Pool or spa heating - all solar heating systems make extra energy under optimal conditions. Why waste it? Warm your pool and get extra use out of it.
Snow melting - you can't really heat the outside with a solar water heater; but you can heat a walk or a car port with solar energy that is not strong enough for other uses. It is your choice.
Solar assisted gardening - root zone heating is both feasible and practical. It is also known to benefit plant growth and to extend the growing season. Gardeners will appreciate the ability to produce earlier crops in the Spring , and maintain production well into the Fall. In the summer, after you have made all of the heat and hot water that you could possibly want, just turn the surplus into the garden! You won't believe the difference.
Excess solar energy can make your compost pile really take off, giving you the best fertilizer and biological starter material that there can be.