Power to the People

Just 200 aluminium smelters
consume the same amount of
power as 1.2 billion people
use domestically

This article is a contextual think-piece which summarises the potential impact the newly developed EnPot aluminium smelter technology could have on the economics of aluminium production, and our future global energy needs.

Author: Dr. Linda Wright PHD, PhD, BSc (Hons) 1st Class

Click here to download the full Think Piece article of Power to the People including Postscripts.


EnPot fundamentally transforms the way electricity is consumed during the aluminium smelting process

The EnPot system breaks the restraints of current aluminium smelting process and provides dynamic control of an aluminium smelter’s potlines. For the first time energy use and production can be increased or decreased by as much as 30%, instantaneously at the turn of a dial.
This promises to be the most transformative breakthrough in primary aluminium production in 125 years, and its development is of global significance.

It actually changes everything to do with the economics of primary aluminium production,” says one of the world’s preeminent experts in aluminium smelting, Dr. Mark Dorreen, Director of the Light Metals Research Centre at The University of Auckland, in New Zealand.

"Aluminium smelting is impossibly huge for the average consumer to comprehend. A medium sized smelter produces around US$1 billion worth of aluminium a year, and essentially requires a dedicated power station to supply its energy needs.

An average sized aluminium smelter consists of 420 pots using between 500-550 megawatt hours of power at a constant rate, enough to power an entire European city of over 1.25 million houses.

In fact the world’s 200 aluminium smelters consume the same amount of power as 1.2 billion people use domestically in their homes,” he says. 

The EnPot system breaks the restraints of current aluminium smelting process and provides dynamic control of an aluminium smelter’s potlines. For the first time energy use and production can be increased or decreased by as much as 30%, instantaneously at the turn of a dial.
This promises to be the most transformative breakthrough in primary aluminium production in 125 years, and its development is of global significance.

“It actually changes everything to do with the economics of primary aluminium production,” says one of the world’s preeminent experts in aluminium smelting, Dr. Mark Dorreen, Director of the Light Metals Research Centre at The University of Auckland, in New Zealand.

Aluminium smelting is impossibly huge for the average consumer to comprehend. A medium sized smelter produces around US$1 billion worth of aluminium a year, and essentially requires a dedicated power station to supply its energy needs.

“An average sized aluminium smelter consists of 420 pots using between 500-550 megawatt hours of power at a constant rate, enough to power an entire European city of over 1.25 million houses.

“In fact the world’s 200 aluminium smelters consume the same amount of power as 1.2 billion people use domestically in their homes,” he says. 

The EnPot System changes everything to do with the economics of primary aluminium production

“The current problem with aluminium smelting is that the process not only requires a lot of electricity; but it needs it continuously to keep the electrolysis process running.

With the existing aluminium primary production process, smelters are built with a very narrow energy use window, that is they cannot vary the energy input of a smelter by much more than plus or minus 5%,” he says.

Essentially an aluminium smelter is designed to operate at full capacity 24/7, 365 days a year, for its entire lifespan. Even routine maintenance is conducted with the smelter running at near full capacity.

Dr. Dorreen says that the maximum- production straightjacket that the aluminium industry currently is in, has a significant and dramatic effect on both the cost of production for individual smelters, as well as the dynamics of the supply and demand curves of the industry as a whole.

“It also creates power supply issues for national grids, especially as nations seek to generate a higher percentage of their electricity from renewable sources, which are inherently more intermittent in their generation,” he says, “and this is good reason for all of us to be interested.” 

Renewable energy - solar panels

Living with renewables

How our future growing energy needs will be met is one of the most globally discussed topics of our time.

If we accept that fossil fuel and nuclear power generation are losing acceptability, and that new future power generation must come from renewable sources, then we must fundamentally change the way we consume energy.

While it is predicted that in the future we will generate enough power from solar sources to power the world, for at least the next 25 years we will have to adjust our consumption patterns to cope with intermittency of power generation.

There are no easy wins when moving to a heavy renewables grid, as there is the inherent problem of intermittency of generation when the sun doesn’t shine and the wind doesn’t blow. Intermittency increases costs to the grid, as you still have to keep backup thermal power generation online. Investing in mass energy storage is the obvious answer, but this adds yet more cost and we are currently technologically short. 

There are no easy wins when moving to a heavy renewables grid

As consumers we will need to adjust our energy use to accommodate intermittency, by being able to purchase electricity when generation is high and prices are low, rather than just when we need it. The answer for consumers is also storage, in both our homes and our electric vehicles, but again we are currently technologically short.

To the free market, the future cost of electricity has to rise in the short to medium term, and this will help change behaviour, both curbing demand and driving energy efficiencies. More importantly however, it will accelerate the development and introduction of new technologies.

To the environmentally conscious, it is these new technologies that hold the key to a truly sustainable future. 

Global demand for aluminium is expected to double as incomes rise in the developing world over the next 15 years

What about the big energy users, the industries that consume nearly 50% of the power generated globally? How can they contribute moving forward?

Aluminium smelting accounts for over 3% of the world’s total electricity use, which is equivalent to 16.5% of total global domestic consumption.

Aluminium is considered one of the most important metals in the history of human civilisation, and is now the second most used metal globally after steel.

Although aluminium oxide is the earth’s most plentiful surface metal, the metallic aluminium we use everyday doesn’t occur naturally and requires smelting to render it into its metallic form. 

Our per capita consumption of aluminium rises with our income as we purchase more consumer goods and seek to light-weight everything from phones and tablets, to cars. 

Our per capita consumption of aluminium rises with our income as we purchase more consumer goods and seek to light-weight everything from phones and tablets, to cars. 

It can be argued that our increasing use of aluminium reduces our consumption of fossil fuels. It is estimated that fuel consumption efficiencies resulting from the light-weighting of vehicles with aluminium already offsets 90% of the energy consumption, and 96% of cumulative greenhouse gas emissions, associated with the primary production of aluminium.

Leading aluminium’s sustainability credentials however, are three facts that also give credibility to the metal’s historic importance. Firstly, it is estimated that 75% of all the aluminium ever manufactured, dating back 125 years, is still in use.

Secondly, aluminium is arguably the most recyclable product in the world, and can be readily recycled perpetually without any deterioration in quality.

Thirdly, recycling aluminium only requires 5% of the energy used to originally smelt it from its ore state. As Albert Einstein theorised, “energy cannot be created or destroyed, it can only be changed from one form to another.” 

What this means is that those window frames in your house are not just inert pieces of metal, they are in fact storing energy, some of it from fossil fuel power generation, for further use when recycling has occurred in another 70-100 years.

 

 

It may be however, that our use of aluminium is only just beginning to get interesting. In April 2015 Stanford University announced its scientists had invented the first high-performance aluminium- ion battery, which compared to the lithium-ion battery, is faster charging, longer lasting, and more powerful. Importantly as lithium is a rare metal and aluminium a plentiful metal, aluminium-ion batteries promise to be significantly cheaper.

The aluminium-ion battery may very well be the technology we need to drive the widespread use of renewable energy, by helping resolve the issues of intermittency with cost effective and powerful energy storage.

But all is not roses when it comes to both the economics and energy consumption associated with primary aluminium production. 

Aluminium is arguably the most recyclable product in the world. 

Aluminium is arguably the most recyclable product in the world. 

In October 2015 Merrill Lynch Wealth Management estimate that 50% of the world’s aluminium smelters are not operating profitably and probably haven’t been since 2009.

As Dr. Dorreen points out the key problem lies with the limitations of the current smelting process.

“ The primary production process of aluminium has remained essentially unchanged since 1886 and it continues to restrict a smelters energy use to a very narrow range.

“Reducing production is not a trivial undertaking, as it requires shutting down part of the smelter, usually a whole pot line, which represents 20-30% of a smelters production and can take up to three months to achieve. 

“Not only does the average pot line represent at least US$1 billion worth of investment, but restarting a pot line again after a shutdown is expensive and can take up to six months to complete. So it’s rarely done,” he says.

50% of the world’s aluminium smelters may not be profitable

Dr. Dorreen says that on an individual basis, the majority of smelters would most likely be making money when the cost of energy is low, but they have no choice but to lose money when electricity prices are high, such as peak consumption times or when electricity generation is low.

“This can be viewed as the ultimate waste, by having to consume electricity at its peak price to produce something only to lose money on it, just because you have no other option. Especially when you consider that during these times, this power could be better utilised elsewhere on the grid.

“On a macro economic level however, the collective impact of not being able to back off full production, means that as an industry the conventional economic paradigms of supply and demand are completely disrupted.

“If there is an oversupply in any normal market scenario, the price will drop until the least-efficient producers decide to either wind back production, or exit the market altogether,” he says. 

Aluminium smelters are large generators of downstream jobs and economic activity
Automotive Aluminium

Dr. Dorreen says that even a relatively short period of oversupply in the aluminium industry can lead to a large inventory being stockpiled quite quickly, making it very difficult for the market to return to any sort of economic equilibrium.

“Prices can remain depressed for extended periods of time in the aluminium industry as current production can’t be scaled back. This means the market not only has to wait until demand rises, but also any stockpiles have been reduced before prices can rebound,” he says. 

If the majority of smelters are currently losing money, then free market thinking would predict that a number of smelters would need to close down.

While a few have closed in recent years, it is clear that many are either being supported by shareholders, with their eye on the long game, or directly or indirectly by governments, or possibly a combination of both. 

There are good reasons why governments are interested in aluminium production, as smelters are big generators of economic activity. All of the aluminium produced by smelters is transformed by thousands of downstream industries into products we buy and use everyday.

Simply put, many of the world’s aluminium smelters are just too big and too important to their national economies to unplug. 

This historic graph illustrates how even short periods of oversupply can lead to stockpiling and depressed prices. Note: the current price of aluminium is US$1479/ tonne. 

EnPot can be economically retrofitted to most of the world’s smelters, and opens up the energy use window

The potential impact of EnPot

So if we accept that nations consume primary aluminium production, not individuals in the free market, then where do we go from here?

“Without a solution to the problem of not being able to vary the electricity consumption of smelters, the whole situation will only get worse in the short to medium term, as power supply tightens and becomes more intermittent as we move towards more renewable generation,” Dr. Dorreen says.

“This is where the EnPot technology will be transformative.

“It is estimated that the EnPot system can be economically retrofitted to 90% of the world’s smelters, and gives smelter operators the ability to turn down energy use by up to 30% almost instantly, assuming they can reorganise the other parts of their business to cope with the decrease in production.

“The implications are enormous, not only for the aluminium smelting industry, but also for the nations that host smelters and that struggle to generate enough clean power to meet domestic consumption at times of peak demand, or at times of low power generation,” he says. 

While the EnPot technology allows for going both up and down by similar amounts, for some smelters it will be impossible to go beyond their current energy use ceiling. A large number of smelters will be able to however, albeit with some infrastructure upgrades. It could be predicted that the ability to go both up and down would become a design prerequisite on any new smelter constructed in
the future. 

The EnPot system is likely to be the biggest breakthrough in aluminium smelting for the last 125 years

Dr. Dorreen says the ability to reduce electricity usage during peak price times, and at times of low generation, and then to make hay while the sun shines by increasing production during low cost times, is a far more efficient and profitable way to smelt aluminium.

“Not only would smelters be able to reduce cost of production by better utilising cheaper power generation, but the industry could avoid the long periods of depressed prices due to oversupply and stockpiling.

For these reasons, the EnPot technology could transform the economic outlook and profitability of a large number of the world’s smelters,” Dr. Dorreen says.

 

To contextualize how big a breakthrough the new EnPot technology is for the aluminium smelting industry, Dr. Dorreen says the EnPot technology is the first transformative change to aluminium smelting since the introduction of the modern pre-baked carbon anodes in the 1950s.

“In terms of gross economic efficiencies however, the EnPot system is likely to be the biggest breakthrough in aluminium smelting for the last 125 years,” he says.

Dr. Dorreen says that the EnPot technology could make the aluminium smelting industry not only more competitive, but more responsive to the wider community and environment around it. 

“As nations try to increase the percentage of power generated from renewable sources, it may even allow the aluminium industry to be part of the solution of accommodating increased intermittency,” he says.

 

Dr. Martin Iffert, CEO of TRIMET Aluminium SE, believes that the EnPot technology could be used like a virtual battery to buffer demand against supply in Germany, as the country seeks to increase its use of renewable power generation under the Energiewende programme.

“ TRIMET’s trials of the EnPot technology indicate that by being able to dynamically increase or decrease our energy use by 25%, TRIMET could in fact become the energy bridge buffering supply and demand in Germany,” he says.

“This would effectively enable TRIMET to become a significant part of Germany’s energy storage capacity. Our goal is to use our smelters to give Germany a virtual battery capacity of 12G Wh, which would be approximately 25% of Germany’s current pump hydro storage capacity,” Dr. Iffert says.

Geoff Matthews, Vice President for Energia Potior Ltd, the company responsible for commercialising the EnPot technology, says that for many countries the installation of the EnPot technology in local aluminium smelters, would help alleviate problems with intermittency in their national grids, and could even enable the decommissioning of fossil fuel or nuclear power stations. 

“The EnPot technology is also much cheaper than building new generation capacity,” he says.

“A full EnPot smelter conversion on an existing medium sized smelter, would cost around US$20m installed and enable the smelter to free up as much as 150 megawatts of power at peak times.

“For some governments, and even power companies, it may make sense to pay smelters to install EnPot, and negotiate with them to free up power in times of low generation, as the capital required to construct this amount of power from new land-based wind power or solar generation is between US$3.3 and 7.5 billion depending on the technology used,” Geoff says.

The amount of power smelters could free up at peak domestic consumption times is significant.

“It is estimated that smelters could free up enough electricity regionally at peak consumption times to power 2.5 million homes in Europe, 1.1 million homes in North America, and 25 million homes in China,” he says.

“In India the electricity freed up during peak consumption times from its four major aluminium smelters, could power over 5.3 million homes.

“This is over 33 million homes in just these four regions of the world,” Geoff says. 

The EnPot technology was installed on 12 trial pots (cells) at TRIMET Aluminium SE Essen, in June 2014
EnPot conversion
“EnPot allows us to break the restraints of the current cell design and open up the operating window,”
— Roman Düssel, Production Manager-Electrolysis, TRIMET Aluminium SE, Essen.

Dr. Pretesh Patel, Chief Engineer for Energia Potior Ltd, was responsible for retrofitting the first EnPot system into a major European smelter in 2014.

Dr. Patel says that the EnPot technology has been running successfully in a partitioned section of a smelter in Germany since June 2014 and has performed above expectations.

“What it provides for the first time is dynamic control of the smelter’s pot-lines so that energy input and aluminium production can be increased or decreased as and when required,” Dr. Patel says.

Roman Düssel, Production Manager – Electrolysis, TRIMET Aluminium SE, Essen, says the goal for TRIMET has been to find pathways to allow the smelter to shift power use by ± 25%.

“ The biggest problem with our conventional cell design is that we cannot maintain an operational cell heat balance when varying cell power, meaning the pots will either ‘tap out’ or freeze over’ if the power input to them is shifted up and down by such a degree,” he says.

“The EnPot technology allows us to dynamically control the heat loss of the pot and therefore maintain heat balance under a wide range of operating conditions. It basically allows us to break the restraints of the current cell design and open up the operating window”, he says.

Roman says TRIMET have easily been able to maintain stable operations with power increases of 20% and reductions of 13%, on the 12 pots installed with the EnPot heat exchangers and are currently only limited by the impact on the rest of the pots in the line, which do not have EnPot.

“ We have proven that when modulating power the pots with EnPot installed operate with approximately 1 DCk Wh/ kg lower energy consumption than pots without EnPot, which is a huge saving,” he says.

Roman says that under normal operating conditions with normal line amperage, the pots with EnPot installed have outperformed the rest of the pots in the line with 0.25 DCkWh/kg lower energy consumption and 0.4% higher current efficiency.

“ These results underpin our confidence in the EnPot technology and we are confident we will realize our goal of ± 25% energy usage when we have it on the whole potline,” he says.

Dr. Patel says that while the TRIMET results are specific to the Essen smelter, they are indicative of the power savings that could be achieved with EnPot when producing aluminium. “In real terms the power savings from installing EnPot in all the German smelters could power 45,000 homes in normal operating mode, and up to 180,000 if modulation was used. At the same time the smelters would be producing aluminium at a cheaper cost per kilogram.”

Dr. Patel says there are also a number of other significant operational benefits the EnPot system delivers to smelter operators. 

The biggest problem is with conventional cell design is that an operational cell heat balance cannot be maintained when varying cell power. EnPot allows dynamic control of the heat loss of the pot to maintain heat balance under a wide range of operating conditions. 

The biggest problem is with conventional cell design is that an operational cell heat balance cannot be maintained when varying cell power. EnPot allows dynamic control of the heat loss of the pot to maintain heat balance under a wide range of operating conditions. 

“Being able to insulate the pots in the situation of a serious power failure delays the solidification of the molten liquid.

Dr. Patel says unplanned shutdowns are serious events, and can even be catastrophic.

“The EnPot system will double the time available before the pots solidify. Not only could this extra time be the difference between a smelter freezing or not, it also allows the operators to try and mitigate some of the effects of an unplanned shutdown so it is easier, or even possible to restart the smelter when power is restored,” he says.

Dr. Patel says the EnPot system also improves the working environment in the potroom for staff, by ducting away a significant amount of heat generated by the pots. 

“The great thing about the EnPot system is that it is relatively inexpensive to retrofit and does not change the intrinsic nature of the process,” he says, “it is also totally non-invasive, and carries no integrity risk to the smelter, I can think of nothing else that gives as much value to all of the smelter’s stakeholders.

“It frees up peak time power for nations to use, it accommodates intermittency in the grid, improves process efficiency and enables smelter operators to control production, increases profits to smelter shareholders, improves working conditions and reduces insurance risk, all at the same time,” Dr. Patel says.

As the free market proponents would say, necessity is the mother of all invention, and all new technology is always adopted just in time.

It seems that on many levels the EnPot technology is right on cue. 

Click here to download the full Think Piece article of Power to the People including Postscripts.