Description: Energy Storage for 24-hour-per-day use, every day of the year
Solar energy is not available at night or on cloudy days. Sometimes, wind does not blow strong enough (9 mph).
There are many proven-and-emerging technologies for storing excess energy for use any time of day. The "best"
storage technique depends on the type of energy. A minimum number of energy-type conversions should be required.
Heat and Cold can be stored in "Thermal Mass." Hot water or ice can can be stored in large well-insulated tanks for
days or weeks. High temperatures (in the 1,000 degrees F range) can be stored in molten salts for a day or so.
Wind-drive compressors can store compressed air indefinitely (in deep wells and high-pressure gas reservoirs).
It can be used at any time to generate electricity, and also for cooling (at the same time) as the pressure is released.
There are many ways to store electricity (from any source) for long periods of time until needed for peak loads.
Chemical batteries are hundreds of years old. The lead-acid battery used in many modern cars has been around since
the late 1800's. Thomas Edison developed storage battery technology for 1890’s electric car 1,000-mile endurance race.
Various forms of 21st century lithium batteries are competing for cost-effectiveness. Electric cars are providing strong
motivation for significant research into improved battery technology for the near future. Off-the-shelf battery technology
is currently sufficient, but not as cost-effective as we expect it to be when we are ready to occupy Emerald Eco-City.
Carbon nanotube batteries are emerging in multiple research laboratories. They offer the promise of holding trillions of
small electric storage cells in only a few inches of space. They are not "off the shelf" or cost effective today, but they may
be much closer by the time we are ready to occupy Emerald Eco-City. Carbon nanotubes are "grown" out of abundant,
inexpensive pure carbon. We will support an aggressive nano-technology research and development laboratory for our
own internal use, and for sale as a strong future income source with many billions of dollars in revenue potential, for the
benefit of consumers around the world (enhancing USA exports, and our international balance of trade).
Over 30 sites in Japan, and a few in the U.S., are using sodium / sulfur “polysulfide”chemical storage. Off-peak power is stored
for use during peak periods. The concept would work well for solar or wind electrical energy storage. The largest example is a
6 Megawatt 8-hour electricity storage system for Tokyo Electric Power Company . We expect many electricity storage innovations soon.
One concept that is being used today to effectively store energy is with gravity. When excess energy is available, water can
be pumped uphill and stored in a large reservoir. When needed, the proper amount of water is released through hydroelectric
turbines to generate only the needed electricity. The water remains in the lower reservoir until it can be pumped up to the
higher reservoir, when excess energy is again available. The water is continually recycled. 2% of America's electricity is
being stored and generated in this way today. We understand the associated energy storage economics very well.
If it does rain during some
seasons, water can be collected in the upper reservoir, providing additional free-fuel part-time
on-demand energy. Our reservoirs may be above ground, covered-and-sealed to reduce evaporation, underground aquifers,
or a location-specific combination. Our gravity energy storage system capacity could be designed to provide electrical energy
for days, weeks, or months. Expansion storage system components can be added as needed over time. Location-specific
design optimization will be required when we make the final decision about where to build on available land.
Eco-City will be built in the dry USA Southwest, which is mostly ringed by mountains. A reservoir storage system
could be built miles away from our city. Wind energy could be collected in mountain passes, and stored in the reservoir.
The windmills could be connected directly to water pumps (without the need to use electricity to less-efficiently power
our water pumps). The reservoir water pressure energy storage potential would not be converted into electricity until it
is needed (when solar power is not available at night, on cloudy days, etc.).
Another way to store energy with gravity is a massive weight (like a very-large-scale version of a grandfather clock weight).
Imagine a huge weight that is roughly 100-feet wide. When excess energy is available, gear-reduction motors could lift the
weight 480 feet high - storing enormous potential energy. When the sun is not shining and the wind is not blowing, the weight
could be gradually lowered over many hours, spinning electrical power generators. It is simply a matter of Engineering Physics
Calculations to properly size one-or-more such systems for on-demand power as needed. This may be cost-effective in some very-flat locations where a water-reservoir system is less feasible, but the gravity-storage principle is similar to water.
There are many unexplored
creative high-and-low-tech ways to store energy for 24-hour-a-day usage whenever needed.
The unprecedented scale of Emerald Eco-City will allow us to investigate the most-cost-effective methods conceivable.
We will implement multiple evolving alternatives and publish our performance monitoring data for worldwide refinement.
No one can predict the technology future with certainty, but Hydrogen is very-likely to become a primary energy storage
medium in a decade. Hydrogen is the most-abundant element in the universe. It is the source of the sun's fusion energy.
Hydrogen was selected to send men to the moon on the Apollo Saturn V rocket, and to send our U.S. Space Shuttle into orbit,
because hydrogen has a high energy density per unit of mass (weight).
Their are many ways to produce hydrogen (H2) today, but some of them release CO2 greenhouse gas, or
they are inefficient
with electrical energy. Laboratories (funded by NASA, et.al.) are currently working on photosynthetic processes that directly
convert sunlight plus H2O water into H2 and O2. These processes work, but they are not yet cost-effective. It is now HOPED
that new nano-technology research (which we will support) will make hydrogen production inexpensive and pervasive.
Burning hydrogen in the atmosphere is a BAD idea, since the high temperature of the intense flame causes nitrogen
atmosphere to combine with oxygen to form various harmful nitrogen oxides (NxOx), which are powerful greenhouse gases.
Some byproducts of combustion (like nitrogen dioxide - NO2 - a component of common smog) are very poisonous.
The future of using hydrogen for Clean, Emerald-Green 24 / 365 Energy Storage is the Hydrogen / Oxygen Fuel Cell.
H2 + O2 react in the presence of a catalyst to form pure laboratory-quality drinking water plus electricity. This was the
technology that was used on Apollo to efficiently provide electrical energy storage and water for sending men to the moon
and back. (Efficient holistic system integration and optimization involves using one system for multiple purposes.)
The current limitation of hydrogen / oxygen fuels cells, and the direct conversion of sunlight and water into hydrogen and oxygen (the opposite process) is that both of these technologies require expensive catalysts (like platinum), which cost more
than other off-the-shelf electricity storage technologies. We have good reason to believe that near-future platinum-free liquid catalysts, nano-technology research, etc. will dramatically lower the cost of using hydrogen to store abundant free-fuel
solar energy for use when the sun is not shining.
Off-the-shelf technology is sufficient for our first Emerald Eco-City energy storage systems, but we expect rapidly-emerging
technologies for tomorrow's electric cars to motivate significant electrical energy storage system economic improvements,
which will obviously provide worldwide benefits to us all. We plan to remain on the leading edge of energy technology.
Lifelong Learning In An Ever-Expanding Universe Of Endless Possibilities
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E-Mail To: ZEDMaster@ZeroEnergyDesign.com