TABLE 3-III

PENDING AND PASSED LEGISLATION: INCENTIVES ENCOURAGING USE OF SOLAR ENERGY SYSTEMS

at a price he considers at least competitive with his available

alternatives.

This cost effectiveness depends on these factors:

Mechanical reliability and effectiveness of the proposed
solar system and its conventional alternatives;

Initial and operating costs of the proposed solar system
and its conventional alternatives;

Financing considerations: cost of money, life-cycle costing;
Available useful solar radiation; and

Thermal loads on the building.

Each of these factors varies from building to building and

across a wide choice of system alternatives. MITRE has performed

*

a detailed analysis of these factors and their impact on the

competitiveness of solar applications in various parts of the United States. The approach and results of this study are summarized below.

3.2.1 Regional Considerations

The effects of climate on heating and cooling loads, the

variation of solar radiation from place to place, and the variations in the cost and availability of alternative fuels dictate a regional approach to the analysis.

One or

Eight regions have been identified in the analysis. two cities are selected to represent each region. The regions

and cities are:

· Northeast

• Southeast

**

Boston, Massachusetts

Washington, District of Columbia
Charleston, South Carolina

*

Unpublished

**

The cities are representative only. Care must be exercised in extrapolating results from one city to another as rapid changes can occur over quite short distances.

The regions are shown in Figure 3-3.

Heating and cooling demands for the ten representative cities are presented in Table 3-IV for heating related to a base of 65°F

and cooling related to a base of 70°F.

*

3.2.2 Baseline SHACOB Systems

The baseline solar systems used in the MITRE analysis are:

System 1.

System 2.

Solar powered heat exchanger with conventional
furnace backup; conventional vapor compression
air conditioner,

Solar powered heat exchanger with conventional
furnace backup; solar absorption air conditioner.

It should be noted that intensive development is being conducted on heat-pump systems, including solar-assisted heat pumps. While no detailed cost and performance figures were available for

this study, these developments promise very useful options, and should be closely monitored.

NOAA Publication #84, Heating and Cooling Degree-Days; NOAA,
September 1973.