Tank Vs. Instant Electric Water Heaters for Solar Systems?

System Design Considerations

When designing a solar-powered water heating system, it’s essential to consider the hot water demand, available solar radiation, and system size. Tank electric water heaters are more efficient for large households or businesses with high hot water demands, as they can store excess heat generated during the day for use during low-solar periods. In contrast, instant electric water heaters are better suited for small-scale systems, such as cabins or RVs, with limited hot water demands.

Cost Analysis

The cost analysis of tank electric water heaters and instant electric water heaters varies depending on the system size and hot water demand. A typical 50-gallon tank electric water heater can cost between $800 and $1,200, whereas an instant electric water heater can cost between $200 and $500. However, tank electric water heaters can be more cost-effective in the long run, as they can store excess heat generated during the day for use during low-solar periods, reducing the reliance on backup energy sources.

Instant vs. Tank Electric Water Heaters

Instant electric water heaters, also known as point-of-use water heaters, are designed to heat water on demand, whereas tank electric water heaters store hot water in a tank for later use. Instant electric water heaters are more suitable for small-scale systems with limited hot water demands, as they can provide instant hot water without the need for storage tanks. However, they can be less efficient than tank electric water heaters, as they require continuous heating and can waste energy when not in use.