Skip navigation
All Places > Renewable Energies > Blog

Battery technologies have undoubtedly become the Holy Grail of the EV industry, just as energy storage is the Holy Grail of renewable power generation/Integration. There are different types of batteries but Lithium-ion batteries are the most popular batteries existing in the market powering our consumer electronics and EVs successfully. The specific energy of a modern lithium-ion battery is about 220-240 Wh/kg which is still not good enough to compete with gasoline powered cars making EVs less viable option for long distance travels. Engineering lighter, more powerful batteries with higher energy density would definitely be a game changing innovation in battery technology systems. One such possibility is to replace modern lithium-ion batteries with so-called lithium-air batteries. Lithium Air battery would be able to accumulate five times more power than lithium-ion technology. This could have a major impact on electric cars market, which now uses lithium-ion batteries.

 

A new kind of battery systems called Lithium Air battery has created lot of excitement among the battery technology researchers because if lithium air battery works then energy density close to that of gasoline could be achieved. The idea of lithium air battery occurred accidently to chemist K M Abraham while testing a battery cell having a small leak in his laboratory in 1995, which provided the cell with far higher energy content than expected. Rather than try to fix the leak, he investigated and discovered the first rechargeable lithium-air (Li-air) battery. Lithium-air battery comprises of a metal electrode which is lithium in this case, electrolyte which could be either aqueous or non-aqueous, and a bi-functional air electrode. Lithium Air Battery works by electrochemically reducing O2 from air and oxidizing the metal electrode to reversibly form solid lithium-oxides. In this way, both the volume and the weight of the battery can be significantly reduced compared to Li-ion systems.

 

So far, we have understood how lithium air battery could work and yield five times more energy density than commercial lithium-ion battery technology, but at the moment it's quite challenging to recharge a lithium-air battery more than a few times due to the oxidation of the lithium anode and production of undesirable byproducts on the cathode that result from lithium ions combining with carbon dioxide and water vapor in the air. These byproducts gum up the cathode, which eventually becomes completely coated and unable to function. These experimental batteries have relied on tanks of pure oxygen — which limits their practicality and poses serious safety risks due to the flammability of oxygen.

 

Successful Customized Lithium Air Cell at University of Illinois at Chicago

 

When researchers were on the cusp of losing hope of making lithium air battery work for significant number of charge/discharge cycles. Researchers at University of Illinois at Chicago developed a custom-made cell using a MoS2 cathode, a protected lithium anode and an EMIM-BF4/DMSO (25%/75%) electrolyte in the lithium–air experiments. This electrolyte composition provides the maximum oxygen reduction and evolution in a three-electrode electrochemical cell. A custom-made simulated air stream of around 79% N2, around 21% O2, 500 p.p.m. CO2, and a relative humidity of 45% at 25 °C was used for the battery experiments. After longterm discharging and charging profiles up to a capacity of 500 mAh g1 with a constant current density of 500 mA g1 were observed. The charge at the first cycle began at 2.92 V, which is very close to the reversible thermodynamic potential of Li2O2 formation (2.96 V versus Li/Li+) and reached a potential of 3.75 V at a capacity of 500 mA g1. The potential gap for the first cycle of the lithium–air system is 0.88 V, increasing to 1.3 V after 50 cycles, followed by a gradual increase to 1.62 V after 550 cycles. The increase in the potential gap during cycling may be due to slow degradation of the protective anode coating and/or the MoS2 cathode. However, no failure was observed in the battery during testing up to 700 cycles. The results indicate a substantial increase in the number of lithium–air cycles achieved when the anode is protected compared with when it is not; with no coating, the lithium–air cell fails after 11 cycles, whereas up to 700 cycles can be achieved with an anode-protection layer [1].

 

Extensive R&D in following areas could make Lithium Air battery a practical reality:

 

  • Optimization of Air Cathode Structure
  • Selection of Appropriate Electrolyte
  • Construction of Laboratory Cell Prototype

 

Optimization of Air Cathode Structure

 

The limiting factor in this system, and nearly all of the metal air batteries, is the air cathode. The performance of the lithium-air battery has been limited by a low rate of oxygen diffusion in the porous cathode. Recognizing that improving the cathode structure is the key to increasing the energy density of the Li air battery.

 

An effective air electrode would need to present a much shorter diffusion path for oxygen and offer the largest possible surface area for Li2O2 deposition. These requirements call for an open porous conductor structure using nanostructured materials. Materials used as cathode supports comprise porous carbon, graphene, carbon nanotubes (CNT) or carbon nanofibers (CNF) with catalysts such as metal oxides.

 

Selection of Appropriate Electrolyte

 

The requirements for the electrolyte in the lithium– air system are as follows:

  • Stable with lithium metal
  • A high oxidation potential
  • A low vapor pressure and high boiling point
  • A high lithium salt solubility and a good chemical stability.

 

Construction of Laboratory Cell Prototype

The main problem lies in making a system that is sufficiently shielded from the external while ensuring an oxygen flow in and out of the device at the same time.

 

The first design by Abraham and Jiang consisted of a pouch cell where a small aperture on the cathode side allowed for uniform oxygen flow. Others have resorted to a modified CR coin-cell design, by perforating the cathode metallic cover with a series of pinholes and then enclosing the cell in an oxygen-filled plastic bag. A similar concept has been applied to Swagelok cells, where oxygen is provided into the system by flowing it through a perforated cathode. The first problem with such designs is the volatility of the electrolyte, which is free to evaporate during cycling and storage. Secondly, the use of such electrolytes brings up the safety hazard posed by the coexistence of reactive lithium and a pure oxygen atmosphere in contact with a flammable organic electrolyte.

 

There is no doubt that the lithium Air battery technology is quite promising but at the same time this technology has lot of challenges which need to be overcome before it becomes a viable and commercial reality. It would be too early to say now whether lithium-air batteries will be cheaper or more expensive than lithium-ion ones. We could assume that they will be cheaper. But the problem is often wrapped in details. It could be possible that in order to solve rechargeability problem, we'd have to add some very expensive additives. Many experts believe that we won't get any prototypes till between 2020 and 2025.

 

References

 

  • [1] Mohammad Asadi, A lithium–oxygen battery with a long cycle life in an air-like atmosphere, doi:10.1038/nature25984

 

  • [2] Nobuyuki Imanishi, Rechargeable lithium–air batteries: characteristics and prospects

 

  • [3] Lorenzo Grande, the Lithium/Air Battery: Still an Emerging System or a Practical Reality?

 

 

 

 

Rudolph Santarromana

Blockchain is getting ready to change the world. From transforming the way banks move money, changing how our medical records are handled to how energy transmitted, stored and monetised. This idea of the decentralized shared ledger will soon be the way most business transactions are done. With more than 50% of major corporations planning to transition to blockchain business applications in 2018, opportunities for investors and entrepreneurs are there for the taking.
According to Accenture multi-year new energy consumer research program survey 2016
1) 69% of consumers are interested in having energy trading marketplace.
2) 47% of consumers plan to sign up for a community solar program managed by a 3rd party and that even allows them to benefit from solar even if they don’t have solar panels on their property within the next 5 years.
This survey clearly shows that consumer habits are changing which means they are more inclined to fulfil their energy needs from decentralized energy resources functioning within their communities rather than traditional power generation sources responsible for polluting our environment.
A microgrid can be described as a cluster of loads, decentralized energy resources (DER) (e.g. PV panels, diesel generators) and energy storage systems (ESS) (e.g. battery, flywheel), which are operated in coordination to supply electricity reliably [1]. On the other hand, blockchain is a secure, transparent and decentralized digital ledger designed for exchanging value/information in a peer-to-peer network [1].
The idea of establishing microgrids to optimize both energy usage and generation to achieve customer goals for resilience, reliability, and sustainability is definitely the way forward for modernizing our electricity network but if combined with blockchain technology full potential of microgrids could be unlocked because the decentralized structure of blockchain perfectly fits into the decentralized approach for control and business processes required to run microgrids. If we combine the attributes of microgrid and blockchain then the energy system of the future could be envisioned being developed in foreseeable future.
Microgrid could optimize the way we produce and consume energy and blockchain could be used as an accounting tool for the accurate documentation of ownership, metering and consumption billing. And let’s imagine if we end up succeeding putting microgrid everywhere on earth. One day, an expanding national grid would decide to connect up these self-sufficient energy powered villages.
But what will the microgrid operators do then? Will their customers simply be poached? Instead, it might be possible to use blockchain distributed ledger as accounting software to keep a record of what electricity residents are consuming, and from where. That way, the operators of the national grid and the microgrid can be paid appropriately. If blockchain or some similar technology could provide that accounting system, it could turn the national grid from being the foe of microgrids in a lot of places to being their friend.
The number of installed microgrids is small, but it's growing in many regions around the world. The International Energy Agency (IEA) estimates that to achieve its goal of universal access to electricity, "70% of the rural areas that currently lack access will need to be connected using mini-grid or off-grid solutions."
The ability to determine what’s more cost effective to pull power from the grid at any given time or to use your neighbour's solar PV that’s very exciting and would play a key role in making energy systems of the future. However, the energy system does not only consist of a physical grid structure but also of the electricity market. In order to be able to talk about a well-functioning energy system, there needs to be a well-functioning market that supports the grid infrastructure as well, blockchain can play a key role in establishing efficient real-time communication strategy between the electricity market and physical grid to make things more decentralized and digitized.
References
[1] Esther Mengelkamp, ” Designing microgrid energy markets A case study: The Brooklyn Microgrid”, 2018.
[2] Andrija Goranovi, ”Blockchain Applications In Microgrids”, 2018.

AI is starting to get into PV reasearch through trials and errors based on results provided in other people's papers.

IN organic solar cells, polymers are so difficult to understand and to prepare that this kind of topic is growing bigger in the next years: https://www.pv-magazine.com/2018/05/31/organic-photovoltaics-designed-by-ai-at-osaka-university/ 

 

Julio Quintana doesn't this remind you what we listen to at the EIT Connect? What was the name of the company researching organic pharmaceutical molecules through mathematical computation?

Imagine if Melisandre could bring Alexander Graham Bell back to life in 21st century, the inventor of telephone, like she brought John Snow back to life in Game of Thrones. Bell would definitely be surprised because he would have never thought in his wildest imagination that communication technologies would be radically disrupted so fast to such an extent that people would even forget one of the greatest inventions of 19th century. Many prominent industries have gone through similar paradigm shifts except energy industry which is still working same as described in blueprint devised by Nikola Tesla in 19th century, starting from generation of electricity from centralized energy grid, and transmission of electricity to passive consumers. There are many reasons to believe that this centralized energy system needs a serious overdue overhaul in order to meet today’s electricity demand in consumer centric manner. I strongly believe that there’s never been a more exciting time to work in the energy industry as its galloping towards decarbonisation, decentralization, digitization and democratization.

Decentralized micro grids offer many benefits over centralized energy systems; centralized energy grid is designed for one directional flows of electricity which is not capable of harnessing full potential of integration of renewable energy technologies; centralized grid is more vulnerable to natural calamities like extreme floods and earth quakes which could lead to power breakouts with no alternatives at hand but creating micro grids would always have some alternative ready to bring life back to normal even if something goes wrong.

If we look at energy transition from fossil fuels to renewables, we could see that something very exciting is happening. It’s not only the way we produce energy is changing but also consumer habits are changing, consumers are becoming prosumers left with extra energy after consumption which brings little or no value at all for them in centralized grid systems;  making our present day centralized grids quite ineffective because they were not designed for bi-directional flows of electricity. The idea of decentralized smart grids looks promising for solving this problem but their full potential could only be unlocked if combined with blockchain technology by allowing producers to trade energy in a decentralized peer-to-peer network of energy producers and consumers without the need of intermediaries. Peer-to-Peer trading and electric vehicle charging are few of the myriad use cases of blockchain being deployed in energy sector at the moment, if explored rigorously blockchain has tremendous untapped potential of creating new business markets within energy sector by connecting energy suppliers and energy consumers in ways never possible before.

 

We have got a vivid roadmap and a compass. Opportunities are limitless because a lot need to be fixed which has not been taken care of, for many decades. Let’s show some proper respect to the generations which are not here yet and our fellow creatures by contributing our part in shaping energy system of the future which ideally should be decarbonised, decentralized, digitized and democratized.

 

energy system blockchain technology smart grids decentralized energy solutions

 

 

References

 

https://blockchainatberkeley.blog/a-new-approach-to-decentralized-energy-5ab2b5460fa0https://blockchainatberkeley.blog/a-new-approach-to-decentralized-energy-5ab2b5460fa0

 

https://medium.com/wepower/blockchain-establishes-decentralized-energy-market-ae413952f6da

 

 

I would like to share here this post from a colleague of mine on the role and trajectory of concentrating solar power in our electricity systems. Here is the reference to our publication: Lilliestam J, Labordena M, Patt A, & Pfenninger S (2017) Empirically observed learning rates for concentrating solar power and their responses to regime change. Nature Energy 2:17094.

 

Author: Johan Lilliestam. Assistant professor of renewable energy policy, ETH Zurich.

 

 

Concentrating solar power (CSP) has the potential to play a key role in balancing renewable energy production, but today the technology is living in the shadow of photovoltaics. A closer look at the cost trends and the history of the industry may give new hope for CSP.

 

 

Two solar power technologies exist today: concentrating solar power (CSP) and photovoltaics (PV). Ten years ago, CSP and PV were similar in terms of installed capacity and cost, but after the hype about Desertec and solar power exports from the desert to Europe about five years ago, they have taken quite different development paths. Whereas PV costs plummeted, CSP costs decreased more modestly; today there are 5,000 MW of CSP, but over 300,000 MW of PV. While PV is conquering the world, CSP is barely clinging to life.

A controllable renewable

The triumph of PV is remarkable, but it also raises concerns: like wind power, PV produces fluctuating electricity depending on weather conditions. With higher shares of such fluctuating sources, the power system may become unstable. Temperate regions in particular regularly face extended periods of simultaneous low wind and low sun: for example, when the winter fog descends on Switzerland for weeks at a time, a system depending purely on PV and wind would fail, even if backed up by battery storage.

As CSP stations can be equipped with thermal energy storage, in which heat harvested by large mirrors during day can be stored and used later, a fleet of CSP stations can deliver fully controllable solar power, also at night (1). Such a fleet can help cover the supply extended low sun/low wind periods in Europe, and balance fluctuating generation in the desert countries themselves: in fact, CSP may be the only renewable option able to provide controllable power at the scale needed.

“Learning rate” gives hope

Yet, the short-term survival of CSP depends on two things: accelerated expansion and sufficient cost decrease to gain attention from policy-makers.

In a recent paper (2), we identified the “learning rate” of CSP and found that it exceeded 20% in the last 5 years: each time the global CSP capacity doubled, investment costs decreased by over 20%. This is a very good value – it is even outcompeting that of PV. This finding gives hope and shows that CSP does not suffer from some intrinsic factor limiting its cost reduction potential: its main ailment is the slow expansion pace.

Continuity allows for cost decrease

However, we found the learning rate to be highly volatile, reflecting the start-stop pattern of the expansion. When CSP started in the US in the 1980s, costs went down quickly, but expansion ceased in 1990 when the only active company went bankrupt. After that, no new plants were built for almost 20 years.

When expansion re-started in Spain in 2007, costs doubled as new companies and engineers without CSP experience entered the stage. As these gained experience, costs started declining again by 2011. The Spanish support scheme was cancelled in 2013 and expansion there stopped, but many Spanish companies survived and moved to other markets, such as Morocco or South Africa, and the cost decrease continued.

Today, the knowledge of how to build CSP plants has spread, and new companies have emerged, in the Middle East, the US and China. The trend of decreasing CSP costs is accelerating; a recent CSP deal in Australia closed at USD 60/MWh – a price competitive with new gas power, and much cheaper than any other controllable renewable option (e.g. wind power coupled with batteries) (3).

Cost pressure in policy support needed

We also found that certain aspects of support policies had a significant impact on cost development. In all countries except Spain, CSP support was designed as auctioning schemes in which the lowest bidder gets to build a power plant. In such schemes, competition and cost pressure are strong, and indeed we see strong cost reductions in the times when CSP expansion happened outside Spain.

In Spain – the only country expanding CSP in 2007–2012 – the support scheme was a feed-in tariff (FIT) that allowed all CSP developers to access a fixed price. Although FITs are generally efficient instruments, the Spanish FIT had two key flaws: the tariff was too high, and it did not decrease over time. Hence, there was no cost pressure in Spain: there, costs could increase while still leaving operators a profit margin – and indeed they did.

Policy design to keep CSP alive

Faster expansion is the key to continued cost reduction, but policy-makers will remain reluctant to provide the necessary support as long as CSP costs are higher than those of other renewables – a chicken and egg problem.

A delicate balance exists between strong cost pressure and sufficiently high tariffs. On the one hand, cost pressure forces companies to innovate and reduce costs in order to stay competitive; on the other hand, sufficiently high tariffs are necessary for these companies to stay in business.

We have shown that well-designed policies that address this balancing act can improve costs quickly. If countries adhere to these principles, CSP will stay alive and the world will keep this weapon in its fight for the secure decarbonisation of electricity systems.

 

 

 

Further information

[1] Desertec aimed at creating a global renewable energy plan.

[2] Pfenninger S, et al. (2014) Potential for concentrating solar power to provide baseload and dispatchable power. Nature Clim. Change 4(8):689-692.

[3] Lilliestam J, Labordena M, Patt A, & Pfenninger S (2017) Empirically observed learning rates for concentrating solar power and their responses to regime change. Nature Energy 2:17094.

 

[4] Lacey S (2017) SolarReserve inks deal with South Australia to supply solar thermal power with storage for 6 cents.(Greentechmedia, London).

Recently I encountered a some news where photovoltaic modules are applied to solar glasses and with more research also to smart lenses.
Here's the link to the work done at KIT, in Karlsruhe: KIT - KIT - Media - Press Releases - PI 2017 - Solar Glasses Generate Solar Power 

 

What do you think about this technologies? Where do you see applications?

Massive photovoltaic power station put into operation in Zhejiang

 

China’s largest photovoltaic (PV) power station built on a fish farm officially began operation on Jan. 11, People.cn reported. Located in Cixi, Zhejiang province, the project cost 1.8 million RMB ($259,927) and covers an area of 300 hectares, with a total installed capacity of 200MW. Its average annual production capacity is expected to reach 220 million kilowatt-hours.

 

The new mode of power generation features PV panels installed above the pond, which serve to provide shade and facilitate fish farming under the water. The power generated by the station will be connected to the state grid, yielding an annual income of 240 million RMB. In addition, another 13 million will be earned through the fishery. The station can meet the power demand of 100,000 households, potentially replacing 7.4 tons of coal.

 

 

 

The end of coal is near: China just scrapped 103 power plants (120GW)

 

China has announced plans to cancel more than 100 coal plants currently in development, scrapping what would amount to a massive 120 gigawatts (GW) of coal-fired electricity capacity if the plants were completed.

 

For a bit of context, the entire US has approximately 305 GW gigawatts of coal capacity in total, and this massive adjustment leaves room for China to advance its development of clean, renewable energy.

 

Despite China's much-publicised pollution problems, the reason for the cancellations is because the country was actually vastly exceeding its planned coal capacity for the future.

 

Per China's five-year-plan for its power sector, it's targeting a coal-fired capacity of 1,100 GW in 2020 – a sizeable increase from its existing 920 GW.

 

But if all 103 plants in development were to be completed, China's capacity would reach 1,250 GW, creating a huge, unnecessary surplus of coal power – which is why the Chinese government is putting on the brakes.

 

In a directive issued this week, the country's National Energy Administration cancelled planning and construction on 85 new coal plants, in addition to 18 facilities canned last year.

 

The 103 cancelled plants span 13 Chinese provinces, and were worth about 430 billion yuan (US$62 billion). Of the 120 GW of cancelled capacity, some 54 GW would have come from projects already under construction.

 

While suspending so much infrastructure will hurt China economically, creating an energy surplus in the future wouldn't be a smart play either.

 

In any case, environmental groups are welcoming the decision to shut down so much planned capacity for one of Earth's most polluting fossil fuels.

 

"Stopping under-construction projects seems wasteful and costly, but spending money and resources to finish these completely unneeded plants would be even more wasteful," Greenpeace told Reuters.

 

While China has come under fire for being evasive about its carbon emissions and has attracted a lot of unwanted attention for a series of local pollution crises, the country is the world's biggest investor in renewable energy.

 

While China is clearly not abandoning coal, its uptake of clean energy saw it account for about 40 percent of global renewable capacity increases in 2015 – building almost 20,000 new wind turbines in that year alone.

 

"The key thing is that yes, China has a long way to go, but in the past few years China has come a very long way," Greenpeace researcher Lauri Myllyvirta told Michael Forsythe at The New York Times.

 

But despite the national directive to pull back on coal infrastructure, some think that actually enforcing the suspension in the provinces affected might be a harder thing to accomplish.

 

According to energy policy researcher Lin Boqiang from China's Xiamen University, overcoming local resistance to halting construction on projects worth billions and employing huge numbers of workers will be a battle in itself.

 

"Some projects might have been ongoing for 10 years, and now there's an order to stop them," he told The New York Times.

 

"It's difficult to persuade the local governments to give up on them."

Description of the technology 

Windcrete is a SPAR type floating substructure designed to carry wind turbines of up toWindcrete - Concrete floating platform for wind turbines 10 MW in deep offshore marine environments with higher reliability and lower installation, maintenance and construction costs.

Windcrete uses reinforced concrete in a monolithic structure with a smooth geometry that provides durable and reliable stability with a long lifespan and significantly reduced maintenance costs.

Thanks to its hollow structure it can be produced on shore and carried floating to the desired location for installation. Its structure also permits controlled floating to be used to erect it and install the wind turbine at low heights. This innovative installation method allows to reduce the need of heavy floating cranes which are quite expensive and scarce. After being towed in the desired location, water is replaced with ballast aggregates; thereby increasing its hydrostatic stiffness and stability. Finally, it uses a mooring system that allows to withstand the various marine and weather conditions to which the structure can be subjected in a deep offshore environment.

 

To give you a easier view of the benefits of this technology I will point out some of them:

  • the concrete spar, compared to a steel spar, costs roughly one third due to the lower cost of the raw material and the more economic production process
  • the O&M costs are overthrown due to the fact that concrete platforms are almost free from maintenance (lesson learnt from O&G platforms)

  • the platform remains stable in very severe ocean conditions without any active control systems 
  • the lifetime of the structure is meant to be more than 50 years


 

Status of the project

Windcrete concept is protected by three Spanish patents and one US patent and has achieved its proof of concept in the framework of the AFOSP project promoted by InnoEnergy. 

 

Numerical simulations and reduced scale experiments have been performed in order to assess the properties and viability of Windcrete concept. This project was very successful and now everything is ready for developing detailed engineering for the construction of a real scale prototype.

 

The team behind the project

Since 2009 a small group of professors and researchers at the UPC-BarcelonaTech in Barcelona have been working in the development of structures for floating wind turbines. The group started up with Professor Climent Molins and Professor Xavi Gironella. In 2010, Alexis Campos joined the group during his Master Thesis, first, and he kept working on the project during his PhD. Pau Trubat and Daniel Alarcón also joined the team during their Master Thesis in 2012n and 2013 respectively.  

                                       

 

For further information about the project and to know our goals, visit the website www.windcrete.com