Solar Hot Water Systems

Installing a system to generate solar hot water complements a home solar electricity system well. Instead of relying solely on a less efficient electric water heater powered by your home solar power system or using natural gas to power your gas powered water heater, you can use the suns rays directly to produce hot water for your home. There are five main types of solar water heating systems sold today:

  1. Batch
  2. Thermosyphon
  3. Open-Loop Direct
  4. Pressurized glycol
  5. Closed Loop Drainback

There have been countless systems invented to generate solar hot water over that last twenty-five years, but these five systems are the premier systems. These systems offer the simplest, most reliable, and longest lasting of all the designs that have preceded them.

Things to note between the various systems is that some are “closed-loop” which means a heat-transfer fluid transfers heat to the water you use through a heat exchanger, while an “open-loop” system heats the water you use directly.

Also there is a different between a “passive” system which uses no moving parts to move the water from collector to end use, and an “active” system which requires moving parts like pumps and valves to get the water to your faucet or shower head.

Now there are many things to consider when choosing the best system for your home based on geographic location, water usage, etc. But there is a system that will be right for you.

Let’s take for example a small household of maybe two people who live in a temperate climate where hard freezes rarely, if ever, occur. In their case they would go with a batch system: it’s small, no moving parts, low maintenance, and easy installation. This works especially well if hot water usage is concentrated in the later part of the day.

Now if the household size where to increase to say three or more people the thermosyphon hot water system would be a better bet, because usage would be higher and most likely spread out over the course of the day.

The household size will dictate the size of system needed and which systems are even capable of meeting the needs of the household. For more information on solar hot water sizing you can find out how to calculate your system requirements on our webpage about solar hot water sizing.

Be aware before you fall in love with a specific system type that only certain systems my qualify for solar power rebates and solar incentives programs in your area. Some systems are relatively easy to install for those motivated do-it-yourselfers, while others should only be installed by trained professionals.

Take a look at the comparison chart below to get an idea of which systems might be suitable for your home.

solar hot water comparison chart

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