MATERIAL MATTERS allow us to concentrate on other problems Enabling the Grid:Local Energy Storage what effectively would be a new major- for the rest of this century With this energy distribution model appliance industry.Since our proposed Although there is plenty of solar ener- the entire North American continent,all unit is very small,it could be easily mar gy,we do not have the technology to the way from the Arctic Circle down to keted to each one of those hundred mil- develop it at a few pennies per kilowatt- Panama,would be wired together in a lion or so energy customers who are seek- hour.Right now we could do it at about giant interconnected electrical energy ing local storage.Since the unit would 20-50 cents a kilowatt-hour (averaged grid.Indeed,we are already very close to have to be inexpensive-a few thousand over a day/night cycle),but that would that now,except that in the new grid,by dollars at most-customers who were not be far too expensive.If you believe with the middle of the century,there would be satisfied could replace their units or trade me that we absolutely need to provide two critical additions.The first would be up to a better model,as they do now with the planet's 10 billion people with the local energy storage.Every one of the other technical products such as comput- potential to pursue a fulfilling lifestyle, hundred million or so sites consuming ers.It would be a way to "PC"this critical where they have a roof over their heads, energy in this grid would have its own aspect of the energy industry.Every five enough food to eat,sufficient mobility, storage unit-the equivalent of an unin- years or so,on average,customers would communications,and the capability to terruptible power supply that not only opt to upgrade their storage unit,based build homes and develop cities,then you gives a home computer a few minutes of on local economic incentives and newly will agree that we have to revolutionize power during an outage,but also can available product improvements driven the world's energy system.We need supply each of our houses or businesses by free markets and entrepreneurship. cheap,clean energy in vast amounts. with 12-24 hours of full operation. Inventive minds would be continually evolving the best possible answer to what The Distributed Energy Grid fits inside this box. The hardest problem will be finding "There has been a lot of talk about Then,every one of those sites in the viable replacements for the energy the hydrogen economy,which I electrical energy grid would be able to use sources we have been relying on for believe is,despite its virtues, one of these units to buffer the grid's ener- decades,oil in particular.Oil is not only a gy fluctuations.Real-time pricing for indi- great primary energy source,it is also the likely to remain a distraction from vidual electrical power usage would give best form in which to transport energy the real,practical solutions to each customer the incentive to buy a unit over continental distances and across that could absorb the power needed to oceans.Most of the oil we import comes our energy needs." generate 100 kilowatt-hours of electricity across the sea in what has become a very in the six-hour time period when energy is efficient process-putting the oil in Imagine that by mid-century,nano cheapest on the grid.People who needed tankers.When we buy a gallon of gas,the technologies,new materials,and possibly more than 100 kilowatt-hours of power or actual dollar cost for that transportation new physics will have enabled us to cre needed virtually trouble-free energy for is less than 10%. ate local storage units for electrical energy longer periods could simply buy addition In contrast,it is much less efficient to that are not much bigger than this lectern. al or larger units.That would be the cus transport natural gas in this way.Natural The units would store 100 kilowatt-hours tomer's decision. gas has to be cooled to liquefy it to form which is enough to run a normal house Basically,this local unit would solve LNG before it goes into the tank.That in for 24 hours.If we tried to run this type of the energy storage problem.With that itself takes a lot of energy.The LNG unit right now using a lead acid battery, solved,it would now be possible to get tanker is more expensive,resulting in the unit would have to be about 20 times most of the energy on the grid from much higher transportation costs,and it this volume-the size of a small room. "unreliable"or episodic sources,like takes more energy to re-gasify and com- The cost would be around $10,000.I wind or solar.Without a local storage press the gas for storage,pipeline trans- believe that if we really put our minds to solution,however,we could not rely on portation,and use when it reaches its it,we could think of a way to shrink the these "other"energy sources to supply destination.We are going to find out unit volume significantly and drop the large amounts of energy on the grid,at exactly how high these costs will be as cost dramatically.There must be many least not at levels above 10-20%.Above time goes on,since most of our natural technologies that would fit inside this those levels,we would need to have all gas will eventually have to be imported. "box"and store that amount of energy. the reserves in place,ready to provide Transporting liquid hydrogen would be On the other hand,if we think about electrical power when the sun stopped vastly more expensive. storing energy on a much larger scale- shining or the wind stopped blowing. say,that of a big power plant that pro- Local energy storage would get us past "Energy as Energy" duces a gigawatt of power-the possibili- that problem and give us an extremely How,then,around the year 2050,are ties are very limited.We could pump robust,terrorist-resistant,delocalized we going to transport energy over vast water uphill and run it back down again electrical energy system. distances while minimizing the costs and (if we had the water and the land),or we getting the amount of power we need? could compress air (if we had large cav- Completing the Grid:High-Voltage The best answer would be to transport erns to store it in).Large-scale energy stor- Transmission Lines energy as energy,not as mass.Instead of age technologies do exist,but,except in In addition to a local system,one other storing energy in some chemical form, special locations,they lack the practicality innovation is needed on the grid to make it keep it as pure energy.There are essential- and desirability of small-scale storage work.We need the capability to transport ly only two ways to do that.We could electrical power in hundreds of gigawatts microwave energy up to a satellite and Commercializing Local Energy Storage over thousands of miles.High-voltage bounce it back down,or we could run it I believe that creating an efficient local transmission lines would be very efficient along wires on the earth's surface.We will storage solution should be one of our for this purpose.In fact,we already have do both,but mostly we will use wires. prime energy targets.Let us develop dc lines that carry electricity for 1500 miles 416 MRS BULLETIN·VOLUME30·JUWE20O5MATERIAL MATTERS 416 MRS BULLETIN • VOLUME 30 • JUNE 2005 allow us to concentrate on other problems for the rest of this century. Although there is plenty of solar ener￾gy, we do not have the technology to develop it at a few pennies per kilowatt￾hour. Right now we could do it at about 20–50 cents a kilowatt-hour (averaged over a day/night cycle), but that would be far too expensive. If you believe with me that we absolutely need to provide the planet’s 10 billion people with the potential to pursue a fulfilling lifestyle, where they have a roof over their heads, enough food to eat, sufficient mobility, communications, and the capability to build homes and develop cities, then you will agree that we have to revolutionize the world’s energy system. We need cheap, clean energy in vast amounts. The Distributed Energy Grid The hardest problem will be finding viable replacements for the energy sources we have been relying on for decades, oil in particular. Oil is not only a great primary energy source, it is also the best form in which to transport energy over continental distances and across oceans. Most of the oil we import comes across the sea in what has become a very efficient process—putting the oil in tankers. When we buy a gallon of gas, the actual dollar cost for that transportation is less than 10%. In contrast, it is much less efficient to transport natural gas in this way. Natural gas has to be cooled to liquefy it to form LNG before it goes into the tank. That in itself takes a lot of energy. The LNG tanker is more expensive, resulting in much higher transportation costs, and it takes more energy to re-gasify and com￾press the gas for storage, pipeline trans￾portation, and use when it reaches its destination. We are going to find out exactly how high these costs will be as time goes on, since most of our natural gas will eventually have to be imported. Transporting liquid hydrogen would be vastly more expensive. “Energy as Energy” How, then, around the year 2050, are we going to transport energy over vast distances while minimizing the costs and getting the amount of power we need? The best answer would be to transport energy as energy, not as mass. Instead of storing energy in some chemical form, keep it as pure energy. There are essential￾ly only two ways to do that. We could microwave energy up to a satellite and bounce it back down, or we could run it along wires on the earth’s surface. We will do both, but mostly we will use wires. Enabling the Grid: Local Energy Storage With this energy distribution model, the entire North American continent, all the way from the Arctic Circle down to Panama, would be wired together in a giant interconnected electrical energy grid. Indeed, we are already very close to that now, except that in the new grid, by the middle of the century, there would be two critical additions. The first would be local energy storage. Every one of the hundred million or so sites consuming energy in this grid would have its own storage unit—the equivalent of an unin￾terruptible power supply that not only gives a home computer a few minutes of power during an outage, but also can supply each of our houses or businesses with 12–24 hours of full operation. Imagine that by mid-century, nano￾technologies, new materials, and possibly new physics will have enabled us to cre￾ate local storage units for electrical energy that are not much bigger than this lectern. The units would store 100 kilowatt-hours, which is enough to run a normal house for 24 hours. If we tried to run this type of unit right now using a lead acid battery, the unit would have to be about 20 times this volume—the size of a small room. The cost would be around $10,000. I believe that if we really put our minds to it, we could think of a way to shrink the unit volume significantly and drop the cost dramatically. There must be many technologies that would fit inside this “box” and store that amount of energy. On the other hand, if we think about storing energy on a much larger scale— say, that of a big power plant that pro￾duces a gigawatt of power—the possibili￾ties are very limited. We could pump water uphill and run it back down again (if we had the water and the land), or we could compress air (if we had large cav￾erns to store it in). Large-scale energy stor￾age technologies do exist, but, except in special locations, they lack the practicality and desirability of small-scale storage. Commercializing Local Energy Storage I believe that creating an efficient local storage solution should be one of our prime energy targets. Let us develop what effectively would be a new major￾appliance industry. Since our proposed unit is very small, it could be easily mar￾keted to each one of those hundred mil￾lion or so energy customers who are seek￾ing local storage. Since the unit would have to be inexpensive—a few thousand dollars at most—customers who were not satisfied could replace their units or trade up to a better model, as they do now with other technical products such as comput￾ers. It would be a way to “PC” this critical aspect of the energy industry. Every five years or so, on average, customers would opt to upgrade their storage unit, based on local economic incentives and newly available product improvements driven by free markets and entrepreneurship. Inventive minds would be continually evolving the best possible answer to what fits inside this box. Then, every one of those sites in the electrical energy grid would be able to use one of these units to buffer the grid’s ener￾gy fluctuations. Real-time pricing for indi￾vidual electrical power usage would give each customer the incentive to buy a unit that could absorb the power needed to generate 100 kilowatt-hours of electricity in the six-hour time period when energy is cheapest on the grid. People who needed more than 100 kilowatt-hours of power or needed virtually trouble-free energy for longer periods could simply buy addition￾al or larger units. That would be the cus￾tomer’s decision. Basically, this local unit would solve the energy storage problem. With that solved, it would now be possible to get most of the energy on the grid from “unreliable” or episodic sources, like wind or solar. Without a local storage solution, however, we could not rely on these “other” energy sources to supply large amounts of energy on the grid, at least not at levels above 10–20%. Above those levels, we would need to have all the reserves in place, ready to provide electrical power when the sun stopped shining or the wind stopped blowing. Local energy storage would get us past that problem and give us an extremely robust, terrorist-resistant, delocalized electrical energy system. Completing the Grid: High-Voltage Transmission Lines In addition to a local system, one other innovation is needed on the grid to make it work. We need the capability to transport electrical power in hundreds of gigawatts over thousands of miles. High-voltage transmission lines would be very efficient for this purpose. In fact, we already have dc lines that carry electricity for 1500 miles “There has been a lot of talk about the hydrogen economy, which I believe is, despite its virtues, likely to remain a distraction from the real, practical solutions to our energy needs