Current Feed-in Tariff Research Articles

Assessment of the potential for developing mini/micro hydropower: A case study in Beppu City, Japan

Study regionBeppu City, Oita Prefecture, Japan was selected as a site of this study. Study focusThis study aims to provide quantitative guidelines necessary for capacity building among various stakeholders to minimize water-energy conflicts in developing mini/micro hydropower (MHP), a baseload renewable energy that is socially necessary, not only to reduce greenhouse gas emissions but also to vitalize local economies by creating jobs related to MHP operations. Using three different methods to calculate river water levels and discharges, the potential power generation by MHP was estimated for six rivers in Beppu City. New hydrological insightsOur results show that installation of MHP facilities can provide stable electricity for tens to hundreds of residents in local communities along the rivers. However, the results are based on the existing infrastructure, such as roads and electric lines. This means that greater potential is expected if additional infrastructures are built to develop further MHP facilities. On the other hand, in Japan, river laws and irrigation right regulations currently restrict new entry by actors to rivers. Therefore, to further develop MHP, deregulation of the existing laws relevant to rivers and further incentives for business owners of MHP facilities, along with the current feed-in tariffs, are required. Meanwhile, possible influences to riverine ecosystems when installing new MHP facilities should also be taken into account.

Uncertainty analysis of wave energy farms financial indicators

In this work, an analysis of the uncertainty that influences wave energy farm financial returns is carried out. Firstly, a methodology to analyze the financial uncertainty through cash flow analysis is developed. A reconstruction of a set of power production life-cycles is made based on the methodology proposed in Ref. [1] using a selection and an interpolation technique. This set of lifecycles allowed to obtain the statistical distributions of the main financial indicators (IRR, NPV and PBP). The high variability of these parameters is explained by the climate variability. Therefore, for the economic study of a wave energy project the influence of the climate conditions is demonstrated and for this purpose a long climate data series is needed. Finally, a second uncertainty source related with the political and legislation environment is studied, focusing on the effect of feed in tariff. This sensitivity analysis of the feed in tariffs is made based on cash-flow algorithm. Current feed in tariffs seemed insufficient in order to get profitable wave energy projects and also an increase in feed in tariff resulted in an increase of variability of financial indicators. Therefore an increase in feed in tariff is not recommended for early stage technologies. Finally, learning curve was also included in this investigation and it appeared as a key parameter in order to get cost effective financial returns.

Modeling of PV generation, battery and hydrogen storage to investigate the benefits of energy storage for single dwelling

This work presents the results of simulation of battery and hydrogen technologies for renewable energy management, load-leveling and peak-shaving in a single grid-connected house in Nottingham United Kingdom where three people live. The house has a PV installation of 4.5 kWp. A stochastic model which takes active occupancy into account is used for simulating the electricity demand. A 10-kWh lead-acid battery and a 1-kW fuel cell together, with a 600-l hydrogen (gas) storage tank at 15 bar (31.3 kWh) are used for these simulations for short (daily cycles) and mid-term (3-day cycles) storage, respectively. Energy balances on a representative summer and winter day for both storage technologies are presented, along with annual balances. The battery increases the local use of PV energy generated on-site by 171%, while the hydrogen increases it by 159%. According to the current feed-in tariff legislation in the UK, the increase of the local use of PV energy means an additional annual income of at least £112 and £102 for the battery and hydrogen storage, respectively.

A methodology for analysis of the renewable electricity feed-in tariff markets

A feed-in tariff model has been enacted in most countries and is well accepted by the European Commission. In principle, the model offers long-term contracts to eligible renewable energy producers, typically based on guaranteed prices for fixed periods of time for electricity produced from renewable energy. This paper presents a methodology that has been developed for the feed-in tariff market approach, which should gradually help eligible producers become better prepared for market competition after long-term contracts expire. The central part of this methodology is the correction of the current guaranteed prices, based on the calculation of the cost-effectiveness ratio of the market model to the current feed-in tariff or non-market model. The common features of the designed market models are the market component, a combination of the guaranteed price with and without market indexing, and the sum of the reduced guaranteed price and the spot electricity price. The methodology has been applied to the current non-market model implemented under Croatian jurisdiction. In this case, seven different market models were designed, which are compared to the existing non-market model. The results of the cost-effectiveness ratio according to different types of renewable energy and market models for a certain period of time are given, described and used for the correction of the current guaranteed price. The first market model has been selected as the most appropriate to replace the existing non-market model in Croatia.

Economic and environmental impact of lead-acid batteries in grid-connected domestic PV systems

Occupants of dwellings with grid-connected photovoltaic (PV) systems can often benefit financially from exporting electricity to the grid. When export prices are lower than import prices, however, occupants are incentivised to time-shift demand in order to avoid exports and reduce imports. To maximise this potential financial benefit, the addition of batteries to the PV system has been proposed to take advantage of the specific commercial opportunity presented to the occupant of trading exported power during the day for imported power during the evening. This paper therefore assesses the economic and environmental impact of the use of lead-acid batteries in grid-connected PV systems under current feed-in tariff arrangements in the UK. The development of a lead-acid battery model is described, which is used to simulate hypothetical power flows using measured data on domestic PV systems in the UK. The simulation results indicate that the net benefit of the battery is negative, even when considering an idealised lossless battery. When realistic energy losses and lifetimes are accounted for, the financial loss for the systems considered here can approach £1000/year. The environmental impact of the use and production of the lead-acid battery is also described, and also found to be negative, further strengthening the argument against the use of lead-acid batteries in domestic grid-connected PV systems.

Assessing the economic wind power potential in Austria

In the European Union, electricity production from wind energy is projected to increase by approximately 16% until 2020. The Austrian energy plan aims at increasing the currently installed wind power capacity from approximately 1GW to 3GW until 2020 including an additional capacity of 700MW until 2015. The aim of this analysis is to assess economically viable wind turbine sites under current feed-in tariffs considering constraints imposed by infrastructure, the natural environment and ecological preservation zones in Austria. We analyze whether the policy target of installing an additional wind power capacity of 700MW until 2015 is attainable under current legislation and developed a GIS based decision system for wind turbine site selection.Results show that the current feed-in tariff of 9.7 ct kWh−1 may trigger an additional installation of 3544MW. The current feed-in tariff can therefore be considered too high as wind power deployment would exceed the target by far. Our results indicate that the targets may be attained more cost-effectively by applying a lower feed-in tariff of 9.1 ct kWh−1. Thus, windfall profits at favorable sites and deadweight losses of policy intervention can be minimized while still guaranteeing the deployment of additional wind power capacities.

Can renewable energy be financed with higher electricity prices? Evidence from a Spanish region

In this paper we estimate the willingness to pay for mix of renewable sources of electric power by means of a discrete choice experiment survey conducted in Spain in 2010. Two main categories of power supply attributes are explored: source of renewable power (wind, solar and biomass) and the origin of such power. The findings suggest that most consumers are not willing to pay a premium for increases in the shares of renewable in their electricity mix. For two of the three renewable sources considered (wind and biomass) an increase of the renewable mix would require a discount. Instead, we record positive willing to pay for increases in the share of both solar power and locally generated power. However, preferences for types of renewable (solar and wind) are found to be heterogeneous. By classifying respondents in two groups according to the implied importance of the share of renewable sources in their power mix we identify a market segment consisting of 20% of respondents that could promote renewable energy in the absence of subsidies. This is because such a segment shows willingness to pay higher than the current feed-in tariffs.

The evaluation of feed-in tariff regulation of Turkey for onshore wind energy based on the economic analysis

Renewable energy sources have become popular with the technological developments, the increase in the price of fossil fuels and the environmental concerns. These factors have also prompted Turkey to utilize her rich renewable energy sources to meet her increasing electricity demand which is around 7% annually. Therefore, the Renewable Energy Law was enacted in 2005 to incentivize the utilization of domestic renewable sources with feed-in tariffs. In this study, onshore wind energy potential of Turkey is analyzed to find out whether these regulations and incentives will help the utilization of onshore wind energy potential. To that end, some background information about technology and cost of onshore wind power plants, the wind energy potential of Turkey and the current regulatory framework related to wind energy are explained. Then, a model is set up to conduct economic analysis by calculating NPV for the base case scenario and under the uncertain environment. The results show that an onshore wind energy potential of about 13GW having a wind speed of 7.5m/s or higher can be utilized profitably with the current feed-in tariff as the wind capacity of more than 100GW cannot be utilized economically.

Optimal time-invariant operation of a power and water cogeneration solar-thermal plant

Abstract Conceptual design, system-level models, and optimization of operation are presented for a cogeneration solar-thermal plant. The solar-thermal energy collected and concentrated in a salt pond is used in a regenerative Rankine steam cycle with an extraction turbine to produce electricity and process steam. The desalination system is based on reverse osmosis (RO) and multi-effect distillation (MED). An equation-oriented modeling environment is used for the development of time-dependent system-level models required for optimization of the plant. A meteorological radiation model is used to estimate the hourly distribution of beam radiation as a function of time (day and hour), location, and local weather (mainly visibility and humidity). A recently developed model is used to estimate the field efficiency, including projection losses and shading/blocking for a given heliostat layout. Time-invariant optimal operating conditions are presented for a summer day, considering Cyprus as a case study. Seawater desalination processes, RO and MED, are modeled by adapting and extending models from the literature. A control-volume model is developed for the steam cycle based on the first and second law, with given isentropic efficiencies, turbine leaks, and a detailed model for thermodynamic properties of steam/water. This model is validated and allows for optimization over a wide range of operating conditions, e.g., various extraction pressures. The optimization problem is formulated as a nonlinear program (NLP) with dynamics embedded and a heuristic global optimization approach is used. The sequential method of optimization is used, decoupling the simulation from the optimization. The results show that for the plant size considered (4 MW e equivalent nominal capacity) and the MED design chosen based on the literature and industry practice, RO is preferred over MED from an energy point of view. In addition, under the current feed-in tariff (FiT) and water prices in Cyprus, extracting steam for MED is not recommended. In contrast, if current market prices for electricity and water in Cyprus are used, i.e., FiT is neglected, with a typical steam cycle design, extracting steam for MED at low pressures yields maximum income. A new process configuration is presented based on the findings from the case studies, resulting in significantly higher income and exergetic efficiencies.