Solar panel & water cylinder

I`m going to install a solar panel system for hot water.
The main heating system is Oil based Rads.
They will provide a 300L water tank. As this is a new build does this mean I don`t have to buy another cylinder for the Radiators or will there have to be 2 cylinders?

Re: Solar panel & watercylinder

Single tank with dual coils.
Leo

Re: Solar panel & watercylinder

Like the one pictured here I presume?

Re: Solar panel & watercylinder

I recently installed a 2 coil tank with the intention of later putting a solar panel onto the extra coil (i was replacing the cylinder so just got the 2 coil). Since heard that the copper coil wouldn't last long due to the intense heat from the panel in the summer. How hot do these things get? Stainless solar coils are apparently the only way to go but isn't there a greater loss in heat transfer through stainless over copper?