Gravity Field Energy Storage and Recovery System

Information

  • Patent Application
  • 20220235745
  • Publication Number
    20220235745
  • Date Filed
    February 14, 2022
    2 years ago
  • Date Published
    July 28, 2022
    a year ago
Abstract
Device for storing energy, using a physical object, such as a mass or buoyant object floating in fluid. A mass is repositioned to greater altitude in a gravitational field to a position of higher potential energy. A buoyant object is forcibly submerged into a fluid, displacing fluid, to a position of higher potential energy. The stored potential energy may be recovered with extremely low loss regardless of the state of charge of the system, or length of time of the storage. Maintaining the charge is indefinitely lossless.
Description
BACKGROUND OF THE INVENTION
Field of the Invention

Significant advances have been made in alternative energy systems as society seeks to ameliorate the deleterious effects inherent in legacy energy systems. Fossil fuel systems rely on the combustion of hydrocarbons such as ethane, n-pentane, methane, n-octane, and coal, which, under perfect conditions, will produce heat and kinetic energy and the by-products of water and carbon dioxide. As an example, the combustion of methane in the presence of air is stoichiometric as





CH4+2(O2+3.76N2)→CO2+2H2O+7.52N2


An array of hydrocarbons that are the constituents of gasoline (a well-known example is n-octane), as well as the hydrocarbons associated with coal and fuel oil, all burn in a similar fashion. Automobile engines rely on the Carnot cycle and gas turbines, powering jet aircraft and marine propulsion, rely on the Brayton cycle to harness, through a mechanical arrangement, the rapid gas expansion of the burning fuel to develop continuous shaft horsepower.


Commercial electric power is produced when coal or fuel oil is burned to boil water, the steam being used to turn a turbine as per the Rankine cycle, producing a continuous shaft horsepower. Nuclear electric power generation utilizes a controlled nuclear fission of uranium and it's byproducts as a heat source to boil water, and similarly, develops a continuous shaft horsepower from a steam turbine. In both cases, the continuous shaft horsepower is used to rotate an electric generator.


The problems associated with our legacy systems dominate our technological, economic, strategic, scientific, and geopolitical landscapes. An energy hungry world seeks to control the world's precious hydrocarbon resources resulting in “blood for oil” military conflicts which themselves carry a risk of escalation to a global scope, raising the terrible specter of exchanged nuclear strikes between states equipped with atomic weapons.


The use of hydrocarbons as a fuel, even under perfect conditions, emits carbon dioxide as a byproduct, which as a “greenhouse gas” is implicated in global warming.1 Rarely are the conditions perfect however, and the burning of hydrocarbon emits many unfortunate byproducts which otherwise pollute the air, causing serious human health problems. 1http://www.globalchange.gov/


Nuclear electric power generation has the advantage that it emits no greenhouse gases. There are, however, a number of thorny problems associated with nuclear power. The mining, refining, and processing of uranium ore into a useable material, is an environmentally costly process with associated health risks.2 The operation of nuclear power stations is not foolproof as the disasters at Three Mile Island, Chernobyl, and Fukushima, demonstrate. The operation of nuclear power reactors produces a plethora of fission products associated with the spent nuclear fuel. Nuclear waste disposal involves the processing, transportation, and storage of these fission products. This presents an ongoing national problem involving challenging technological, scientific, strategic, and political issues.3 Moreover, spent nuclear fuel presents a security risk, as the proliferation of fissile materials can present opportunities to “rogue states” to obtain weapons grade nuclear materials. 2http://www.gjem.energy.gov/moab/3http://www.energy.gov/photos/yucca-mountain


The development and deployment of alternative energy systems beyond the legacy systems has the potential to alleviate many of the above problems. Light energy from the Sun striking the Earth is a far greater potential source of energy than all of the world's proven oil reserves. But new challenges arise due to the nature of the alternative systems.


Many of the alternative energy systems are not continuous systems but are time-varying as they only generate power when the alternative energy source is available. Solar powered photovoltaic cells produce appreciable power only when sufficient sunshine is available. Wind generators produce power only when the wind is blowing. Tidal water systems generate energy only when the water is moving, etc. This non-continuous, or periodic power harvesting technology requires massive energy storage systems to transform the periodic energy pulses to a quasi-continuous system to meet society's demand.


Description of Related Art

Each of the periodic alternative energy systems rely on an energy storage system to capture the excess energy and deliver it when required. A typical alternative energy system will generate electrical energy. Solar photovoltaic cells, wind generators, tidal and wave generators will use batteries and a battery charging system to store excess electrical energy. When required, the batteries will be switched from charging mode into discharging mode to apply the stored electrical energy. The delivered electrical energy is in the form of Direct Current (DC) electrical energy and may require the use of DC to DC converters and DC to AC (Alternating Current) inverters to deliver the stored energy in a form that is directly usable.


These periodic alternative energy systems then, rely on the added complexity and expenses related to energy conversion and chemical battery storage technologies. Chemical Batteries suffer from low energy/power density, poor low-temperature performance, limited cycle life, intrinsic safety limitations, and high cost.


An important consideration in any energy conversion technology is the efficiency of the system which describes the losses inherent in the conversion. Lead acid batteries are commonly used in small photo voltaic systems. Sandia National Laboratories studied lead acid battery efficiencies and found that efficiencies are as low as 50% if the battery is at a high rate of charge when charging begins. Also, partial charging is deleterious to the battery itself:

    • This result has important implications to operational PV systems. That is, if a battery is partially charged for several consecutive cycles (for example, the array is marginally sized and there is a series of less than full sun days in the winter) the useable battery capacity decreases each cycle, even though the same amount of energy has been presented to the battery each day. This is the result of battery inefficiencies, electrolyte stratification, and sulfate buildup during these partial charges.4 4A Study of Lead-Acid Battery Efficiency Near Top-of-Charge and the Impact on PV System Design John W. Stevens and Garth P. Corey Sandia National Laboratories, Photovoltaic System Applications Department Sandia National Laboratories, Battery Analysis and Evaluation Department PO Box 5800, MS 0753 Albuquerque, N. Mex. 87185-0753


Thus, time-varying alternative energy systems rely upon a storage technology which is inherently inefficient and problematical from an operational, financial, and design standpoint. What is required is an alternative energy storage system that does not require batteries. The Gravity Field Energy Storage & Recovery System Invention is designed to deliver this alternative solution.


SUMMARY OF THE INVENTION

The Gravity Field Energy Storage & Recovery System [GFESRS] invention is a mechanical, electrical and electronic system that has the ability to harness any electrical or mechanical power source and allow it to do work to configure a mechanical system into a state of high potential energy, using either a hi-mass object in a gravitational field or a large buoyant object submerged into a fluid.


The charging cycle consists of repositioning a massive object in a gravity field to a position of higher potential energy. The potential energy can be stored without loss for extended periods of time.


The potential energy stored in the invention can be recovered on demand. The energy recovery mode consists of releasing the massive object in the gravity field in a controlled fall, producing a kinetic energy which can then be transformed into a useable form of energy such as electricity, pneumatic, or hydraulic power.


The work done to elevate the mass in the gravitational field then, is manifested as potential energy. The potential energy is stored indefinitely as long as the mechanism is in working order. This energy storage technique will not lose any potential energy over time as many other energy storage systems will.


When the system requires the stored potential energy to be released and recovered, the energy recovery cycle is activated. The mass suspended in a gravitational field is coupled to an apparatus that can convert the stored potential energy. The locking mechanism is released and allows the force of gravity to deliver a controlled acceleration of the mass towards the center of gravity. As the mass is accelerated in the gravitational field, the energy conversion apparatus, converts the kinetic energy into a form that can perform the useful work that system requires.


The present invention works the same in the context of a fluid whether the fluid is gas or liquid. Typically, the mass is denser than the surrounding fluid and energy is recovered in a controlled fall. This is the case if the mass is in air or water. This method would also work in a vacuum. If the mass is less dense than the surrounding fluid, it would be buoyant and tend to “float.” In such a case, mechanical energy can be stored by forcing the mass to submerge into the fluid. The energy can be recovered by allowing the mass to float, recovering the energy as the mass displaces upward. This would apply to a buoyant object in water, or a lighter than air vessel or dirigible. Forcing the dirigible toward the center of the earth would be to reposition it to a position of higher potential energy. This energy can be recovered in a “controlled float” as the tethered dirigible rises in the atmosphere. Forcing a buoyant object in water to submerge stores energy which can be recovered as the object is allowed to rise.


Thus, a buoyant object can be repositioned to a position of higher potential energy by forcing it to submerge into a fluid and can be used to store energy. The energy storage can be released on demand, producing a kinetic energy which can then be transformed into a useable form of energy such as electricity, pneumatic, or hydraulic power. Thus a massive object can be repositioned to a position of higher potential energy by raising its altitude and can be used to store energy. The energy storage can be released on demand, producing a kinetic energy which can then be transformed into a useable form of energy such as electricity, pneumatic, or hydraulic power.


Grid Scale Gravity Field Storage systems requires large volumes, whether a buoyant object or a massive object is employed. An effective way to manage this is use a multiplicity of storage units. As the scale of the storage system increases the physical size of the system necessarily increases which becomes a limiting factor in that the number of potential installation sites decreases. Also, a proliferating number of storage units would each require dedicated machinery in the charge and discharge cycle, adding to cost, which is a factor effecting economic viability.


To overcome these issues, a Distributed Gravity Field Energy Delivery and Storage System is disclosed.


Public utilities commonly deliver power over a distribution network of electrical conductors. Some utilities deliver power by distributing steam through a network of pipes. The present invention distributes mechanical energy via known diesel locomotive type and known track type, and stores it onsite of its end user or grid scale storage installations. Power from a multiplicity of power sources, including, but not limited to, a power grid, an electrical generator, solar energy, hydroelectric energy, geothermal energy, wind energy, ocean tidal energy, ocean current energy, ocean wave energy, ocean thermal energy, nuclear fission, nuclear fusion, electromechanical energy, energy from a chemical reaction. are delivered to the locomotive via an electrical conductor, whether by electrified third rail, or electrified overhead conductor, to a contact on the locomotive.


The diesel locomotive is itself a power plant, using powerful, a high efficiently diesel engine, to generate electricity which powers drive motors on the wheels. That power can be used to charge a storage system via a power take off shaft. The locomotive can move between a multiplicity of storage units, whether buoyant type or mass type, in and out of cities, from hill to valley, marsh to salt flat. The locomotive can also be a platform for alternative power generation, whether that be a mounted gas turbine, hydrogen fuel cell, or other, where the fuel is part of the locomotive payload. This offers fast and flexible retooling to take advantage of varying fuel costs, moving quickly to adapt to low prices in natural gas, hydrogen, JET-A or the like. The locomotive could also be the platform for an electric generator such the storage unit could be discharged through the locomotive, obviating the need for a generator at each storage unit. However, this is likely unattractive economically, since the period of peak demand is short compared to the likely charging period, and releasing all the stored energy quickly would require a generator at each storage unit.


The three major power consumers sectors in the United States are the retail sector, the residential sector, and the industrial sector—each consuming an approximately equal third of the power generated in the U.S. The industrial sector demands consistent power levels around the clock, every day of the year. The retail and residential sectors' demand varies seasonally and at different times of the day, at different days of the weak. This leads to demand pricing, where utilities charge a different price for power, depending on the season, weather, time of day and/or the current instantaneous actual demand. This is particularly onerous to industry since it's fixed cost structure cannot be easily predicted—the cost of energy varying in real time. Peak demand, which translates to high cost, occurs in hot weather during the middle of the day when air conditioning is prevalent. And, in colder seasons, peak demand occurs in the morning when people are going to work, and late afternoon and evening when they are home. Low demand occurs at night, when there is little human activity, though night time may very well be a time of intense wind generation.


If industry could store cheap energy at night when demand is low, and release it during the day when energy prices rise, industry could mitigate the problem of price volatility and lower the overall cost of energy to the business. This would also hasten the development, by making more attractive, green, alternative energy sources like wind and solar, which suffer from the problem of intermittency of generation, which prevents them from becoming a viable grid scale power source.


Factories commonly have rail sidings which take delivery of raw materials, ship finished products, and can now take delivery of mechanical energy for storage. Factories at waterside can have buoyant storage units, or “float farms” jutting out into the waterway on piers. High tension power transmission companies can offload excess power to storage facilities at intermediate points in their transmission networks of their own choosing, sited on land that tends to be inexpensive.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1) Locomotive Mounted System



FIG. 2 Cable mounted buoyant system as in



FIG. 3 Rack and gear buoyant system



FIG. 4 Tower mounted cable/mass system



FIG. 5 Tower mounted buoyant system



FIG. 6 Ground mounted buoyant system



FIG. 7 Array of storage systems accessed by rail mounted system as in FIG. 1





DETAILED DESCRIPTION OF THE INVENTION

The Gravity Field Energy Storage & Recovery System [GFESRS] Invention is a mechanical, electrical and electronic system that can store energy from a variety of sources. The energy is directed at a mechanical/electrical arrangement designed to raise a large massive object in a gravitational field, storing the energy as potential energy in the field.


The Force of Gravity is described as the mutual physical attraction which every particle in the universe has with every other particle in the universe. Newton discovered the universal law of gravitation in the year 1666 and described the force of gravity as






F
=


G


M
a



M
b



r
2






Where Ma and Mb are the masses of two particles, r is the distance between the particles, and G is a constant of proportionality. The constant G was first measured by Cavendish in 1771 and the accepted value today is






G=6.67×10−11 Nm2/kg2


A large ensemble of particles such as a planet, acts as an aggregated single object with a mass equal to the sum of the masses of the particles, and the force of gravity directed at the center of mass of the ensemble. Thus, the force of gravity upon an object near the surface of the Earth is






F
=


G


M
e


m


r
2






Where Me is the mass of Earth taken as 5.98×1024 kg, m is the mass of an object infinitesimally less massive than earth, and r is the distance between their centers of mass. The force is direct toward the center of the earth.


The acceleration due to gravity is









a
=



F
m







=




GM
e


r
2








=





9.8






m
/

s
2







or







32






ft
/

s
2











and interestingly, is independent of the mass of the object. This is the acceleration of gravity near the surface of the earth, which is usually denoted with a lower case italic g.


We calculate the change in g with increasing altitude, such







g


(
r
)


=


GM
e


r
2












Δ






g


(
r
)



=





d





g

dr


Δ





r







=




-


2


GM
e



r
3




Δ





r







=




-


2





g

r



Δ





r








and the fractional change is








Δ





g

g

=

-


2

Δ





r

r






At the earth's surface where r=6×106 m and so g increases one part per million for every increase in altitude of 3 meters. This insignificant change is very important in considering the present invention since the efficiency of the energy storage does not change in relation to the state of charge.


Aristotelian mechanics, which was accepted for thousands of years, believed that a force was necessary to maintain a body in uniform motion. Newton, through experimentation found rather, that a force acting upon a body accelerates the body according to his famous 2nd Law







F
=

d

d

t




Mv




The law in one dimension







F


(
x
)


=

m



d

v


d

t







Can be integrated as







m





x
a


x
b






d

v


d

t



d

x



=




x
a


x
b





F


(
x
)



d

x






And after a formal procedure we find that





½mvb2−½mva2=∫xaxbF(x)dx


where the term ½mv2 is known as the kinetic energy and the right hand side is called work as the particle moves and changes velocity from a to b.


In shorthand we say






K
b
−K
a
=W
ba


This formula is known as The Work-Energy Theorem in one dimension.


In practice we see that a canon ball traveling at high velocity may hit the hull of a ship and its velocity reduces to zero. It is the change in velocity which imparts the energy and does work on the hull. We also see that the velocity the canon ball, instead of being supplied by the expanding gasses in the canon could be supplied by a drop from a vertical height. The canon ball dropped from rest at a given height h above the ground will deliver a kinetic energy to do work on the ground in proportion to its height above the ground. We can call this a potential energy which can be released at will. It will require work to elevate the canon ball to its prearranged height. As it turns out the potential energy is equal and opposite the kinetic energy. We say






E=K+U


Where U denotes the potential energy of the system and E is the total mechanical energy of the system which is always constant since mechanical energy is conserved. Thus, as a mass at rest at a given height represents a potential energy, gravity will accelerate the mass and convert it to kinetic energy as the potential energy is reduced.


The Gravitational Energy Field Storage & Recovery System [GEFSRS] Invention operates within gravitational fields. These gravitational fields can be naturally occurring on planets and related celestial bodies.


When we do work to separate masses that are gravitationally attracted to each other we create a form of potential energy. This invention shows how to harness these forces to store energy and then recover this stored energy on demand.


We harness energy from a variety of sources to perform the work of repositioning the mass in the gravitational field driving the mass opposite the force vector of the gravitational attraction. This allows us to increase the potential energy in the system. Once energy is stored by the repositioning of the mass, we have the ability to recover the energy immediately or to store it indefinitely. The potential energy will remain intact indefinitely if the positioning apparatus remains intact. Once stored, maintaining this energy is lossless for an indefinite period of time unlike battery systems. This is the energy storage phase. Unlike battery systems, energy storage can be implemented incrementally up to the storage limit of the system, regardless of the state of charge or history of the system, without loss of efficiency.


The stored energy can be released and recovered by controlling the acceleration of the mass as the potential energy becomes kinetic energy. This kinetic energy can be converted to a plurality of useful energy forms. These energy forms include electrical, pneumatic, hydraulic and other forms.


Once we have secured the initial energy storage we can chose to

    • 1. Add energy to the system
    • 2. Keep the energy stored
    • 3. Release the energy from the system.


The energy storage phase can be repeated with random or continuous amounts of energy until the GEFSRS embodiment reaches it energy storage limits. The stored energy can remain for indefinite periods of time without loss to the stored potential energy.


The stored energy can be released by controlling the acceleration of the Mass to the Earth. The conversion of the stored energy as potential energy gees becomes kinetic with the start of the release cycle. This kinetic energy can do work and the work can create a plurality of energy forms. These energy forms can be electrical, pneumatic, hydraulic power, or other forms.


General System Configuration

Referring to FIG. 1 A Diesel locomotive of know type, using a rail system of known type provides torque through one or more Power Take-Off Shaft 2 (PTO) to Storage Device 1. The Storage Device can be one of several storage device types or mixtures of devices.


Torque is directed to PTO via Transmission 3 which selects input from either locomotive power source, locomotive mounted power source 6, or electric motor 4. A third rail electric power source 9 is contacted by Electric contact 8 to provide power to Electric Motor 4 which turns PTO 2 through Transmission 3. The same arrangement can be accomplished through overhead wires and contacts. The electrified rails or conductors or powered by a multiplicity of power sources including off shore wind etc. Electric control device 5 selects from 6 Locomotive mounted Power Source 6 or Electrified third rail 9. Shaft 11 connects Electric motor 4 to transmission 3.


The torque at PTO is directed from either of a multiplicity of power sources including

    • A) The diesel locomotive engine
    • B) The diesel locomotive drive motors
    • C) The electrified third rail or overhead conductor
    • D) Locomotive mounted power source such as hydrogen fuel cell, gas turbine, jet engine, or other.


Grid scale Gravity Field Storage systems requires large volumes, whether a buoyant object or a massive object is employed. An effective way to manage this is use a multiplicity of storage units. As the scale of the storage system increases the physical size of the system necessarily increases which becomes a limiting factor in that the number of potential installation sites decreases. Also, a proliferating number of storage units would each require dedicated machinery in the charge and discharge cycle, adding to cost, which is a factor effecting economic viability.


To overcome these issues, a Distributed Gravity Field Energy Delivery and Storage System is disclosed.


Public utilities commonly deliver power over a distribution network of electrical conductors. Some utilities deliver power by distributing steam through a network of pipes. The present invention distributes mechanical energy via known diesel locomotive type and known track type, and stores it onsite of its end user or grid scale storage installations. Power from a multiplicity of power sources, including, but not limited to, a power grid, an electrical generator, solar energy, hydroelectric energy, geothermal energy, wind energy, ocean tidal energy, ocean current energy, ocean wave energy, ocean thermal energy, nuclear fission, nuclear fusion, electromechanical energy, energy from a chemical reaction. are delivered to the locomotive via an electrical conductor, whether by electrified third rail, or electrified overhead conductor, to a contact on the locomotive.


The diesel locomotive is itself a power plant, using powerful, a high efficiently diesel engine, to generate electricity which powers drive motors on the wheels. That power can be used to charge a storage system via a power take off shaft. The locomotive can move between a multiplicity of storage units, whether buoyant type or mass type, in and out of cities, from hill to valley, marsh to salt flat. The locomotive can also be a platform for alternative power generation, whether that be a mounted gas turbine, hydrogen fuel cell, or other, where the fuel is part of the locomotive payload. This offers fast and flexible retooling to take advantage of varying fuel costs, moving quickly to adapt to low prices in natural gas, hydrogen, JET-A or the like. The locomotive could also be the platform for an electric generator such the storage unit could be discharged through the locomotive, obviating the need for a generator at each storage unit. However, this is likely unattractive economically, since the period of peak demand is short compared to the likely charging period, and releasing all the stored energy quickly would require a generator at each storage unit.


The three major power consumers sectors in the United States are the retail sector, the residential sector, and the industrial sector—each consuming an approximately equal third of the power generated in the U.S. The industrial sector demands consistent power levels around the clock, every day of the year. The retail and residential sectors' demand varies seasonally and at different times of the day, at different days of the weak. This leads to demand pricing, where utilities charge a different price for power, depending on the season, weather, time of day and/or the current instantaneous actual demand. This is particularly onerous to industry since it's fixed cost structure cannot be easily predicted—the cost of energy varying in real time. Peak demand, which translates to high cost, occurs in hot weather during the middle of the day when air conditioning is prevalent. And, in colder seasons, peak demand occurs in the morning when people are going to work, and late afternoon and evening when they are home. Low demand occurs at night, when there is little human activity, though night time may very well be a time of intense wind generation.


If industry could store cheap energy at night when demand is low, and release it during the day when energy prices rise, industry could mitigate the problem of price volatility and lower the overall cost of energy to the business. This would also hasten the development, by making more attractive, green, alternative energy sources like wind and solar, which suffer from the problem of intermittency of generation, which prevents them from becoming a viable grid scale power source.


Factories commonly have rail sidings which take delivery of raw materials, ship finished products, and can now take delivery of mechanical energy for storage. Factories at waterside can have buoyant storage units, or “float farms” jutting out into the waterway on piers. High tension power transmission companies can offload excess power to storage facilities at intermediate points in their transmission networks of their own choosing, sited on land that tends to be inexpensive.

    • 1 Storage Device
    • 2 Power Take-Off Shaft
    • 3 Transmission
    • 4 Electric motor
    • 5 Electronic control device
    • 6 Locomotive mounted Power Source
    • 7 Electric interconnect
    • 8 Electric contact
    • 9 Electrified third rail
    • 10 Power Source to third rail
    • 11 Shaft

Claims
  • 1. An energy storage device comprising: a first shaft comprising an input end and an output end to input rotational kinetic energy to be stored; a main shaft comprising an input end and an output end; a transmission operably connected to the output end of the first shaft and to the input end of the main shaft such that the transmission can change a rotation ratio between the first shaft and the main shaft; a storage unit comprising an object to be displaced vertically such that potential energy due to gravity can be increased;where the object is a buoyant object;where the object is rigidly fixed to rack, wherein the rack is operably connected to a gear, wherein the gear is rigidly attached to the main shaft, such that the rotation of the main shaft displaces the object vertically to increase potential energy;a second shaft comprising an input end and an output end to output the stored energy; a second transmission operably connected to output end of the main shaft and to the input end of the second shaft such that the transmission can change the rotation ratio between the main shaft and the second shaft;where the first shaft is operably connected to the power take off shaft of a diesel locomotive.
  • 2. The storage device in claim 1 where the object is a massive object.
  • 3. The storage device in claim 1 where the object is rigidly fixed to cable, wherein the pulley is operably connected to a pulley, wherein the pulley is rigidly attached to the main shaft, such that the rotation of the main shaft displaces the object vertically to increase potential energy;
  • 4. The storage device in claim 3 where the object is a massive object.
  • 5. The storage device in claim 1 where an electric motor on the diesel locomotive is operably connected to the power take off shaft and diesel locomotive is operably connected to an electrified third rail, such that the electrified third rail can power the power take of shaft.
  • 6. The storage device in claim 5 where a multiplicity of power sources, including a hydrogen fuel cell, gas turbine, or others, mounted on the diesel locomotive are operably connected to the power take off shaft.
  • 7. The storage device in claim 5 where the electrified third rail is operably connected to a multiplicity of input power sources including one or more sources of energy selected from the following: a power grid, an electrical generator, solar energy, hydroelectric energy, geothermal energy, wind energy, ocean tidal energy, ocean current energy, ocean wave energy, ocean thermal energy, nuclear fission, nuclear fusion, electromechanical energy, energy from a chemical reaction, and mechanical energy.
Continuations (1)
Number Date Country
Parent 14490630 Sep 2014 US
Child 17671560 US