In a general way the solar insolation means how much sunlight incident on the surface of the earth, due to difference of latitude and longitude, the solar insolation levels for different region are not uniform. You may compare your location to the following two extreme locations. The average annual insolation levels for Central Australia: 5.89 kwh/m1/day- Very high and Helsinki, Finland: 2.41kwh/m2/day- Very low. To know insolation levels for your area please click on the map below: ( data courtesy of NASA- Surface meteorology and Solar Energy Data Set)