What do you know about Solar water Heaters ?
Solar water heaters are a great way to generate hot water for your home, hotel, or apartment without spending a fortune on electricity bills. Why? These use sunlight to fuel the heating process. In other words, nature is paying your electricity bills.
How the Solar Water Heater works
The Solar water system captures thermal energy from the sun that it uses to heat water
A Solar hot water system is composed of 4 major components
- Collector
These are installed on the roof. They capture sunlight and convert it to heat energy
- Heat transfer liquid
These carry the heat from solar collectors to water tanks.
- Storage Tank
These store hot water when it is not in use
- Controller System
This is the most important part of a solar hot water system. It senses when there is heat to be harvested from the collector and activates the pump to bring that down into the tank where it can be used
- Backup Heater
The backup heater operates on cloudy days when it’s difficult to generate enough heat. It, therefore, provides backup to generate hot water for your property with electricity.
There are 2 categories of Solar water heaters.
- Active Solar Water Heaters
Direct circulation systems:
Pumps circulate household water through the collector and into the home
Pros: Automatic controllers installed on the system sense when sunlight is being collected.
Cons: Best for areas where temperatures rarely fall below freezing. Only works for single-application domestic use.
Indirect circulation systems:
Pumps circulate a non-freezing, heat transfer liquid through the collector and a heat exchanger. This heats the water that then flows into the home
Pros: Still functions in freezing temperatures. Suitable for multiple solar heating applications
Cons: Can be more expensive than direct circulation systems.
- Passive Solar Water Heating Systems
Integral collector-storage passive systems:
These require cold water to be pumped into the solar collector in batches
Pros: They work well in households with significant daytime and evening hot-water needs.
Cons: Best in areas where temperatures rarely fall below freezing but overall can be less effective.
Thermosyphon systems:
Water flows through the system when the water rises as cooler water sinks. The collector must be installed below the storage tank so that water will rise into the tank
Pros: Reliable system.
Cons: Contractors must pay careful attention to the roof design because of the heavy storage tank. Can be more expensive than integral collector-storage systems.
Sizing your solar water heating system involves determining the total collector area as well as the storage volume you’ll need to meet your household’s hot water needs
Ref: Energy.gov
