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.     

Analysis of the EU renewable energy directive by a techno-economic optimisation model

The EU renewable energy (RES) directive sets a target of increasing the share of renewable energy used in the EU to 20% by 2020. The Norwegian goal for the share of renewable energy in 2020 is 67.5%, an increase from 60.1% in 2005. The Norwegian power production is almost solely based on renewable resources and the possibility to change from fossil power plants to renewable power production is almost non-existing. Therefore other measures have to be taken to fulfil the RES directive. Possible ways for Norway to reach its target for 2020 are analysed with a technology-rich, bottom-up energy system model (TIMES-Norway). This new model is developed with a high time resolution among others to be able to analyse intermittent power production. Model results indicate that the RES target can be achieved with a diversity of options including investments in hydropower, wind power, high-voltage power lines for export, various heat pump technologies, energy efficiency measures and increased use of biodiesel in the transportation sector. Hence, it is optimal to invest in a portfolio of technology choices in order to satisfy the RES directive, and not one single technology in one energy sector.     

A method for allocating renewable energy source subsidies among final energy consumers

In a new context of growing need for renewable energy sources (RES), tariff design has become a critical component of energy system regulation. A methodology for allocating the cost of RES subsidies that ensures an optimal balance between compliance with the main regulatory principles of tariff design and each state's specific policy is of cardinal importance in the current context. This paper presents and discusses a novel methodology to allocate the RES subsidy costs, which consists of distributing them among final energy consumers, in proportion to their consumption, regardless of the type of final energy consumed (liquid fuels, gas, electricity or coal).     

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.     

Renewable energy policy and electricity market reforms in China

The article examines the potential effectiveness of the renewable energy policy in China and its regulatory Law framework. It frames the option of renewable energy technology within the background of the long-lasting electricity problems that China has faced including serious supply shortages, reliance on coal, and severe environmental contamination. Its dual administrative and ownership system based on state and privately owned industry is discussed together with the market reform measures adopted in the sector. Current renewable energy policy is analysed, and the scope of the 2005 Renewable Energy Promotion Law is investigated. This is conducted within the context of the electricity sector reform that China adopted, and its effects upon the prospects of encouraging as well as expanding the development of renewable energy. This study draws upon primary information collected from interviews with stakeholders on the policy adequacy, and identifies three main types of shortcomings that have interfered with a more successful expansion of renewable energy in China.     

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.     

Renewable electricity in Sweden: an analysis of policy and regulations

This study aims to analyse the developments in renewable energy policy making in Sweden. It assesses the energy policy context, changes in the choice of policy instruments, and provides explanations behind policy successes and failures. Swedish renewable energy policy has been developing in a context of uncertainty around nuclear issues. While there has been made a political decision to replace nuclear power with renewables, there is a lack of consensus about the pace of phasing out nuclear power due to perceived negative impacts on industrial competitiveness. Such uncertainty had an effect in the formulation of renewable energy policy. Biomass and wind power are the main options for renewable electricity production. Throughout 1990s, the combined effect of different policy instruments has stimulated the growth of these two renewable sources. Yet, both biomass and wind power are still a minor contributor in the total electricity generation. Lack of strong government commitment due to uncertainty around nuclear issues is a crucial factor. Short-term subsidies have been preferred rather than open-ended subsidy mechanisms, causing intervals without subsidies and interruption to development. Other factors are such as lack of incentives from the major electricity companies and administrative obstacles. The taxation system has been successful in fostering an expansion of biomass for heating but hindered a similar development in the electricity sector. The quota system adopted in 2003 is expected to create high demand on biomass but does not favour wind power. The renewable energy aims are unlikely to be changed. Yet, the future development of renewable energy policies especially for high-cost technologies will again depend strongly on nuclear policies, which are still unstable and might affect the pace of renewable energy development.     

Mapping the potential for decentralized energy generation based on renewable energy sources in the Republic of Croatia

There are regions in the Republic of Croatia (underdeveloped, devastated by war, depopulated, as well as islands and mountainous areas) which are still disconnected from the electricity network or where the current network capacity is insufficient. In addition, these regions have good renewable energy potential. Since the decentralized energy generation (DEG) covers a broad range of technologies, including many renewable energy technologies (RET) that provide small-scale power at sites close to the users, this concept could be of interest for these locations. This paper identifies the areas in Croatia where such systems could be applied. Consideration is given to geographical locations as well as possible applications. Wind, hydro, solar photovoltaic, geothermal, and biomass conversion systems were analyzed from a technological and economic point of view. Since the renewable energy sources (RES) data for Croatia are rather scarce, the intention was to give a survey of the present situation and an estimate of future potential for DEG based on RES. The energy potential (given as capacity and energy capability) and production costs were calculated on a regional basis and per type of RET. Finally, the RES cost–supply curves for 2006 and 2010 are given.     

Supply amount and marginal price of renewable electricity under the renewables portfolio standard in Japan

The Renewables Portfolio Standard (RPS) in Japan requires that approximately 1.35% of each retail supplier's electricity sales in FY2010 come from renewable energy sources (RES), for example, photovoltaics, wind, biomass, geothermal, and small hydropower. To help retail suppliers and renewable generators develop effective strategies, this study provides a quantitative analysis of the impact of this measure. We assume the supply conditions for electricity generation from renewable energy sources (RES-E) based on regional resource endowments, and we derive the cost-effective compositions of renewable portfolios, RES-E certificate prices, and additional costs to retail suppliers. The future prospects of RES-E are assessed based on technology, region, and year up to FY2010. The analysis reveals that wind power and biomass power generated from municipal waste will provide the majority of the total supply of RES-E under the RPS. It also indicates that the marginal price of RES-E certificates will be approximately 5.8 JPY/kWh (5.2 USc/kWh) in FY2010, in the case wherein the marginal price of electricity is assumed to be 4 JPY/kWh (3.6 USc/kWh). In order to elaborate on this further, sensitivity analyses for some parameters of RES and the price of electricity are provided. The dynamic supply curves of RES-E certificates are also indicated.     

Governmental policy and prospect in electricity production from renewables in Lithuania

In Lithuania, the generation of electricity is based on the nuclear energy and on the fossil fuels. After the decommissioning of Ignalina nuclear power plant in 2009, the Lithuanian Power Plant and other thermal plants will become the major sources of electricity. Consequently, the Lithuanian power sector must focus on the implementation of renewable energy projects, penetration of new technologies and on consideration of the future opportunities for renewables, and Government policy for promoting this kind of energy. Production of electricity from renewable energy is based on hydro, biomass and wind energy resources in Lithuania. Due to the typical climatic condition in Lithuania the solar photovoltaics and geothermal energy are not used for power sector. Moreover, the further development of hydropower plants is limited by environmental restrictions, therefore priority is given to wind energy development and installation of new biomass power plants. According to the requirements set out in the Directive 2001/77/EC of the European Parliament and of the Council of 27 September 2001 on the promotion of electricity produced from renewable energy sources in the internal electricity market [Official Journal L283, 33–40, 27 October 2001], 7% of gross consumption of electricity will be generated from renewable energy by 2010 in Lithuania. The aim of this paper is to show the estimation of the maximum renewable power penetration in the Lithuanian electricity sector and possible environmental impact.     

Optimization of energy production system in the Dodecanese Islands

The ongoing depletion of the fossil fuels and the dependency of the economies on them have made the need for new sources of energy more obvious. Renewable energy sources (RES) can ensure the sustainable development of the communities, and especially of those in which RES are in abundance. This study deals with the exploitation of RES in the Dodecanese Islands. Specifically, it is examined the optimum percentage by which the renewable sources can participate in the energy production system. Three different scenarios are examined. The first scenario considers that the existent system should be used less than 75% for environmental reasons, in the second scenario, a minimization of the electricity production cost is sought without any environmental constraints, while in the third scenario, it is considered that the RES’ participation in the electricity production would be 30% at most according to the current legislation. The environmental impacts from the energy production are quantified and a comparison is made between the impacts resulting from the existing system and the system found from the first scenario, because this is the scenario with the highest penetration of the RES to the energy production system.     

Challenges to China's transition to a low carbon electricity system

We examine the challenges to China's transition to a low carbon electricity system, in which renewable energy would play a significant role. China's electricity system currently lacks the flexibility in planning, operations, and pricing to respond to conflicting pressures from demand growth, rising costs, and environmental mandates in a way that simultaneously maintains reliability, decarbonizes the system, and keeps prices within acceptable bounds. Greater flexibility crucially requires the ability to more systematically and transparently manage and allocate costs. This will require re-orientating sector institutions still rooted in central planning, and strengthening independent regulation. Some of the necessary changes require fundamental political and legal reforms beyond the scope of energy policy. However, the system's flexibility can still be increased through the development of traditional planning and regulatory tools and approaches, such as an avoided cost basis for energy efficiency investments, more integrated planning to improve the coordination of generation, transmission, and demand-side investments, and a transparent ratemaking process. The judicious application of OECD electricity sector experience and skills can support these developments.     

Distributed power generation: A case study of small scale PV power plant in Greece

In recent years, energy systems have been undergoing a development trend characterised by privatisation of the most important energy sectors (electricity and natural gas) that has turned former monopolies into free-market competitors. Furthermore, community awareness of environmental impact caused by large conventional power plants is growing, together with a greater interest in distributed-generation (DG) technologies based upon renewable energy sources (RES) and cogeneration. In this context, renewable energy technologies are emerging as potentially strong competitors for more widespread use. Despite the remarkable progress attained over the past decades, RES have not yet been fully integrated into the power sector. Some RES-technologies have already achieved a significant market share. The industry is now quite mature, although far from having developed its global potential.     

Renewable energy and policy options in an integrated ASEAN electricity market: Quantitative assessments and policy implications

Energy market integration (EMI) in the ASEAN region is a promising solution to relieve the current immobilization of its renewable energy resources and would serve the fast increasing demand for electricity in the region. EMI could be further extended with coordinated policies in carbon pricing, renewable energy portfolio standards (RPS), and feed-in-tariffs (FIT) in the ASEAN countries. Using a linear dynamic programming model, this study quantitatively assesses the impacts of EMI and the above-mentioned policies on the development of renewable energy in the power generation sector of the region, and the carbon emissions reduction achievable with these policies. According to our results, EMI is expected to significantly promote the adoption of renewable energy. Along with EMI, FIT appears to be more cost-effective than RPS and is recommended for the ASEAN region, albeit political barriers for policy coordination among the countries might be a practical concern. In addition, an RPS of 30% electricity from renewable sources by 2030, which is considered politically a “low-hanging fruit”, would achieve moderate improvements in carbon emissions reductions and renewable energy development, while incurring negligible increases in the total cost of electricity.     

Assessment of Korean customers’ willingness to pay with RPS

To increase the use of renewable energy, the Korean government will introduce the Renewable Portfolio Standard (RPS) in 2012. The RPS places responsibility for extra renewable energy costs on the consumers and allows price competition among different renewable sources. Accordingly, this study analyzes through the contingent valuation (CV) the willingness of Korean households to pay more for electricity generated by wind, photovoltaic (PV), and hydropower. Our empirical results show that, although the willingness to pay (or WTP) was highest for wind power and lowest for hydropower, the differences in WTP among the renewable sources were statistically insignificant. This suggests that Korean consumers prefer a renewable portfolio that minimizes power supply costs.The average WTP for all three energy types was KRW 1562.7 (USD 1.350) per month per household, which was approximately 3.7% of the average monthly electricity bill in 2010. This amount represents only 58.2% of what the Korean government allocated in its budget to the new and renewable energy dissemination program in 2010. Thus, our results imply that the promotion of the new and renewable energy dissemination program may be difficult only with the WTP for electricity generated from renewable sources. Specifically, the mean WTP will not support the set-aside dissemination capacity for PV after 2014.     

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.     

A missing link? The case of Norway and Sweden: Does increased renewable energy production impact domestic greenhouse gas emissions?

This article examines how the EU׳s RES directive¹ will impact domestic greenhouse gas emissions in Norway and Sweden by 2020. The directive aims for a higher RES share in the energy consumption mix, and Norway and Sweden have established a common electricity certificate scheme to help achieve these RES goals. In terms of how these two national RES plans will impact domestic emissions by 2020, factors such as nuclear power, consumption changes and the energy balance must be considered. The most practical approach to evaluate the plans’ impact on emissions is to focus on changes in carbon-based consumption within the three directive sectors.The Norwegian RES action plan will not affect domestic emissions unless the electricity surplus generated by the certificate market is used to phase out fossil fuels in domestic sectors beyond the scope of the RES directive. The use of electricity to phase out fossil fuel consumption in the offshore sector would substantially reduce Norwegian emissions figures. The Swedish plan would positively impact Swedish greenhouse gas emissions; however, this impact is limited, primarily because a substantial increase in energy consumption is expected.     

Algerian renewable energy assessment: The challenge of sustainability

Algeria plays a very important role in world energy markets, both as a significant hydrocarbon producer and as an exporter, as well as a key participant in the renewable energy market. Due to its geographical location, Algeria holds one of the highest solar potentials in the world. This paper presents a review of the present renewable energy situation and assesses present and future potential of renewable energy sources (RESs) in Algeria. This paper also discusses the trends and expectation in solar systems applications and the aspects of future implementation of renewable energies in the Middle East and North Africa (MENA) region status. The problem related to the use of RES and polices to enhance the use of these sources are also analysed in this paper. In addition the available capacity building, the technical know-how for each RES technology and localizing manufacturing of renewable energy equipments are defined. The co-importance of both policy and technology investments for the future Algerian markets of RES and competitiveness of the solar/wind approach is emphasized. Some examples of policy significantly impacting Algerian markets are reviewed, and the intention of the new Algerian RES initiative is discussed.     

Integration of optimal combinations of renewable energy sources into the energy supply of Wang-An Island

This is a case study of Wang-An Island's energy demands and potential renewable energy sources (RESs). Optimal integration of RESs was simulated using the EnergyPLAN model. The RES evaluation indicated an annual production potential of 458.1 GWh, which substantially surpassed local energy requirements of 22.3 GWh. The potential of yearly electricity generation from RESs of 299.7 GWh apparently outnumbers local electricity demand of 6.4 GWh as well, indicating that 100% renewable electricity would be achievable if surplus electricity can be stored and then reused during an electricity deficit. Electricity production from fully exploited RESs is able to supply only 5.8 GWh of electricity mainly caused by mismatches in times of electricity demand and production. The integrated optimization can supply 3.7 GWh of electricity. A deficit of 2.68 GWh can be compensated for through electricity storage or biomass energy. Although the total amount of generated renewable electricity during the whole year cannot yet satisfy the total amount of yearly demand, electricity storage can help to satisfy most of the electricity needs for the year.