Solar Thermal Collection and Delivery

A home’s roof space may not even face south or may not be strong enough to support the system. If roof areas will not work, homeowners can also consider exterior walls, free-standing or ground systems.

Another factor is the home heating system. Solar thermal systems are well suited for radiant floor heating systems and boilers with hot water radiators. Forced-air systems using a heat exchanger work but lose some efficiency. Solar collectors, however, do provide or assist with hot water needs for a household.

In northern climates with very cold temperatures or long periods of cloudy skies, a backup system will be needed. A house that is drafty and lacking in energy efficiency will need backup. Even the comfort levels of household members — especially elderly members who prefer a higher thermostat setting — need to be kept in mind. Lenders and building codes may also require a backup system.

Possible Restrictions

Check out local codes or covenants that may restrict options. Some municipalities have objected to systems obstructing side yards, unlawful height additions on roofs, violation of historic district regulations, and excessive roof loads.

Cost may be a factor. To make a solar system cost-effective, it should be used most of the year and not sit idle in the summer. Year-round hot water operation improves the cost effectiveness of the system.

A system works best for a budget if it can provide 40 to 80 percent of a home’s heating needs. An active system that supplies less than 40 percent of a home’s heating needs does make much economic sense.

When shopping for a system, compare certified solar collector equipment by checking ratings stickers from the Solar Rating and Certification Corporation.

Costs for an active solar heating system vary greatly and, in part, with competition in the marketplace. In Wisconsin, for example, where there is little competition, an evacuated-tube system for hot-water delivery only in a single-family residence costs between $9,000 and $12,000.