Solar hot water seems counter intuitive.

[LucidEnergy]

I have never understood this, although I don't know exactly how the system works.

The time of year when solar water heaters and working most efficiently is the season when your hot water needs are the lowest. Heating is rarely need in summer, and this is when the system is able to heat water the most.

[St Rhenium]

I think it's more of a 'slow burning' investment. Sure, your needs are smaller in the summertime, but you still need [i]some[/i]. This solar power can help to provide that. And in winter, solar power isn't nearly [i]as[/i] effective, but it it isn't completely redundant and will at least produce a fraction of the energy you're in need of, which is a fraction better than nothing.

[JamesH]

I think you underestimate how much solar energy there is in winter. It is only cold because of the air, but there is still a significant amount of solar radiation hitting the panels. Sure less than summer, but easily enough to make a significant dent in heating costs.

[Zarostulus]

I think there is less radiation hitting the panels. The sun is at a lower angle, so less is likely to make it to Earth's surface. On top of that, having 6 hours of daylight instead of 16 is a bit of a tough pill to swallow with solar.