Deployment Of Renewable Technologies Research Articles

A meta-analysis of learning curves to improve energy policy: Lessons from the United States and Brazil

In this research we applied the learning curves approach to help policy managers decide between a set of protectionism or competitive measures in order to reduce energy prices. By estimating the competitiveness parameters of the most important energy resources in Brazil and United States, such as photovoltaics, wind, biomass, hydro, nuclear, natural gas, oil and coal, we inferred which policy should be recommended to reduce their costs to the society. The learning curves approach takes three main effects into consideration, namely learning by doing effect, scale effect and learning by searching effect (also named research and development effect). In this context, the article has two primordial purposes. The first is to estimate the effects of the learning process on the competitiveness of the main energy technologies. The second is to propose regulatory measures and energy policies aiming to encourage the deployment of renewable technologies. Data from the United States and Brazil were used to optimize the information available based on the maturity of each energy technology. The results of the learning curves for those two countries showed that the main driver leading to a decrease in costs of photovoltaics, wind, nuclear, natural gas, and oil was the learning by doing effect. The learning by searching effect led to a reduction in costs in the cases of wind, biomass, and coal. In turn, the scale effect contributed to reducing the costs of hydro, wind and biomass. Therefore, specific energy policies were proposed for each renewable source.

Game theory-based renewable multi-energy system design and subsidy strategy optimization

Renewable multi-energy systems have become a promising solution for deep decarbonization. However, government subsidy is needed to incentivize the deployment of renewable technologies for emission reduction. Here, we provide a game theory-based modeling framework along with tailored solution strategy for optimizing multi-energy system design and renewable subsidy strategies. We apply our modeling framework to four pilot towns in China for studying how government and consumers interact with each other to achieve their respective goals with minimum costs. We show that government subsidy policies can effectively promote renewable penetration or reduce carbon emissions, and photovoltaic panels and wind turbines absorb most of government subsidy in renewable penetration and emission cap cases, respectively. We also analyze in detail the optimal energy technology operations for meeting targets of government and pilot towns. We find that only increasing renewable penetration cannot achieve deep decarbonization; however, directly imposing carbon emission cap causes heavy government financial burden. Hence, we recommend an economic two-phase decarbonization pathway, namely first increasing renewable penetration to reduce dependence on fossil energy and then imposing a carbon emission cap to fulfill deep decarbonization. Our two-phase decarbonization pathway can be applied to other cities in China and worldwide, aiming to promote renewable energy penetration, reduce reliance on fossil fuels, and finally realize carbon neutral cities. Our proposed game theory-based modeling framework can also be extended to various temporal and spatial scales for studying how different entities can cooperate together for deep decarbonization.

Plummeting costs of renewables - Are energy scenarios lagging?

Wind and solar energy play a pivotal role in deep decarbonization pathways for the future. However, energy scenario studies differ substantially in the contribution of these technologies, as the technology selection in models strongly depends on the choice of techno-economic parameters. In this article, we systematically compare the cost assumptions for solar and wind technologies in global, regional and national energy scenario studies with costs observed in reality and with recent remuneration from market auctions. Specially, we compared the capital expenditure (CAPEX) and the levelized cost of electricity (LCOE) towards the year of 2050 when available with historical market prices and auction prices. Our results indicate that the trend of rapid cost declines has been structurally underestimated in virtually all future energy scenario analyses and suggest that even the most recent studies refer to obsolete or very conservative values. This leads to underestimating the future role and level of deployment of renewable technologies. We recommend an open database for costs of renewable technologies to enhance the accuracy and transparency of future energy scenarios.

Regenerative gas turbines and steam injection for repowering combined cycle power plants: Design and part-load performance

The fast increase in electricity demand and the need to meet the carbon dioxide emissions reduction targets are fostering the role of natural-gas based technologies for both distributed and centralized power generation. Due to their reliability and high-efficiency, combined cycle gas turbines (CCGTs) are regarded as a short to mid-term “bridge” technology towards a secure and cleaner electricity system, characterized by the full deployment of renewable technologies. In this context, it is important to explore potential options to upgrade the capacity of CCGTs, provided that the design of new facilities currently faces challenges related to insufficient financial resources and the lack of suitable sites for their installation.This study investigates a novel concept for repowering CCGTs. The solution proposed relies on the integration of a cogeneration unit based on a regenerative gas turbine (RGT), providing additional power capacity and superheated steam to be injected into the existing CCGT. Compared to traditional repowering techniques, the option proposed in this study is able to enhance the power production without drastically reducing the efficiency of existing CCGT. The simulation study investigates the effect of RGT operating conditions on techno-economic performance of the integrated power plant (IPP), referring to the marginal and the overall power productions. With the aim to assess the plant flexibility, the part-load operation of IPP is also analyzed, assuming an inlet guide vane (IGV) and turbine inlet temperature (TIT) control schedule.Simulation results found out that the repowering approach proposed allows for a maximum power increase of more than + 70%, at the expense of a penalty on net efficiency of around 1% pts compared to the existing CCGT. The repowered CCGT can also be operated at part-load, while providing remarkable energy and economic performances.

Quantifying Decay Rates of Electrochemically Active Species Using Microelectrode Voltammetry

The availability, abundance, and energy density of fossil resources have driven progress over the last century leading to dramatic improvements in quality of life worldwide. However, to avert catastrophic climate change, there is an increasingly urgent need to reduce carbon emissions without stifling economic growth. Deep decarbonization necessitates mass deployment of renewable technologies, such as wind and solar photovoltaic, to displace existing carbon-intensive electricity generation. Though increasingly inexpensive, the inherent difficulties in converting the intermittent output of renewable installations into reliable, dispatchable power sources represents an important constraint and motivates research into storage technologies to buffer the intermittency without significantly increasing the cost of electricity.There are several large-scale energy storage technologies available but all suffer some drawbacks. Pumped hydro storage, currently responsible for 99% of the energy storage market in the U.S., has high energy efficiency and is inexpensive with long cycle and calendar life; however, there have been few new installations in the U.S. due largely to the difficulty of permitting new sites, financing large projects, and meeting geographic requirements1,2. Redox flow batteries (RFBs) are an electrochemical technology that holds promise for long duration energy storage due to their location independence, lower capital cost, decoupled energy and power specifications, and inherent safety. The current state of the art RFBs employ vanadium as the active species which is relatively expensive. As system level costs decline, the cost of RFBs will approach materials cost and so finding less expensive materials if critical to reducing RFB price. Some redox active species used to store electricity in RFBs undergo decomposition due to residing outside the thermodynamic solvent stability window, optical sensitivity, or air sensitivity. These decay pathways consume active materials and reduce the lifetime of the RFB. Determining the kinetic parameters of this decomposition and quantifying the impact on system lifetime is the task we address here.Here, we demonstrate the utility of microelectrodes for quantifying rapid decay in electrochemical systems containing soluble redox active components. By holding a sufficiently reducing or oxidizing potential on a microelectrode, as compared to the equilibrium potential of the redox couple of interest, limiting currents can be continuously monitored without significantly altering the state-of-charge of the bulk solution. From this current, a concentration can be extracted and its time-dependent evolution can be fit to a general rate equation. As a model reaction, we evaluate the decay of permanganate, which is under consideration as a positive electrolyte material in alkaline aqueous RFBs3. Preliminary studies have shown permanganate auto reduces to manganate and oxygen, introducing a potential flammability hazard and decreasing the lifetime of RFBs4–6. A better understanding of the factors that influence this decay process will inform mitigation strategies. We find that the decay of permanganate is strongly dependent on supporting electrolyte pH. The decay order was found to approximate a second order with the rate constant near 40 M-1 min-1 in the least stable supporting salt concentrations and approaches zero in the most stable conditions. These numerically fit parameters are in close agreement with observed decomposition times and agree with parameters calculated using UV-vis spectroscopy. The talk will include development of the microelectrode technique, benchmarking with model compounds and UV-vis spectroscopy, and, finally, demonstration on a rapidly decaying model species, permanganate. We anticipate that the technique developed here can be applied to other systems experiencing similarly rapid decay that frustrates conventional methodologies.

Physical adequacy of a power generation system: The case of Spain in the long term

Generation adequacy is a key ingredient to security of electricity supply. We develop a stochastic model of demand and supply (from different technologies) for measuring it from a physical or technical point of view. We adopt several metrics of supply shortfalls. Next we demonstrate the model by example. Because of limited interconnections with neighboring countries, Spain can be considered an electric island. We get numerical estimates of the parameters underlying the model. We then resort to Monte Carlo simulation to derive the risk profile of the adequacy metrics in the coming decades. We consider up to ten scenarios, with different demand paths and generation parks. The proposed deployment of renewable technologies and the envisaged closure of coal-fired and nuclear stations result in greater risk of shortages. For one, assuming that demand grows at 1.36% per year, from 2020 to 2030 the expected energy not served increases more than 400-fold as coal and nuclear capacities are reduced; the factor runs into the tens of thousands by 2040 and 2050 when those technologies cease to operate. These results are potentially important for policy makers, system operators, and power companies involved in the construction of the European internal electricity market.

Explaining the Diffusion of Renewable Electricity Technologies in Canadian Remote Indigenous Communities through the Technological Innovation System Approach

This paper applies the Technological Innovation System (TIS) approach for the first time in the context of remote indigenous communities in Northwest Territories (NWT) and Ontario, Canada, to explain the diffusion of Renewable Energy Technologies (RETs). These communities need reliable and sustainable electricity to address social, environmental and economic development issues. The study examines the diffusion of RETs during the 2000–2016 period, identifies the systemic and transformational failures responsible for the functional performance of the TISs, and generates insights about factors that have the potential to sustain the development of RET projects. Findings suggest that the TIS-proposed causal mechanisms were present and performed as expected. Since the accumulation of TIS functions influences the rate of deployment of renewable technologies, policy intervention to improve local learning and networking could lead to accelerated diffusion of RETs to the benefit of remote communities and other stakeholders.

A comparison of storage systems in neighbourhood decentralized energy system applications from 2015 to 2050

The potential of both long-term (hydrogen storage) and short-term (batteries and thermal) storage systems in decentralized neighbourhoods are assessed using a multi-objective optimization approach that minimizes both costs and CO2 emissions. A method is developed, which evaluates the performance of long and short-term storage systems in the future based on multi-objective optimization. More specifically, hydrogen storage is investigated for its future potential to be used as a long-term storage in a decentralized context and it is compared with short-term storage systems such as batteries and thermal storage. In order to analyze potential future developments, a scenario approach is deployed based on the Intergovernmental Panel of Climate Change’s ‘Special Report on Emissions Scenarios’. Three future scenarios are defined and simulated for the years of 2015, 2020, 2035, and 2050 for both a rural and an urban neighbourhood in Switzerland. Based on the scenarios, the energy demand and renewable potential projections until 2050 are simulated including retrofitted buildings and renewable potential in the neighbourhoods. The Pareto front of solutions is then benchmarked against national carbon and energy targets from 2020 until 2050. In addition, a range of parameter assumptions (e.g., for economic variables, policy changes, environmental conditions) are used in each scenario to incorporate uncertainty into the analysis. The long-term storage potential of hydrogen, in particular, is evaluated for its capability to shift renewable surpluses in summer towards demand later in the year. From the results, it is predicted that neighbourhoods with high renewable surpluses (i.e., in rural settings) should consider the advantages of a hydrogen storage system from 2035 to 2050. For neighbourhoods with low surpluses, short-term battery and thermal storage systems are predicted to be sufficient for load shifting. It is also observed that a high feed-in remuneration undermines on-site consumption, thus resulting in lower levels of storage deployment due the selling of production back to the centralized electricity grid. Lastly, it is concluded that both an increase in renewable technology deployment and in the retrofit rate of buildings will both be required to meet energy targets for the two case studies. As the renewable potential in urban contexts is limited, it is particularly important for older building stock to be retrofitted at a high rate (more than 2% of buildings per year) in order to reduce the end energy demand of the buildings. The approach used in this article is widely applicable both in spatial scope (e.g., other decentralized energy systems, geographies) and temporal scope (e.g., different years, scenarios) and allows for an optimization with a range of objective functions, thus making it an effective approach to identify the renewable and storage technologies that can contribute to most of the decarbonization of the building stock in the future.

Renewable Energy Technologies and Carbonless Anthropogenic Global Warming (CAGW)

Several world governments are now formulating policies that introduce massive increases of renewable technologies without a detailed Environmental Analysis. This happens, in-spite of the fact that most of the “renewable” technologies harvest energy from large, global scale, naturally existing, warming and cooling Earth systems (see note 4 at the end of this document). This is likely happening because we have been conditioned to think only in terms of CO2 as a direct danger to our global environment. Since the renewable technologies do not produce CO2 during their operation, then it has been assumed that an Environmental Analysis is not necessary. But increase in CO2 – an otherwise necessary plant food molecule – is avoided only because of its unique ability to cause some warming - proportional to its presence in our atmosphere. This means that it is this small extrawarming that we want to avoid if possible, not the CO2 itself. Furthermore, this “CO2 warming” seems to be only one of several anthropogenic contributors to the “undesirable warming”. Are there other contributors to anthropogenic global warming which we have neglected? This is what this study suggests that is happening with regards to a massive deployment of renewables. The conclusions suggest that there are additional Carbonless Anthropogenic Global Warming (CAGW) processes which we have neglected to consider and which increase our Global Heat Flux Density, and hence temperature. Some of these heat fluxes likely result from the hasty introduction of renewable technologies, without a complete environmental analysis. Another heat source is the total energy that humanity is generating with all technologies. Most of it ends up as heat in our atmosphere. A preliminary study has been conducted on the three popular renewable energy technologies: - hydro, solar and wind, to identify and possibly quantify if extraction and harvesting of energy from nature impacts locally and hence globally the heat flux density, thus altering the temperature, of the Earth system. It has been noted that so far, environmental scientists have been dealing with measuring, averaging and projecting global temperatures. But variability of these temperatures results from variabilities in the density of incoming and outgoing heat fluxes. This thermodynamic analysis focuses on these heat fluxes along with conservation of energy for our Global Earth system. This study suggests, that while all three of these renewable technologies mitigate the direct production and release of CO2; solar panels are likely causing increasing rates of incoming heat intake, which results in extra heat added to the Earth system. Wind turbines are likely causing decreasing rates of heat dissipation or cooling, which also increases the heat energy retained by the Earth system. Hydro does not involve global heat fluxes and seems to be thermally neutral. Consequently, two out of the three renewable technologies – solar and wind - seem to be causing an increased global heat flux density and hence temperature. These temperature increases are independent and additional to any CO2 warming. The positive feedback of the water vapor in our atmosphere amplifies further such small warmings, in a similar way that the small anthropogenic warming of CO2 is amplified to cause AGW even though it represents only 2% of the GHG’s in our atmosphere. In this case the warming has been named Carbonless Anthropogenic Global Warming (CAGW). Preliminary evidence suggests that Earth warming due to (CAGW) might be more significant than the warming saved from the lack of CO2 emissions, due to the deployment of renewable technologies. It is concluded 462 therefore, that these two renewable technologies should be subjected to an “in depth” simulation and analysis prior to their significant deployment for baseload electricity production.

The role of community acceptance in planning outcomes for onshore wind and solar farms: An energy justice analysis

The deployment of renewable technologies as part of climate mitigation strategies have provoked a range of responses from various actors, bringing public acceptance to the forefront of energy debates. A key example is the reaction of communities when renewable projects are proposed in their local areas. This paper analyses the effect that community acceptance has had on planning applications for onshore wind and solar farms in Great Britain between 1990 and 2017. It does this by compiling a set of indicators for community acceptance and testing their association with planning outcomes using binomial logistic regression. It identifies 12 variables with statistically significant effects: 4 for onshore wind, 4 for solar farms, and 4 spanning both. For both technologies, the visibility of a project, its installed capacity, the social deprivation of the area, and the year of the application are significant. The paper draws conclusions from these results for community acceptance and energy justice, and discusses the implications for energy decision-making.

Renewable Energy Governance in India: Challenges and Prospects for Achieving the 2022 Energy Goals

India has set colossal renewable energy (RE) targets (achieving 175GW of renewable energy capacity by 2022) which need a clear strategy roadmap, integrated planning and a whole-of-system approach. However, the loopholes in institutional mechanisms are bound to hinder the process of policy formulation and implementation for the aspired quantum leap. This paper is an attempt to observe governance of renewable energy in India while exploring the issues and challenges that have been stalling the process of clean energy uptake. The paper finds that despite the comprehensive policy and regulatory frameworks, the large disconnect between the central policies and regional needs has created barriers for deployment of renewable technologies. The paper emphasizes the provision for clean energy financial support to be made available to the states for addressing the disparities between RE potential and the development cost, and planning for better grid management systems. The RE targets also demand an intensive capital market development and innovative financial support mechanisms and products. While aligning itself with the clean energy goals, India needs to focus significantly on the energy needs of the rural population which has been grappling with electricity cuts and brownouts. For regions with limited or no electricity supply, the government should aggressively promote the ideas of off-grid solar power and micro grids. The paper also recommends the possibilities for private sector investments, rural entrepreneurship and public- private ventures for filling in the gaps, and thus harnessing the potential of RE-rich states.

Ensuring diversity of national energy scenarios: Bottom-up energy system model with Modeling to Generate Alternatives

Long-range energy scenarios are commonly used to inform national energy policy decisions. Although the scenario approach aims to expand the spectrum of futures considered, in the past energy scenarios have not been diverse enough to include less expected real-world developments. We use a bottom-up energy system model EXPANSE with Modeling to Generate Alternatives (MGA) to assess the diversity of the existing ensemble of multi-organization, multi-model Swiss electricity supply scenarios. We show that both for 2035 and 2050 existing scenarios cover well the various possibilities in deployment of individual electricity generation technologies in terms of installed capacity or produced electricity. When analyzing scenarios as a whole, we find that in 2035 there is a lack of scenarios with high electricity demand and greater deployment of renewable technologies occurring simultaneously, as well as scenarios with a negligible or negative share of net electricity import. In 2050, there is also a lack of scenarios that depict high electricity demand and conservative deployment of new renewable technologies, especially solar PV. We propose six additional scenarios to be included to increase the diversity of the ensemble of Swiss electricity supply scenarios and achieve better understanding of the future possibilities and uncertainties.

New technology adoption for Russian energy generation: What does it cost? A case study for Moscow

Russia is frequently referred to as a country with substantial energy efficiency and renewable energy potential. In 2000–2008 energy-gross domestic product (GDP) ratios were improved by 35%, however, the contribution of technological progress accounts for only 1% of the energy-GDP ratio reduction. At the same time, although new policy mechanisms to stimulate renewable energy development have been recently introduced, renewable technology deployment has not yet taken off. Economic theory suggests that there is no better incentive for industry development than cost signals. This paper adapts the levelised cost of energy methodology to examine the cost structures associated with electricity generation by conventional and new technology types for a Russian region (Moscow). The model, run for two fuel price scenarios, allowed us to conclude that the regional energy supply system is heavily dependent on the natural gas price and that the diversification provided by technology development will be beneficial for the energy security of the region. We conclude that new and renewable technologies become cost-effective for electricity generation as domestic natural gas prices reach parity with export prices. However, strong political and financial support is needed to boost technological development and renewables application in Russia.

Practitioner comment - Local Energy Collaboration: The role of local authorities in community energy

The UK Government’s Community Energy Strategy promotes a community approach that is claimed by both government and grassroots to be able to lead to a step change in the deployment of renewable technology and local empowerment. However research into community energy innovations suggests that, on their own, ‘grassroots’ projects face barriers to their deployment and an ability to make a significant impact on UK energy generation. In 2012 the House of Commons Energy and Climate Change Committee published a critical report on the Energy Bill and practitioners are reporting that the current energy supply and distribution model is no longer fit for purpose. With evidence that some Local Authorities are looking to develop energy strategies for local generation and supply, could collaboration between Local Authorities and the Community sector deliver local, low carbon energy generation and supply that is able to meet the demands of a changing energy landscape? Using evidence from the stakeholder survey conducted by the Association for Public Service Excellence (APSE), this paper investigates the opportunities and barriers to delivering local energy generation and supply and proposes a new approach in local energy strategies.

Benefits of European Climate Policies for Mercury Air Pollution

This paper presents the methodology and results of impact assessment of renewable energy policies on atmospheric emissions of mercury in Europe. The modeling exercise described here involves an interaction of several models. First, a set of energy scenarios has been developed with the REMix (Renewable Energy Mix) model that simulates different levels of penetration of renewable energies in the European power sector. The energy scenarios were input to the GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) model, which prepared projections of mercury releases to the atmosphere through 2050, based on the current air pollution control policies in each country. Data on mercury emissions from individual sectors were subsequently disaggregated to a fine spatial resolution using various proxy parameters. Finally, the dispersion of mercury in the atmosphere was computed by the chemistry transport model, implemented to the air quality system, Polyphemus. The simulations provided information on changes in concentrations and depositions of various forms of mercury over Europe. Scenarios that simulate a substantial expansion of renewable energies within the power sector indicate extensive co-benefits for mercury abatement, due to the restructuring of the energy system and changes in the fuel mix. The potential for mercury reductions in Europe depends on the rate of fuel switches and renewable technology deployment, but is also influenced by the stringency and timing of the air quality measures. The overall scope for co-benefits is therefore higher in regions relying on coal combustion as a major energy source.

Renewables and the future of energy meteorology

Renewables and the future of energy meteorology

Modeling the transition towards a sustainable energy production in developing nations

The paper investigates how renewable technologies could promote the transition towards a sustainable energy production in developing nations. Based on two different developing nations in terms of economic, technological and institutional structure: South Africa and Senegal, we implemented scenarios in a bottom-up PowerPlan model in order to analyze the transition toward a sustainable electric production. Two scenarios have been considered: a business-as-usual (BAU) and a hybrid renewable energy (HRE) scenario. In the first scenario (BAU) we assume that the electricity demand is entirely satisfied by an increase of the investment in the current supply structure based on fossil-fuel energy source. Whereas in the renewable energy scenario, we assume 20% and 30% of the electricity supply being generated from renewable resources by 2020 and 2030 respectively. Focusing on wind and solar photovoltaic technologies, our results show the cost-competitiveness of renewable energy deployment in South Africa. In the case of Senegal, our results show that fossil-fuel resource remains the most competitive to generate electricity in the nation during the next coming years as long as environmental advantages of renewable resource are not considered. Our research indicates that in the case of a centralized electricity supply option, both a scale effect and a learning improvement could eventually strengthen the competitiveness of renewable technology deployment in developing nations.

An energy pricing scheme for the diffusion of decentralized renewable technology investment in developing countries

The purpose of this paper is to investigate price support for market penetration of renewable energy in developing nations through a decentralized supply process. We integrate the new decentralized energy support: renewable premium tariff, to analyze impacts of tariff incentives on the diffusion of renewable technology in Senegal. Based on photovoltaic and wind technologies and an assessment of renewable energy resources in Senegal, an optimization technique is combined with a cash flow analysis to investigate investment decisions in renewable energy sector. Our findings indicate that this support mechanism could strengthen the sustainable deployment of renewable energy in remote areas of Senegal. Although different payoffs emerged, profits associated with a renewable premium tariff are the highest among the set of existing payoffs. Moreover in analyzing impacts of price incentives on social welfare, we show that price tariffing schemes must be strategically scrutinized in order to minimize welfare loss associated with price incentives. Finally we argue that a sustainable promotion of incentive mechanisms supporting deployment of renewable technology in developing nations should be carried out under reliable institutional structures. The additional advantage of the proposed methodology is its ability to integrate different stakeholders (producers, investors and consumers) in the planning process.

Wind farms in rural areas: How far do community benefits from wind farms represent a local economic development opportunity?

Although the large-scale deployment of renewable technologies can bring significant, localised economic and environmental changes, there has been remarkably little empirical investigation of the rural development implications. This paper seeks to redress this through an analysis of the economic development opportunities surrounding wind energy development in rural Wales. The paper concludes that the economic development outcomes to rural areas from wind generation projects to date have been questionable. Increasing the flow of conventional economic benefits to rural economies in terms of incomes and jobs is shown to be difficult because of the nature of the local supply side in remote areas. Partially as a consequence of this, developers of wind farms have come to routinely provide diverse forms of community benefits to ‘affected communities’, but these have yet to evolve into significant tools of economic development. In any case, the flows of revenues from community benefits are dwarfed, in quantitative terms, by the revenue streams that might be channelled to rural areas through a broader community ownership of wind energy projects. However, although a few local successes have been achieved, the scope for realising the returns from community ownership remains low in the Welsh case, with a series of impediments considered. We close the paper by suggesting means through which economic outputs might be improved.