In support of the Office of Energy Storage and Distribution of the U.S. Department of Energy (DOE), Pacific Northwest Laboratory has produced a microcomputer-based software package, called RELY, to assess the impact of sodiumsulfur cell reliability on constant current discharge battery performance.The Fortran-based software operates on IBM microcomputers and IBM-compatibles that have a minimum of 512K of internal memory.The software package has three models that provide the following: 1) a description of the failure distribution parameters used to model cell failure, 2) a Monte Carlo simulation of battery life, and 3) a detailed discharge model for a user-specified battery discharge cycl e.

This report provides a performance assessment of the designs for the storage and shipping operations of the MRS facility. These activities, referred to as back-end operations, including handling canistered spent fuel and secondary waste in the shielded canyon cell, in onsite yard storage, and in repository shipping cask loading areas. This analysis verified that the MRS facility back-end operations as designed are capable of handling 3600 metric tons of uranium (MTU) per year if the facility operates seven days per week (24-hour days). The cask cart utilization rate is highest, in use about 50% of the operating year. Cask cart utilization refers to the utilization of the shielded canyon cell repository shipping cask loadout port (also referred to as the exit port) and the cask cart that serves that port. The receiving and handling facility design specifies two loadout ports, one for each side of the facility. This analysis also determined that a throughput rate of 3000 MTU per year could be achieved with five-day week facility operation.

A computer model called GEOCITY has been developed to systematically calculate the potential cost of district heating using hydrothermal geothermal resources. GEOCITY combines climate, demographic factors, and heat demand of the city, resource conditions, well drilling costs, design of the distribution system, tax rates, and financial factors into one systematic model. The GEOCITY program provides the flexibility to individually or collectively evaluate the impact of different economic and technical parameters, assumptions, and uncertainties on the cost of providing district heat from a geothermal resource. Both the geothermal reservoir and distribution system are simulated to model the complete district heating system. GEOCITY consists of two major parts: the geothermal reservoir submodel and the distribution submodel. The reservoir submodel calculates the unit cost of energy by simulating the exploration, development, and operation of a geothermal reservoir and the transmission of this energy to a distribution center. The distribution submodel calculates the unit cost of heat by simulating the design and operation of a district heating distribution system. GEOCITY calculates the unit cost of energy and the unit cost of heat for the district heating system based on the principle that the present worth of the revenues will be equal to the present worth of the expenses including investment return over the economic life of the distribution system.

This paper discusses the capabilities and structure of the computer simulation model AQUASTOR. The model optimizes system design and calculates the life-cycle cost of an aquifer thermal energy storage (ATES) system coupled to a district heating (cooling) system. AQUASTOR has the flexibility to simulate a wide range of system configurations, with a large number of technical and economic parameters available for defining the energy storage and distribution systems. The model combines the technical characteristics of storage and distribution systems with financial and tax conditions for the entities operating the two systems into one techno-economic model. This provides the flexibility to individually or collectively evaluate the impact of different economic and technical parameters, assumptions, and uncertainties on the cost of providing district heating (cooling) with an ATES system.

This paper describes both technical and economic assessments undertaken in support of the Seasonal Thermal Energy Storage (STES) portion of the Underground Energy Storage Program. The FY 82 effort was comprised of four major activities: (1) completion of a detailed economic investigation of the cost of heat storage in aquifers; (2) documentation and preparation of a user's manual for AQUASTOR, a computer model for cost analysis of ATES coupled with district heating or cooling; (3) a combined technical and economic evaluation of several ice storage concepts; and (4) a detailed economic investigation of the cost of chill storage in aquifers.

Results are reported of an investigation to estimate the cost of aquifer thermal energy storage (ATES) from a seasonal heat source. The cost of supplying energy (hot water) from an ATES system is estimated. Three types of loads are investigated: point demands, residential developments, and a multidistrict city. The point demand investigation estimates the cost of ATES-supplied process heat for an industrial user, or space conditioning heat for an entity with an existing hot water distribution system, such as an airport or university. The residential systems investigated are homogeneous developments of: (1) suburban single family homes; and (2) high-rise apartments, under two climatic conditions - a cold climate as typified by Minneapolis, Minnesota, and a moderately cool climate as typified by Seattle, Washington. The multi-district city investigated is Richland, Washington, with a climate midway between that of Seattle and Minneapolis. Several technical and economic factors are found to control the economic performance of an ATES system. Costs are found to be prohibitive for systems of small size, long transmission distances, and employing expensive purchased thermal energy. ATES is found to be cost-competitive with oil-fired and electric hot water delivery systems under a broad range of potential situations. (LEW)

A computer model called GEOCOST has been developed to simulate the production of electricity from geothermal resources and calculate the potential costs of geothermal power. GEOCOST combines resource characteristics, power recovery technology, tax rates, and financial factors into one systematic model and provides the flexibility to individually or collectively evaluate their impacts on the cost of geothermal power. Both the geothermal reservoir and power plant are simulated to model the complete energy production system. In the version of GEOCOST in this report, geothermal fluid is supplied from wells distributed throughout a hydrothermal reservoir through insulated pipelines to a binary power plant. The power plant is simulated using a binary fluid cycle in which the geothermal fluid is passed through a series of heat exchangers. The thermodynamic state points in basic subcritical and supercritical Rankine cycles are calculated for a variety of working fluids. Working fluids which are now in the model include isobutane, n-butane, R-11, R-12, R-22, R-113, R-114, and ammonia. Thermodynamic properties of the working fluids at the state points are calculated using empirical equations of state. The Starling equation of state is used for hydrocarbons and the Martin-Hou equation of state is used for fluorocarbons and ammonia. Physical properties of working fluids at the state points are calculated.