• Sunlight is an inexhaustible source of renewable energy. Capturing and using it to heat water does not produce CO2 or any other greenhouse gas.
• The primary energy source—sunlight—has no cost. Solar hot water systems also enjoy generous renewable energy incentives.
• Solar hot water systems are often cost-effective when properly designed for local climates needs, especially when included in new construction and financed with the rest of the home.

There are a large number of possible solar hot water system designs, although only a handful are appropriate for year-round use in Wisconsin. At North Wind, one of our goals is to make sure you understand the options that work in Wisconsin and then choose the one that makes the most sense for you.

Collectors

Collectors are responsible for “collecting” the sunlight and providing heat to a solar hot water system. There are two main types of collectors:

1. Flatplate. Flatplate collectors consist of an absorbing sheet made of and/or glazed with some solar absorbent material. Beneath the sheet are coiled tubes within which the liquid in the system (water for a direct system, some other liquid for an indirect system) is heated. Flatplate collectors are very durable and have a strong historical track record of durability.
2. Evacuated. Evacuated tube collectors consist of a series of glass tubes laying next to each other parallel. Inside each tube is a second tube, known as an absorber tube, within which the liquid in the system is heated. Evacuated tubes can be cost effective and can perform well in cold conditions.

Aesthetics

As any property owner can appreciate, the appearance of a property’s exterior is as important as its interior. That is why North Wind encourages anyone considering a solar hot water system for the financial and environmental benefits to also consider its aesthetic qualities.

For example, North Wind offers hot water systems from VELUX®, a global leader in skylights and solar technology. These systems are designed to integrate as much as possible with the roof on which they are installed. Yet VELUX systems are still some of the most affordable systems available—offering a unique combination of cost-effectiveness and elegance.

Learn more about what North Wind and VELUX can offer you.

Circulation Systems

The major challenge for a solar hot water system in central Wisconsin is avoiding freezing in the winter. This can be accomplished by choosing a closed-loop circulation system, of which two are recommended:

1. Drainback. A drainback system is a closed-loop, indirect solar hot water system that drains liquid from the collector when the pump is turned off (i.e., when the tank is hot and no more heat is needed). This helps prevent freezing in the winter as well as overheating in the summer.
2. Pressurized systems. A pressurized system is a closed-loop, indirect solar hot water system that uses a water/anti-freeze mix as the heating fluid. This offers excellent protection from the winter cold. Also, because it is pressurized, it can use a small pump, one that can even be powered by a small solar electric system.

One of the advantages of a solar hot water system is that there is almost always a system that makes sense for your needs and goals. The disadvantage is that, with so many options and configurations available, it isn’t immediately obvious which is the best system for you.

That is why for some sites, North Wind recommends that you conduct a detailed site assessment as a first step in the design and installation of a solar hot water system.

A site assessment provides information about your hot water needs, the type of configuration that will be most cost-effective, a ball park system cost, and a guideline for completing the process of designing and installing a system.