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Archive for the category “storage”

New Approach Pumped Hydro Storage

A company from Stuttgart, Germany proposes a new way of thinking about hydro storage. The design entails a giant cylinder with a stone piston sawn out of rock. During times with excess renewable energy the piston is lifted by water pressure from underneath. The potential energy can be retrieved by letting the piston sink again, propelling turbines.

A first pilot of 30 m deep and 20 m diameter is to be build in Saudi-Arabia, but no financial means have been allocated so far. Paperware so far.

[heindl-energy.com] – Company site
[spiegel.de] – Tüftler machen Gefällekraftwerk ohne Gefälle möglich

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The Hydrogen Electrolyser

Salt Water Batteries

[wikipedia.org] – Salt water battery

Batteries Keep On Getting Cheaper

The average price of a lithium-ion battery pack is down to $209/kilowatt-hour and the prices are set to fall below $100/kWh by 2025, according to a Bloomberg New Energy Finance.

[cleantechnica.com] – Batteries Keep On Getting Cheaper

High Temperature Electrolysis


Sunfire’s field of operation

Dr. Oliver Born: this presentation is mainly about using waste heat steam for hydrogen production. With steam you can typically achieve 20% higher efficiency with steam than with low temperature water.

[wikipedia.org] – High-temperature electrolysis

During electrolysis, the amount of electrical energy that must be added equals the change in Gibbs free energy of the reaction plus the losses in the system. The losses can (theoretically) be arbitrarily close to zero, so the maximum thermodynamic efficiency of any electrochemical process equals 100%. In practice, the efficiency is given by electrical work achieved divided by the Gibbs free energy change of the reaction.

In most cases, such as room temperature water electrolysis, the electric input is larger than the enthalpy change of the reaction, so some energy is released as waste heat. In the case of electrolysis of steam into hydrogen and oxygen at high temperature, the opposite is true. Heat is absorbed from the surroundings, and the heating value of the produced hydrogen is higher than the electric input. In this case the efficiency relative to electric energy input can be said to be greater than 100%.

[sunfire.de] – Sunfire company site

[sunfire.de] – Low cost hydrogen production
Sunfire achieves 82% electrolysis efficiency in their hydrogen generator modules.
Input: saturated steam 40 kg/h @ 150°C and pressure: 3 bar(g)

British contribution: scaling up electrolysis to 100 MW

Hamburg Tests Thermal Storage of WindPower

The thermal store for wind energy, which is being developed in Hamburg, is a joint project between Siemens, Hamburg Energie and TUHH. The German Federal Ministry for Economic Affairs and Energy is funding the project.

Siemens-Gamesa will build a thermal energy storage of 1000 tonnes of rock fill, that at 600 degrees Celsius will provide 30 MWh electricity. This is the equivalent of the batteries of 50 e-vehicles.

[siemensgamesa.com] – Start of construction in Hamburg-Altenwerder: Siemens Gamesa to install FES heat-storage for wind energy

World-Record Pumped-Hydro Storage for Scotland?

An anonymous energy blogger named “Scottish Scientist” has posted a proposal for a giant pumped hydro storage facility in the Scottish Highlands with the potential to service most of Europe.

The numbers are massive:

Height dam: 300 meter
Width dam: 2,000 meter
Max. water elevation: 650 meter
Storage volume: 4.4 billion m3
Lake surface area: 40 km2
Energy content: 6,800 GWh or 283 GW days

The new storage facility would have “enough capacity to balance and back-up the intermittent renewable energy generators such as wind and solar power now in use for the whole of Europe!”

If one “limits” the area to a circle with a radius of 3,000 km and applies 800 kW transmission lines, a two-way storage efficiency of 79% could be achieved. However, if limited to the North Sea area, one-way losses could be reduced to 7%.

The proposed design would includ a “stepped-canal solution”, see picture above. The biggest cost would be building a large canal of 170 meter width, which would require to move more earth than in the Panama Canal project to allow for discharging water speeds of 10-11 m/s.

[scottishscientist] – World’s biggest-ever pumped-storage hydro-scheme, for Scotland?
[Google Maps] – Strathdearn
[savestrathdearn.com] – Save Strathdearn Valley (local resistance to be expected)
[euanmearns.com] – The Loch Ness Monster of Energy Storage

Lithium Mining

[wikipedia.org] – Lithium

Read more…

Aqueous Sulfur Flow Battery for Ultralow-Cost Long-Duration Electrical Storage

MIT:

Here, we demonstrate an ambient-temperature aqueous rechargeable flow battery that uses low-cost polysulfide anolytes in conjunction with lithium or sodium counter-ions, and an air- or oxygen-breathing cathode. The solution energy density, at 30–145 Wh/L depending on concentration and sulfur speciation range, exceeds current solution-based flow batteries, and the cost of active materials per stored energy is exceptionally low, ∼US$1/kWh when using sodium polysulfide. The projected storage economics parallel those for PHS and CAES but can be realized at higher energy density and with minimal locational constraints.

[cell.com] – Air-Breathing Aqueous Sulfur Flow Battery for Ultralow-Cost Long-Duration Electrical Storage

Cleantechnica.com calls for caution:

[cleantechnica.com] – Sulfur Battery Promises Less Expensive Grid Scale Storage Solution

You can take this story with a grain of salt, literally and figuratively. Researchers at MIT, responding to a challenge issued by the US Department of Energy, have developed a new battery for use by utility companies to store electricity that costs 100 times less than the conventional lithium ion batteries in use today. The new battery uses sulfur, air, water, and salt — all readily available materials that are cheap to buy. The new battery has store twice as much energy as a typical lead acid battery. Their research was published for the first time on October 11 by energy journal Joule… Under the leadership of former Energy Department head Steven Chu, the Joint Center for Energy Storage Research set a goal of reducing grid storage battery costs by a factor of five while increasing energy density also by a factor of five and all within five years… “Through an accidental laboratory discovery, we figured out that it could actually be oxygen, and therefore air. We needed to add one other component, which was a charge carrier to go back and forth between the sulfur and air electrode, and that turned out to be sodium.” The total chemical cost of their proposed battery is roughly $1 per kilowatt-hour. Since all the chemical components of the battery are dissolved in water, the researchers decided to use a flow battery architecture. In a flow battery, a system of pumps and tubes causes the components of the battery to flow past each other, generating chemical reactions that help it capture electrons… The sulfur-oxygen-salt battery under development currently has a useful life of 1500 hours — far less than the 20-year lifespan needed to attract commercial interest in the technology. The researchers have a long way to go yet, but the prospect of ultra low cost grid storage makes their quest worthwhile.

Largest European Battery Plant to be Built in Sweden

[source]

The Swiss engineering company ABB has teamed up with Northvolt of Sweden to build the largest lithium-ion battery plant in Europe in order to meet growing demand from the automotive industry. The plant should rival the Gigafactory in the Nevada desert. Target: 32 GWh in 2023. 80-100 million euro will be necessary to get production started.

[reuters.com] – ABB teams up with Northvolt on Europe’s biggest battery plant

Evaluation 12 out of 36 Power-to-Gas Projects in Germany

Short German study regarding an inventory of power-to-gas projects, see map. Currently in Germany there are 36 PtG projects operational and 12 of those were highlighted, all demonstration projects. Start date projects 2010-2017. Power range 0.15 MW bis 6.3 MW. 9 projects are about hydrogen production, in 2 projects produced hydrogen is converted into methane. Reported efficiencies: 65-80% which includes heat utilization.

Potential PtG in transport, heat, electricity storage and system integration

Most potential in systems integration and transport. Efficiency increases hydrogen production until 2030 are estimated as between 5-10%. Potential cost decrease until 2030: 30-70%. The majority of respondents expect PtG to be competitive with natural gas between 2020-2040 and of those a majority between 2020-2030.

[zukunft-erdgas.info] – Praxis und Potenzial von Power-to-Gas (pdf)
[nymoen-strategieberatung.de]
[deepresource] – Power to Gas

EasyJet Believes in Electric Flying

EasyJet says that electric flying could be with us in a decade and for that purpose has begun a partnership with US firm Wright Electric to build a battery-powered plane for two hours flight duration.

[theguardian.com] – EasyJet says it could be flying electric planes within a decade
[money.cnn.com] – Your airliner may be flying electric within a decade
[telegraph.co.uk] – EasyJet could be flying battery-powered electric planes within the next 10 years

Solar-to-Fuel System Recycles CO2 to Make Ethanol and Ethylene

Schematic of a solar-powered electrolysis cell which converts carbon dioxide into hydrocarbon and oxygenate products with an efficiency far higher than natural photosynthesis. Power-matching electronics allow the system to operate over a range of sun conditions. (Credit: Clarissa Towle/Berkeley Lab)

Lawrence Berkeley National Laboratory has designed a “competitor” for natural photosynthesis in plants in a setup where CO2 from the atmosphere is transformed into Ethanol (C2H5OH or CH3−CH2−OH or C2H5−OH) and Ethylene (C2H4 or H2C=CH2) using renewable electricity, with an efficiency far greater than in plants: 3-5% vs 0.2-2%.

[newscenter.lbl.gov] – Solar-to-Fuel System Recycles CO2 to Make Ethanol and Ethylene
[wikipedia.org] – Ethanol
[wikipedia.org] – Ethylene
[wikipedia.org] – Photosynthetic efficiency

Water Splitting Catalyst Breakthrough?

Molecular models representing a 2D heterostructure made of graphene (gray background hexagonal lattice), and islands on top of hexagonal WS2 and MoS, as well as an alloy of the two. Water (H2O) molecules in red (oxygen) and gray (hydrogen) come from the bottom left hand side and get transformed catalytically after interacting with the heterostructures into H2 bubbles (top right hand side). Credit: Penn State Materials Research Institute.

Platinum is a near perfect catalyst for splitting water molecules into hydrogen and oxygen. The only drawback is that it is very expensive. Researchers from Houston, Penn State and Florida State University claim to have found a cheaper replacement: Molybdenum disulfide (MoS2). A Swiss team already proposed this solution in 2011.

No efficiency numbers are given.

The Wiley link from 2016 mentions 12.4%

[phys.org] – Low cost, scalable water splitting fuels the future hydrogen economy
[phys.org] – Researchers report new, more efficient catalyst for water splitting
[pubs.rsc.org] – Amorphous MoS2 films as catalysts for electrochem. H2 prod. in H2O
[pubs.acs.org] – Amorphous Molybdenum Sulfides as Hydrogen Evolution Catalysts
[onlinelibrary.wiley.com] – MoS2 as a co-catalyst for photocatalytic hydrogen production from water
[wikipedia.org] – Molybdenum disulfide
[wikipedia.org] – Gibbs free energy

Renewable Cooling – Ice Energy

Solutions like these can be seen as a storage facility. Produce ice when there is abundant cheap renewable electricity and release the cold when it is needed and electricity supply is low and prices are high.

Liquid Air Energy Storage

[source]

Core idea: freeze air with excess renewable electricity for storage purposes and when you need electricity, warm the liquid air with heat from the environment and as such create high pressure air that can be used to drive a generator. Advantage: scalability, mature technology, low cost, high lifespan, possibility to include waste heat (for instance from powerstations) to increase efficiency. 50 MWh typical storage volume (“entry level”).

Round-trip efficiency:

In isolation the process is only 25% efficient, but this is greatly increased (to around 50%) when used with a low-grade cold store, such as a large gravel bed, to capture the cold generated by evaporating the cryogen. The cold is re-used during the next refrigeration cycle. Efficiency is further increased when used in conjunction with a power plant or other source of low-grade heat that would otherwise be lost to the atmosphere. Highview Power Storage claims an AC to AC round-trip efficiency of 70%, by using an otherwise waste heat source at 115 °C. The IMechE (Institution of Mechanical Engineers) agrees that these estimates for a commercial-scale plant are realistic. However this number was not checked or confirmed by independent professional institutions.

[source]

[lowcarbonfutures.org] – Liquid Air Technologies – a guide to the potential
[highview-power.com] – Highview company site
[energystorage.org] – Liquid Air Energy Storage (LAES)
[renewableenergyworld.com] – A Look at Liquid Air Energy Storage Technology
[wikipedia.org] – Cryogenic energy storage
[the-linde-group.com] – Liquid Air Energy Storage (LAES)
[highview-power.com] – Liquid air storage tour
[wikipedia.org] – Georges Claude
[wikipedia.org] – Liquefaction of gases

[source]

Read more…

2015 World Solar Challenge Award Ceremony Closing Video

One month to go to the Solar Challenge 2017 in Australia.

Dutch participants:

Technical University Eindhoven

Technical University Delft

Technical University Twente

LG Chem to Invest $387M in New Polish Battery Factory

Location: Kobierzyce Commune near Wroclaw in southwestern Poland
Production start: 2020
Production volume: 100,000 320km range EV batteries/year .

The site will be the first large EV lithium-ion battery factory in Europe.

[koreaherald.com] – LG Chem to invest W436b in Polish unit
[lgchem.com] – LG Chem Starts Construction of an EV Battery Plant in Poland
[lgchem.com] – Global presence LG Chem

Energy Storage With Gravity Train

Here an alternative approach to pumped hydro storage: sending a train with heavy concrete load up and down a hill. Once pushed to the hill top, energy can be won back via regenerative braking. Round trip efficiency 80%. Weight individual train: 300 ton. Planned track in a desert in Nevada will have a length of 9.2 km with an elevation of 640 m. Optimal slope: 7.2%.

[interestingengineering.com] – Concrete Gravity Trains May Solve Storage Problem

Vestas and Tesla to Combine Forces

The world’s largest wind turbine manufacturer Vestas wants to add storage facilities to its wind farms, hence the new relationship with battery manufacturer Tesla. With an ever increasing installed base of wind power, with a supply of electricity that is inherently variable, storage is becoming increasingly important.

Tesla wants to expands its customer base and move beyond car batteries and home powerwalls.

[bloomberg.com] – Vestas Joins With Tesla to Combine Wind Turbines With Batteries
[windpowermonthly.com] – Vestas confirms Tesla joint project

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