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Stellar Energy Defends Plasma Gasification Waste to Energy Plan for Bahamas

Steve Gill, Board Advisor the firm planning a plasma gasification waste to energy plant for the Bahamas, Stellar Energy, has responnded to recent criticism of the plans by the Waste Resources Development Group (WRDG).

Stellar Energy remains committed to the provision of a world class waste management, remediation and clean energy production facility for the Bahamas. Stellar has worked tirelessly for over 6 years at its cost in advancing the project.

It is with disappointment that we are seen as an easy target by some local entities with a vested interest in the current practice, which has resulted in an unmanaged toxic waste dump that continues to have a significant, negative effect on this beautiful island; notably hazardous leachate that breaches the water table and noxious fires, both underground and open air.

The need to ameliorate this situation is plain to see, with the added benefit of a continuous supply of clean, renewable energy at less than half the current cost to Bahamian inhabitants. WRDG (which consists of consortia of small waste handlers and processors) is quick to point out their concerns over one of the proposed technologies-Gasplasma®.

When processing over 1000tpd of highly organic waste the only proven technology with long run time history is mass burn incineration, one can only imagine the furore that would have occurred if this solution had been proposed by Stellar for this project, as well as public outcry. Stellar looked for a new technology with significant risk mitigation, via the combination of two proven (at scale) technologies; gasification and DC Plasma Arc.

Our chosen technology provider, Advanced Plasma Power’s CEO Rolf Stein, supports rebuttal of these allegations made by the projects detractors. He said ‘The Gasplasma technology is based on two long proven technologies (fluidised bed gasification and plasma furnace) deployed in multiple locations around the world.

The Gasplasma technology brings benefits of efficiency and environmental improvement in the generation of power, the reduction in hazardous waste and lower water consumption compared to other waste to energy solutions. Confidence in the technology has been demonstrated by the recent investment by National Grid (UK) in a Gasplasma based project in the UK which is under construction.

Our work with Stellar and the EPC partner to date indicates that the proposed solution will not only deliver renewable power but provide a controlled and substantially more environmentally improved situation than the status quo’

To further mitigate any residual risk Stellar had ensured the whole project was underwritten with a comprehensive process guarantee by one of the world’s eminent and most experienced EPC contractors.

WRDG voice concerns about the proposed cost; again we feel the need to bring balance here. The $650mio figure was a first estimate that was subject to review following 3 separate FEL studies; waste characterisation, landfill study and resultant plant configuration.

Stellar undertook the first of these studies at its own cost, the results of which already bought the indicative capex down some $200 mio to $450mio. Stellar remains very confident that the last two studies would bring the cost down even further to meet its aim of sub $350mio. The irony here is that all costs of this project were to be borne by Stellar, not the Bahamas government or any allied body, public or private.

Again unfounded allegation of significant tipping fee increases are without foundation as Stellar’s business model is based on current pricing. The project bankability is underpinned by a PPA, like all energy projects of this kind in order to make the project fundable. The proposed PPA would have seen prices for clean, continual power brought down by more than 50%, so where we ask is the downside?

As a further commitment to the island and the legacy this project would bring is that Stellar had committed at its cost, to provide a “Centre of Excellence” whereby local labour would have been trained to world class standards and independently certified with NEBOSH/IOSH qualifications to allow maximum local labour content in the construction and operational phases.

To date we have seen no such offering in any shape of form from any of these detractors, in particular WRDG or their intent to work together for the common good.

Energy-efficient engine turns waste hot water into electricity

By James Randerson

A new engine that generates electricity from waste hot water could reduce energy consumption and carbon emissions for thousands of different businesses, from cargo shipping to data centres.

So says Exergyn, a firm based in Dublin, Ireland, which plans to run the first industrial trials of its technology next year.

Globally, Exergyn estimates that the heat lost in waste hot water from industrial processes amounts to around twice the energy in Saudi Arabia’s annual oil and gas output.

“There’s just so much waste hot water in the world,” says Exergyn CEO Alan Healy. “In most cases [companies] are actually spending energy to cool it.”

Cut carbon emissions

Cargo ships, for example, typically pump waste hot water from the engine around the vessel to cool it down. And in data centres, electricity-hungry fans are used to dissipate the heat generated by rows of servers. Finding an efficient way to capture and use this wasted energy would both reduce costs and cut carbon emissions.

The Exergyn Drive uses the quirky properties of an alloy of nickel and titanium called nitinol. You can bend nitinol out of shape, but when heated it undergoes a phase transition and reverts to its original crystal lattice structure. This “shape memory” property makes nitinol desirable in a wide range of applications, including medical devices, unbreakable sunglasses and NASA’s Mars rovers.

It also has another unusual quality. Unlike most materials, nitinol expands when cooled, rather like water does when it turns to ice (think of the mess in your freezer when you leave a bottle of beer to cool in there too long).

“There aren’t many materials in the universe that do that,” says Mike Langan, Exergyn’s head of product management.

These two properties drive the Exergyn engine. Inside the device, a bundle of metre-long nitinol wires are attached to a piston. Hot and cold water is alternately flushed over the wires every 10 seconds, which causes them to rapidly expand and contract by 4 centimetres, driving the piston up and down. A hydraulic system converts that forceful linear motion into rotary motion, which in turn drives a generator. The engine produces 10 kilowatts of electricity from around 200 kW of thermal energy in the waste hot water.

Free energy

That might not be hugely efficient, but this is “free” energy that would otherwise be wasted. And often, money and energy would be spent actively cooling down the waste water.

The company has spent three years perfecting the design and modifying the material so that it will keep working for millions of cycles. It was awarded 2.5 million euros from the European Commission’s Horizon 2020 fund last year to help bring the technology to market and is now planning three industrial tests in 2017, at Dublin Airport and two landfill sites. In all three cases, the Exergyn technology will use warm water at 90 °C or less – from a gas engine at the airport and from biogas generators at the landfill sites – to produce electricity on-site.

In addition to harnessing waste heat from industry, the company hopes that the engine could expand the geothermal energy market. At the moment, generating electricity from geothermal sources in a cost-effective manner requires very hot water at high flow rates. That typically means digging very deep wells with a wide diameter, which hugely increases drilling costs. Langdon says that Exergyn’s technology makes a broader range of geothermal sites viable, as it works with water at a lower temperature and flow.

John Blowes, a past president of the Institution of Diesel and Gas Turbine Engineers, who has seen the technology but has no stake in the company, agrees there is a “massive” range of applications. But he says that only a small percentage of these will be viable unless the company can produce the technology cheaply. “It comes down at the end of the day, for me, to commercial viability,” he says.

Langan says the combination of no fuel costs and the mechanical simplicity of the machine means that Exergyn will be able to keep costs down. He says it can currently generate electricity at £40 per MWhr – cheaper than gas and coal.

Perovskite combination rivals silicon solar cell efficiency

The hybrid photovoltaic cell has a claimed efficiency of 21.7 percent, already better than the 10 to 20 percent of standard polycrystalline silicon solar cells currently in use(Credit: Onur Ergen/UC Berkeley)

The hybrid photovoltaic cell has a claimed efficiency of 21.7 percent, already better than the 10 to 20 percent of standard polycrystalline silicon solar cells currently in use(Credit: Onur Ergen/UC Berkeley)

Scientists working at the University of California, Berkeley (UC Berkeley), and Lawrence Berkeley National Laboratory (LBNL) have created a hybrid photovoltaic cell from multiple layers of different perovskite materials that has a claimed a peak efficiency of 26 percent. It’s said that the cell can easily be sprayed onto flexible surfaces to make bendable, high-efficiency solar panels.

A hybrid organic-inorganic conglomerate, perovskite is used in solar cells to capture light in a similar way to common silicon-based solar cells by converting incoming photon energy into electrical current. Unlike rigid silicon semiconductor materials that require a great deal of expensive processing and manipulation to turn them into solar cells, however, perovskite photovoltaic devices are said to be cheaper and easier to make, in addition to being much more flexible.

The new UC berkeley/LBNL device is also very efficient thanks to a sandwich of two types of perovskite separated by a single-atom thick layer of hexagonal boron nitride (sometimes referred to as “White graphene”) with each perovskite slice designed as a graded bandgap layer (put simply, of low resistance and high gain) able to absorb different wavelengths of light. This combination effectively creates a photovoltaic cell able to collect and convert energy across most of the light spectrum.

“This is realizing a graded bandgap solar cell in a relatively easy-to-control and easy-to-manipulate system,” said Alex Zettl, a UC Berkeley professor of physics. “The nice thing about this is that it combines two very valuable features – the graded bandgap, a known approach, with perovskite, a relatively new but known material with surprisingly high efficiencies – to get the best of both worlds.”


In detail, the perovskite materials are made of methyl and ammonia organic molecules, with one containing tin and iodine and designed to absorb infrared light in the 1 electron volt (eV) range, and the other consisting of lead and iodine doped with bromine that absorbs amber photons of energy at 2 eV. A single-atom layer of boron nitride then provides an intermediate junction to operate in tandem and create electricity from across the light band.

This entire layered combination is then stabilized mechanically by placing it on top of a lightweight graphene aerogel to enhance the formation of fine-grained perovskite crystals as well as serve as a moisture barrier to stop the water-soluble perovskites falling to pieces. Lastly, the whole conglomeration has a gold electrode attached to the underside, along with a gallium nitride layer added to the uppermost part that gathers up the electrons generated when the cell is exposed to light. And all this with an active layer just 400 nanometers thick.

“Our architecture is a bit like building a quality automobile roadway,” said Zettl. “The graphene aerogel acts like the firm, crushed rock bottom layer or foundation, the two perovskite layers are like finer gravel and sand layers deposited on top of that, with the hexagonal boron nitride layer acting like a thin-sheet membrane between the gravel and sand that keeps the sand from diffusing into or mixing too much with the finer gravel. The gallium nitride layer serves as the top asphalt layer.”

With a standard operating efficiency of around 21.7 percent, the new wide spectrum hybrid perovskite cell is already better than the 10 to 20 percent efficiency of standard polycrystalline silicon solar cells currently in use in a host of commercial equipment and household solar systems. Even the best silicon solar cells made today are lucky to get over 25 percent efficiency, and are complex and expensive to produce.

“We have set the record now for different parameters of perovskite solar cells, including the efficiency,” said Zettl. “The efficiency is higher than any other perovskite cell – 21.7 percent – which is a phenomenal number, considering we are at the beginning of optimizing this.”

“Our theoretical efficiency calculations should be much, much higher and easier to reach than for single-bandgap solar cells because we can maximize coverage of the solar spectrum,” added Onur Ergen, a UC Berkeley physics graduate student.

The possibility exists to add further layers of hexagonal boron nitride-separated perovskite to help increase efficiencies even further, but the researchers believe that the thin new material may be efficient enough, and certainly sufficient for producing acceptable efficiencies for commercial production.

“People have had this idea of easy-to-make, roll-to-roll photovoltaics, where you pull plastic off a roll, spray on the solar material, and roll it back up,” said Zettl. “With this new material, we are in the regime of roll-to-roll mass production; it’s really almost like spray painting.”

The results were recently published in the journal Nature Materials.

Powered By Waste – Creating Fuel From Landfill Gas

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Report: Coal, biomass mix may be in military jet fuel future

The U.S. Defense Logistics Agency and the Connecticut Center for Advanced Technology recently released results of a research project that investigated the technical feasibility, commercial viability and environmental compliance of the use of liquefied coal and biomass mixtures as a military jet fuel replacement.

Overall, the research “showed potentially highly effective alternative fuel resources that can end the current debate,” according to the project report. Objectives of the study included the investigation, through analyses and testing of the use of domestic coal and biomass mixtures to make liquid fuel (CBTL), with a focus on gasification.

The project team executed gasification testing and analyses of 150 coal-biomass feedstock tests, performing them at five different partner and facility locations—the Energy and Environmental Research Center in Grand Forks. N.D., the U.S. DOE National Carbon Capture Center in Wilsonville, Alabama, Westinghouse Plasma Corporation at Madison, Pennslyvania, ThermoChem Recovery International, Inc. in Durham, North Carolina, and Emery Energy Company in Laramie, Wyoming.

All CO2 footprint projections of alternative jet fuel made from solid feedstocks tested were below the petroleum baseline for blended jet fuel (50 percent alternative fuel plus 50 percent petroleum-based fuel), thereby satisfying Section 526, according to the report.

Other major findings included:
– When coal was the sole feedstock, the CO2 footprint was the largest and required the most capture.
– Increasing percentages of biomass in the solid feed generally resulted in lower CO2 footprints and smaller amounts of required capture.
– Torrefied wood offers advantages in blending with coal and lowering the CO2 footprint for the CBTL plant.
– Municipal solid waste and biomass (considered to be “nuisance plants” in areas where they are abundant) may be economically feasible for use as feedstocks.
– Feedstock preparation and feed system design are critical to the successful development of a large-scale CBTL project.
– Electricity generation and CO2 displacement credits from CBTL are significant contributors to lower GHG emissions. At a ratio of 30 percent biomass, emissions were 38 to 62 percent below the baseline; with 10 percent biomass, 13 to 33 percent below the baseline; and with no biomass, 2 to 18 percent below the baseline.

On economic findings, the study found that on the rough order of magnitude, cost estimates using the techno-economic model for a 50,000 barrel-per-day CBTL plant with an entrained flow gasifier or transport gasifier showed average required selling price (RSP) of jet fuel ranged from approximately $134 to $170 per barrel, on a crude oil equivalent basis. Instances where coal was the sole feedstock resulted in the lowest RSP; increasing the percentages of raw biomass in the solid feed generally resulted in a higher RSP. Using torrefied rather than raw biomass resulted in a lower RSP, according to the report.

The project team concluded that blending various grades of coal with biomass presents a credible approach for reducing carbon dioxide emissions and producing alternative jet fuel.

The report also includes several factors that can improve commercial viability of CBTL technology, as well as recommendations for future study.

Small Scale Tri-Generation System Uses Waste Gasification

German micro power generation technology developer, ENTRADE, has launched a biowaste powered tri-generation high temperature gasification system for providing power, heat and cooling.


German micro power generation technology developer, ENTRADE, has launched a biowaste powered tri-generation high temperature gasification system for providing power, heat and cooling.

The mass produced, sub £200,000 system is claimed to be the world’s smallest combined cooling, heat and power (CCHP) unit fuelled by regional available biomass waste.

The technology is said to be based on a high-temperature, carbon-neutral and highly efficient gasification process.

It uses solid biomass waste to generates up to 30 kW of electricity, 60 kW of heating and/or cooling up to 30 kW of cooling, said to beenough for 22 American single family homes, a small production facility or even a village in developing countries.

ENTRADE said that one E3 unit is a turnkey solution small enough to be easily transportable on a pickup truck.

So far over 100 types of solid waste are certified for use in the system, including nut shells and other regional biomass.

“Here it is: The world’s smallest tri-generation power plant fuelled by waste, that will have a huge impact on the everyday-life of millions of people without any access to clean energy,” said ’ Julien Uhlig, ENTRADE’s CEO.

“The strong demand out of the world market is a hint to be sure that it’s an idea whose time has come,” he continued. “The E3 is ready to go into mass production.”

The company plans to produce up to 45 units per month with a target of 600 units in 2016.

An interview with Julien Uhlig can be viewed below.

Researchers develop sodium-ion battery in 18650 format

Jules Verne recognized the potential of sodium batteries in 1869 – they powered the futuristic submarine of Captain Nemo, who found their “electro-motor strength” to be twice that of zinc batteries.

Now scientists at the French research network RS2E have brought sodium batteries into the 21st century, producing the first sodium-ion battery in the industry-standard 18650 format (a cylindrical format used in consumer electronics and Tesla automobiles). Several other labs are also working on Na-ion batteries, but RS2E is the first to announce the development of an 18650 prototype.

Batterie sodium-ion (Na-ion) au format industriel standard « 18650 », posée sur un tas de sel (NaCl). Il s’agit de la première batterie au sodium mise au point dans ce format. Dans ce type de batterie, les ions sodium transitent d’une électrode à l’autre au fil des cycles de charge et de décharge. Elle représente une alternative aux batteries lithium-ion actuellement utilisées dans les ordinateurs portables ou encore les voitures électriques. Elle présente l’avantage d’utiliser un élément 1 000 fois plus abondant et aussi moins coûteux que le lithium : le sodium. Ses performances en densité d'énergie sont comparables à celles des premières batteries lithium-ion avec une marge de progression importante.  20150016_0006

Na-ion batteries could offer lower cost thanks to the abundance of sodium, and the prototype shows promising performance. The energy density of the new Na-ion cell is 90 Wh/kg, comparable with that of the first lithium-ion batteries. Its lifespan exceeds 2,000 charge/discharge cycles, and it is capable of charging and discharging rapidly.

The next step is to optimize and increase the reliability of the cell with a view to future commercialization.

“The first application, the most obvious, would be grid storage: storing renewable energy. We are talking about a market as big as the EV market,” said Jean-Marie Tarascon, a professor at the Collège de France and one of the heads of the RS2E network.

A New and Simple Source of Green Power: Water

Professor Jimmy Yu is associate director of the Institute of Environment, Energy and Sustainability at CUHK.

Professor Jimmy Yu is associate director of the Institute of Environment, Energy and Sustainability at CUHK.

Solar power is one of the most promising forms of creating “green” energy. But could we take the process a step further and generate other kinds of energy using the sun’s rays?

CUHK Professor Jimmy Yu Chai-mei believes he has found the answer. By using chemicals such as cadmium sulfide and, separately, simple elements such as red phosphorus, the chemist has produced promising results in generating energy by splitting water molecules using sunlight.

Water splitting does not occur in the absence of catalysts. Professor Yu has been examining ways of expediting that process by adding a photocatalyst that will speed up the decomposition of the water molecules to produce hydrogen, functioning much as chlorophyll in a plant, using sunlight to induce a chemical reaction. The hydrogen can then be stored and used in power plants or as fuel for vehicles.

Red phosphorous acts as a catalyst to speed up the decomposition of water molecules to produce hydrogen, which can then be used in power plants or as fuel for vehicles.

Red phosphorous acts as a catalyst to speed up the decomposition of water molecules to produce hydrogen, which can then be used in power plants or as fuel for vehicles.

Hydrogen power holds plenty of potential because it contains no carbon. On combustion, water molecules are formed, which are harmless to the environment. That makes it preferable to typical fossil fuels, which do contain carbon and so in combustion form greenhouse gases such as carbon dioxide.

There are hundreds if not thousands of materials that can function as photocatalysts. Titanium dioxide can act as a photocatalyst – but it only works when irradiated with ultraviolet light.

Professor Yu has discovered that adding the semiconductor cadmium sulfide, a highly active catalyst, into the equation allows the titanium dioxide to extend its photo-response to the shorter bandwidths of visible light.

Subsequently Professor Yu and his team have also shown that red phosphorus, the most stable and commonly found of three forms of that element, can help break up water. Phosphorous makes up around 0.1 percent of the Earth’s crust, so there are hundreds of billions of tons of it that can be extracted fairly easily and cheaply. “It is always available, that’s the beauty of it. It will never be used up,” says Professor Yu.

Put red phosphorus into water at room temperature and expose it to sunlight, and you will see bubbles of hydrogen forming. “We were the first people to observe that property of red phosphorus,” Professor Yu says.

The chemist sees that as the most elegant method of inducing photocatalysis, using a stand-alone element rather than a compound. “Simple is beautiful,” Professor Yu says. It marks the first time a single element had been used as a photocatalyst. “That’s as simple as you get.”

Thanks to the finding, Professor Yu made the ranks of the “World’s Most Influential Scientific Minds” in 2014, as compiled by Reuters.

Now the challenge is to scale up the process. So the chemist hopes engineers can take those findings and achieve sustainable clean energy production.

“We are hardly at a commercial scale yet,” Professor Yu says. But he hopes his laboratory experiments can inspire others. “We hope to offer some possible solutions.”

by Alex Frew McMillan

Chaotic Motion Device Aims for Scalability, Portability

The world is full of “chaotic motion,” in other words, continuous but non-uniform types of physical excitation that are nevertheless pervasive and commonplace. Ocean waves are a naturally occurring example. So is the movement of people as they walk or run in everyday life. What almost all have in common is that they represent a nearly limitless source of energy if only a means could be found to convert them into a reliable form of electric power generation.

Methods of doing so have long been a focus of engineering research. A UK-based company has come up with something different: a single type of device that could be scaled to provide useful, usable power from a few watts to hundreds of kilowatts depending on the scale of the motion source.


The company is WITT Energy based in Plymouth in South West England and founded by a husband and wife team, Martin and Mairi Wickett. Their aim was to find a means of converting bi-directional movement to rotation. Their initial idea has now been embodied into the design for a device that goes by the name Whatever Input to Torsion Transfer (WITT). It is claimed to be one of the first ever practicable pieces of equipment with the potential to translate multiple degrees of motion – up, down, backwards, forwards and rotation about an axis – into a single output able to drive a generator to produce electricity. (Watch a video of the generator in action.)

The basic principle involves the use of pendulums that react to external movement. These drive a flywheel and gearbox that in turn drive a conventional generator. The potential benefits could be considerable.

The first is its potential scalability from a wearable device to something that could be mounted in a boat to exploit its pitching and rolling motions. Second, all of the essential working parts can be sealed inside a housing pierced only by the wires carrying the electric current, thereby making it resilient to damage from external forces. Another is that it could be able to produce power across a wide range of excitation – a marine device, for example, should continue to operate in storm conditions. It also would be flexible in operation and could be used to charge batteries if there was no immediate need for power or if the source of motion was intermittent.

The company’s commercial director Nicholas Gill says that the device has already won at least one award for innovation – the 2013 Gulfstream Navigator Award worth $100,000 made by the Ocean Exchange organization, an international venture that seeks to recognize environmentally friendly innovation with a potential for global application. He says the device is also attracting interest from the German conglomerate Schaeffler, which Gill says has agreed to work with WITT to help refine the concept. Both the Indian and U.S. defense departments also have expressed interest, he says.

The defense departments’ interest has been stimulated in part by the device’s potential to be built into a soldier’s backpack. Gill says this would enable the device to provide a means of constantly recharging the batteries used to power electronic equipment that military personnel now carry. He says that a WITT device weighing two pounds and capable of generating 10W of power could feasibly be developed and would be sufficient to meet military applications.

A prototype of such a device has been tested and, Gill says, has achieved a “peak power” output of 5W. Further lightweighting of almost all its component parts could help boost power output towards that target figure. Moreover, Gill says that the company could exploit the need for the pendulums to retain some weight by making them incorporate batteries, which would contribute “net zero weight” to the device.

That possible application is likely to be beaten into real use by a larger version of the concept that is capable of generating as much as 200W. WITT Energy is developing that device in cooperation with UK precision engineering operation Gibbs Gears. Gill says that this device is intended for marine use although the company has also recognized that fixed floating objects such as marker buoys present a potential market. A prototype is scheduled to appear by “the third quarter of 2016” with a market launch possibly in 2017, he says.

Gill says that by late 2015 the company will launch a crowdsourcing push that aims to bring in at least $1.1-4.5 million.

Clear Solar Panels Could Offer Energetic Window Retrofit

Engineers from Michigan State University (MSU) are designing transparent solar panels that could be retrofit to existing glass-covered buildings to generate electric power.

Traditional opaque solar panels such as silicon soak up much of the sun’s light, including visible light, and convert it to energy. A transparent panel allows visible light to shine through and making light that is invisible to the human eye—such as ultraviolet and infrared—do the work.

By making the solar panels transparent, MSU materials scientist and chemical engineer Richard Lunt and his team are creating the potential for them to cover existing windows.

However, making the panels clear is a challenge. So the team came up with ways to layer patterns onto the cell in a way that makes them uniformly transparent. The transparent solar cell under development incorporates thin coatings of organic and inorganic nanostructure materials that selectively harvest the parts of the solar radiation spectrum that are not visible to the eye.

“We actually used a variety of different stencils to pattern our devices,” Lunt says. Each active material has its own pattern. After every layer, the researchers put down a new stencil and in this way build complex structures, he adds.

Team member Margaret Young is testing whether the same process can be used on thin plastic.

“This is much lighter and much more flexible, so instead of rebuilding windows, we could just put this over an existing window,” she says.

Lunt says that he expects that in the next 20 years, this type of technology will be deployed extensively—turning cities and landscapes into solar harvesting systems, surfaces and solar farms without the aesthetic issues that today’s opaque solar panels create.