So we built big tanks with a lever system like a piston on your car. Fill the left piston with water. With a small hole in the middle. For flow. If you do the math right you get the horse to walk up the stairs and stand on that piston(header really) the water drops slowly all day forced out of the hole spinning a turbine translating to electricity, preferably a battery. Horse never has to go down stairs thankfully, just back up the stairs to the other side. Moving from one side~ 3 meters every 12 hours should do it.
Basically, horse bed one side. Horse day lounge area other
Someone used to tell me one of the largest exports of Panama City Beach when I lived there was mulch. They would ship it to China for fuel apparently. Never would have thought about a smaller town shipping trees half a world away… Talk about inefficient.