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Promising hydrophilic membranes with fast and selective ion transport for energy devices

In addition to well-established Nafion™ membranes which are currently the best trade-off between high-performance and cost in proton exchange fuel cells (PEM), methanol fuel cells, electrolysis cells etc. As our energy resources are diversifying, there is a growing demand for efficient and selective ion-transport membranes for energy storage devices such as flow batteries.

A Sumitomo Electric flow battery for energy storage of a solar PV plant. (Photo: Sumitomo Electric Co.)

Redox flow batteries – the energy storage breakthrough

The high demand for a reliable and cost-effective energy storage systems is reflected in the increased diversity of technologies for energy storage. Among different electrochemical storage systems, one of the most promising candidates are redox-flow batteries (RFBs). They could meet large-scale energy storage requirements scoring in high efficiency, low scale-up cost, long charge/discharge cycle life, and independent energy storage and power generation capacity.

Since this technology is still young, the development of commercially and economically viable systems demands:

  • improvement of the core components e.g. membranes with special properties,
  • improvement of energy efficiency
  • reduction in overall cost system.

Meeting demands for redox flow batteries

Two research teams in the United Kingdom, one from Imperial College and the other from the University of Cambridge, pursued a new approach to design the next generation of microporous membrane materials for the redox-flow batteries. They recently published their data in the well renown journal Nature Materials. Well-defined narrow microporous channels together with hydrophilic functionality of the membranes enable fast transport of salt ions and high selectivity towards small organic molecules. The new membrane architecture is particularly valuable for aqueous organic flow batteries enabling high energy efficiency and high capacity retention. Importantly, the membranes have been prepared using roll-to-roll technology and mesoporous polyacrylonitrile low-cost support. Hence, these innovative membranes could be cost effective.
As the authors reported, the challenge for the new generation RFBs is development of low-cost hydrocarbon-based polymer membranes that features precise selectivity between ions and organic redox-active molecules. In addition, ion transport in these membranes depends on a formation of the interconnected water channels via microphase separation, which is considered a complex and difficult-to-control process on molecular level.

The new synthesis concept of ion-selective membranes is based on hydrophilic polymers of intrinsic microporosity (PIMs) that enable fast ion transport and high molecular selectivity. The structural diversity of PIMs can be controlled by monomer choice, polymerization reaction and post-synthetic modification, which further optimize these membranes for RFBs.

Two types of hydrophilic PIM have been developed and tested: PIMs derived from Tröger’s base and dibenzodioxin-based PIMs with hydrophilic and ionizable amidoxime groups.

The authors consider their approach innovative because of

  1. The application of PIMs to obtain rigid and contorted polymer chains resulting in sub-nanometre-sized cavities in microporous membranes;
  2. The introduction of hydrophilic functional groups forming interconnected water channels to optimize hydrophilicity and ion conductivity;
  3. The processing of the solution to produce a membrane of submicrometre thickness. This further reduces ion transport resistance and membrane production costs.

Ionic conductivity has been evaluated by the real-time experimental observations of water and ion uptake. The results suggest that water adsorption in the confined three-dimensional interconnected micropores leads to the formation of water-facilitated ionic channels, enabling fast transport of water and ions.

The selective ionic and molecular transport in PIM membranes was analyzed using concentration-driven dialysis diffusion tests. It was confirmed that new design of membranes effectively block large redox active molecules while enabling fast ion transport, which is crucial for the operation of organic RFBs.

In addition, long-term chemical stability, good electrochemical, thermal stability and good mechanical strength of the hydrophilic PIM membranes have been demonstrated.

Finally, it has been reported that the performance and stability tests of RFBs based on the new membranes, as well as of ion permeation rate and selectivity, are comparable to the performances based on a Nafion™ membranes as benchmark.

(Mima Varničić, 2020, photo: Wikipedia)

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Energy storage in The Netherlands

Electricity Portfolio

In our previous blog post of the Frontis series on European energy storage markets we took a closer look at Spain. In our final post in this series we show where The Netherlands are positioned. The Netherlands are one of only two net gas exporting countries in the EU, along with Denmark. The domestic energy consumption reflects the abundance of the resource, with over 50% of electricity generated in the Netherlands coming from natural gas. With coal representing another 31%, the Netherlands are heavily centered around fossil-based electricity. Renewables represent less than 10% of electricity generated.

By 2020, renewable energy is to represent 14% of the entire Dutch energy supply, as mandated by the EU in the Renewable Energy Directive (2009/28/EC). This corresponds to an electricity sector with over 30% renewable energy generation.

There has been criticism directed towards the Netherlands for the progress made. According to projections in their 2009 National Renewable Energy Action Plan, the Netherlands should have reached nearly 20% renewable electricity in 2014. This lackluster progress prompted a statement from the EU Commission in its 2017 Second Report on the State of the Energy Union, where the EU Commission stated the Netherlands were the only member state to not exhibit average renewable energy shares which were equal or higher than their corresponding action plan trajectories in 2013/2014.

The EU Commission also stated that the Netherlands was one of the three countries (others: France, Luxembourg) with the biggest efforts required to fill 2020 targets.

Existing Energy Storage Facilities

To date, the Netherlands has almost 20 MW of energy storage capacity either operating (14 MW), contracted (1 MW), or under construction (4 MW).

All energy storage facilities in the Netherlands are electro-chemical, with the exception of the contracted 1 MW Hydrostar underwater compressed air energy storage project in Aruba (Caribbean). Hydrostar is a Canadian company specializing in underwater compressed air energy storage technologies.

The vast majority of the 20 MW of installed energy storage capacity in the Netherlands is spread over just three facilities: the Netherlands Advancion Energy Storage Array (10 MW Li-ion), the Amsterdam ArenA (4 MW Li-ion), and the Bonaire Wind-Diesel Hybrid project (3 MW Ni-Cad battery).

The Netherlands Advancion Energy Storage Array was commissioned in late 2015 and provides 10 MWh of storage to Dutch transmission system operator TenneT. The project, which represents 50% of all Dutch energy storage capacity, provides frequency regulation by using power stored in its batteries to respond to grid imbalances.

The 4 MW Amsterdam ArenA lithium-ion project was commissioned 2017 for PV integration and back up power purposes. The 3 MW Bonaire Wind-Diesel Hybrid project is a battery array located on the Dutch Caribbean island of Bonaire and used as a buffer between intermittent wind energy and the diesel-generation stations on the island.

The remaining 3 MW of Dutch energy storage projects are spread over 21 sub-100 kW facilities, mainly geared towards electric vehicle (EV) charging. Mistergreen, a leading developer of EV charging stations in the Netherlands has constructed 750 kW of LI-ion energy storage arrays at its various electric vehicle charging stations.

Energy Storage Market Outlook

Gearing up for significant market growth for electric vehicles in the Netherlands, there has been a considerable amount of effort to expand the country’s network of quick charging stations. This trend will have to continue in order meet the demand for the 1-million electric vehicles expected in the Netherlands by 2025, so one could expect that there will be large growth in the sub-100 kW Li-ion stations that have already started popping up around the country.

There is little information available regarding the need for large-scale energy storage but the overall need is likely low due to the low penetration of renewables in the electricity sector. However, there is significant focus on energy efficient/independent/self-sufficient housing.

Like Italians, the Dutch are very accustomed to using natural gas in their homes. This, coupled with the push for energy self-sufficient housing could present a unique market for residential power-to-gas systems in the Netherlands.

(Jon Martin, 2020, photo: Fotolia)

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High-performance biomass molecule for better Diesel fuel

In our previous blog posts we have discussed resource recovery from waste related to the wastewater treatment and showed improved and enforced regulations have a positive impact on water quality and public health. Now we show that clever catalytic processes can be used to extract valuable commodities from waste agricultural products.

Low-cost waste biomass can serves as renewable source to produce a sustainable alternative to fossil carbon resources in order to meet the need for the environmentally friendly energy. For example, the C2 and C4 ethers derived from carboxylic acids obtained from biomass are promising fuel candidates. It has been reported, that when using ethers biofuel parameters such as ignition quality and sooting have significantly improved compared to commercial petrodiesel (>86% yield sooting index reduction). Ignition quality (cetane number) was improved by more than 56%.

The scientists from National Renewable Energy Laboratory, together with their colleagues from Yale University, Argonne National Laboratory, and Oak Ridge National Laboratory are working on a joint project with the goal of co-optimization of fuels and engines. The research focuses on improving fuel economy and vehicle performance while at the same time reducing emissions through identification of blendstock derived from biomass.

In their recent article, published in the renown journal PNAS, a novel molecule, 4-butoxyheptane, has been isolated in a high-yielding catalytic process from lignocellulosic biomass. Due to its high oxygen content, this advantageous blendstock can improve the performance of diesel fuel by reducing the intrinsic sooting tendency of the fuel upon burning.

The research team has reported a “fuel-property-first” approach in order to accelerate the development process of producing suitable oxygenate diesel blendstocks.

This rational approach is based on following steps:

  1. Fuel Property Characterization – includes mapping and identification of accessible oxygenates products; predicting fuel properties of those products a priori by computationally screening
  2. Production process – development of the conversion pathway starting from biomass. Includes continuous, solvent-free synthesis process based on a metal/acid catalyst on a liter-scale production of the chosen compound
  3. Testing and analysis – with the goal to validate and compare fuel property measurements against predictions

Fuel properties of target oxygenates that have been investigated are related to the health- and safety- aspects such as flash point, biodegradation potential, and toxicity/water solubility, as well as market and environmental aspects such as ignition quality (cetane number), viscosity, lower heating value and sooting potential reduction with oxygenated blendstocks. As a result, 4-butoxyheptane, looked as the most promising molecule to blend with and improve traditional diesel. It has been shown, that the fuel property measurements largely agreed with predictive estimations, validating accuracy of the a priori approach for blendstock selection.

The mixture at 20-30% blend of 4-butoxyheptane molecule into diesel fuel has been suggested as favorable. The improvement in autoignition quality as well as significant reduction of yield sooting index from 215 to 173 (20% reduction) demonstrates that the incorporation of this molecule could improve diesel emission properties without sacrificing performance. In terms of flammability, toxicity, and storage stability, the oxygenate fuel has been evaluated to be at low-risk.

Life-cycle analysis show that this mixture could be cost-competitive and have the potential in significant greenhouse gas reductions (by 50 to 271%) in comparison to petrodiesel.

As research is a perpetual process, more of it is necessary and should include testing of the bioblendstock in an actual engine and production of the biofuel in an integrated process directly from biomass.

(Mima Varničić, 2020, photo: Pixabay)

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Energy storage in Spain

Spain’s Energy Landscape

In our previous post we reported on the prospects of energy storage in Denmark. Now we are moving back south. While it is commonly assumed that solar is the key driver of renewable energy production in Spain, wind represents more than three times the energy production than solar − Spain is a world leader in wind power. In 2014, Spain had the 4th most installed wind capacity, globally and wind energy accounted for 18% of total Spanish electricity production in 2015. Gas and coal still make up over one-third of electricity production in Spain.

Electricity Production in Spain (Source: International Energy Agency, 2015)

While fuel oil is still used for electricity in Spain, it should be noted that this is exclusive to the non-peninsular areas of Spain (i.e. Canary Islands, Balearic Islands, Cueta, Melilla, and several other small islands).

By 2020, 20% of Spain’s final energy consumption must come from renewable energy sources – as mandated in the 2009 EU Directive 28. However, Spain will likely miss this target. In the early 2000’s Spain was a global leader in renewable energy. For example, in 2005 Spain became the first country to mandate PV installations on all new buildings and ranked 5th globally in total renewable energy investments. However the renewable energy industry has stagnated significantly over the past decade. Unfortunately, Spain, which drove the global market in 2008, has virtually disappeared from the PV picture due to retroactive policy changes and new tax on self-consumption.

The policy changes and self-consumption taxes allude to the Royal Decree 900/2015 on self-consumption, a law enacted by the Spanish government in October 2015, which aims to financially penalize the self-consumption of electricity. Under the new law solar PV producers (residential PV owners, for example) are required to not only pay a tax on the energy they self-consume, but also must pay the same transmission & distribution fees they would have paid on an equivalent amount of electricity purchased from the grid. In addition to these charges and taxes, owners of systems 100 kW and smaller – most residential system owners – are prohibited from selling excess electricity from the grid. Instead, they must give it to the grid for free. Furthermore, this law is retroactive; meaning existing PV systems must comply or face a penalty. Penalties under the self-consumption law range from as low as EUR 6-million up to a maximum of EUR 60-million – about twice the fine for leaking radioactive waste. The Spanish government see’s self-consumption as a risk to tax revenues at the current high electricity prices.

Spain is still the world leader in concentrated solar power capacity (2.5 MW). However, no new plants were constructed since and there are currently no new plants under construction or in planning.

Energy Storage Market Outlook – Spain

Although initial drafts of the “self-consumption” law had strict provisions against battery storage systems, the final version does permit energy storage systems – although under conditions that make them impractical. While owners of solar-plus-storage systems are subject to additional charges, they also cannot reduce the amount of power that they have under contract from their utility company.
At this point in time, it appears as if the self-consumption law has effectively halted any investment in renewable energy and/or energy storage projects in Spain.

(Jon Martin, 2019; Photo: Wikipedia)

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Global wastewater resources estimated

In our last post on water quality in China, we pointed out a study that shows how improved wastewater treatment has a positive effect on the environment and ultimately on public health. However, wastewater treatment requires sophisticated and costly infrastructure. This is not available everywhere. However, extracting resources from wastewater can offset some of the costs incurred by plant construction and operation. The question is how much of a resource is wastewater.

A recent study published in the journal Natural Resources Forum tries to answer that question. It is the first to estimate how much wastewater all cities on Earth produce each year. The amount is enormous, as the authors say. There are currently 380 billion cubic meters of wastewater per year worldwide. The authors omitted only 5% of urban areas by population.

The most important resources in wastewater are energy, nutrients like nitrogen, potassium and phosphorus, and the water itself. In municipal wastewater treatment plants they come from human excretions. In industry and agriculture they are remnants of the production process. The team calculated how much of the nutrient resources in the municipal wastewater is likely to end up in the global wastewater stream. The researchers come to a total number of 26 million tons per year. That is almost eighty times the weight of the Empire State Building in New York.

If one would recover the entire nitrogen, phosphorus and potassium load, one could theoretically cover 13% of the global fertilizer requirement. The team assumed that the wastewater volume will likely continue to increase, because the world’s population, urbanization and living standards are also increasing. They further estimate that in 2050 there will be almost 50% more wastewater than in 2015. It will be necessary to treat as much as possible and to make greater use of the nutrients in that wastewater! As we pointed out in our previous post, wastewater is more and more causing environmental and public health problems.

There is also energy in wastewater. Wastewater treatment plants industrialized countries have been using them in the form of biogas for a long time. Most wastewater treatment plants ferment sewage sludge in large anaerobic digesters and use them to produce methane. As a result, some plants are now energy self-sufficient.

The authors calculated the energy potential that lies hidden in the wastewater of all cities worldwide. In principle, the energy is sufficient to supply 500 to 600 million average consumers with electricity. The only problems are: wastewater treatment and energy technology are expensive, and therefore hardly used in non-industrialized countries. According to the scientists, this will change. Occasionally, this is already happening.

Singapore is a prominent example. Wastewater is treated there so intensively that it is fed back into the normal water network. In Jordan, the wastewater from the cities of Amman and Zerqa goes to the municipal wastewater treatment plant by gravitation. There, small turbines are installed in the canals, which have been supplying energy ever since their construction. Such projects send out a signals that resource recovery is possible and make wastewater treatment more efficient and less costly.

The Frontis technology is based on microbial electrolysis which combines many of the steps in wastewater treatment plants in one single reactor, recovering nutrients as well as energy.

(Photo: Wikipedia)

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China has improved inland surface water quality

During the last decades, China has achieved rapid development in technology and economics, however at a huge environmental cost. The deterioration of inland surface water quality is considered one of the most serious environmental threats to ecosystem and ultimately public health.

Since 2001, China made major efforts to tighten the application of environmental rules in order to stop water pollution emitted by cities, farm and industry. According to the government’s “10th National Five-Year Plan”, large investments were made for pollution control and wastewater discharge regulation systems.

Small research studies showed that with this campaign, Chinese’s lakes and rivers got cleaner. Since then water quality has improved significantly − however, other parts of country still have problems with polluted water.

Now, a team of researchers of the at the Chinese Academy of Sciences in Beijing, has published one of the most comprehensive national investigation of China’s surface water quality in the renown journal Science. The researchers investigated all regions of the country to learn how surface water responds to multiple driving forces over time and space. Their report covers the assessment of water quality by means of three parameters: dissolved oxygen level (DO), chemical oxygen demand (COD) and ammonium nitrogen (N) in inland surface waters. They performed monthly site-level measurements at major Chinese rivers and lakes across the country between 2003 and 2017.

Due to regional variations in China’s inland water quality as well as the dynamics in multiple anthropogenic pollution sources, such studies are crucially important to identify the necessary regulation measures and water quality improvement policies adapted to ecosystem sustainability at all diverse country regions.

The results show that during the past 15 years, annual mean pollution concentration has declined across the country at significant linear rates or was maintained at acceptable levels. Consequently, the annual percentage of water quality have increased by 1.77% for COD, 1.83% for N and 1.45% for DO per year. While China has not yet implemented environmental water standards, the study shows that China’s water quality is improving nonetheless.

The best news is that the notoriously high pollution levels have declined as cities and industry have worked to clean up and reduce their discharges. According to the authors, the most visible alleviation was noticed in northern China, while in the western region of the country water quality remained at their low pollution level throughout the observation period. The reason is likely that pollution is caused by human activity, of which there is less in those parts of the country.

Despite large efforts toward decreased pollution discharges, urban areas are still considered as the major pollution centers. These areas face additional pressure due to the constant migration and fast urbanization of the rural regions. Especially in northern China, with high-density human activity and exploding urbanization, achieving and maintaining a clean environment is a permanent struggle.

To further reduce pollution and improve water quality, the authors recommend that future activities focus on water management systems and the water pollution control. For both, the central government issued guidelines to control and improve water use and pollution discharge at regional and national levels for 2020 and 2030.

At Frontis Energy, we certainly support activities in China that help improving the countries water quality and public health. The Frontis technology gives its user an incentive to to clean wastewater before discharge by extracting its energy. Our patent pending solutions are based on microbial electrolysis which helps to extract energy from wastewater and apply in particular to China.

Mima Varničić, 2020

(Photo: Gil Dekel / Pixabay)

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Energy storage in Denmark

Denmark’s Electricity Portfolio

In our last post of our blog series about energy storage in Europe we focused on Italy. Now we move back north, to Denmark. Unsurprisingly, Denmark is known as a pioneer of wind energy. Relying almost exclusively on imported oil for its energy needs in the 1970s, renewable energy has grown to make up over half of electricity generated in the country. Denmark is targeting 100 percent renewable electricity by 2035, and 100 percent renewable energy in all sectors by 2050.

Electricity Production in Denmark (2016)

Proximity to both Scandinavia and mainland Europe makes exporting and importing power rather easy for the Danish system operator, Energinet.dk. This provides Denmark with the flexibility needed to achieve significant penetration of intermittent energy sources like wind while maintaining grid stability.

While the results to-date have been promising, getting to 100 percent renewable energy will still require a significant leap and the official policies that Denmark will use to guide this transition have yet to be delivered. However, there has been some indication at what the ultimate policies may look like. In their report Energy Scenarios for 2020, 2035 and 2050, the Danish Energy Agency outlined four different scenarios for becoming fossil-free by 2050 while meeting the 100 percent renewable electricity target of 2035. The scenarios, which are primarily built around deployment of wind energy or biomass, are:

  • Wind Scenario – wind as the primary energy source, along with solar PV, and combined heat and power. Massive electrification of the heat and transportation sectors.
  • Biomass Scenario – less wind deployment that in the wind scenario, with combined heat and power providing electricity and district heating. Transportation based on biofuels.
  • Bio+ Scenario – existing coal and gas generation replaced with bioenergy, 50% of electricity from wind. Heat from biomass and electricity (heat pumps).
  • Hydrogen Scenario – electricity from wind used to produce hydrogen through electrolysis. Hydrogen used as renewable energy storage medium, as well as  transportation fuel. Hydrogen scenario would require massive electrification of heat and transport sectors, while requiring wind deployment at faster rate than the wind scenario.

Agora Energiewende and DTU Management Engineering, have postulated that this scenario report does in fact show that transitioning the Danish energy sector to 100 percent renewables by 2050 is technically feasible under multiple pathways. However, Danish policy makers must decide before 2020 whether the energy system will evolve into a fuel-based biomass system, or electricity-based wind energy system (they must decided which of the four scenarios to pursue).

Energy Storage Facilities – Denmark

Regardless of which energy policy scenario Denmark decides to pursue, energy storage will be a central aspect of a successful energy transition. There are currently three EES facilities operating in Denmark, all of which are electro-chemical (batteries). A fourth EES facility – the HyBalance project – is currently under construction and will convert electricity produced by wind turbines to hydrogen through PEM electrolysis (proton exchange membrane).

Project Name

Technology Type

Capacity (kW)

Discharge (hrs)

Status

Service Use

RISO Syslab Redox Flow Battery Electro-chemical Flow Battery 15 8 Operational Renewables Capacity Firming
Vestas Lem Kær ESS Demo 1.2 MW Electro-chemical Lithium-ion Battery 1,200 0.25 Operational Frequency Regulation
Vestas Lem Kær ESS Demo 400 kW Electro-chemical Lithium-ion Battery 400 0.25 Operational Frequency Regulation
HyBalance Hydrogen Storage Hydrogen Power-to-Gas 1,250 Operational Renewables integration
BioCat Power-to-Gas Methane Storage Methane Power-to-Gas 1,000 Decommissioned Gas Grid Injection & Frequency Regulation

The HyBalance project is the pilot plant undertaking of Power2Hydrogen, a working group comprised of major industry players and academic research institutions aimed at demonstrating the large-scale potential for hydrogen from wind energy. The plant will produce up to 500 kg/day of hydrogen, used for transportation and grid balancing.

Worth noting is the decommissioned BioCat Power-to-Gas project, a pilot plant project which operated from 2014 to 2016 in Hvidovre, Denmark. The project, a joint collaboration between Electrochaea and several industry partners (funded by Energienet.dk), was a 1 MWe Power-to-Gas (methane) facility built to demonstrate the commercial capabilities of methane power-to-gas. The BioCat project was part of Electrochaea’s goal of reaching commercialization in late 2016, however, as of early 2017 no further updates have been given.

Energy Storage Market Outlook − Denmark

The energy storage market in Denmark will be most primed for growth should policy follow the Hydrogen Scenario, where massive amounts of hydrogen production will be needed to eliminate the use of fossil fuels across all sectors.

Renewable energy produced gases (hydrogen, methane) have the potential to balance the electricity grid in two primary ways: balancing supply and demand (“smart grid”), and balancing through physical storage. The smart grid, an intelligent electricity grid where production and consumption are administered centrally, presents significant opportunity for electrolysis technologies as short-term “buffer” storage (seconds to minutes). Bulk physical storage of renewable energy produced gases can act as a longer-term storage solution (hours, days, weeks, months) to help maintain flexibility in a fossil-free energy grid (The Danish Partnership for Hydrogen and Fuel Cells).

Without the hydrogen scenario, the potential for hydrogen-based energy storage in Denmark will be limited. In their 2016 report “potential of hydrogen in energy systems”, the Power2Hydrogen working group concluded that:

  • hydrogen electrolysers would not provide any significant upgrade on flexibility for renewables integration over today’s sufficiently flexible system, and;
  • by 2035, with the increased wind production, it was concluded that hydrogen electrolysers would in fact improve system flexibility, allowing for even more extensive penetration of wind energy in the system.

The potential for renewable energy produced gases in Demark is extremely high. There is a very distinct possibility that power-to-gas type of systems will be the linchpin of Denmark’s energy transition. While there appears to be little opportunity in the short-term, there will be extensive opportunity in the medium-to-long-term should the official energy transition policy focus on the hydrogen scenario, or a similar renewable gas based policy.

Read here our next post on the prospects for energy storage in Spain.

(Jon Martin, 2019)

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Future challenges for wind energy

Many people believe that there is no need for improvement because wind turbines have been working for decades. Wind energy has the potential to be one of the world’s cheapest energy sources. In a recent article in the Science magazine, major challenges have been addressed to drive innovation in wind energy. Essentially three directions were identified:

  1. The better use of wind currents
  2. Structural and system dynamics of wind turbines
  3. Grid reliability of wind power

In order to make better use of wind currents, the air mass dynamics and its interactions with land and turbines must be understood. Our knowledge of wind currents in complex terrain and under different atmospheric conditions is very limited. We have to model these conditions more precisely so that the operation of large wind turbines becomes more productive and cheaper.

To gain more energy, wind turbines have grown in size. For example, when wind turbines share larger size areas with other wind turbines, the flow changes increasingly.

As the height of wind turbines increases, we need to understand the dynamics of the wind at these heights. The use of simplified physical models has allowed wind turbines to be installed and their performance to be predicted across a variety of terrain types. The next challenge is to model these different conditions so that wind turbines are optimized in order to be inexpensive and controllable, and installed in the right place.

The second essential direction is better understanding and research of the wind turbine structure and system dynamics . Today, wind turbines are the largest flexible, rotating machines in the world. The bucket lengths routinely exceed 80 meters. Their towers protrude well over 100 meters. To illustrate this, three Airbus A380s can fit in the area of ​​one wind turbine. In order to work under increasing structural loads, these systems are getting bigger and heavier which requires new materials and manufacturing processes. This is necessary due to the fact that scalability, transport, structural integrity and recycling of the used materials reach their limits.

In addition, the interface between turbine and atmospheric dynamics raises several important research questions. Many simplified assumptions on which previous wind turbines are based, no longer apply. The challenge is not only to understand the atmosphere, but also to find out which factors are decisive for the efficiency of power generation as well as for the structural security.

Our current power grid as third essential direction is not designed for the operation of large additional wind resources. Therefore, the gird will need has to be fundamentally different then as today. A high increase in variable wind and solar power is expected. In order to maintain functional, efficient and reliable network, these power generators must be predictable and controllable. Renewable electricity generators must also be able to provide not only electricity but also stabilizing grid services. The path to the future requires integrated systems research at the interfaces between atmospheric physics, wind turbine dynamics, plant control and network operation. This also includes new energy storage solutions such as power-to-gas.

Wind turbines and their electricity storage can provide important network services such as frequency control, ramp control and voltage regulation. Innovative control could use the properties of wind turbines to optimize the energy production of the system and at the same time provide these essential services. For example, modern data processing technologies can deliver large amounts of data for sensors, which can be then applied to the entire system. This can improve energy recording, which in return can significantly reduce operating costs. The path to realize these demands requires extensive research at the interfaces of atmospheric flow modeling, individual turbine dynamics and wind turbine control with the operation of larger electrical systems.

Advances in science are essential to drive innovation, cut costs and achieve smooth integration into the power grid. In addition, environmental factors must also be taken into account when expanding wind energy. In order to be successful, the expansion of wind energy use must be done responsibly in order to minimize the destruction of the landscape. Investments in science and interdisciplinary research in these areas will certainly help to find acceptable solutions for everyone involved.

Such projects include studies that characterize and understand the effects of the wind on wildlife. Scientific research, which enables innovations and the development of inexpensive technologies to investigate the effects of wild animals on wind turbines on the land and off the coast, is currently being intensively pursued. To do this, it must be understood how wind energy can be placed in such a way that the local effects are minimized and at the same time there is an economic benefit for the affected communities.

These major challenges in wind research complement each other. The characterization of the operating zone of wind turbines in the atmosphere will be of crucial importance for the development of the next generation of even larger, more economical wind turbines. Understanding both, the dynamic control of the plants and the prediction of the type of atmospheric inflow enable better control.

As an innovative company, Frontis Energy supports the transition to CO2-neutral energy generation.

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Turbocharged lithium batteries at high temperatures

One of the biggest hurdles for the electrification of road traffic is the long charging time for lithium batteries in electric vehicles. A recent research report has now shown that charging time can be reduced to 10 minutes while the battery is being heated.

A lithium battery can power a 320-kilometer trip after only 10 minutes of charging − provided that its temperature is higher than 60 °C while charging.

Lithium batteries that use lithium ions to generate electricity are slowly charged at room temperature. It takes more than three hours to charge, as opposed to three minutes to tank a car.

A critical barrier to rapid charging is the lithium plating, which normally occurs at high charging rates and drastically affects the life and safety of the batteries. Researchers at Pennsylvania State University in University Park are introducing an asymmetrical temperature modulation method that charges a lithium battery at an elevated temperature of 60 °C.

High-speed charging typically encourages lithium to coat one of the battery electrodes (lithium plating). This will block the flow of energy and eventually make the battery unusable. To prevent lithium deposits on the anodes, the researchers limited the exposure time at 60 °C to only ~10 minutes per cycle.

The researchers used industrially available materials and minimized the capacity loss at 500 cycles to 20%. A battery charged at room temperature could only be charged quickly for 60 cycles before its electrode was plated.

The asymmetrical temperature between charging and discharging opens up a new way to improve the ion transport during charging and at the same time achieve a long service life.

For many decades it was generally believed that lithium batteries should not be operated at high temperatures due to accelerated material degradation. Contrary to this conventional wisdom, the researchers introduced a rapid charging process that charges a cell at 60 °C and discharges the cell at a cool temperature. In addition, charging at 60 °C reduces the battery cooling requirement by more than 12 times.

In battery applications, the discharge profiles depend on the end user, while the charging protocol is determined by the manufacturer and can therefore be specially designed and controlled. The quick-charging process presented here opens up a new way of designing electrochemical energy systems that can achieve high performance and a long service life at the same time.

At Frontis Energy we also think that the new simple charging process is a promising method. We are looking forward to the market launch of this new rapid charging method.

(Photo: iStock)

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Energy storage in Italy

Italy’s Electricity Portfolio

In our previous post we briefed you on the energy storage potential in the United Kingdom. With Brexit, Italy will become the third largest member state after Germany and France. With extensive mountain terrain in the north, Italy has long been dependent upon hydroelectric generation. Until the mid 1960s hydropower represented nearly all electricity production in Italy. The installed capacity of hydropower has been stagnant since the mid 1960s, with a rapid growth in fossil fuel based generation driving the overall share of hydropower fall from ~90% to 22% in 2014. A detailed breakdown of electricity sources in Italy is shown below.

Electricity Production in Italy (2014)

Considerable effort has been made to transition Italy to a low carbon electricity sector. As of 2016, Italy had the 5th highest installed solar capacity in the world and the 2nd highest per capita solar capacity, behind only Germany. In addition to its impressive solar progress Italy ranks 6th worldwide in geothermal with 0.9 GW.

Italy’s solar growth was propelled by feed-in-tariffs that wer enacted in 2005. This provided residential PV owners with financial compensation for energy sold to the grid. However, the feed-in-tariff program ceased on 06 July 2014 after the €6.7 billion subsidy limit was reached.

Even with its impressive accomplishments in renewable energy, traditional thermal generation (natural gas) still account for ~60% of total electricity generation in Italy. How much effort will go into reducing this number is still unclear. Italy has committed to 18% renewables by 2020 and is nearly 70% of the way there already so there is little urgency on reducing fossil-based electricity from the perspective of meeting this target. However, Italy is heavily reliant on fossil fuel imports (Deloitte) and energy security requirements will likely continue to push the development of more domestic electricity sources like renewables.

Energy Storage Facilities

Italy is dominating the electro-chemical energy storage market in Europe. With over 6,000 GWh of planned and installed electro-chemical generating capacity (~84 MW installed capacity), Italy is far ahead of 2nd place UK. This is largely due to the massive SNAC project by TERNA (Italy’s TSO), a sodium-ion battery installation totaling nearly 35 MW over three phases. A breakdown of energy storage projects, by technology type can be seen below.

Energy Storage Projects by Type (Sandia National Laboratories)

Service Uses of Energy Storage

In Italy, electrical energy storage is used almost exclusively for grid support functions; mainly transmission congestion relief (frequency regulation). While it may not be a direct case of renewables firming, congestion issues can be traced to the variability of solar power, meaning electrical energy storage development in Italy is largely driven by the need to integrate solar power.

Energy Storage by Service Use Type (Sandia National Laboratories)

Energy Storage Market Outlook

Italy is one of the top markets in the EU for energy storage and is primed for growth. The Italian TSO, TERNA, has been investigating selling energy storage as a service. In 2014 the AEEG, the electrical regulator under which TERNA operates, proposed that batteries should be treated as generation sources similar to cogeneration plants. Italy has always been a market completely dominated by a small number of big centralized utility companies and this trend is likely to continue when it comes to EES deployment. These companies have been focusing their efforts on battery technologies and are expected to continue down this path.

However, the private market could present great opportunity for P2G. The International Battery & Energy Storage Alliance have summarized the reality of Italy’s untapped energy storage market as follows: “With high solar output of 1,400 kWh/kWp, net residential electricity prices around 23 cent/kWh and currently no FIT, the Italian energy market is considered to be highly receptive for energy storage.”

Italy is now well-stocked with residential PV systems that can no longer collect subsidies. Combine this with the fact that the vast majority of homes in Italy burn natural gas imported from Russia, Libya and Algeria and it is clear that Italy presents a unique opportunity for P2G at a residential/community level. This is echoed by Energy Storage Update who in 2015 concluded that Italy was “one of the top four markets worldwide for PV-and-battery-based energy self-consumption.”

While it is unclear exactly how many residential PV systems there are in Italy, it was speculated in late 2015 that there were over 500,000 PV plants in Italy.

In our next post, we are looking at the situation for energy storage in Denmark.

(Jon Martin, 2019)