Giorgio Szegö Bucharest 27 th May, 2005 The Challenge of Electricity Storage

 Protection of life on planet heart  Electricity and life expectancies  A world demand  Price spread in the electricity market  Nuclear “renaissance”  Renewable energy sources  Nuclear power  Long term bulk electricity storage systems  Bulk Energy Storage: cost analysis  Some applications  Load management: cost analysis  Renewables matching: cost analysis  Compatibility with the existing power systems Contents

Protection of life on planet heart Climate change Global warming Greenhouse gas emissions, balanced by thin powders Sea level rise...over the past 100 years, sea level has risen by 1.0 to 2.5 millimeters per year. Sea level will rise at a rate of about two to five times the current rate over the next 100 years from the combined effect of ocean thermal expansion and increased glacier melt. Antarctica and Greenland, the world's largest ice sheets, make up the vast majority of the Earth's ice. If these ice sheets melted entirely, sea level would rise by more than 70 meters. Heart temperature has never been so high in the last years!!

Electricity and life expectancies Energy consumptions and life expectancies are strictly related Increasing consumption of energy is associated with longer life expectancies Source: Atlante Geografico De Agostini

Electricity and life expectancies World population (billions) Source: United Nations publications

Electricity and life expectancies World Energy consumptions Source: Chevron

A world demand The most energy demand will come from developing countries In 2030 the world’s energy needs are expected to be almost 60% higher than they are now In developing countries 1,6 billion people have a very low life expectancies and no access to electricity Will supply of electricity for all cause the end of the Planet Heart?

Energy storage: a possible solution? Price spread in the electricity market Why don’t we buy electricity when the price is low and sell when it’s high?

Nuclear “renaissance” Everybody agree the nuclear option Without nuclear power it’s impossible to reduce greenhouse gas emissions do you want to be politically correct, but technically wrong? The only solution to carry out the Clean Development Mechanism (CDM), as stated in the Kyoto protocol, is the use of large hydro and nuclear generation systems. Nuclear power does not contribute to the major cause of climate change; it has zero emissions of CO 2 and of sulfure dioxide. A coal plant emits six million tons of carbon dioxide and sixteen thousand tons of nitrous oxide

Renewable energy sources …renewable energy sources! Solar power Wind power but they do not work, indeed….

…the weather is capricious Renewable energy sources Solar and wind power can only produce energy intermittently …environmental problems All discontinuous renewable energies must be complemented by a long term bulk electricity storage system For instance wind farms require millions of kilograms of concrete and steel …to build a solar power plant takes more energy than the whole energy produced by the same solar power plant during all its life cycle

Nuclear power The production of electricity via nuclear power plants cannot be tuned to demand Nuclear power production must be complemented by long term bulk storage system

For periods of 1 to 8 hours, or more Long term bulk electricity storage systems  batteries  compressed air energy storage (CAES)  pumped hydro  hydrogen  cryogenics

Some applications Energy is stored during off-peak hours (typically at night) and then discharged during peak hours. This not only saves money on the basis of the difference between peak and off-peak rates, but also provides a more uniform load factor for the generation, transmission and distribution systems. Renewable energy sources, such as wind and solar, are desirable because they are nonpolluting and in plentiful supply. By their very nature, however, they are intermittent; often the profile of energy generation does not coincide with the demand cycle. Energy storage can be used to match the output of renewable sources with any load profile. Load management Renewables matching Source: SANDIA

pumps underground, pressured vessels, liquid Production Storage used to activate the compressor of a turbine. This operation uses 60% of the total power. Use Compatibility with the existing power systems CAES

via electrolysis, fuel cells or nuclear Production  pressured vessels  cryogenics  metal hydrides Storage Hydrogen can be mixed with natural gas (70% - 30%) and burned in a turbine Use Compatibility with the existing power systems

it needs a water reservoir not only at the top but also at the bottom Storage  very efficient  in some countries its implementation is impossible  compatible with the existing power systems Use Compatibility with the existing power systems Hydro pumping pumps Production

Bulk Energy Storage: cost analysis Source: SANDIA

Load management: cost analysis Source: SANDIA

Renewables matching: cost analysis Source: SANDIA

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