In July 2007 Burrstone Energy Center Plant, Faxton-St. Lukes Healthcare and Utica College collaborated to design and install a Â 3.6-megawatt Combined Heat and Power (CHP) cogeneration facility. This provides a co-generating power system that operates in cognizance with the power grid. The system is devised as a co generating plant with Natural gas powered generator set power and power from National Grid - New York.
The Burrstone project provides 3.6 MW of power to St. Lukes Hospital, Nursing home and Utica College. The project will produce power for all three users and supply steam heat to the hospital. It will create electricity and useful heat for use Faxton - St.Lukes and Utica College. Cogeneration will help reduce greenhouse gas emissions, provide more stable and reliable services for the hospital patients and college students and reduce the demand on the local utility grid. This plant was developed byÂ Cogen Power and Technologies. The CHP cogeneration facility will be owned and operated by Burrstone Energy Center, LLC.Â
In July 2007, Burrstone Energy Center Plant, Faxton- St. Lukes Healthcare, Utica College and NYSERDA installed, commissioned and began operating and monitoring the CHP system. The Burrstone Energy Center's cogeneration plant includes four engine-generators that serve the electrical services for three separate facilities near Burrstone Road in Utica, NY:
One 1100 kW engine serves the college, two 1100 kW units serve the hospital, and a 334 kW engine serves the home. All four engines are located in a new facility near the hospital's boiler house. It has a total capacity of 3.6 MW operating on natural gas.
The project will be evaluated on the following metrics:
Reduce the demand on the local utility grid.
Cogeneration will help reduce greenhouse gas emissions.
Provide more reliable services for hospital patients and college students.
Performance of the engine-generator technology using natural gas as fuel.
Company name and location
The name of the company being studied, as stated previously, is Burrstone Energy Center. This plant was built by Cogen Power Technologies, the Newest Bette & Cring Company which specializing in cogeneration Projects offering turnkey solutions providing off-balance sheet financing & plant operation for varied customers. The location of Burrstone Energy Center, LLC is 22 Century Hill Drive, Utica, New York - 13501.
1.3 Reasons for Utilizing a Natural gas generator set
Natural gas is the cleanest of all the fossil fuels. Composed primarily of methane, the main products of theÂ combustionÂ of natural gas are carbon dioxide and water vapor, the same compounds we exhale when we breathe. Â Natural gas, emitting fewer harmful chemicals into the atmosphere than other fossil fuels, can help to mitigate some of these environmental issues. Figure 1 shows the amount of CO2 emitted by various fuel based engines. Economically natural gas is more efficient since only 10 % of the produced gas wasted before consumption and it does not need to be generated from other fuels. Due to economic, environmental, and technological changes, natural gas has become the fuel of choice for new power plants. In fact, in 2000, 23,453 MW (megawatts) of new electric capacity was added in the U.S. Of this, almost 95 percent, or 22,238 MW were natural gas fired additions. The electrical production in the United States for 2006 from the Power Source- Combined Cycle Natural Gas is as follows - The units in operation are1686, the total Nameplate Capacity is 266269 MW which is the 20.1% of the total capacity. The annual production is 505 billion kWh which constitutes 12.4% of the annual production.
Figure1: Comparison of CO2 emissions from electricity generation.
1.4 How does a Natural gas generator work?
A natural gas generator set is illustrated in Figure 1. The basic configuration including compressor, turbine, and permanent-magnet generator, in this case all mounted on a single shaft. Incoming air is compressed to three or four atmospheres of pressure and sent through a heat exchanger called a recuperator, where its temperature is elevated by the hot exhaust gases. By preheating the compressed incoming air, the recuperator helps boost the efficiency of the unit. The hot, compressed air is mixed with fuel in the combustion chamber and is burned.
The expansion of hot gases through the turbine spins the compressor and generator. The exhaust is released to the atmosphere after transferring much of its heat to the incoming compressed air in the recuperator.
Figure 2: Microturbine power plant. Air is compressed (1), preheated in the recuperator (2), combusted with natural gas (3), expanded through the turbine (4), cooled in the recuperator (5), and exhausted (6). From Cler and Shepard (1996).
2. Project description
The cogeneration plant on the St. Lukes campus of St. Lukes Healthcare creates both electricity and heat for use at St. Lukes and Utica College. It is estimated that this plant will provide all of the power at St. Lukes Hospital, 75% of the power at Utica College, and 50% of the power at St. Lukes nursing home.
Burrstone Energy Center will enter into a 15-year lease for approximately 2 acres of land on the St. Lukes campus with the option for two additional five-year terms
Saving $800,000 annually on the energy bill and going "green" is the anticipated result for the Burrstone Energy Center. The new 3.6-megawatt combined heat and power (CHP) co-generation plant is a cooperative effort of Faxton - St. Lukes Healthcare (FSLH), Utica College and Burrstone Energy Center, LLC, and has been made possible, in part, by a $1 million co-funding contract with New York State Energy Research and Development Authority (NYSERDA).Â
2.1 Type of loads supplied by Burrstone Energy Plant
The major loads supplied by Burrstone Energy Center are lighting, space heating, ventilation at St. Lukes and Utica College. The pumps, boilers and powering the instruments are the various other loads been dealt by the Burrstone Energy Plant. It powers St. Lukes Hospital, Utica College, and St. Lukes nursing home.
2.2 Burrstone Energy Center overall energy profile
Since this project started in August of 2009 there is limited information on the load profile for Burrstone Energy Center. This is no information available on the load profile before the project.
The total energy generated output at St. Lukes Home for the last 3 months is
Table 1: Generator Output Energy
Table 1 represents the energy usage that was avoided by Burrstone Energy Center.
Table 2: Total Facility Purchased Energy
Table 3: Avoided Costs
Utica comes under the Load Zone E and hence the tariff is calculated henceforth using National Grid Business Tariff.
The total of electric costs from Table 3 for the past 3 months is $29664.18 .To calculate the dollars per kWh, we used kWh (the total of table 1). This is the total savings for the three months from only St.Lukes Home.
The total of electric costs from Table 3 is 29664.18. To calculate the dollars per kWh, we will use kWh (the total of table 1).
= $ 0.02536 /kWh
The Burrstone Energy Center did not release its previous load data, so the figures given are the load after the CHP was installed.
The total energy generated output at St.Lukes Hospital for the last 3 months is
Table 4: Generator Output Energy
Table 4 represents the energy usage that was avoided by Burrstone Energy Center.
Table 5: Total Facility Purchased Energy
Table 6: Avoided Costs
The total of electric costs from Table 6 for the past 3 months is $106599.89 .To calculate the dollars per kWh, we used kWh (the total of table 4). This is the total savings for the three months from only St.Lukes Hospital.
The total of electric costs from Table 6 is 106599.89. To calculate the dollars per kWh, we will use kWh (the total of table 4).
= $ 0.0460 /kWh
The Burrstone Energy Center did not release its previous load data, so the figures given are the load after the CHP was installed.
In a Petition filed on July 9, 2007, Burrstone Energy Center LLC (Burrstone) requested an issuance of a Declaratory Ruling finding that the 3.6 MW cogeneration facilities in Oneida County will not be regulated under the Public Service Law (PSL).
The generator produces the energy needed for the various entities powered by Burrstone Energy Center and the rest of the energy is supplied by National Grid- New York.
2.3 Project Scope
The project scope is to build a reliable and self sufficient power system to power St.Lukes hospital and Utica College and not relying on National Grid Mohawk entirely. A natural gas powered CHP system serves the purpose. The project objective was to of obtain the following benefits:
1. Reduced on-site energy costs.
2. The application of a recovered-heat powered
3. Improved energy reliability.
4. Reduced peak load on the grid.
5. Emergency power during blackouts.
2.4 Outage Profile
There have been no recorded outage details of the plant for the duration of its existence from August 2009 to August 2010.
3.1 Statement of the Problem
The problem that was addressed by this project was to reduce the greenhouse emissions and have a reliable power system operation for all the three entities which are powered by Burrstone Energy Center.
3.1.1 Energy savings:
Because St. Lukes home and hospital electricity needs were served 100% from the grid, the first and most obvious energy savings was their electricity from the grid. From Table 2 and 3, the total cost from June, 2010 to August, 2010, if supplied by the grid, would have been $136264.07 and the purchased energy from the grid is $111424.19. The total cost for the gas input is $12283.89 In order to further increase the energy savings is the use of the recovered heat to operate an absorption chiller and supply heat to the heating units. From the earlier equation, the following can be assumed:
Price per kWh without the CHP Project:
= $ 0.03934 /kWh
The other energy savings that must be included is the ability to sell the excess electricity to National Grid- New York thus providing a revenue stream that did not exist prior to the project. This could be a future enhancement for the project.
Revenue gains per kWh with the CHP Project:
= $ 0.001995 /kWh
This is the cost savings of the plant for the duration of 3 months from St.Lukes home alone.
As can be seen, substantial savings have been made in the first year of operation. These savings could be even larger if the energy usage prior to the project was known as it would have helped in the development of natural gas generator based plant.
The reliability has increased greatly because now has the ability to be supplied from the grid or supplied by their generator.
3.2 Technologies Implemented:
A schematic diagram of the project's implementation is shown. This follows the standards given by NYSERDA.
Figure 3: Simple Schematic CHP System
Measured Data Points
WG - Power Generated (net internal parasites)
WP - Parasitic Power (external parasitic)
FGG - Natural Gas Flow into Generator
QHR - Useful Heat Recovery
QD - Heat that is Dumped or Unused
WT - Total Facility Power
FGT - Total Facility Gas Flow/Use
The cogeneration system equipment selected was as
Two internal combustion engines with total capacity of 1.1 MW for St. Lukes Hospital.
One internal combustion engines with total capacity of 1.1 MW for Utica College.
One internal combustion engines with total capacity of 334 kW for St. Lukes Nursing Home.
The Burrstone Energy Plant produces 7000lb/hr of 100psig steam and 700gal/min of 200oC of hot water. The plant's output serves 70% thermal demand and 80% power demand. The cogeneration and the utility provide power to the customers which are St. Lukes Hospital, Utica College and St. Lukes Nursing Home. All the energy generated is not utilized by the customers and hence the 1.1 MW power from St.Lukes Hospital and the 600 kW power from Utica College is feed back to the utility company.
The environmental benefits include reduced usage of CH4 by 21,000 dekatherms and reduced emissions of CO2 by 4,000 tons per year. This is equal to planting 800arces of forest and taking off 600 cars off the road.
This plant is operated by Cogen Power Technologies.
GE's Jenbacher engine is used as a generator for its high efficiency system, durability and reliability. The various features of the generator is the un cooled exhaust gas manifold, cross flow cylinder head, scraper ring, gas mixer, high performance spark plug, turbocharger ,electronic ignition system, knock control system, TecJetTM gas dosing valve, fuel mix charging, miller valve timing to mention a few. The various generators come under the technology group of greater than 800 kW Reciprocating Engine (Lean Burn).
The generator type is an induction type generator. The primary heat recovery method is hot water from the engine. The primary heat recovery use is domestic hot water and the secondary heat recovery use is process steam.
Advantages of using these generators are that they have high specific output with high electrical efficiency. It has individual cylinder heads which increases ease of maintenance. The service life of the spark plug is 15,000 operating hours. The controlling of all the systems on a module, clear visuals and graphical online treads and alarm management make this generator set the most viable option available and hence these have been used as generators.
Along with supplying electricity, the CHP project included a cogeneration heat recovery loop. The loop uses heat available from the engine exhaust and jacket water. The cogen loop provides thermal energy to the digester system and the absorption chiller.
3.3 Assumptions made
There was no reference to any assumptions made for this project.
3.4 Economic Justifications
There was no information found regarding the economic justifications of this project. However, the economic benefits of this project include the reduced dependency on electricity expenditures needed to operate the normal loads. A second advantage is the ability to be able to sell electricity back to the grid - National Grid- New York.
3.5 Project Cost and Benefits
The total cost of the project was $13,000,000. Burrstone Energy Center contributed $12,000,000 and NYSERDA contributed $1,000,000 towards the $13,000,000. There was no information on how Burrstone Energy Center funded the $12,000,000 that they contributed to the project.
Using the energy savings from plant is an obvious benefit after taking care of the initial investment. This is a very crude estimate since not all savings are realized and the time value of money is neglected.
Another obvious benefit is the environmental benefit that is obtained by the reduction in methane released resulting in the reduction of greenhouse gas affects. Emergency Power is supplied to the various entities during Blackouts. A financial benefit is that it saves $800,000 per year.
4. Project Implementation
4.1 How the project was implemented
The implementation of the project is not well audited. The CHP system described by NYSERDA is taking as a template for designing of the plant and the monitoring system.
The implementation plan required the following aspects:
Â· Engineering design
Â· Installation of equipment and co-ordination systems
Â· Technology transfer
As mentioned this project is a year old in its operation and there is much more data and monitoring to be done so that the technology can be transferred to others. The results of these points have proven to be positive and efficient system design is constructed.
4.2 The energy consumption profile
Figures 4 through 12 (data measured daily over the period of months) show the energy consumption profiles for Burrstone Energy Center(BEC) powering St.Lukes home and St.Lukes Hospital which is available on the NYSERDA website. The most important observation is that these profiles show that BEC is able to sustain their own loads mostly and draw some energy from the grid.
As more data is gathered on this project the results will become more evident with the avoided costs of electricity and the sale of electricity showing the overall cost savings.
The facility is made up of four engines that will run on natural gas, all of which are between 60-80
percent efficient. The excess heat produced by the engines will be captured and either transported to
the facilities for heat or to make steam for the hospital.
Cogeneration will reduce greenhouse gas emissions by about 4,000 tons annually, provide more reliable
services for hospital patients and college students, and reduce the demand on the local utility. Given this
increased power stability and reliability the two organizations are expected to save hundreds of
thousands of dollars per year as a result, among other benefits.
A natural gas generator set is an able and executable method to provide a fuel source to a distributed generation device. Natural gas-fired DG turbine generators, release less than one-quarter of the emissions of sulfur dioxide (SO2), less than 1/100th of the nitrogen oxides (NOX), and 40% less carbon dioxide (CO2) than many new coal-boiler power plants; these units are clean enough to be sited within a community among residential and commercial establishments (DPCA, 1998). Economically natural gas is more efficient since only 10 % of the produced gas wasted before consumption and it does not need to be generated from other fuels.
The increase in reliability of power supply is an added advantage and this would provide power even during a blackout to the Hospital , Home and College. The added benefit is the heat recovery system that can be used for space heating.
The savings in a fiscal year on the revenue cannot be undermined and this has been a model for profit generation as well as a boon for the environment. Department of Energy has been very promoting in processing the Distributed generating system projects and the funding from NYSERDA has been of a great help. As the technology is ever changing and the move towards greener energy natural gas based plant would hopefully be supplying the major energy needs of United States of America.