I) EXECUTIVE SUMMARY 3

II) INTRODUCTION 4

III) PROJECT DESCRIPTION 5

IV) SITE VISTIT 6

V) HYDROLOGY 7

VI) PROPOSED POWERHOUSE LOCATION 11

VII) WATER SURFACE ELEVATIONS 13

VIII) MODEL METHOLOGY 15

IX) RESULTS 16

X) DISCUSSION 18

XI) RECOMMENDATIONS 20

XII) BUDGET 21

APPENDICIES 22

A detailed, computerized, daily model was used to predict electrical production at Sparhawk Mills Hydro Site for the installed turbine-generating units. The period of record, 1950 to 2003, was used. Since a USGS Gauge is located 1800 feet downstream of the project, direct flows from the gage were used in the model.

The average annual historic gross electrical production of the site, for 1950 to 2003 the average was approximately 938,000KWh.

A detailed cost analysis was preformed on the cost of completely rebuilding the two automatically adjustable Hydrolec H-9-H turbines and the one manually adjustable Hydrolec H-9-H turbine. The cost to rebuild the two automatically adjusting turbines is $76,300 or $38,140 per turbine. The cost to rebuild the manually adjustable turbine is $38,140. The total cost to rebuild all three turbines is $ 104,300.

John Carroll has hired Fay Engineering Services (FES) to make an energy production study and generating equipment repair/overhaul pricing of its hydroelectric generating plant located at Sparhawk Mills in the Town of Yarmouth, Maine. For the purposes of this report, the existing equipment consisting of three Hydrolec H-9-H tube turbines was used to estimate the plants average energy production.

The production analysis is based upon a detailed, daily, production model of the site. It utilizes 53 years of United States Geological Survey's (USGS) stream flow data (1950 to 2003) from the USGS gauging station at Yarmouth, Maine. This gauge is located 1800 feet downstream of the Sparhawk HEP on the Royal River. No tributaries contribute to the Royal River’s drainage area below the bridge street dam and above the USGS gaging station. Therefore the USGS gage data can be used directly in the model without drainage area modification factors.

Gage # 01060000 is located on the right bank, 2.325 river miles upstream of the Royal River’s confluence with Casco Bay. The drainage area at the gage is 141 square miles. The average discharge for fifty three years is 272 cubic feet per second (cfs).

The recorded daily average flows at the gage can be used to construct a matrix of flows for the period of record. This data can be input into a computerized production model to accurately predict the sites annual electrical production.

The number one and the number two units have been recently rebuilt by the current owner. The third unit will need to be rebuilt in order to put it back online. A complete rebuild of the unit three machine is recommended due to the increase in reliability and reduction in environmental liability due to oil leaks. Further discussion of the rebuild is addresses later in this report.

The Project Dam is called Bridge Street Dam. It is located in the Town of Yarmouth, Maine, 200 feet upstream of the Bridge Street Road Bridge. Its coordinates are 43 degrees, 48 minutes, 05.49 seconds north and 70 degrees, 11 minutes, 04.01 seconds west. It drains approximately 141 square miles of drainage area, impounds a reservoir of 5.2 acres and stores 10 acre-feet at normal pool elevation of 41 msl. The height of the dam from its toe to the top of its abutment is 12 feet.

The project is a FERC exempted hydroelectric power plant, rated at 270 KW on 18 to 21 feet of head. It was originally constructed to provide manufacturing power to the mill located downstream. The original equipment fell into disrepair and was eventually abandoned. In 1984 a FERC exemption P-8417 was issued and the site was rehabbed with three new Hydrolec turbine-generators, a new penstock, new headworks, and dam repairs.

The appurtenant features consist of a one hundred and thirty five foot long, concrete-gravity spillway, a fish ladder, intake works for the penstock, penstock, powerhouse, and equipment. The Denali fish ladder is located at the spillways right abutment. The Maine Department of Marine Resources owns and operates the facility. A ten foot wide concrete walled intake is located in the dam’s left abutment. A 45 foot long fish screen prevents aquatic life from entering the intake area. A ten foot wide section of trash racks is mounted in the concrete intake structure. A head gate is located behind the trash racks to shut off flow to the penstock. The 7 foot diameter steel penstock is 200 feet long and runs from the penstock headworks to the equipment/generating room of the mill. The penstock is made of old rail road tank cars and appears to be in good condition. The penstock enters the mill and trifurcates for each of the three units. The trifurcations come through a concrete thrust block in the basement of the mill. Before the end of the trifurcations, each section has a 60" butterfly valve. At the end of each trifurcation is a bolted pipe flange, where the Hydrolec tube turbines are attached.

There are three Hydrolec H-9-H submersible tube turbines and generators located at Sparhawk Mills. The Hydrolec’s contain a four bladed adjustable pitch Kaplan head, connected through a planetary gearbox to an oil immersed generator. The generator is contained in a steel tank in the water flow stream. In the two automatically adjusting turbines, the blade pitch is controlled by oil pressure and a pressure actuator. The blade pitch can be changed at any time by reducing or increasing the unit’s oil pressure with a hydraulic power-pack. The manually adjustable turbine’s blade pitch can only be changed by hand. The turbine must be stopped, removed from the water, and an adjustment screw on the side adjusted. Then the turbine is re-installed.

The automatically adjusting turbines can turn down to a low flow with a higher overall efficiency curve than the manually adjustable turbine. The estimated efficiency curves are located in the appendicies. However, the automatically adjustable turbines are less reliable than then the manual adjusting turbines (the adjustable kaplan head is a complex piece of mechanical equipment).

Each turbine is rated for 90 KW at 80 cfs. The automatically adjusting turbines will turn down to a flow of 26 cfs and a production of 25 KW. It was estimated for purposes of the model that the manually adjusting turbine will turn down to 30 cfs and a production of 14 KW.

The turbine’s draft tubes are directly incorporated into the end of the tube turbines frame. The draft tubes discharge into a 70 foot long, fifteen foot wide tailrace, which discharges back into the Royal River.

The site was visited on Saturday, April 21^st, 2007. Present at the inspection were Mr. John Carroll, Ms. Celeste Fay, Bill Fay, and Will Fay of Fay Engineering Services. The weather was mild and sunny. A preliminary site tour was made. The appurtenant facilities and equipment was inspected. The dam, impoundment, shoreline, headworks, penstock, switch gear, control system, power pit, Hydrolec generating equipment, and tailrace.

The existing generating equipment, located in the room above the turbine pit was examined in detail. The owner, John Carroll was interviewed by Fay Engineering Services about the site in general and about specific issues concerning the items list above. This interview was extremely helpful in completing this report.

　V) HYDROLOGY:

The drainage area of a river station is that area bounded by the drainage divide. The divide is that line which defines the direction a drop of rainwater will flow. If the drop falls on one side of the divide it flows to the river. If the drop falls on the other side it flows away from the river into the next river basin. The divide is usually the tops of the surrounding hills. Such a drainage area can be defined for the USGS gage for the Royal River at Yarmouth, Maine (141 square miles). The USGS gage is located directly downstream of the dam, with no contributing drainage area between the two. Therefore, the flow at the gage can be considered the flow at the dam, with no modification factors. This means there is no uncertainty about the gages correlation of flow with the flow at the dam. The drainage area of the Bridge Street Dam was also measured with a digitalized USGS Mapping program called TopoScout.

　Figure Three : Drainage Area of Bridge Street Dam

Figure Four: Average Annual Flows at Sparhawk Mills

Figure Five: Average Monthly Flows at Sparhawk Mills

Figures Six and Seven demonstrate the minimum and maximum extremes at Stevens Pond for each year of the period of record.

Figure Eight is a flow duration curve for Sparhawk Mills.

Figure Eight: Flow Duration Curve

The model’s estimate of the average production of Sparhawk Mills, for the period of record is 938,000 KWh/year.

Since Sparhawk Hydro does not have a purchase and sales agreement, it will be selling the power not offset on site at dump rates to the Independent Service Operator (ISO-NE). The average ISO dump power rate for the Maine Power Group over the last four years has been $0.05588/KWh. If no electrical usage was offset at the mill, the 938,000 KWh/year production would make $52,400 per year from electrical generation based on the four year ISO average.

If a $0.025/KWh REC contract was obtained an average of $23,400/year would be made from the sale of REC’s. This is a total plant income of $ 75,850/year.