You can see all my Guardian columns online at http://www.theguardian.com/profile/bernie-bulkin
From Guardian Sustainable Business, 1 October 2014
Energy Efficient Air Conditioning
If we are going to get global consumption of power on to a much more efficient basis, one of the challenges is air conditioning. Could we find a breakthrough that would cut 90% of the electricity required for space cooling?
Air conditioners in use today work on the same principle as refrigerators, but instead of dumping the heat into the room (which is what happens at the back of a refrigerator) it is sent outdoors. Air conditioners use a lot of electricity because they involve repeated cycles of compressing a gas to a liquid, and that consumes power. In Singapore, a small, hot, developed country, about 30% of household power is used for air conditioning, and in commercial buildings it is 40%! (http://www.greentechmedia.com/articles/read/stat-of-the-week-47-percent)
Because a lot of global economic development has happened, and will happen, in hot climates, the demand for air conditioning can be expected to increase markedly over the coming decade. There is a need for a much more energy efficient way to accomplish space cooling. Of course, the simplest thing to do is to refrain from excessively air conditioning a work or living space. A few degrees higher setting of the thermostat in those chilly restaurants, hotels, homes and offices would go a long way to saving energy.
But what about the device itself? If the energy cost of compressing the gas back to a liquid is the critical step, is there any way to reduce or eliminate this? There is an old idea that is now being revived as a result of advances in chemical materials technology. Certain materials have a strong tendency to adsorb (that is bind to the surface) water vapour. When this happens, heat is released. Suppose that cool water vapour picks up heat from a hot room, and is then directed outside to where the adsorbing material is located. The water is trapped and the heat released to the atmosphere. Now to get the water back off the material, as cool vapour, only a small amount of heat needs to be applied to the solid. Ideally this would come from solar energy, or from some other source of waste heat. If neither is available, a small electric heater is required. Devices doing air cooling on this principle are known as adsorption chillers.
The problem is that until recently the materials available at a reasonable cost, such as silica gel (the stuff that is in those little packets you get with various purchases, to keep them dry) do not trap very much water, so you need a lot of them to cool a space. The resulting adsorption chillers are large and heavy – and weight is a consideration for air conditioners, which are often placed on a roof. Now new materials are being developed that are a step change in the amount of water they can hold. These materials are known as metal-organic framework (MOF) compounds. Some of the recent ones, developed by Dr Raya al Dadah at the University of Birmingham, at Heinrich Heine University in Dusseldorf, and at MIT in the US, will adsorb more than four times as much water as silica gel. As the name implies, these materials are made of various metals, such as zirconium or chromium, bound together with a loose web of carbon atoms, so that there is a much greater surface area with sites where water molecules can be bound.
But the work of the chemists and engineers is not done. Many materials will work well for a few cycles of adsorption and its reverse, desorption. But a commercial adsorption chiller needs to keep up this performance for thousands of cycles without requiring a change of the MOF. The first materials are undergoing such tests, and if they succeed we might soon see commercial air conditioning using 10% of the energy required for today’s units.
Bernie Bulkin is a director of Ludgate Investments, HMN Colmworth, and K3Solar. He was chair of the Office of Renewable Energy for the UK Government from 2010-2013, and a member of the UK Sustainable Development Commission. He was formerly chief scientist of BP.
From Guardian Sustainable Business, 2 May 2014
South Korea Leading on Smart Grid
There is a lot of discussion of "smart grid" these days. I sometimes feel it is one of those phrases that people use for whatever suits their purposes without much substance behind it. But talking with technical staff and leadership at Korean utilities companies, I found that they have a very clear vision, and there is going to be a huge number of technical opportunities for those who can supply pieces to fulfil that vision.
Smart grid to the South Koreans is a platform for a complete rethinking of the electricity grid to make it capable for the 21st century. To the maximum extent, the "smart" is built into the grid via software rather than hardware. You might think this is more vulnerable to failure – they don't see it that way. Rather, they use software for the intelligence because it can be upgraded more regularly, can learn as demand patterns change, and can respond to new technologies more readily.
Within this platform are six key components:
1. Smart power – Intelligent monitoring of the demand, high level of fault tolerance and fast restoration in case of failures. In the UK we would add the ability to import large quantities of power from interconnectors, turned on or off with very short notice.
2. Smart service – Providing domestic, commercial and industrial customers with electricity tariffs and services tailored to their needs, incorporating the ability to verify test data and to flow power in two directions everywhere.
3. Smart place – Allowing the introduction of intelligence in the home, particularly in major appliances that generate most of the demand; real time pricing and demand management.
5. Smart transport – Sophisticated systems for managing the connection of massive numbers of electric vehicles to the grid so that their demand is met without overwhelming the system.
6. Smart renewables – Connecting a large number, and diverse set, of variable sources of generation to the grid while maintaining high levels of stability.
If we cast our minds back to the early days of the internet, Cisco laid out a vision of this sort for the web, highlighting where all the technology needs were that could make this vision a reality. In response to that vision companies were created, nurtured, and in many cases acquired by Cisco. This is just what the Koreans are doing, and on a grand scale.
Are all the technologies to make this happen commercially available today? No, but the components are there, and if big countries provide the demand then technology suppliers will respond. The grid in the UK in its present form is 60 years old, more or less, and was designed around big coal fired power stations feeding large and small demand centres. Over time it accommodated nuclear and gas generation, and has coped reasonably well with interconnection to French nuclear and substantial amounts of wind. But it is not "smart", certainly not in the sense outlined above. There is now an opportunity to create a lot of new technologies to respond to a real smart grid initiative.
From Guardian Sustainable Business, 7 March 2014
The Future of Solar Power?
We all know that the daily input of solar energy onto the earth’s surface is many times all of our energy needs, but cheap and efficient conversion of sunlight, especially to electricity, has remained elusive. Yes, there is a lot of photovoltaic material installed around the world today, more than 100 gigawatts, but the efficiency with which that is converted to kilowatt hours is relatively poor, usually 15% or less. So while more than 85% of the photovoltaics (PV) used today are made from crystalline silicon, there is an ongoing background of science searching for new materials that could do the job better. The criteria for ‘better’ are greater efficiency, with cheap materials that are readily available, solid, durable under prolonged exposure to sunlight and weather, and, if possible, fairly transparent. Well, a lot of challenges, and there have been many false dawns. A number of these have scored high on efficiency, but with materials that are exotic, so that any scale-up would be limited by availability and cost.
Now there is excitement, and it is over a class of materials known as perovskites. Perovskite is the term for a particular mineral crystal structure, most commonly a calcium titanium trioxide mineral, and is applied to anything that adopts this same structure. Perovskite materials for solar cells were first reported in 2009, (organo lead halides in case you are interested) but they were very low efficiency and had to remain liquid in use. Not promising. But it caught the attention of several research groups, in particular that of Henry Snaith at Oxford, and Andrew Rappe at the University of Pennsylvania. By doing some clever polymer chemistry, they were able to make solid perovskite solar cells, and then, in only 18 months, engineered these up to efficiencies of 16%. It took decades of research on silicon to get such improvements. But the polymer was expensive and complex. Still, Science magazine classed perovskite solar cells as one of the breakthroughs of 2013.
In the way of science and engineering working together, the great solar cell scientist and inventor Michael Graetzel in Lausanne was intrigued, and figured out just how these cells were transporting the electrons, and how that polymer worked. With that information, it has recently been possible for scientists at Notre Dame University in the US to realize that the complex polymer could be replaced by something as simple as copper iodide. OK, their first cell is not yet up to the 16% efficiency, but there was a benefit: while the polymer based cells declined in current over time, the copper iodide ones did not.
So perovskite PV is at the point of, perhaps, maximum optimism. There are predictions that the efficiencies could reach 50%, the costs could fall to well below where silicon might get to in 10 years, and the science points to it being desirable to make these cells thicker, rather than as thin films, meaning they can be suitable as window or roofing materials. And the prototype cells produced have partial transparency.
Yes, there are already companies working on commercializing. Snaith has formed Oxford PV, and has already attracted £2 million of start-up funding. Perovskites are the clean tech material development most worth watching right now.
*********
From Guardian Sustainable Business 4 April 2014
Lithium Sulfur Graphene Batteries
It has long been clear that energy storage is a priority to enable a whole range of cleantech innovation, from vehicle electrification to utility scale storage for variable sources of power. But since batteries are made by combination of various simple chemical reactions, pretty much limited by the elements in the periodic table that are available in large quantities, most ideas have been tried. Thomas Edison once said, ‘if someone tells you they have a wonderful new battery, disbelieve them’.
So the trick is to find some new development in materials science that enables the characteristics of an existing battery to be radically improved. And for many applications, and particularly for electric vehicles, we want to be able to store a lot of energy with the smallest possible weight, so the units of the key metric are Watt hours/kilogram. A typical lithium ion battery achieves 200 Wh/kg, while the familiar lead acid battery is about 40 Wh/kg. Another key factor is how the battery performs as it goes through cycles of charging and discharging, and for an electric car you would want more than 1000 cycles without serious deterioration. It’s also good if the batteries don’t catch fire when being charged!
In the last few months there seems to be a breakthrough on this, starting with a battery that has been seen as promising for some time, the lithium sulfur battery. These started as a modification of the chemistry of lithium ion batteries, but were put aside because they deteriorated rapidly in as few as a dozen charge cycles. Now researchers at Lawrence Berkeley Labs in California have further modified these cells using graphene oxide – a treated version of the very thin carbon layers whose discoverers at the University of Manchester won the Nobel Prize in physics in 2010. The Lawrence Berkeley scientists figured out what was causing the deterioration (complex sulfur chemistry) and then used a graphene based sandwich to stop it happening. And for good measure they also changed the electrolyte and made several other alterations to the cathode.
The result: a battery that can store more than twice the Wh/kg of a Li ion battery, and has already shown that it can do 1500 charge cycles without deterioration – probably more. Experts who have looked at this indicate that these lithium sulfur graphene batteries could enable electric vehicles with a range of more than 300 miles on a single charge.
This is still at an early stage. We don’t know yet what the cost is going to be, or even at what scale these batteries will be most useful. The inventors talk about everything from laptops to cars to energy storage from wind farms. Usually, batteries find a niche where they are most effective, but until further development occurs we can’t know what that will be for lithium sulfur graphene.
This development is one of many that show the unique ability of graphene to revolutionise some well-known device applications. It is also a product of the last two decades of emphasis on applying nanotechnology to electronics problems. We can expect a steady stream of such developments over the next few years.
From Guardian Sustainable Business, 1 October 2014
Energy Efficient Air Conditioning
If we are going to get global consumption of power on to a much more efficient basis, one of the challenges is air conditioning. Could we find a breakthrough that would cut 90% of the electricity required for space cooling?
Air conditioners in use today work on the same principle as refrigerators, but instead of dumping the heat into the room (which is what happens at the back of a refrigerator) it is sent outdoors. Air conditioners use a lot of electricity because they involve repeated cycles of compressing a gas to a liquid, and that consumes power. In Singapore, a small, hot, developed country, about 30% of household power is used for air conditioning, and in commercial buildings it is 40%! (http://www.greentechmedia.com/articles/read/stat-of-the-week-47-percent)
Because a lot of global economic development has happened, and will happen, in hot climates, the demand for air conditioning can be expected to increase markedly over the coming decade. There is a need for a much more energy efficient way to accomplish space cooling. Of course, the simplest thing to do is to refrain from excessively air conditioning a work or living space. A few degrees higher setting of the thermostat in those chilly restaurants, hotels, homes and offices would go a long way to saving energy.
But what about the device itself? If the energy cost of compressing the gas back to a liquid is the critical step, is there any way to reduce or eliminate this? There is an old idea that is now being revived as a result of advances in chemical materials technology. Certain materials have a strong tendency to adsorb (that is bind to the surface) water vapour. When this happens, heat is released. Suppose that cool water vapour picks up heat from a hot room, and is then directed outside to where the adsorbing material is located. The water is trapped and the heat released to the atmosphere. Now to get the water back off the material, as cool vapour, only a small amount of heat needs to be applied to the solid. Ideally this would come from solar energy, or from some other source of waste heat. If neither is available, a small electric heater is required. Devices doing air cooling on this principle are known as adsorption chillers.
The problem is that until recently the materials available at a reasonable cost, such as silica gel (the stuff that is in those little packets you get with various purchases, to keep them dry) do not trap very much water, so you need a lot of them to cool a space. The resulting adsorption chillers are large and heavy – and weight is a consideration for air conditioners, which are often placed on a roof. Now new materials are being developed that are a step change in the amount of water they can hold. These materials are known as metal-organic framework (MOF) compounds. Some of the recent ones, developed by Dr Raya al Dadah at the University of Birmingham, at Heinrich Heine University in Dusseldorf, and at MIT in the US, will adsorb more than four times as much water as silica gel. As the name implies, these materials are made of various metals, such as zirconium or chromium, bound together with a loose web of carbon atoms, so that there is a much greater surface area with sites where water molecules can be bound.
But the work of the chemists and engineers is not done. Many materials will work well for a few cycles of adsorption and its reverse, desorption. But a commercial adsorption chiller needs to keep up this performance for thousands of cycles without requiring a change of the MOF. The first materials are undergoing such tests, and if they succeed we might soon see commercial air conditioning using 10% of the energy required for today’s units.
Bernie Bulkin is a director of Ludgate Investments, HMN Colmworth, and K3Solar. He was chair of the Office of Renewable Energy for the UK Government from 2010-2013, and a member of the UK Sustainable Development Commission. He was formerly chief scientist of BP.
From Guardian Sustainable Business, 2 May 2014
South Korea Leading on Smart Grid
There is a lot of discussion of "smart grid" these days. I sometimes feel it is one of those phrases that people use for whatever suits their purposes without much substance behind it. But talking with technical staff and leadership at Korean utilities companies, I found that they have a very clear vision, and there is going to be a huge number of technical opportunities for those who can supply pieces to fulfil that vision.
Smart grid to the South Koreans is a platform for a complete rethinking of the electricity grid to make it capable for the 21st century. To the maximum extent, the "smart" is built into the grid via software rather than hardware. You might think this is more vulnerable to failure – they don't see it that way. Rather, they use software for the intelligence because it can be upgraded more regularly, can learn as demand patterns change, and can respond to new technologies more readily.
Within this platform are six key components:
1. Smart power – Intelligent monitoring of the demand, high level of fault tolerance and fast restoration in case of failures. In the UK we would add the ability to import large quantities of power from interconnectors, turned on or off with very short notice.
2. Smart service – Providing domestic, commercial and industrial customers with electricity tariffs and services tailored to their needs, incorporating the ability to verify test data and to flow power in two directions everywhere.
3. Smart place – Allowing the introduction of intelligence in the home, particularly in major appliances that generate most of the demand; real time pricing and demand management.
5. Smart transport – Sophisticated systems for managing the connection of massive numbers of electric vehicles to the grid so that their demand is met without overwhelming the system.
6. Smart renewables – Connecting a large number, and diverse set, of variable sources of generation to the grid while maintaining high levels of stability.
If we cast our minds back to the early days of the internet, Cisco laid out a vision of this sort for the web, highlighting where all the technology needs were that could make this vision a reality. In response to that vision companies were created, nurtured, and in many cases acquired by Cisco. This is just what the Koreans are doing, and on a grand scale.
Are all the technologies to make this happen commercially available today? No, but the components are there, and if big countries provide the demand then technology suppliers will respond. The grid in the UK in its present form is 60 years old, more or less, and was designed around big coal fired power stations feeding large and small demand centres. Over time it accommodated nuclear and gas generation, and has coped reasonably well with interconnection to French nuclear and substantial amounts of wind. But it is not "smart", certainly not in the sense outlined above. There is now an opportunity to create a lot of new technologies to respond to a real smart grid initiative.
From Guardian Sustainable Business, 7 March 2014
The Future of Solar Power?
We all know that the daily input of solar energy onto the earth’s surface is many times all of our energy needs, but cheap and efficient conversion of sunlight, especially to electricity, has remained elusive. Yes, there is a lot of photovoltaic material installed around the world today, more than 100 gigawatts, but the efficiency with which that is converted to kilowatt hours is relatively poor, usually 15% or less. So while more than 85% of the photovoltaics (PV) used today are made from crystalline silicon, there is an ongoing background of science searching for new materials that could do the job better. The criteria for ‘better’ are greater efficiency, with cheap materials that are readily available, solid, durable under prolonged exposure to sunlight and weather, and, if possible, fairly transparent. Well, a lot of challenges, and there have been many false dawns. A number of these have scored high on efficiency, but with materials that are exotic, so that any scale-up would be limited by availability and cost.
Now there is excitement, and it is over a class of materials known as perovskites. Perovskite is the term for a particular mineral crystal structure, most commonly a calcium titanium trioxide mineral, and is applied to anything that adopts this same structure. Perovskite materials for solar cells were first reported in 2009, (organo lead halides in case you are interested) but they were very low efficiency and had to remain liquid in use. Not promising. But it caught the attention of several research groups, in particular that of Henry Snaith at Oxford, and Andrew Rappe at the University of Pennsylvania. By doing some clever polymer chemistry, they were able to make solid perovskite solar cells, and then, in only 18 months, engineered these up to efficiencies of 16%. It took decades of research on silicon to get such improvements. But the polymer was expensive and complex. Still, Science magazine classed perovskite solar cells as one of the breakthroughs of 2013.
In the way of science and engineering working together, the great solar cell scientist and inventor Michael Graetzel in Lausanne was intrigued, and figured out just how these cells were transporting the electrons, and how that polymer worked. With that information, it has recently been possible for scientists at Notre Dame University in the US to realize that the complex polymer could be replaced by something as simple as copper iodide. OK, their first cell is not yet up to the 16% efficiency, but there was a benefit: while the polymer based cells declined in current over time, the copper iodide ones did not.
So perovskite PV is at the point of, perhaps, maximum optimism. There are predictions that the efficiencies could reach 50%, the costs could fall to well below where silicon might get to in 10 years, and the science points to it being desirable to make these cells thicker, rather than as thin films, meaning they can be suitable as window or roofing materials. And the prototype cells produced have partial transparency.
Yes, there are already companies working on commercializing. Snaith has formed Oxford PV, and has already attracted £2 million of start-up funding. Perovskites are the clean tech material development most worth watching right now.
*********
From Guardian Sustainable Business 4 April 2014
Lithium Sulfur Graphene Batteries
It has long been clear that energy storage is a priority to enable a whole range of cleantech innovation, from vehicle electrification to utility scale storage for variable sources of power. But since batteries are made by combination of various simple chemical reactions, pretty much limited by the elements in the periodic table that are available in large quantities, most ideas have been tried. Thomas Edison once said, ‘if someone tells you they have a wonderful new battery, disbelieve them’.
So the trick is to find some new development in materials science that enables the characteristics of an existing battery to be radically improved. And for many applications, and particularly for electric vehicles, we want to be able to store a lot of energy with the smallest possible weight, so the units of the key metric are Watt hours/kilogram. A typical lithium ion battery achieves 200 Wh/kg, while the familiar lead acid battery is about 40 Wh/kg. Another key factor is how the battery performs as it goes through cycles of charging and discharging, and for an electric car you would want more than 1000 cycles without serious deterioration. It’s also good if the batteries don’t catch fire when being charged!
In the last few months there seems to be a breakthrough on this, starting with a battery that has been seen as promising for some time, the lithium sulfur battery. These started as a modification of the chemistry of lithium ion batteries, but were put aside because they deteriorated rapidly in as few as a dozen charge cycles. Now researchers at Lawrence Berkeley Labs in California have further modified these cells using graphene oxide – a treated version of the very thin carbon layers whose discoverers at the University of Manchester won the Nobel Prize in physics in 2010. The Lawrence Berkeley scientists figured out what was causing the deterioration (complex sulfur chemistry) and then used a graphene based sandwich to stop it happening. And for good measure they also changed the electrolyte and made several other alterations to the cathode.
The result: a battery that can store more than twice the Wh/kg of a Li ion battery, and has already shown that it can do 1500 charge cycles without deterioration – probably more. Experts who have looked at this indicate that these lithium sulfur graphene batteries could enable electric vehicles with a range of more than 300 miles on a single charge.
This is still at an early stage. We don’t know yet what the cost is going to be, or even at what scale these batteries will be most useful. The inventors talk about everything from laptops to cars to energy storage from wind farms. Usually, batteries find a niche where they are most effective, but until further development occurs we can’t know what that will be for lithium sulfur graphene.
This development is one of many that show the unique ability of graphene to revolutionise some well-known device applications. It is also a product of the last two decades of emphasis on applying nanotechnology to electronics problems. We can expect a steady stream of such developments over the next few years.
