Abstract:
A scalable micro-grid for providing power to areas remote from the existing power grid. At least two power pods linked in parallel. Each power pod has at least one, micro-turbine fueled by methane gas. As power needs increase, additional power pods are added to the system to meet the additional power needs. The power pods have redundancy such as a diesel genset to ensure continuous power. Power pods are more environmentally friendly than diesel generators and independent of existing power grid. Installation of a power pods requires a short lead-time and thus can be put into operation as soon as the need for more power arises. The power generation source is close to the power consumption point. Removal cost is minimal and the equipment can be reused in another remote power generation locale.

Description:
CROSS-REFERENCE 
       [0001]    This application is a continuation application of U.S. patent application Ser. No. 11/854,969, filed on Sep. 13, 2007, which claimed the benefit of US Provisional Application No. 60/631,838, Filed Nov. 30, 2004, both of which are incorporated herein in their entireties by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates generally to a scalable self-supporting power generation station utilizing divergent, but complimentary technologies for use in locations remote from an existing power grid. 
         [0003]    It is, in some instances, necessary to have a power supply in a location remote from an existing electric power grid. For example, mining or drilling operations often occur in locations remote from an existing power grid. However, these activities still require a reliable, continuous source of power. There is need for a dependable, continuous power source to maintain operations in remote locations. The proper allocation of the respective power generation technologies is determined by the Supervisory Control and Data Acquisition (SCADA) tracking the dynamic loads. 
         [0004]    For example, there are methane gas reserves in the western United States. The depth of the gas varies throughout the reserve. Where the gas is located closer to the surface, such as within 200 feet of the surface, small, 5 to 10 horsepower motors are sufficient to run the pumps. In other areas, the gas is located deeper in the earth—in some cases, over 1,500 feet below the surface. In such instances, pumps with 10 to 50 horsepower motors are needed to pump the gas in these areas. The wells are often located in areas remote from an existing power grid. Thus, there is a need for a method to provide reliable, continuous power to the wells in a cost effective manner. Further, there is a need for a power supply that is readily expandable to allow for expansion of the number of wells. 
         [0005]    For example, the largest US gas exploration and production is located in remote northeast Wyoming and southeast Montana. There is expected to be 43,000 new wells over the next 13 years. Gas companies have traditionally utilized a central coal power generation plant with an electric grid eventually built out to the remote well sites. The electricity is required to power pumps that remove water from the wells and to compress the gas. Some gas companies also use portable diesel engine-generators as a means of power until the electric grid reaches the new well. 
         [0006]    In the past, power was supplied to the wells, either by expanding the existing power grid, or by using diesel generators. Expanding the existing grid involves running high voltage lines to the well field. This solution is very costly to the gas company, as the power company requires the user to pay for the installation/expansion of the grid and for its removal at the end of the project, in addition to paying for the electricity, transmission charges and other fees. There is a need for a system that is economical and independent of the existing power grid. 
         [0007]    A significant problem with expanding the existing power grid is the long lead-time needed for expansion. There is a need for a scalable solution where the expansion can occur in a time efficient manner so that companies can produce gas faster. There is a need for a system that allows for expansion in a relatively short time frame such as a similar time frame as is required to develop a new well. 
         [0008]    The overhead towers and high voltage wires are obtrusive, unsightly and not environmentally friendly. The impact of overhead towers and high voltage wires is not insignificant. Gas companies have been stalled by lawsuits arising out of landowner complaints about the power lines and towers. Thus, there is a need for unobtrusive power generation that minimizes any negative effect on the environment. There is a need for a system that is better for the environment than expanding an existing power grid. A second prior art solution is to use diesel generators. However, there are environmental impact issues that arise when using diesel generators. There is a need for a system with minimal environmental impact. Further, using diesel generators is prohibitively expensive. 
       SUMMARY OF THE INVENTION 
       [0009]    A scalable, self-supporting power generation station is described herein. The station utilizes divergent, but complimentary technologies, such as reciprocating engine-generators with bi-fumigation and micro-turbines  30 , for use in locations remote from an existing power grid. 
         [0010]    The present invention comprises a scalable micro-grid for providing power to areas remote from an existing power-grid. The power system was developed to power a gas pumping operation. However, due to its scalability, the inventive system is not limited to pumping operations and can be used to power any remote system, such as drilling and mining. 
         [0011]    The system comprises at least two power pods  10  linked in parallel. Each power pod  10  comprises at least one micro-turbine  30 , fueled by methane gas. As the power needs increase, additional power pods  10  can be added to the system to meet the additional needs. The power pods  10  preferably have redundancy such as a diesel genset to ensure continuous power. A genset is a combustion engine driving an electrical generator. Not only are the power pods  10  more environmentally friendly than diesel generators, the power pods  10  are completely independent of existing power grids. The inventive system is better for the environment. It is clean burning and there are no overhead towers or high-voltage wires. 
         [0012]    The power pods  10  have a short lead-time and thus can be put into operation as soon as the need for more power arises. The power generation source is close to the power consumption point. Any removal cost is minimal and the equipment can be reused in another remote power generation locale. 
         [0013]    A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawings which set forth an illustrative embodiment and which are indicative of the various ways in which the principles of the invention may be employed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0014]    For a better understanding of the invention, reference may be had to the following Figures, which further describe an embodiment of the present invention and which include drawings and exemplary screen shots therefor: 
           [0015]      FIG. 1  is a flow chart depicting a first embodiment of a power pod as described in detail below. 
           [0016]      FIG. 2  is a schematic diagram of a first embodiment of a power pod as described in detail below 
           [0017]      FIG. 3  is an isometric view of a first embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Turning now to the Figures, wherein like reference numerals refer to like elements, there is illustrated a self-supporting power generation station. 
         [0019]    There are methane gas reserves in the western United States. The depth of the gas varies throughout the reserve. Where the gas is located closer to the surface, such as within 200 feet of the surface, small, 5 to 10 horsepower motors are sufficient to run the pumps. In other areas, the gas is located deeper in the earth—in some cases over 1,500 feet below the surface. Pumps with 10 to 50 horsepower motors may be needed to pump the gas in these areas. The deep wells are usually located in an area remote from any existing power grid. The present invention supplies reliable, continuous power to wells in a cost effective manner. Further, the power supply is readily expandable to allow for expansion of the number of wells. 
         [0020]    The largest US gas exploration and production is located in remote northwest Wyoming and southeast Montana. 43,000 new wells are expected in the next 13 years. The present invention comprises a system to supply power to these remote wells in a scalable, cost effective, prompt and environmentally-friendly manner. 
         [0021]    Methane gas wells typically run 24 hours a day, every day of the year. Therefore, it is important that the power source have at least one built-in redundancy. In addition, it is preferable that gross power generated exceeds the peak demand. By way of example, and in no way limiting, a well field having 32 wells, where on average each well has a 10-horsepower motor, two power pods  10  may be used, connected in series. In this scenario, each power pod  10  services  16  wells. Preferably, the power pods  10  are located in a central location. 
         [0022]    As seen in the figures, each power pod  10  may comprise reciprocating engine-generator  20 , which may be fueled by a combination of coal bed methane (CBM) gas and diesel fuel and at least one micro-turbine  30 . Reciprocating engine generator  20  supports dynamic loading and redundancy. Depending on load dynamics (as monitored by SCADA), reciprocating engine generator  20  may be in one of three states: (i) not running or steady state load; (ii) running in parallel with micro-turbine  30  at a ratio determined by the load or SCADA; or (iii) supporting the entire dynamic load such as when micro-turbines  30  are not running. 
         [0023]    Power pod  10  preferably comprises two or four micro-turbines  30  fueled by CBM. Micro-turbines  30  are preferably connected in parallel, and support base-loading steady state load conditions. Depending on load dynamics (as monitored by SCADA), micro-turbines  30  may be in one of three states: (i) not running or dynamic load; (ii) running in parallel with reciprocating engine generator  20  at a ratio determined by the load or SCADA; or (iii) supporting the entire load in a steady state base load when reciprocating engine generator  20  is not running. 
         [0024]    As seen, for example, in  FIG. 3 , power pod  10  comprises at least one enclosure  40 . Enclosure  40  is preferably an all weather enclosure. Preferably, there are two enclosures  40 . First enclosure  40  may house controls  60  and distribution equipment (not shown), while second enclosure  40  may house generators  20  and micro-turbines  30 . Alternatively, bi-fuel reciprocating genset (not shown) can be used in addition to micro-turbines  30 . Enclosure  40  may be transportable. In the embodiment depicted in  FIG. 3 , enclosure  40  measures 8 feet wide, 8.5 feet high and 20 feet long. Preferably, enclosure  40  comprises access door  50 . Enclosure  40  may operate alone or in combination with a second enclosure  40  with controls  60 . Preferably, power pod  10  comprises two enclosures  40 . Preferably, enclosure  40  is an 8-foot by 20-foot Iso Containers to house micro-turbines  30 . 
         [0025]    Power pod  10  may be pre-assembled to allow for rapid transportation to a desired location for set-up. A pre-assembled power pod  10  may comprise an enclosure  40  with two micro-turbines  30 , a control system  60 , power electronics (not shown), lubricating oil systems (not shown), an engine alternator assembly (not shown), a recuperator (not shown), a gas boost compressor (not shown), ventilation  70 , and a power panel (not shown). A distribution panel can be added to provide power distribution feed. 
         [0026]    As stated above, each enclosure  40  preferably houses two micro-turbines  30 . Preferably, the micro-turbines  30  are rated 80 kW each with a gas compressor. Each power pod  10  preferably also comprises a 300 kW reciprocating generator with weather proof enclosure mounted on skid with SCADA equipment (such as Virtual Power Plant™ by Encorp) with weather proof enclosure mounted on the same skid as reciprocating generator  20 . Generator  20  preferably comprises a bi-fumigation system. 
         [0027]    Power pod  10  preferably also includes hardware and software (not shown) to access each power pod  10  via telephone or computer network for remote control, such as start-up, stop, configuration management and troubleshooting. 
         [0028]    Preferably, generators  20  are fueled by unprocessed methane gas. Alternative fuel sources could be used. However, unprocessed coal bed methane gas is accessible at the generation site. The methane gas should be supplied at sufficient pressure to facilitate generators  20 . Generators  20  preferably generate power at 480 V. It is preferable that the gross power generated by power pods  10  exceeds peak demand. For example, if a power pod  10  services  16  wells with an average 10 hp motor, the gross power generated exceeds the peak demand by 73%. It is also preferable that there is redundancy in the system since the pumps run continuously. In one embodiment (not shown), diesel generators or preferably bi-fuel reciprocating generators are used as back up. In an alternative embodiment, if one power pod  10  fails, excess gross power of one or more operating power pods  10  is used to supply pumps. In yet another embodiment, redundancies in the system include both at least one diesel generator or one bi-fuel reciprocating genset and the ability to use the excess power generated. 
         [0029]    A typical well production area can be serviced by a power pod  10  having four micro-turbines  30 , each producing 320 kW of continuous power to service approximately 20 wells. There is approximately one “drop” supporting every 3-4 wells or approximately 6-7 drops from each power pod  10  to the wells. 
         [0030]    Optionally, the power pods  10  can include virtual control devices to increase the control and efficiency of the pumps. It is preferable that the harmonics are kept within IEEE 519 limits by use of harmonic transformers. One virtual control that would be suitable for this application is Virtual Power Plant™, which monitors the load dynamics so the proper ratio of power generation resources (reciprocating generators  20  to micro-turbines  30 ) is utilized. Virtual controls also provide for paralleling of power generation resources, diagnostics, monitoring, service alarm cell out and future import/export of power to accommodate micro grids. 
         [0031]    Linked power pods  10  act as a micro-grid for servicing the well field. The micro-grid can be expanded by linking additional power pods  10  to the system. Preferably, additional power pods  10  are added by connecting adjoining cites via radial drops. Power pod  10  is preferably monitored via satellite. This is useful since the power pod  10  is used in relatively remote locations. Micro-turbines  30 , generators  20 , fuel level, paralleling gear, SCADA and MCC are all monitored. Preferably, the controls include internal diagnostics and allow a user to make some repairs and run diagnostic testing via satellite or other communication network. 
         [0032]    During the initial set up of a power pod  10  for a methane gas well field, bi-fuel genset of power pod  10  runs on diesel fuel. As the pumps begin to supply unprocessed methane gas, micro-turbines  30  are energized. Initially, the well field&#39;s power requirements may be more dynamic than the micro-turbines  30  can tolerate. In that case, micro-turbines  30  will supply the baseline power, while generator  20  will provide additional power to power the motor at peak load times. After a time, micro-turbines  30  are able to supply in excess of the well fields power needs. At that point, generators  20  will be used as a back-up power supply only. Additional back-up power can be provided to other power pods  10  on the micro grid. 
         [0033]    Power pods  10  are environmentally friendly. Micro-turbines  30  may run on methane gas, while generators  10  may run on 20% diesel and 80% natural gas and thus burn cleaner than a traditional diesel genset. 
         [0034]    Two power pods  10  can be connected in series to form a micro-grid. Additional power pods  10  can be added to the micro-grid via radial drops. Thus, the system is scalable. 
         [0035]    Power pods  10  use natural gas and thus are environmentally friendly. Furthermore, they can be moved to another location and used again. 
         [0036]    Power pods  10  can be started using the bi-fuel genset running on diesel fuel only, thus a power pod  10  is completely independent of existing power grids. 
         [0037]    Because enclosure  40  may be fully assembled, power pod  10  can be operational with a very short lead time. The transportable enclosure  40  can be moved to a location, installed and be up and running with a very short lead-time. It can be linked to other power pods  10  to form a micro-grid. When the power needs change, additional power pods  10  can be added or removed. The transportable power pod  10  could be moved to another location. Power pod  10  is a more economical, cost effective and timely solution than the prior art remote power generation. It is also a more environmentally friendly solution than the prior art solutions. 
         [0038]    While specific embodiments of the present invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. In addition, it is to be understood that all patents discussed in this document are to be incorporated herein by reference in their entirety. Accordingly, the particular arrangement disclosed is meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any equivalents thereof.