Commanding attention - new turbine technology19 September 2006
A positive displacement energy system is being commercialised for applications where water is being wasted, write Craig A Huffman and R Edward Hart
Imagine for a moment a factory's wasted steam, or a water reservoir that is sending water supplies down to a town becoming the fuel to generate cheap power. In the past, due to a lack of head for traditional turbines the economics did not allow for smaller (30kW or less) applications. However, US-based Internal Hydro International Incorporated (IHDR) has built a system which it says can use a smaller head, without any of the ordinary drawbacks of traditional turbine systems, for a reasonable return on investment.
The company, which is headquartered in Tampa, Florida, has designed the Energy Commander V (EC V) for industrial flows, natural gravity lines, and numerous other uses. It has positioned its technology to be placed in large numbers on low head dams that would not support traditional hydro turbines, industrial cooling outlets, and a large array of excess pressure situations, including water, steam, and gas pressure reduction situations in many industrial, refining, and municipal pipelines. IHDR's Energy Commander systems began as a single cylinder dual cycle (1) kilowatt generation unit utilising a one inch (2.54cm) line (EC III), to four and eight cylinder in-line 30kW systems with a six inch (15.24cm) inlet at 65 psi (EC IV).
The latest version is the Energy Commander V (EC V), which utilises a rotary 12 cylinder slice concept. Each Energy Commander V system has a projected market price of US$45,000 to US$50,000 per 30kW system – equating to US$1500 to US$1700 per kW. The system may also qualify for available tax credits and renewable energy credits.
The EC V system is employed in an industrial setting in Mobile, Alabama for customer demonstrations, production familiarisation, and certifications.
How the energy commander works
When head and flow is inadequate for traditional turbines, and the available inlet size which can be supported needs to be smaller than that of available micro-turbines, the IHDR technology is being readied as the ecological and efficient answer for gravity flows, and wasted fluid flows in a multitude of industrial applications. With a system that is patented for the creation of electrical energy using positive displacement instead of turbines, IHDR is commercialising a 30kW electricity rotary cylinder system for production of energy from a six inch (15.24cm) flow of water. By utilising a reverse flow controlling system, the technology takes the flow of water in through the pipe, where it flows through a proprietary channelling system, through the control valves and into the pistons. The force of the mass of water enters a closed cylinder, then forces the cylinder down on the drive shaft through the drive shaft system, then onto a cam shaft which forces the drive shaft to turn the generator. The cylinders are dual cycle, so water pushes the cylinder in both directions within the shaft, again, by use of the reversing controller setup. The water is then pushed out of the system into a separate channel and back into a pipeline to continue on its flow path. The drop in pressure from use of the system is immaterial in all of the uses where the system will be deployed since the flow is either excess pressure or wasted pressure after the flow was already utilised.
The 'slice' concept is used in production of the EC V 12 cylinder base unit. As built, each rotary 360o slice houses twelve four inch (10.16cm) cylinders, which can be stacked with other slices to provide the 30kW of standard output. Slices can be added or subtracted based upon the flow that is present at any one location. The rotary design takes less space than the previous model, as the cylinders are circularly aligned and the unit is sited vertically. Even with four slices, the EC V is only just over 48 inches (121.92cm) by 48 inches in height, length and width.
IHDR has submitted a proposal for the placement of 40 units of its EC V low impact hydro units with the US Army Corps of Engineers (USACE) for the W. Kerr Scott dam site, located in North Carolina, and is studying other projected USACE placements. With a planned minimum 1.2MW power output at this single location, the projected annual revenue is US$750,000 from the site. IHDR's proposal will be a basis for other multi-set units to be installed in the more than 70,000 non-electricity producing dams in the U.S. Thousands of those sites will be targeted to outfit them with the EC V system, where traditional turbine systems have never been able to run due to the low-head flows. The proposal shows that the EC V is able to be implemented on low head flows, where turbine systems were studied, and could not compete due to the low head, and the smaller intake of the EC V system. With just over a 19.8m drop at Kerr dam, IHDR's proposal is for a bank of 40 30kW units contained in a single structure to operate at between 30 and 40 psi. IHDR is working with USACE to complete the submission process and a revenue sharing plan for the electricity produced. The system will use the 100 year low water flow mark to receive the necessary flow for the units. The units will be housed in a single structure at the base of the dam, which will enable the system to be virtually on line at all times. If any one or group of units experienced a maintenance issue, the other units would still be on-line. Other private dams have also expressed a desire to implement units during the near time current production cycle of the Energy Commander.
Another text-book application for the Energy Commander system is its application in municipal water flow pipes from reservoirs, utilising large force gravity feeds as the water goes down the pipelines. In this manner, IHDR has worked in Europe, through Cm2, its Italian based production partner for Europe, and is currently reviewing placements for the systems along water supply pipelines in southern California where pressure reduction valves are required to slow the gravity flows. In Europe, and in Italy in particular, the aqueduct system has been studied by Cm2 for just such application of multiple sets of the Energy Commanders in a single location due to the ready availability of water in pipelines with psi of 200 or more, and the use of pressure reduction systems along such routs. By its nature, the Energy Commander is a pressure reduction system which can take that wasted energy and convert it to the mechanical force to produce electricity. In the situation in southern California, the pressures present cause the use of up to three stages of pressure reduction stations along pipelines that are not sufficient for micro turbines of any appreciable power, while the same pipelines can utilise multiple Energy Commanders. The use of the system on such water systems is non-hazardous, does not heat the water, and no additional materials are added. Only water comes into contact with the piping, the internal stainless components of the system, and other non-attributive materials.
The system does not cause oxidation to the water flow, and it readily accepts filters to maintain fish and organic life, meaning it is considered environmentally friendly. The use of the system in existing dams can avoid many of the drawbacks that face turbines, including environmental and other issues, and will most often use only the overflow such as the Kerr dam project.
Production and marketing
With a European partner – Cm2 of Italy – IHDR is positioned to produce the unit in quantity for both European and US applications which are aligned for the unit to be placed. The EC V has already been pre-purchased for use in Ghana for residential power using gravity fed lines, and for the oil and gas exploration industry in a well field setting utilising natural salt water or water evacuation pressures.
IHDR's traditional business plan calls for the units to be held as assets of the corporation, with the electrical production value, tax credits, and renewable energy credits to be held by the company, with some split of revenue or savings of the electricity value with the landowner or user. IHDR is also considering selling, or leasing the units, directly to power generators or water companies within a specific geographical area that purchase a technology license. The units are being designed for a five to seven year life, with easy change out maintenance of parts. IHDR will also utilise a satellite burst transmission reporting system in order to track the energy production of the units, and multiple channels of maintenance points.
Even though the Energy Commander system has been identified for placement in many applications in the industrial settings, few will qualify for the number of units to be placed in any single location as the low head dam projects that have and will present themselves.
Given the ability of the system to run so many units in a single setting, the costs associated with the grid connection, piping connection, and other hard costs could be reduced. Although the first placements of the Energy Commanders will be in industrial settings and gravity fed pipelines, the application to the low head dam systems will be a large component of its placements. The systems positive environmental aspects, lower cost, small intake, and small footprint may mean it can provide a viable electric generation option where none existed before.