Free-piston kinetic engines have been the subject of intensive research during the past twenty-five years and many engine manufacturers tried to build commercial free piston engine models because of its attractive features, such as increased weight to power ratio and reduced frictional losses by the elimination of a heavy crank shaft with substantial vector angle losses.
Over time, all of them gave up, primarily due to faulty actuation methodology after failing to develop suitable actuation means of timing and running the engine. There are many prior art patents that describe various means to actuate a free-piston engine such as slide valves used by old steam engines with problematic mechanical connections, poppet valves, reed valves, timing cams, electrically operated solenoid valves, and pressure actuation methods using a slave piston and cylinder designed to produce pressure differentials as the engine runs to drive an actuator assembly, and many other prior art attempts at actuation— all having substantial limitations.
Prior art kinetic engines of the electrically operated solenoid valve design are extremely problematic because they over-heat with continuous use of over a few hundred cycles per minute as heat builds up in the resistance coils, they require a supply of electricity to operate, require an electronic control module, and need proximity sensors to operate.
Prior art free-piston kinetic engines of the pressure-actuated design have a substantial number of severe problems, such as the location at which actuation takes place varies with changes in temperature and pressure. Even when the engine does actuate, often it is not at the desired stroke length with the piston stoke being too short or too long.
All of these problems encountered by prior art free-piston engines attempts have been eliminated by the U.S. Megawatts Linear Engine and its novel exhaust-actuated means of timing, whose advantages are:
(1) No electricity is required to start or operate the kinetic engine; and,
(2) Capable of attaining high speed, high flow rate precision actuation; and,
(3) The site of actuation is exactly established by the position of the exhaust ports at the end of the desired piston stoke length; and,
(4) The full force of the working fluid is available for actuation; and,
(5) Full actuation takes place as the movement of the actuator cylinder must be sufficient to open the actuator exhaust ports in response to the pressure differential from the working fluid’s higher pressure to the lower exhaust pressure; and,
(6) Elimination of compression pistons cylinders needed for prior art pressure actuation means of timing, which means fewer moving parts are required; and,
(7) Increased power to weight ratio; and,
(8) Reduced frictional losses by elimination of the heavy crank shaft with substantial vector angle losses; and,
(9) Lesser parasitic engine power losses due to the elimination of the slave pistons and cylinders for prior art pressure actuation that consume substantial power.
Cost & Performance Advantages of U.S. Megawatts Generators Over Recip Engines & Gas Turbines
The U.S. Megawatts Generator offers significant price and size reductions on a normally high-cost product that no responsible CEO or CFO can afford to ignore. The Linear Engine-based U.S. Megawatts Generator holds the potential to be nearly 20% more efficient and 50% less-expensive than a Gas Turbine generator.
As coal-fired power plants and property owners with a natural gas connection realize they can lower their operating costs and increase their profits by fuel-switching to natural gas-generated electricity – they are going to seek out the lowest-cost natural gas-fueled electric generating equipment they can find.
The U.S. Megawatts Generator offers a lower-cost higher-performance alternative to retrofitting their power plants with the same old expensive Natural Gas Turbine Generators — made by GE, Siemens, Mitsubish, Alstom or other turbine-makers — at costs > $1,000,000 per MW.
While a turn-key 100-MW GE or Siemens Gas Turbine facility will cost >$100-million – a 100-MW Linear Engine-based U.S. Megawatts Generator would cost approximately $50-million – half the cost of a turbine.
Gas Turbines are twice as expensive as a Linear Engine-based U.S. Megawatts Generator because Gas Turbines are more than twice the size, much more complicated to build, are sensitive to operate, and prone to turbine blade failures that are expensive to fix.
Because of its market disruptive price differential, U.S. Megawatts, Inc. managers believe they will be successful in capturing a significant share of the market by selling their simpler, lower-cost and more efficient Linear Engine-based U.S. Megawatts Generators direct to budget-minded CEOs/CFOs of the major electric power producers in the USA and worldwide that are fuel-switching from Coal to Natural Gas – and direct to large end-user electricity-customers (factories, shopping centers, retail superstores and other local property owners) who are connected to a natural gas meter and want to lower their cost of electricity.
Because many of these companies’ executives have fiduciary duties to their shareholders to save money, save time, save energy and reduce emissions – they will be more inclined to adopt use of a just-as-effective U.S. Megawatts Generator at one-half the cost of a Gas Turbine alternative.
Switching From Coal to Natural Gas. With the EPA’s Mercury and Air Toxics Rule (aka “Utility MACT”) and the Cross State Air Pollution Rule (CSAPR) regulations in effect, it will become prohibitively expensive for America’s Coal-fired power plants to sufficiently clean up their emissions.
The rules require new plants to emit a maximum of 1,000 pounds of carbon dioxide per megawatt hour. While the newest natural-gas-fired power plants emit about 800 pounds of carbon per megawatt hour, new coal plants emit 1,600-1,900 pounds per megawatt hour (requiring additional expensive pollution-abatement costs).
According to EPA modeling and announcements from electricity producers, nearly 35 gigawatts of electricity capacity will close because of these two rules. At-risk plants that may be uneconomical to upgrade represent about 70,000 megawatts of generating capacity. These at-risk plants provide about 9.3% of total US electric power generation .
For the 570+ coal-fired power plants in America offering 315-gigawatts of on-demand power, one-third began operating between 1940 and 1969, and it may not be economically viable to install emission scrubbers and state of the art pollution controls to clean up their emissions – especially when, for almost the same money, they could upgrade their facility to burn cleaner, cheaper natural gas instead.
The average emissions rates in the United States from natural gas-fired generation are: 1135 lbs/MWh (Mega Watt hours) of carbon dioxide, 0.1 lbs/MWh of sulfur dioxide, and 1.7 lbs/MWh of nitrogen oxides. Compared to the average emissions from burning coal, natural gas produces half as much carbon dioxide, less than a third as much nitrogen oxides, and one percent as much sulphur oxides.
While U.S. coal prices have increased by more than 70% in the past decade (inflation adjusted), the monthly average price for Natural Gas delivered to electric generators is at a 10-year low, due to America’s new abundant 100-plus-year supply of fracked shale gas, whose price is expected to remain at <$4-$5 per mmbtu (perpetuating the supply of lower-cost electricity).
Electricity from a conventional coal-fired power plant costs 9.5 cents/per kilowatt hour to produce, compared with 6.6 cents at a conventional modern gas plant, according to EIA’s Energy Outlook 2011.
This is why the electric industry is switching from Coal to Natural Gas as their preferred fuel of choice.
In 2010, coal-fired plants produced 340,000 megawatts of electricity, or 45 percent of total U.S. electricity production.
For the first time since the EIA began collecting such data, the percentage of electricity generated from natural gas-fired power plants is equal to (and overtaking) electric generation from coal-fired plants.
Each fuel now provides over 96-million megawatthours of electricity, or 32% of total electric generation in the USA.
With the cost of coal-powered electricity now being twice that of natural gas, the economics of natural gas has dethroned coal as the nation’s key source of electric power. U.S. Megawatts, Inc.’s natural gas-fueled Linear Engine-based U.S. Megawatts Generator will be the lower-cost and higher-performing alternative to today’s more expensive but less-efficient diesel-fueled and natural gas-powered reciprocating engine-generators and gas turbine-generators.
U.S. Megawatts, Inc. anticipates strong demand from Coal-fired power plant owners. U.S. Megawatts multi-MW sized Generators will cost significantly less than, and offer performance advantages over, their more complicated, expensive competitors (GE, Siemens and Fuji) offering Gas Turbine Generators.
U.S. Megawatts, Inc. also anticipates that increased demands on the nation’s centralized electrical power systems and incidences of electricity shortages, power quality problems, rolling brownouts, weather-related blackouts, and Coal-based electricity price spikes will encourage more and more residential and business customers of the local Electric Utility to install their own (or buy electricity from) on-site, lower-cost, natural gas-fired kW-sized U.S. Megawatts Generators.
Rather than satisfy increasing electrical needs by building more large centralized power plants and long-distance transmission lines that are expensive and lose energy along the way — building smaller localized power generators close to, or at, the point of use is more efficient, reliable and cleaner.
Note the 73% loss of energy for existing Electricity Distribution system and retention of 90% of the energy using natural gas to generate power on-site, where the power is needed. This confirms the need to generate on-site power using natural gas.
While there are various Distributed Energy and Alternative Energy resources available — not only are all of the Renewable Energy (Geothermal, Hydroelectric, Wind and Solar) technologies more expensive to permit, build and operate than natural gas-fueled electric generators, but Wind and Solar power systems operate intermittently, and are unable to provide a reliable always-available, baseload power source that consumers demand (because the Sun does not shine and the Wind does not blow almost 2/3 of the time).
This is why natural gas is the most logical, lowest-cost option for new electric generation capacity in America.
Of the more than 580 coal-fired power plants still in operation in the USA, 341 are operated by electric utilities, 100 by independent power producers, and the remainder by industrial and commercial electricity producers.
The Linear Engine-based U.S. Megawatts Generator is scalable to virtually any power output, from portable kW units to fixed-site MW units– limited only by the pressure and volume of the input energy source (which defines the optimum piston diameter, cylinder stroke length, SPM strokes-per-minute speed and exit pressure output to generate rotary shaft torque).