solar panel/pump heating spa need simple circuit to restrict over powering pump

[devid3an]

Hey guys

Im new and know very little about electrical know how but have done a course years ago in basic electronics so have some idea

anyways i have a spa pool that i have hooked up to a small circualting pump that operates on 8w and i have solar panel that produces a maximium of 10w, it pumps water from my spa through 200metres of coiled black pipe on a roof top of a small pump shed that is 1.2metres of the ground, but anyways it works very well to heat and pump the water but only at full sunlite in summer, i would like to add on another 10w solar panel so it could possibly work at low level sun(cloudy) but don't want to cook the pump, how do i wire something in to restrict the power to 8w, also how do i wire the solar panels series or parrelal, i want this to be very basic as thats what its about

any possitive feedback welcome

thanks for ready

[computerpc101]

you can add another 10 w panel parallel together, ( I assume that most solar panel build in diode(s).

It should be fine, Most important factor is voltage, Although water pump is 8w and solar panel is 20W, As long as they are rated 12 v. They should be fine, However, If you are really picky, you might consider using 12 volts charger controler or some cheap 2A LM317 adjustable voltage regualtor for speed adjust, It will regulate voltage for stable operation.

[devid3an]

it doesn't appear to have a diode ( i do know what i diode shoud look like) it is 12v but does have any circuitry that is visable unles its mirco

[devid3an]

so with that theory if i added a 30what solar panel @12volts in parrell it shoul be fine?