Posted on January 26, 2020February 9, 2020 by admin

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:

The better use of wind currents
Structural and system dynamics of wind turbines
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.

Posted on November 30, 2019January 30, 2020 by admin

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.

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 2^nd highest per capita solar capacity, behind only Germany. In addition to its impressive solar progress Italy ranks 6^th 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 2^nd 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)

Posted on October 31, 2019November 30, 2019 by admin

Energy storage market in the United Kingdom

The UK’s Electricity Portfolio

In our last post about the EU energy storage market we gave a brief overview of Germany’s situation. Now, we show how the United Kingdom prepared itself for its energy transition. Traditionally, the UK’s energy mix has been dominated by fossil fuels. This remains the status quo today, as approximately 60% of the electricity generated in the UK comes from fossil fuel sources, with another 20% coming from nuclear.

UK electricity production 2015 (Source: The UK Government)

While the UK has been heavily dependent on carbon-intensive sources of electricity, in 2008 they committed to a 15% renewable energy target (by 2020) and 80% reduction in CO₂ emissions (by 2050; Department of Energy & Climate Change). However, the UK has stated that they will miss the 15% renewable target for 2020, due to the lack of properly designed policy measures. There has been considerable pressure to transition to a low carbon market and with one-quarter of existing generating capacity (mainly coal and nuclear) expected to close by 2021; it is expected that growth in renewable energy will lead to more energy storage capacities.

In 2011 the UK government, acknowledging that their current market structure would not be able to accommodate the scale or rate of investment in clean energy needed, proposed a shift to a capacity-based market, that is, a market in which a central agency procures capacity years in advance, in order to adequately plan for and control future generation. The proposed market reform would help drive the transition to low carbon energy by providing renewable energy producers revenue stability through carbon pricing and feed-in-tariffs (FITs). The capacity market was operational after the first energy auctions in late 2015.

The UK has made excellent progress on its short-term clean energy goals and there is optimism that this trend will continue. Large-scale development of low carbon generation technologies such as wind and solar is expected to continue.

Energy Storage Facilities

As of late 2016, there were 27 non-PHS EES plants representing 430 MW of installed capacity in the UK (Sandia National Laboratories). The UK’s energy storage portfolio is dominated by electro-chemical based technologies (primarily lead-acid and lithium-ion battery installations). This is shown below.

The prevalence of electro-chemical technologies appears to be continuing the short-term as well; five of the seven energy storage projects currently under development in the UK are electro-chemical. While this is a rather small sample size, the decreasing costs of lithium-ion battery storage is a point of focus for the UK.

Service Uses of Energy Storage

UK Energy Storage Facilities by Service Use Type (Source: Sandia National Laboratories)

As was shown for Germany, only a very small fraction of EES facilities are dedicated to renewables capacity firming. The existing EES capacity is almost exclusively dedicated to critical transmission support (on-site power). While nearly all of the EES capacity under development is dedicated to bulk energy storage (electric energy time shift).

There is still considerable uncertainty around the growth of EES in the UK, and with such a small sample size it is difficult to infer any correlation from the data in the figure above. According to the previous UK government, however, being geographically isolated and a net importer of electricity, one would expect the UK to place a heavier focus on renewables capacity firming in the long-term.

Energy Storage Market Outlook

The UK is in the midst of a major restructuring of their electricity generating portfolio and the market under which these assets operate. With a large portion of the existing capacity due for retirement in the next 10-15 years, the UK faces challenges in meeting energy needs while balancing decarbonization efforts. As part of this, major investment is needed in all areas of the electrical grid, including energy storage.

In its Smart Power publication, the National Infrastructure Commission outlined that while the UK is being faced with challenges to cover aging infrastructure this represents an opportunity to build efficient and flexible energy infrastructure. The Commission stated that energy storage was one of the three key innovations for a “smart power revolution”.

Many other official government bodies have expressed similar thoughts regarding energy storage. In its Low carbon network infrastructure report, the Energy and Climate Change Committee stated that “storage technologies should be deployed at scale as soon as possible”, while urging the Government to eliminate the outdated and unfair regulations that have been handcuffing energy storage development in the UK (Garton and Grimwood).

In April 2016, the Government acknowledged concerns regarding the regulatory hurdles facing energy storage projects (primarily double-charging of network charges) and stated that they would begin working with the National Infrastructure Commission and ECCC to investigate the issue. While there may be regulatory hurdles hindering energy storage in the UK, the Government has shown commitment through funding. Since 2012, the government has contributed over £80 million to energy storage research. In addition to this, the Department of Energy and Climate Change have developed a new £20 million fund to help drive innovation in energy storage technologies.

Overall, the outlook for energy storage in the UK is positive. There is considerable pressure to begin developing energy storage facilities at scale from not only industry, but also many government bodies. Investors are ready as well. As stated by the National Infrastructure Commission: “businesses are already queuing up to invest”.

Simply put: regulatory hurdles are holding back growth in the UK energy storage market. With the Government making major strides in renewable energy development and being vocal about its commitment to making the UK a leader in energy storage technology, these regulatory hurdles will likely be relaxed and there should be considerable growth in the UK energy storage market in the near-term.

At this point, specific technology types and service uses have not been hypothesized in detail. However, with the UK being geographically isolated and a net importer of electricity, logic would suggest an emphasis on renewables capacity firming in the long-term to maximize domestic consumption of renewable energy. Rapidly decreasing costs in electro-chemical technologies, coupled with the fact that much of the existing gas-fired capacity will be reaching end of life by 2030 suggest that the UK EES market would not be ideal for P2G technologies.

In our next post, we focus on Italy.

(Jon Martin, 2019)

Posted on September 29, 2019November 30, 2019 by admin

Energy storage market in Germany

Germany’s electricity portfolio

In our last posts we introduced electrical energy storage (EES) and the EU market for EES. Now, we focus on some important EU members, beginning with Germany. The country’s electrical energy portfolio reflects its status among the most progressive countries in the world in terms of climate action. As of November 2016, Germany had produced ~35% of its 2016 electricity needs from renewable sources as outlined in the Figure below.

Electricity Production in Germany (Source: Fraunhofer ISE)

The growth of renewable energy has been driven by Germany’s strong energy transition policy – the “Energiewende” – a long-term plan to decarbonize the energy sector. The policy was enacted in late 2010 with ambitious GHG reduction and renewable energy targets for 2050 (80-95% reduction on 1990 GHG levels and 80% renewable-based electricity).
A major part of the 2010 Energiewende policy was the reliance on Germany’s 17 nuclear power plants as a “shoulder fuel” to help facilitate the transition from fossil fuels to renewables. In light of the Fukushima disaster just six months after the enactment of the Energiewende, the German government amended the policy to include an aggressive phase-out of nuclear by 2022 while maintaining the 2050 targets. This has only magnified the importance of clean, reliable electricity from alternative sources like wind and solar.

Existing Energy Storage Facilities

As of late 2016, there is 1,050 MW of installed (non-PHS) energy storage capacity in Germany. The majority of this capacity is made up of electro-mechanical technologies such as flywheels and compressed air energy storage (CAES; see figure below).

Capacities of EES Types in Germany (Source: Sandia National Laboratories)

However, these numbers are somewhat skewed based on the fact that the electro-mechanical category is essentially two large capacity CAES plants. In reality, electro-chemical projects (mainly batteries) are much more prevalent and represent the vast majority of growth in the German storage market. There are currently 11 electro-chemical type energy storage projects under development in Germany and no electro-mechanical projects under development (see figure below).

Number of EES Projects by Type (Sandia National Laboratories)

Services Uses of Energy Storage

As outlined earlier, there are a multitude of service uses for EES technologies. Currently the existing EES fleet in Germany serves grid operations and stability applications (black start, electric supply capacity), and on-site power for critical transmission infrastructure. A breakdown of service uses in the German market is shown below.

Service Uses of Energy Storage Facilities in Germany (Sandia National Laboratories)

Most notable in is the fact that renewables capacity firming only represents 0.3% of EES currently operating in Germany, excluding pumped hydro storage. In order to understand this, it must be noted that Germany is a net exporter of electricity (next figure below). Having one of the most reliable electrical grids in the world and an ideal geographical location give Germany excellent interconnection to a variety of neighboring power markets; making it easy to export any excess electricity.

This “export balancing” is a primary reason why the EES market has not seen similar growth as renewable energy in Germany − it is easy for Germany to export power to balance the system load during periods of peak renewable production. However, there are negative aspects of this energy exporting such as severe overloading of transmission infrastructure in neighboring countries.

Net Exports of Electricity with Average Day-Ahead Market Pricing for Germany in 2015 (Source: Fraunhofer ISE)

Energy Storage Market Outlook

Logic seems to indicate that with aggressive renewable energy targets, a nuclear phase-out, and increased emphasis on energy independence Germany will need to develop more EES capacity. However, many have conjectured that the lagging expansion of EES in the short and medium term will not pose a barrier to the Energiewende. In fact, some claim that EES will not be a necessity in the next 10-20 years. For example, even when Germany reaches its 2020 wind and solar targets (46 GW and 52 GW, respectively), these would generally not exceed 55 GW of supply and nearly all of this power will be consumed domestically in real-time. Thus, no significant support from EES would be required.

The German Institute for Economy Research echos these sentiments and argue that the grid flexibility needed with significant renewable energy capacity could be provided by more cost-effective options like flexible base-load power plants and better demand side management. Additionally, innovations in power-to-heat technologies which would use surplus wind and solar electricity to feed district heating systems present significant opportunity, while creating a new market of energy service companies.

Power-to-Gas

Germany’s Federal Ministry of Transport and Digital Infrastructure found that P2G is ideally suited for turning excess renewable energy into a diverse product that can be stored for long periods of time and Germany has been the central point for P2G technology development in recent years. There are currently seven P2G projects either operating or under construction in Germany.

While there is work being done, economically feasible production of P2G is currently not achievable due to limited excess electricity and low guaranteed capacity. This limited excess electricity, is an example of the effect of power exports discussed earlier. While there may not be a significant commercial market in the short-term, introduction of P2G for transport could act as an additional driver behind continued renewable energy development in Germany.

In our next post, we cover the energy storage market of the United Kingdom.

(Jon Martin, 2019)

Posted on August 24, 2019November 30, 2019 by admin

Energy storage in the European Union

Grid integration of renewables

In our previous post of this blog series on Electrical Energy Storage in the EU we briefly introduced you to different technologies and their use cases. Here, we give you a short overview over the EU energy grid. Supplying approximately 2,500 TWh annually to 450 million customers across 24 countries, the synchronous interconnected system of Continental Europe (“the Grid”) is the largest interconnected power network in the world. The Grid is made up of transmission system operators (TSOs) from 24 countries stretching from Greece to the Iberic Peninsula in the south, Denmark and Poland in the north, and up to the black sea in the east. The European Network of Transmission System Operators (ENTSO-E) serves as the central agency tasked with promoting cooperation between the TSOs from the member countries in the Grid. The ENTSO-E, in essence, acts as the central TSO for Europe. With over 140 GW of installed wind and solar PV capacity, the EU trails behind only China in installed capacity. A breakdown of the individual contributions of EU member states is shown below in the figure above.

Energy Storage in the EU

For this study a number of European countries were selected for more detailed investigation into energy storage needs. These countries were selected based on a combination of existing market size, intentions for growth in non-dispatchable renewable energy and/or energy storage, and markets with a track record of innovation in the energy sector.

On a total capacity basis (installed and planned MW) the top three energy storage markets within the EU are: Italy, the UK, and Germany. These countries were selected on the basis of these existing market sizes.

Spain and Denmark were selected based on their large amounts of existing renewable energy capacity and − in the case of Denmark − the forecasted growth in renewable energy and energy storage capacity.

While still lagging behind the rest of the EU in terms of decarbonization efforts and having a small portion of their energy from renewable sources, the Netherlands were also selected for further investigation.

Each of the selected countries (Germany, UK, Italy, Spain, Denmark, Netherlands) are discussed in the proceeding sections, providing a more detailed overview outlining their current electricity portfolios and decarbonization efforts, current energy storage statistics, and a brief discussion on market outlook.

Pumped Hydro Storage

With over 183 GW of installed capacity worldwide, pumped hydro storage is the most widely implemented and most established form of energy storage in the world. Due its extensive market penetration, technology maturity, and the fact that this blog is aimed at emerging new storage technologies, the data presented in the following posts excludes this technology.

Find more details about the energy storage market of selected European countries in our next postings.

(Jon Martin, 2019)

Posted on July 28, 2019September 29, 2019 by admin

Electrical energy storage

Electrical Energy Storage (EES) is the process of converting electrical energy from a power network into a form that can be stored for converting back to electricity when needed. EES enables electricity to be produced during times of either low demand, low generation cost, or during periods of peak renewable energy generation. This allows producers and transmission system operators (TSOs) the ability to leverage and balance the variance in supply/demand and generation costs by using stored electricity at times of high demand, high generation cost, and/or low generation capacity.
EES has many applications including renewables integration, ancillary services, and electrical grid support. This blog series aims to provide the reader with four aspects of EES:

An overview of the function and applications of EES technologies,
State-of-the-art breakdown of key EES markets in the European Union,
A discussion on the future of these EES markets, and
Applications (Service Uses) of EES.

Table: Some common service uses of EES technologies

Storage Category	Storage Technology
Pumped Hydro	Open Loop
Pumped Hydro	Closed Loop
Electro-chemical	Batteries
	Flow Batteries
	Capacitors
Thermal Storage	Molten Salts
	Heat
	Ice
	Chilled Water
Electro-mechanical	Compressed Air Energy Storage (CAES)
	Flywheel
	Gravitational Storage
Hydrogen Storage	Fuel Cells
	H₂ Storage
	Power-to-Gas

Unlike any other commodities market, electricity-generating industries typically have little or no storage capabilities. Electricity must be used precisely when it is produced, with grid operators constantly balancing electrical supply and demand. With an ever-increasing market share of intermittent renewable energy sources the balancing act is becoming increasingly complex.

While EES is most often touted for its ability to help minimize supply fluctuations by storing electricity produced during periods of peak renewable energy generation, there are many other applications. EES is vital to the safe, reliable operation of the electricity grid by supporting key ancillary services and electrical grid reliability functions. This is often overlooked for the ability to help facilitate renewable energy integration. EES is applicable in all of the major areas of the electricity grid (generation, transmission & distribution, and end user services). A few of the most prevalent service uses are outlined in the Table above. Further explanation on service use/cases will be provide later in this blog, including comprehensive list of EES applications.

Area	Service Use / Case	Discharge Duration in h	Capacity in MW	Examples
Generation	Bulk Storage	4 – 6	1 – 500	Pumped hydro, CAES, Batteries
	Contingency	1 – 2	1 – 500	Pumped hydro, CAES, Batteries
	Black Start	NA	NA	Batteries
	Renewables Firming	2 – 4	1 – 500	Pumped hydro, CAES, Batteries
Transmission & Distribution	Frequency & Voltage Support	0.25 – 1	1 – 10	Flywheels, Capacitors
	Transmission Support	2 – 5 sec	10 – 100	Flywheels, Capacitors
	On-site Power	8 – 16	1.5 kW – 5 kW	Batteries
	Asset Deferral	3 – 6	0.25– 5	Batteries
End User Services	Energy Management	4 – 6	1 kW – 1 MW	Residential storage

Learn more about EES in the EU in the next post.

(Jon Martin, 2019)

Posted on June 30, 2019July 28, 2019 by admin

EU market summary for energy storage

Electrical energy storage (EES) is not only a vital component in the reliable operation of modern electrical grids, but also a focal point of the global renewable energy transition. It has been often suggested that EES technologies could be the missing piece to eliminating the technical hurdles facing the implementation of intermittent renewable energy sources. In the following blog posts, selected EES markets within the European Union will be evaluated in detail.

With over 80 MW of installed wind and solar capacity, Germany is by far the leading EU nation in the renewable energy transition. However, experts have argued that Germany’s need for widespread industrial scale energy storage is unlikely to materialize in any significant quantity for up to 20-years. This is due to a number of factors. Germany’s geographic location and abundance of connections to neighbouring power grids makes exporting any electricity fluctuations relatively easy. Additionally, when Germany reaches its 2020 targets for wind and solar capacity (46 GW and 52 GW, respectively) the supply at a given time would generally not exceed 55 GW. Nearly all of this would be consumed domestically, with no/little need for storage.

When evaluating energy storage in the UK, a different story emerges. Being an isolated island nation there is considerably more focus on energy independence to go along with their low-carbon energy goals. However, the existing regulatory environment is cumbersome, and poses barriers significant enough to substantially inhibit the transition to a low-carbon energy sector – including EES. The UK government has acknowledged the existence of regulatory barriers and pledged to address them. As part of this effort, a restructuring of their power market to a capacity-based market is already underway. The outlook for EES in the UK is promising, there is considerable pressure from not only industry, but also the public and the government to continue developing EES facilities at industrial scale.

Italy, once heavily hydro-powered, has grown to rely on natural gas, coal, and oil for 50% of it’s electricity (gas representing 34% alone). The introduction of a solar FIT in 2005 lead to significant growth in the solar industry (Italy now ranks 2nd in per capita solar capacity globally) before the program ended in July 2014. In recent years there has been notable growth in electro-chemical EES capacity (~84 MW installed), primarily driven by a single large-scale project by TERNA, Italy’s transmission system operator (TSO). This capacity has made Italy the leader in EES capacity in the EU, however the market is to-date dominated by the large TSOs.

However, the combination of a reliance on imported natural gas, over 500,000 PV systems no longer collecting FIT premiums, and increasing electricity rates presents a unique market opportunity for residential power-to-gas in Italy.
Denmark is aggressively pursing a 100-percent renewable target for all sectors by 2050. While there is still no official roadmap policy on how they will get there, they have essentially narrowed it down to one of two scenario: a biomass-based scenario, or a wind + hydrogen based scenario. Under the hydrogen-based scenario there would be widespread investment to expand wind capacity and couple this capacity with hydrogen power-to-gas systems for bulk energy storage. With the Danish expertise and embodied investment in wind energy, one would expect that the future Danish energy system would be build around this strength, and hence require significant power-to-gas investment.

The renewable energy industry in Spain has completed stagnated due to retroactive policy changes and taxes on consumption of solar generated electricity introduced in 2015. The implementation of the Royal Decree 900/2015 on self-consumption has rendered PV systems unprofitable, and added additional fees and taxes for the use of EES devices. No evidence was found to suggest a market for energy storage will materialize in Spain in the near future.

The final country investigated was the Netherlands, which has been criticized by the EU for its lack of progress on renewable energy targets. With only 10% of Dutch electricity coming from renewable sources, there is currently little demand for large-scale EES. While the Netherlands may be lagging behind on renewable electricity targets, they have been a leader in EV penetration; a trend that will continue and see 1-million EVs on Dutch roads by 2025. In parallel with the EV growth, there has been a large surge in sub-100kW Li-ion installations for storing energy at electric vehicle (EV) charging stations. It is expected that these applications will continue to be the primary focus of EES in the Netherlands.

Similar to Italy, the Dutch rely heavily on natural gas for energy within their homes. This fact, coupled with an ever-increasing focus on energy independent and efficient houses could make the Netherlands a prime market for residential power-to-gas technologies.

Read more about electrical energy storage here.

Jon Martin, 2019

(Photo: NASA)

Posted on June 10, 2019July 28, 2019 by admin

Machine learning makes smarter batteries

Renewable energies, such as wind and solar energy are naturally intermittent. To balance their demand and supply, batteries of, for example, electric vehicles can be charged and act as an energy buffer for the power grid. Cars spend most of their time idle and could, at the same time, feed their electricity back into the grid. While this is still a dream of the future, commercialization of electric and hybrid vehicles is already creating a growing demand for long-lasting batteries, both for driving as well as grid buffering. Consequently, methods for evaluating the state of the battery will become increasingly important.

The long duration of battery health tests is a problem, hindering the rapid development of new batteries. Better battery life forcasting methods are therefore urgently needed but are extremely difficult to develop. Now, Severson and her colleagues report in the journal Nature Energy that machine learning can help to predict computer battery life by creating computer models. The published algorithms use data from early-stage charge and discharge cycles.

Normally, a figure of merit describes the health of a battery. It quantifies the ability of the battery to store energy relative to its original state. The health status is 100% when the battery is new and decreases with time. This is similar to the state of charge of a battery. Estimating the state of charge of a battery is, in turn, important to ensure safe and correct use. However, there is no consensus in the industry and science as to what exactly a battery’s health status is or how it should be determined.

The state of health of a battery reflects two signs of aging: progressive capacity decline and impedance increase (another measure of electrical resistance). Estimates of the state of charge of a battery must therefore take into account both the drop in capacity and the increase in impedance.

Lithium ion batteries, however, are complex systems in which both capacity fade and impedance increase are caused by multiple interacting processes. Most of these processes cannot be studied independently since they often occur in simultaneously. The state of health can therefore not be determined from a single direct measurement. Conventional health assessment methods include examining the interactions between the electrodes of a battery. Since such methods often intervene directly in the system “battery”, they make the battery useless, which is hardly desired.

A battery’s health status can also be determined in less invasive ways, for example using adaptive models and experimental techniques. Adaptive models learn from recorded battery performance data and adjust themselves. They are useful if system-specific battery information are not available. Such models are suitable for the diagnosis of aging processes. The main problem, however, is that they must be trained with experimental data before they can be used to determine the current capacity of a battery.

Experimental techniques are used to evaluate certain physical processes and failure mechanisms. This allows the rate of future capacity loss to be estimated. Unfortunately, these methods can not detect any intermittent errors. Alternative techniques use the rate of voltage or capacitance change (rather than raw voltage and current data). In order to accelerate the development of battery technology, further methods need to be found which can accurately predict the life of the batteries.

Severson and her colleagues have created a comprehensive data set that includes the performance data of 124 commercial lithium-ion batteries during their charge and discharge cycles. The authors used a variety of rapid charging conditions with identical discharge conditions. This method caused a change of the battery lives. The data covered a wide range of 150 to 2,300 cycles.

The researchers then used machine learning algorithms to analyze the data, creating models that can reliably predict battery life. After the first 100 cycles of each experimentally characterized battery their model already showed clear signs of a capacity fade. The best model could predict the lifetime of about 91% data sets studied in the study. Using the first five cycles, batteries could be classified into categories with short (<550 cycles) or long lifetimes.

The researchers’ work shows that data-driven modeling using machine learning allows forecasting the state of health of lithium-ion batteries. The models can identify aging processes that do not otherwise apparent in capacity data during early cycles. Accordingly, the new approach complements the previous predictive models. But at Frontis Energy, we also see the ability to combine generated data with models that predict the behavior of other complex dynamic systems.

(Photo: Wikipedia)

Posted on February 9, 2019February 9, 2019 by admin

Wind Energy

Wind energy is short for the conversion of energy captured from wind to electrical or mechanical energy. Wind power turbines produce electrical energy and windmills produce mechanical energy. Other forms for wind energy conversion are wind pumps which use wind energy to pump water or sails which drive sail boats.

The cheapest US energy prices by source and county, Source: Energy Institute, University of Texas Austin

Since its first use on sail boats, wind energy is wide spread. Windmills have been used for more than 2,000 years as source of mechanical energy. The Scotsman James Blythe was the first who demonstrated the transformation of wind energy into electrical energy. As wind energy is a renewable source of energy, electrical energy generated by wind turbines is a clean and sustainable form of energy. Wind energy is often also cheaper than natural gas, for example throughout the entire American Midwest, as shown by the Energy Institute of University of Texas, Austin. It is therefore not surprising that wind energy is one of the fastest growing markets in the renewable energy sector worldwide. In 2015, 38% of all renewable energy in the United States and the European Union was generated by wind turbines.

Wind and solar energy production in the US and Canada in 2015. Sources: EIA, Statistics Canada

More efficient than single wind turbines is the use of wind parks where clusters of large turbines constantly generate electrical power. There are two kinds of wind parks, on-shore and off-shore wind parks. Off-shore wind parks are often more expensive but do not use valuable farmland as it is often the case for on-shore wind parks. However, wind parks on farmland can be a valuable addition for farmers seeking an extra income.