Heating my pool in Aruba with a heat exchanger

My situation is the following. My pool in Aruba is only about 78F without heating. I would like to heat my pool to about 84 degrees. The constant wind cools the pool, also the evaporation, so although the air temperature is constantly around 90F during the day, the pool water is not more than 78-79F. I can't ship a pool heat pump, the cost can be really expensive including shipping and taxes. I have a Bowman titanium heat exchanger 135, which has 75k BTU heat load at 140F degrees. My pool is about 8000 gallons. I can use some boiler water for the heat exchanger, but I am at loss to calculate what the capacity of this boiler should be. The boiler will be installed in my pool shed where I have also the pool filter, pump and the heat exchanger and I will insulate the water lines. Does anybody have any knowledge about how big this boiler needs to be? I have some knowledge about the circuit, I need a pump and an Aquastat for the boiler circuit. The Bowman heat exchanger will be installed as per their specifications on the pool line. The boiler heated water will enter the heat exchanger and heat the pool water. But what type of electric boiler do I need, how big should it be? There is no natural gas or propane in Aruba, but I can eventually install some solar panels to produce the electricity for this boiler, so hopefully this will not cost me an arm and a leg. Thank you so much, I hope someone will know the answer.