Mppt to heating element, could you point me in the right direction?

I’ve been looking into making hot water to help heat my house. i would like to run the panels directly to the heating element. this would be a completely separate system. now i realize i can’t just run the wire to the elements because it would be very wasteful. i need to control the panel output with mppt. im pretty good with a uno so that would be the device i would like to use to do this. i’m thinking someone has already done something like this before. all i’m able to find on the net is going from the panels to battery’s. that’s very different the going to a heating element. a heating element isn’t all that picky. can someone tell me a web site or maybe someone on this forum has a write up on how they did what i want to do.

found something. field test of a photovoltaic water heater. from the building and fire research laboratory national institute of standards and technology. interesting setup. use a micro computer and 6 heating elements wired in parallel. first elements is hard wired to the array. the next 5 are connected when needed using mechanical relays. doesn’t even use mppt. the micro computer measures the solar irradiance in the plane of the array and decides the optimal amount of elements to use. wow, drop dead simple.