National Renewable Energy Laboratory

NREL North American 

Radiation Atlas

Ray George

Pamela Gray-Hann

Presented to the American 

Energy Society, Forum 2

April 24, 2001

Operated for the U.S. Department of Energy by Midwest Research Institute • Batte

NREL/PR-550-40033Presented at the 2001 Solar Energy Forum: The Power to Choose held on April 21-25, 2001
Disclaimer and Government License

This work has been authored by Midwest Research Institute (MRI) under Contract No. DE-AC36-9Department of Energy (the “DOE”). The United States Government (the “Government”) retains anthe work for publication, acknowledges that the Government retains a non-exclusive, paid-up, irrevpublish or reproduce the published form of this work, or allow others to do so, for Government purNeither MRI, the DOE, the Government, nor any other agency thereof, nor any of their employeesor implied, or assumes any liability or responsibility for the accuracy, completeness, or usefulness product, or process disclosed, or represents that its use would not infringe any privately owned rig

specific commercial product, process, or service by trade name, trademark, manufacturer, or otheimply its endorsement, recommendation, or favoring by the Government or any agency thereof. Tauthors and/or presenters expressed herein do not necessarily state or reflect those of MRI, the Dagency thereof. 
NREL Solar Atlas

• Http://www.nrel.gov/gis• Currently includes 48 contiguous states • Alaska and Hawaii will be added in the 
Goals of NREL Solar A

• Deliver basic solar performance estima

general users.

• Deliver a wide variety of additional info

more advanced users.

• Be easy to use, full featured, and exten
Components of NREL So

• Solar resource datasets from NREL So

Assessment function and other sources

• Internet Map Server technology from E

including political and infrastructure dat

• Links to Renewable Resource Data Ce

(rredc.nrel.gov) for supplemental documdatasets.
Typical Solar Atlas U

Same users who currently use the Solar Data Manual for Flat-Plate and ConcentrCollectors

Need to estimate performance for any of solar collectors, for any location, for any annually.

Include PV sellers, homeowners, as well researchers and analysts (scientists, stuengineers)
NREL Solar Radiation Pr

• National Solar Radiation Data Base (NS

only, 30 year time series, measured and radiation.

• NSRDB derived products - Solar collecto

buildings manual, TMYs.

• Solar Radiation Data Grids
NREL Solar Radiation Da

• Uses CSR (Climatological Solar Radiatio

devised by Dr. Gene Maxwell.

• Produces monthly and annual estimates 

radiation for each of 14 different solar coorientations (patterned after NREL “Red 

• Estimated uncertainty of annual estim
Fixed Flat-Plate Colle

• Flat-Plate Collector Facing South 

Tilt=0

• Flat-Plate Collector Facing South 

Tilt=Latitude-15

• Flat-Plate Collector Facing South 

Tilt=Latitude

• Flat-Plate Collector Facing South 

Tilt=Latitude+15

• Flat-Plate Collector Facing South 

Tilt=90
Tracking Flat-Plate Col

• 1-Axis Tracking Flat-Plate Collector wit

Axis, Axis Tilt=0

• 1-Axis Tracking Flat-Plate Collector wit

Axis, Axis Tilt=Latitude-15

• 1-Axis Tracking Flat-Plate Collector wit

Axis, Axis Tilt=Latitude

• 1-Axis Tracking Flat-Plate Collector wit

Axis, Axis Tilt=Latitude+15

• 2-Axis Tracking Flat-Plate Collector
Tracking Concentrat

Collectors

• 1-Axis Tracking Concentrating C

East-West Horizontal Axis

• 1-Axis Tracking Concentrating C

North-South Horizontal Axis

• 1-Axis Tracking Concentrating C

North-South Axis, Axis Tilt=Latitu

• 2-Axis Tracking Concentrating C
PV Atlas - Map GUI Fea

• U.S. Map with terrain overlay, states, N• Legend window with 7 data selections 

collectors, Data Grid spreadsheets, NSspreadsheets).

• Multiple navigation aids (terrain, counti

highways).

• Variable size data retrieval window with 

capability.

• Map navigation and data retrieval toolb

Single Collector Data R

• Zoom into your desired area until grey 

appear.

• Select one of 5 collector types in legen

(Tilt=Latitude is the default).

• Select “Data Identity” tool.• Choose any desired cell with the mous• Monthly and annual radiation for the co

appears in data window on right side of 

14 Collector Spreadshe

Table Retrieval

• Zoom into your desired area until grey 

appear.

• Select ‘View Data Tables with Hotlink” • Select “Hotlink” tool.• Choose any desired cell with the mous• Spreadsheet data table with monthly an

radiation for all 14 collectors appears in on right side of screen.

Download Spreadshee

Table

• Selected spreadsheet data table appea

window on right side of screen.

• Select the data window “Frame” with th• Choose “File:Save Frame As” on menu• File “idno.txt” appears in your directory• For Data Grid, idno is a 6 digit cell id.• For NSRDB, idno is a 5 digit WBAN nu
Spreadsheet Data Ta

• Table can be loaded into Excel using T

Wizard as a “Delimited” file with “commdelimiter. 

• NREL can provide a macro program to 

into Excel and create graphics for all 14 

Data Table - Excel Gra

Cell No: 178355

Lat: 36.45

Long: -118.55

Elev(m): 2630

Stn Type: Data Grid

Fixed Tilt Collector Facing Equator

0.01.02.03.04.05.06.07.08.09.0

kWh/m2/day

Horiz Lat - 15 Lat Lat + 15 90

Tracking 

0.02.04.06.08.0

10.012.0

kWh/m2/day

Horiz Lat - 15 

Tracking Collector

0.01.02.03.04.05.06.07.08.09.0

kWh/m2/day

1-Axis, EW, Horiz 1-Axis, NS, Horiz 1-Axis, NS, Tilt=Lat 2-Ax

Average Solar Radiation for Flat Plate Collectors

 Average Direct Beam Solar Radiation for Concentrating Collectors

Developed by the Na

Solar Radiation Data fo

Flat-Plate and Concentrating Co
PV Atlas - (near) fut

enhancements

• Alaska and Hawaii• Two more map interfaces, one for Trac

Plates and one for Tracking Concentra

• Maps of the solar resource.• Map interface to various sources of sol

data (CONFFRM, BSRN, WRDC, etc.)