Adding solar heater pump/pressure question

[J.P.M.]

I understand that roof mounted solar heaters require more pump power - my question is does this also result in higher pressure within the plumbing? My plumbing is only 1 1/2"

In a closed system the "static" pressure will be higher at the bottom of the system than at the top. The steady state flow induced pressure drop in a closed system is independent of elevation and is a function of the fluid being pumped, its flow rate and fluid characteristics, the system configuration (elbows, pipe sizes,length, etc) and it's other components (valves, instruments, etc).

For drain back systems, startup requires additional pump "head" capacity so that fluid can overcome the pressure induced by the elevation. Once filled, The head pressure is offset by the fluid in the "downhill" side of the system and such a system has the same type of flow induced pressure losses and the closed system.

[Ward L]

Yes, for the water to flow there has to be more pressure.

[MikeInRialto]

I understand that roof mounted solar heaters require more pump power - my question is does this also result in higher pressure within the plumbing? My plumbing is only 1 1/2"