What are the advantages and disadvantages of solar water heaters?

Advantages of solar water heaters include:
1. Energy saving: A part of household living expenses is water and electricity, but using solar water heaters can save more than 90% of electricity and gas costs, which is very economical.
2. Environmental protection: It reduces the development of other non-renewable energy sources, which has a positive effect.
3. Safety: When using solar water heaters, there are no hidden dangers of poisoning or electric shock, and it is safe and reliable.
4. Economical: The initial investment is relatively large, but it is still relatively economical in the long run.
Disadvantages of solar water heaters include:
1. Inconvenient installation: brackets need to be installed on the roof, which takes up a lot of space.
2. Difficulty in maintenance: The dust on the solar water heater needs to be cleaned regularly to prevent excessive accumulation of dust from affecting the use effect.
3. Not suitable for cold areas: Due to the poor thermal insulation ability of solar water heaters, it may not be able to meet the demand for hot water in cold areas in winter.