Introduction and Overview

Diversity of renewable energy resources in the United States 1-3 Figure 2. Outline for Technology Characterizations 1-8 Figure 1. Biomass gasification combined cycle (BGCC) system schematic 2-7 Figure 2. Low-pressure direct Figure 3. Indirect Figure 4. Material and energy balance for the 1997 base case 2-16 Figure 1. Direct-fired biomass electricity generating system schematic 2-22 Figure 2. Material and energy balance for the 1997 base case 2-29 Figure 3. Material and energy balance...

Performance Indicators

The assumed economic life of the battery system is 30 years, requiring battery component replacements at appropriate intervals. The structure and power conditioning system are expected to last 30 years 18 . Battery replacement charges vary by the type of the battery and the number of years until replacement. One manufacturer claims that the type o f flooded lead-acid batteries they use should be replaced every three years 25 . When VRLA batteries are used mor e widely for renewable applications...

Overall Perspectives on the Renewable Technologies

While each of the characterized renewable technologies is discussed in detail in this document, the following summary presents an overview of current status and applications for each. Biomass The use of forestry and agricultural residues and wastes in direct-combustion systems for cogeneration o f electricity and process heat has been a well-established practice in the forest-products industry for many years. Us e of these feedstocks in utility electric power plants has also been demonstrated...

Current Technology

Current Performance Operational data for current technology is widely available from California windfarms and other locations around the world. Performance indicators for the base year are a composite of commercial technology available in 1996, including turbines from the DOE Near-Term Product Development Project 21-23 and from several othe r manufacturers 24 . These turbines include fixed and variable speed designs, most of which use one or more low cost, induction generators. The 1996...

Tables

Emissions from a high-pressure, direct gasification system 2-11 Table 2. Performance and costs Table 3. Resource Table 1. Biomass power plant gaseous and particulate emissions 2-25 Table 2. Performance and costs Table 3. Feedstock Table 4. Resource Table 1. Previous, existing, or planned biomass co-firing applications 2-39 Table 2. Performance and cost indicators Table 3. Gaseous, liquid, and solid effluents Table 4. Resource Table 1. Environmental impacts of geothermal flashed steam...

Initial System Application Hybrid Plants

To reduce the financial risk associated with the deployment of a new power plant technology and to lower the cost o f delivering solar power, initial commercial-scale gt 30 MW e power towers will likely be hybridized with conventiona l fossil-fired plants. Many hybridization options are possible with natural gas combined-cycle and coal-fired or oil-fired Rankine plants. One opportunity for hybrid integration with a combined cycle is depicted in Figure 4. In a hybrid plant, the solar energy can...

References

Status Report on Solar Thermal Power Plants, Pilkington Solar International 1996. Report ISBN 3-9804901-0-6. 2. Assessment of Solar Thermal Trough Power Plant Technology and Its Transferability to the Mediterranean Region - Final Report, Flachglas Solartechnik GMBH, for European Commission Directorate General I External Economic Relations, and Centre de Developpement des Energies Renouvelables and Grupo Endesa, Cologne , Germany June 1994. 3. Integrated Solar Combined Cycle Systems ISCCS...

Battery Technologies

This appendix assumes that current R amp D activities will lead to significant improvements in the cost and performanc e of battery storage systems. As these improvements take place, battery storage systems will compete with conventional sources of peak electric power generation, such as gas turbines, diesel generators, or uninterruptible power supply units. Flooded lead-acid and VRLA batteries are commercially available today, although not in designs wholly suited to utility applications. Zinc...

System OM Costs

Operation amp maintenance costs consist of fixed and variable costs. Fixed costs include cooling and genera l maintenance at the site. Variable costs include recharging the batteries and periodically replacing the batteries. These O amp M costs are presented as annual expenses in the prior table. The cooling charge is based on a power managemen t system which consists of eight modules, each one of which is the same size as the system being characterized here 18 . The unit must be installed in...

Engines

Solar Linear Stirling Engines

The engine in a dish engine system converts heat to mechanical power in a manner similar to conventional engines , that is by compressing a working fluid when it is cold, heating the compressed working fluid, and then expanding i t through a turbine or with a piston to produce work. The mechanical power is converted to electrical power by a n electric generator or alternator. A number of thermodynamic cycles and working fluids have been considered fo r dish engin e systems. These include...

Collector Technology

One Axis Parabolic Trough Collector

The basic component of the solar field is the solar collector assembly SCA . Each SCA is an independently trackin g parabolic trough solar collector made up of parabolic reflectors mirrors , the metal support structure, the receiver tubes, and the tracking system that includes the drive, sensors, and controls. Table 2 shows the design characteristics of th e Acurex, single axis tracking M.A.N., and three generations of Luz SCAs. The general trend was to build large r collectors with higher...

System Application Benefits and Impacts

Application This document describes the use of a battery storage system in conjunction with a PV system to avoi d or reduce the purchase of more costly on-peak power. However, energy storage systems can also play a flexible, multifunction role in an electric supply network to manage resources effectively. Battery energy storage systems are use d for a variety of applications, such as power quality assurance, transmission and distribution T amp D facility deferral , voltage regulation, spinning...

Performance and Cost Discussion Plant Performance

Increasing the performance of the solar collectors and power plant are one of the primary opportunities for reducin g the cost of trough technology. Collector performance improvements can come from developing new more efficien t collector technologies and components but often also by improving the reliability and lifetime of existing components. Table 4 shows the annual performance and net solar-to-electric efficiency of each of the technology cases describe d above. The 1997 baseline case...

Max Power Tracker Power Conditioning System

DC components exclusively DC and AC components Accommodate high-voltage and current Accommodate lower voltage which is less costly Dedicated to PV Not technology-specific Battery subsystem Most PV storage subsystems today consist of flooded lead-acid batteries. Improved valve -regulated lead-acid VRLA batteries are now emerging in utility systems. Advanced batteries such as lithium ion and zinc bromine are being developed and are at different levels of size and readiness for utility operation....

Payback Period

For co-fired biomass a simple payback period was calculated instead of a levelized COE. As a retrofit opportunity , co-firing will be pursued by plant owners only if paybacks of a few years can be achieved. Simple Payback is define d as total capital investment divided by annual energy savings, to obtain years until payback. In simple payback, n o consideration is given to the time value of money and no discount rates are applied to dollar values in future years. I n the co-fire analyses, the...

Receivers

The receiver absorbs energy reflected by the concentrator and transfers it to the engine's working fluid. The absorbing surface is usually placed behind the focus of the concentrator to reduce the flux intensity incident on it. An apertur e is placed at the focus to reduce radiation and convection heat losses. Each engine has its own interface issues. Stirling engine receivers must efficiently transfer concentrated solar energy to a high-pressure oscillating gas, usually heliu m or hydrogen. In...

SEGS Plant Operating Experience

The nine operating SEGS plants have demonstrated the commercial nature of the Luz parabolic trough collecto r technology and have validated many of the SEGS plant design concepts. Additionally, many important lessons hav e been learned related to the design, manufacture, construction, operation, and maintenance of large-scale paraboli c trough plants 7,8,9 . Solar Field Components A simple problem with a single component, such as an HCE, can affect many thousands o f components in a large solar...

Schematic Figure Of Stirling Engine In Solar Powered Stirling Engine

Kinematic Stirling Engine

Dish engine technology is the oldest of the solar technologies, dating back to the 1800s when a number of companie s demonstrated solar powered steam-Rankine and Stirling-based systems. Modern technology was developed in the late 1970s and early 1980s by United Stirling AB, Advanco Corporation, McDonnell Douglas Aerospace Corporatio n MDA , NASA's Jet Propulsion Laboratory, and DOE. This technology used directly-illuminated, tubular sola r receivers, the United Stirling 4-95 kinematic Stirling...

Cost Reductions

Table 4 shows the total plant capital cost for each technology case on a kW m2 basis. The technology shows a 30 cost reduction on a kW basis and a 55 reduction on a m2 basis. These cost reductions are due to larger plants being built, increased collector production volumes, building projects in solar power park developments, and saving s through competitive bidding. In general, the per kW capital cost of power plants decreases as the size of the plan t increases. For trough plants, a 49...

Integrated Solar Combined Cycle System ISCCS

Solar Combined Cycle

The ISCCS is a new design concept that integrates a parabolic trough plant with a gas turbine combined-cycl e plant 2,3 . The ISCCS has generated much interest because it offers an innovative way to reduce cost and improv e the overall solar-to-electric efficiency. A process flow diagram for an ISCCS is shown in Figure 2. The ISCCS use s solar heat to supplement the waste heat from the gas turbine in order to augment power generation in the steam Rankine bottoming cycle. In this design, solar...

Utilityscale Flatplate Thin Film Photovoltaics Land Water and Critical Materials Requirements

Land area needs are based on calculating the array area required to produce the desired output, amount of energy per square meter of array and then multiplying this area by a factor of about 2.5 to account for packing the arrays without shadowing. At 10 system efficiency, a PV system produces about 100 W m2 of array. Including the packing factor, this is 40 W m2 of land area. A MW would thus require 25,000 m2 of land, or about 0.025 km2. In the early years, we expect system efficiency to be...

Financial Model and Results

The FATE2-P Financial Analysis Tool for Electric Energy Projects financial analysis model was used to analyze th e data provided in the Technology Characterizations. This spreadsheet model was developed by Princeton Economi c Research, Inc. and the National Renewable Energy Laboratory for the U.S. Department of Energy. FATE2-P can be used for either the revenue requirements or the discounted rate of return approach. It is used by the DOE renewable energy R amp D programs for its planning...

Balance of Station Costs

Balance of Station BOS costs include foundations, control electrical hardware , site preparation, electric collection system and transmission lines, substation, windfarm control and monitoring equipment, O amp M facilities and equipment, initial spare parts, shipping, resource assessment, surveying, legal counsel, project management and administration, permits, construction insurance, and engineering services. Since land cost is listed on Table 1 as a percent of revenue and not an initial...