National weather forecast for Tuesday October 15.

The dark spheres ranging in size from golf to tennis balls could be “tar balls”, a mixture of oil and debris.

The environmental benefits of switching from gas to electric are well known. New research now shows it could help save your budget, as well as the planet.

Preliminary testing by Randwick City Council has identified the black balls that have washed up on Coogee, Maroubra and Gordons Bay beaches as “tar balls”, made from oil and debris.

National weather forecast for Wednesday October 16.