High-resolution maps of solar collector performance using a climatological solar radiation model

摘要

This paper will present a new methodology for producing estimates of the monthly and annual average performance of different types of flat-plate and concentrating solar collectors. The estimates are made on a uniform spatial grid with 40 km resolution. These estimates should be highly useful both to create maps to facilitate visualization of the solar resource, and as the basic data behind analytical studies of solar resources, deployment scenarios, CO{sub}2 mitigation strategies, and economic assessments. Our initial use of this methodology will be in the continental United States, where supporting data is available to evaluate the model outputs. In future years we hope to utilize this technique world-wide, especially in areas where the surface data are lacking. The National Renewable Energy Laboratory (NREL, Golden, CO) has developed the Climatological Solar Radiation (CSR) model to estimate climatological averages of daily-total solar radiation at a 40 km spatial resolution (1). The CSR model is operational and has been usefully applied to the United States as well as several international areas. The model uses, as input, monthly climatological mean values of cloud cover, precipitable water vapor, aerosol optical depth, surface albedo, and total column ozone. These input parameters are available from various sources such as NASA and NCDC (National Climatic Data Center). The outputs from the original version of CSR are monthly mean daily total values of Global Horizontal, Direct Normal, and Diffuse radiation. Our latest revision to the model allows us to calculate the monthly mean output for the various collector types such as tilted flat-plate surfaces, one- and two- axis flat-plate collectors, and concentrating collectors. Summarized hourly data for these orientations are available in the "Solar Radiation Data Manual for Flat-plate and Concentrating Collectors". These were produced for the 239 individual sites in the United States National Solar Radiation Data Base (NSRDB). Maps of the output from the various collectors are available on the NREL Renewable Resource Data Center web site (rredc.nrel.gov). Our new CSR model output maps will look similar to these, but with 40 km resolution, using over 10, 000 grid points for the USA alone. At this writing, we have modeled and made evaluations of two types of solar collectors, a flat-plate (PV) system facing south with tilt--latitude, and a one-axis tracking concentrator (solar thermal parabolic trough) oriented in a North-South direction. We present here an evaluation of these two types of collectors, as well as for Global Horizontal (PV system with tilt = 0 degrees) and Direct Normal (2-axis tracking concentrator). We also present preliminary sample maps of the United States for these collector types.