Solar Panel Size Calculator


First, enter the average sunshine hours per day for your location. NOTE: You should choose the time of year with the least sunshine hours per day (i.e. mid winter) to ensure year-round operation of your energiser. To assist with this we have gathered data for America, Australia and South Africa. To view this data select your country under the Choose Location (Optional) Heading. For other locations, try to find your own weather data. If no data is available, record your own, or, make a conservative estimate of the FULL sunshine hours (not simply dawn to dusk) during winter at your location.

Then simply choose the energiser you wish to use. If yours is not listed, select 'Other' and enter the current draw when prompted. Finally, click the Calculate button.

Map of sunshine hours/day in June

Map of sunshine hours/day annually

Location Sun Hours
Alexander Bay 7.66
Bloemfontein 7.63
Cape Town 5.70
Durban 5.18
East London 7.42
Gough Island 6.92
Johannesburg 7.42
Kimberly 8.63
Marion Island 6.37
Pietersburg 7.92
Port Elizabeth 6.90
Pretoria 7.70
Upington 7.68

State City Sun Hours
Alabama Birmingham 4.39
Alaksa Nome 1.29
Alaska Anchorage 1.58
Alaska Fairbanks 1.29
Alaska Juneau 1.61
Arizona Phoenix 7.61
Arizona Tucson 7.9
Arkansas Little Rock 5.35
California Las Angeles 6.77
California San Diego 6.97
California San Francisco 5.03
Colorado Denver 5.97
Colorado Great Junction 5.16
Connetictut Hartford 4.52
DC Washington DC 2.12
Florida Fort Lauderdale 6.45
Florida Jacksonville 5
Florida Kissimmee 5.16
Florida Miami 6.45
Florida Orlando 5
Georgia Atlanta 5.16
Hawaii Honolulu 6.81
Idaho Boise 3.39
Illinois Chicago 3.39
Indiana Indianapolis 3.55
Iowa Des Moines 4.52
Kansas Wichita 5.93
Kentucky Louisville 3.38
Louisiana New Orleans 5.32
Maine Portland 4.53
Maryland Baltimore 4.68
Massachusetts Boston 4.84
Michigan Detroit 2.87
Minnesota Duluth 3.06
Minnesota Minneapolis 3.39
Mississippi Meridian 4.6
Mississippi Vicksburg 4.22
Missouri Kansas City 4.52
Montana Billings 3.39
Montana Great Falls 4.03
Nebraska Omaha 4.73
Nevada Las Vegas 7.74
New Hampshire Hanover 6.23
New Jersey Atlantic City 5.02
New Mexico Albuquerque 7.08
New York New York City 4.84
North Carolina Cape Hatteras 4.35
North Dakota Bismarck 4.32
North Dakota Fargo 4.15
North Dakota Williston 4.18
Ohio Cincinnati 3.48
Ohio Cleveland 2
Ohio Columbus 3.32
Oklahoma Oklahoma City 5.32
Oregon Portland 2.26
Pennsylvania Pittsburgh 2.42
Rhode Island Providence 6.4
South Carolina Colubia 6.05
South Dakota Rapid City 4.63
Tennessee Memphis 4.84
Texas Austin 4.84
Texas Brownsville 4.68
Texas Dallas 5
Texas Houston 4.84
Utah Salt Lake City 4.08
Vermont Burlington 3
Virginia Richmond 4.8
Washington Seattle 1.68
Wisconsin Green Bay 3.38
Wisconsin Madison 3.93
Wyoming Cheyenne 5.48
Wyoming Lander/Hunt 6.07

Battery Size Calculator


Select an energiser (or select "Other" and enter the average current drain) in the section above, then enter the minimum acceptable charge level for your battery, based on the battery type. We recommend 50% for standard lead acid, 25% for deep cycle. Then enter the longest number of consecutive bad weather days (i.e. no sunshine) you expect to experience at this site and click on Calculate.