1 Revised Solar Water Heating Deemed Savings Estimates June 4, 2003

2 Reason for Revisions Current “Deemed” Values based on system with 40 sq.ft. collector area Initially proposed deemed savings values to cover three “generic” sizes used in Oregon Tax Credits and “Brightway” specifications –37.3 sq.ft. –60.0 sq.ft. –74.6 sq.ft. RTF Recommended Adding More Size Ranges

3 Originally Proposed Deemed Savings for Solar DHW Systems Solar ZoneCollector Area = 37.3 sq. ft. (kWh/yr) Collector Area = 60.0 sq. ft. (kWh/yr) Collector Area = 74.6 sq. ft. (kWh/yr) Zone 1 1,800 2,200 2,400 Zone 2 1,900 2,300 2,500 Zone 3 2,100 2,600 2,700 Zone 4 2,400 3,000 3,200 Zone 5 2,500 3,200 3,400

4 Revised Deemed Savings for Solar DHW Systems Solar Zone Collector Area = 20–30 sq.ft. (kWh/yr) Collector Area = 31– 40 sq.ft. (kWh/yr) Collector Area = sq. ft. (kWh/yr) Collector Area = sq. ft. (kWh/yr) Collector Area = sq. ft. (kWh/yr) Collector Area = sq. ft. (kWh/yr) Zone 11,4001,7001,9002,1002,3002,700 Zone 21,5001,8002,1002,3002,4002,500 Zone 31,7002,0002,3002,5002,700 Zone 41,8002,3002,7002,9003,1003,200 Zone 51,9002,4002,8003,1003,3003,400