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Solar Position, Sun Charts, Solar Climatic, Collector Orientation...

Tools that give sun position, climatic data for solar design, and radiation on a solar collector.

Tools to design window overhangs.

Directory of page:

Solar Site Survey

Collector Orientation

Solar Position, Radiation and Climatic Data

Heating and Cooling Degree Days Data

Window Shading and Overhang Tools

Wind Resource

PV System Performance

New -- SketchUp for sun modeling...

Solar Site Survey
Solar Site Survey...	If you are going to do a solar project, you need to do a Solar Site Survey to make sure that your site gets enough sun during the right times of year to make the project work. This free and simple survey only takes an hour and is fun and educational. Its a must do for any type of solar project!
Sun Tracker -- an iPhone application http://www.imeasuresystems.com/	This is a nice application from Andrew for the iPhone that allows you to do a solar site survey using the iPhone's built in sensors for measuring elevations and azimuth angles for the survey of the horizon. While I've not had a chance to actually try it, it looks to me as though it would do a good job. $15 at the iPhone App store.
Solar Pathfinder http://www.solarpathfinder.com/index	The Solar Pathfinder has been around for many years, and is used by many solar professionals to do solar site surveys. Basically its a glass dome, and the reflection of the objects on the horizon is used to assess the effect of objects on the horizon that would block the sun. Now offered with software assistant. Probably a bit of overkill for the DIYer building one or two projects.
Effect of Collector Orientation On Performance
Radiation On Collector Gary	A tool that provides radiation levels on a flat plate collector for sunny days as a function of collector location (lat and long) and orientation. Use to answer questions like what if I can't aim my collector due south?
Effects of Tilt and Azimuth On Annual Incident Solar Radiation For the United States Locations Craig Christensen and Greg Barker www.hawaiirdp.org/... (pdf)	This very good paper provides a very simple set of contour plots that show optimum collector orientation, and the performance effect for deviations from optimal. Covers only the US, but the general relationships would be useful elsewhere. Some limitations -- read the cautions in the paper. (Thanks very much to Dana for re-finding this paper!)
Solar Position, Solar Radiation, Solar Design Climatic Data
Sun Charts http://solardat.uoregon.edu/SunChartProgram.html	A Sun Chart for your area is a must have tool to determine how much of the time sun will shine on your collectors. See site survey for how it works.
GAISMA http://www.gaisma.com/en/	This site gives sunset/sunrise times, as well as solar insolation, temperatures, precip, ... (thanks to WYWhiteWolf for suggesting this)
Climate Consultant, UCLA Energy Design Tools http://www2.aud.ucla.edu/energy-design-tools/	Climate Consultant is one of the UCLA Energy Design Tools. It provides a variety of ways to visualize weather for a specific location. Weather data files are available for hundreds of locations. This is a brand new version, and is very easy to use. "It graphically displays climate data in either metric or imperial units in dozens of ways useful to architects including monthly bar charts, timetable charts, and psychrometric charts, sun shading charts, and sun dial charts." One of the most interesting charts is the Psychrometric chart with overlays that show the design strategies (e.g. passive solar, evaporative cooling, ..) will work for the location in question.
Psychrometric Charts A tutorial on using the charts... Using Psychrometric Charts...	Psychrometric Charts are very useful for working human comfort problems and air conditioning schemes, and working out condensation problems. Climate Consultant (just above) provides temperature/humidity data overlaid on a Psychrometric Chart for many locations.
Solar Time to Local Time -- Solar Noon, NOAA www.srrb.noaa.gov/highlights/sunrise/sunrise.html	A helpful calculator that gives sunrise, solar noon, and sunset in local time for any location and any date. Helpful in many situations, including finding true south at your location.
Print Your Solar Noon Calendar http://www.solar-noon.com/	Very handy tool that prints out solar noon for every day of the year for your exact location. (thanks very much to Bill for suggesting this)
Surface meteorology and Solar Energy NASA http://eosweb.larc.nasa.gov/cgi-bin/sse/sse.cgi?na+s01#s01	Solar radiation and solar geometry data from derived from satellite observations. Provides data for anywhere in the world. Provides solar parameters for solar thermal, PV, solar cooking, etc. based on 10 year history for your exact location.
Radiation On Collector Gary	A tool that provides radiation levels on a flat plate collector for sunny days as a function of collector location (lat and long) and orientation. Use to answer questions like what if I can't aim my collector due south?
More Solar Radiation and Weather Data Sources NOAA http://lwf.ncdc.noaa.gov/oa/ncdc.html NOAA CLIM20 Weather Summaries by City NOAA year to date degree days NREL (and other) Solar Radiation and Climatic Data http://rredc.nrel.gov/solar/pubs/redbook/ Total and diffuse radiation or building surfaces: Solar Radiation Data Manual for Buildings Typical Meteorological Year weather files http://rredc.nrel.gov/solar/old_data/nsrdb/tmy2/	NOAA provides a variety of weather related products and data. The CLIM20 product provides pretty detailed historical weather summaries for many US towns. It includes temperatures, precip, and heating and cooling degree days. Lots of good data. NOAA year to date degree days provides deg day totals for the current year. Updated each week. NREL Redbook: Average weather conditions and solar radiation of collectors at various orientations for many US cities. Based on 30 year weather records. Try downloading the pdf version for your state. Can be used to roughly calculate gain for collectors. NREL Bluebook: The Solar Radiation Manual for Buildings gives total and diffuse radiation on S, N, E, W and horizontal surfaces. This can be used as base data for many passive gain calculations. TMY weather files give provide typical hour by hour weather files to provide weather input for simulations.
Heating and Cooling Degree Days
Energy CAP Free Degree-Day Weather Tools http://www.energycap.com/weather/	A nice set of free web tools that give heating and cooling degree day information for 1200 locations. Provides historic, current, and even near term degree day forecasts. Very easy to use. Note that a default balance point temperature is 55F is used -- you can change it to the more usual 65F if you wish.
Year to Year Degree Day Comparisons http://www.weatherdatadepot.com/dd.asp (see: FREE Degree Day Report) An example of how to make apples to apples comparisons of fuel use in for two years ...	This report provides month by month comparison of heating and cooling degree days between two years you select. This allows you to make apples to apples comparison of fuel use for two years, and to see the actual effect of changes you made to reduce energy use. An example of how to make apples to apples comparisons of fuel use in for two years ...
Degree Days.net -- Worldwide Degree-Day Tool http://www.degreedays.net/	Nice tool for heating or cooling degree-day summaries for locations around the world. The data comes from Weather Underground stations, so it may be easier to find a location near you.
NCDC Degree-Day Maps Heating and Cooling Degree Day Maps Heating Degree Day Map of US (130K) Cooling Degree Day Map of US (100K) National Climatic Data Center http://lwf.ncdc.noaa.gov/oa/ncdc.html	Heating and cooling degree-day maps for the US.
Window Shading and Overhangs
Designing Shading Overhangs with Google SketchUp http://www.sketchup.com/ Example -- Using SketchUP to model sun and shadows on a home...	SketchUp is a free 3D drawing tool from Google. In addition to being easy to use as a general purpose drawing tool, it offers a built in sun. You can easily draw a wall with a window and overhang (or a whole home), and play the sun over it for various times of day and times of year. Shading structures of all types can be modeled, including trees, solar sails, shade walls, window fins, ... Sun patterns inside the home are also shown. It would be good for modeling sunspaces and greenhouses as well. An example showing how to set it up for home ...
Sustainable By Design Solar Tools http://www.susdesign.com/design-tools.html	Some very well done (and free) tools for designing overhangs, determining sun position, ... The overhang design tool is very good.
Wind
Got Wind? -- How to use the Wind Resource Atlas of the United States	The Wind Resource Atlas of the United States will give you a rough idea if you are in a locations with wind potential -- here is how to use it.
PV
PVWatts -- A Performance Calculator for Grid-Connected PV Systems From NREL http://rredc.nrel.gov/solar/calculators/PVWATTS/ This is a really useful tool.	An easy calculator you can use to find out how much power you will get from a PV installation in your area. It calculates PV system performance based on hour by hour records for sun in your area. Version 1 is very easy to use, and works worldwide. Version 2 allows more detailed inputs, but seems rather complex and puzzling at times to me.