response (DR) programs. To effectively manage numerous and distributed TCLs, intermediate coordinators, e.g., aggregators, as a bridge between end users and dispatch operators are required to model and control TCLs for serving the grid. Specifically, intermediate coordinators get the access to fundamental models and response modes of TCLs, make control strategies, and distribute control signals to TCLs according the requirements of dispatch operators. On the other hand, intermediate coordinators also provide dispatch models that characterize the external characteristics of TCLs to dispatch operators for scheduling different resources. In this paper, the bottom-up key technologies of TCLs in DR programs based on the current research have been reviewed and compared, including fundamental models, response modes, control strategies, dispatch models and dispatch strategies of TCLs, as well as challenges and opportunities in future work.     

Risk-based optimal operation of power,heat and hydrogen-based microgrid considering a plug-in electric vehicle

The growing interest in integrating variable renewable energy resources (RES), besides global concerns about greenhouse pollution, brings multiple challenges for eco and environmentally-friendly operation of systems. Meanwhile, the simultaneous energy supply can improve energy efficiency and mitigate the fluctuation of RES compared with a single-energy system. Therefore, this paper seeks to investigate the optimal scheduling of heating, power, and hydrogen-based microgrid incorporated with RES and plug-in electric vehicles (PEV). The fuel-cell-based hydrogen and electrolyzer facilities are integrated into the multi-energy system to investigate the power-to-hydrogen and hydrogen-to-power technologies in the model. Besides typical electric and thermal loads, the proposed system can directly sell hydrogen to hydrogen-based industrial applications. The PEV as a flexible resource is employed to facilitate the integration of solar energy. Due to the substantial uncertainty from solar energy, price, load, and EVs' arriving and departing times, the risk management of the model based on the conditional value-at-risk is developed to show the operator's behavior against the random inputs and their risk. Results show that integrating the hydrogen storage and plug-in electric vehicle in the model results in a daily cost reduction of up to 9.28%.     

Global Renewable Energy Resources

Renewable energy sources (RES) supply 14% of the total world energy demand. RES are biomass, hydropower, geothermal, solar, wind, and marine energies. The renewables are the primary, domestic and clean or inexhaustible energy resources. The percentage share of biomass was 62.1% of total renewable energy sources in 1995. Large-scale hydropower supplies 20 percent of global electricity. Wind power in coastal and other windy regions is promising as well.