U.S. Department of Energy - Energy Efficiency and Renewable Energy

Federal Energy Management Program

New and Underutilized Technology: Solar Water Heating

The following information outlines key deployment considerations for solar water heating within the Federal sector.


Solar water heating uses solar thermal collectors to heat water.


Solar water heating is applicable in most building categories.

Climate and Regional Considerations

Solar water heating is best in regions with high insolation.

Key Factors for Deployment

The Energy Independence and Security Act (EISA) of 2007 requires 30% of hot water demand in new Federal buildings and major renovations to be met with solar water heating equipment providing it is life-cycle cost effective.

Federal agencies must consider collector placement location to optimize solar water heating efficiency.

Ranking Criteria

Federal energy savings, cost-effectiveness, and probability of success are ranked 0-5 with 0 representing the lowest ranking and 5 representing the highest ranking. The weighted score is ranked 0-100 with 0 representing the lowest ranking and 100 representing the highest ranking.

Federal Energy Savings Cost Effectiveness Probability of Success Weighted Score
0.6 3.0 4.3 41