When you accelerate hard, the computer shuts down the A/C and the alternator to sent all engine power to the wheels. I never heard of the heater shutting down, but maybe because the system is being run on the battery during that time it's shut down.

At least the above is probably what is going on with your car. It's normal.

There is NO POINT in asking questions like yours without DETAILS! On many EURO CARS this means that the ELECTRIC AUXILIARY WATER PUMP is bad or fuse to it is bad! ON JAPANESE and DOMESTIC cars, it usually means you have LOW COOLANT LEVEL or that you have a gasket problem, like on most GM engines after warranty is up! Many cars under HARD FULL OUT acceleration shut OFF the A/C compressor to make more power! ALWAYS INCLUDE Year, make, model, mileage, country of origin, and ENGINE SIZE with your questions here! ALl cars are NOT created equal!

Not that it would make any difference what year it was the question is without any useful information.

solenoid?

We have no idea what year make and model car you drive.