TABLE 8.2. Emergy Analysis of Solar Voltaic Power Installation in Austin Texas. Annual Contributions and Requirements (from Environmental Accounting, Howard T. Odum, c1996)
Note | Item | Data and Units (J, g or $) | Solar Transformity (sej/unit) | Solar Emergy (x10^15 sej/yr) | Em$ ($/yr*) | |
1 | Solar energy | 2.67 x 10^7 kWh | 1 | 0.096 | 60 | |
2 | Design installation | 1.94 x 10^4 $ | 2.8 x 10^12 | 54.30 | 27,160 | |
3 | Materials cost | 1.63 x 10^4 $ | 2.8 x 10^12 | 45.60 | 22,820 | |
4 | Collector cost | 5.68 x 10^4 $ | 2.8 x 10^12 | 159.00 | 79,520 | |
5 | Administrative cost | 1.2 x 10^5 $ | 2.8 x 10^12 | 336.00 | 168,000 | |
6 | Operation and maintenance | 4.0 x 10^4 $ | 2.8 x 10^12 | 112.00 | 56,000 | |
7 | Concrete | 2.23 x 10^3 lb | 1.5 x 10^13 | 33.40 | 16,725 | |
8 | Structural steel | 1.16 x 10^4 lb | 4.16 x 10^11 | 4.80 | 2,413 | |
9 | Steel building | 1.47 x 10^2 lb | 4.16 x 10^11 | 0.06 | 30 | |
10 | Rebar | 7.8 x 10^3 lb | 4.16 x 10^11 | 3.24 | 1,622 | |
11 | Copper wire | 26.7 lb | 4.49 x 10^13 | 1.20 | 600 | |
12 | Total from economy (items 2-11) | 749.70 | 374,951 | |||
13 | Electric power output | 1.8 x 10^12 J | 2.0 x 10^5 | 360 | 180,000 | |
Emergy yield ratio: 360 x 10^15 sej/yr / 749.7 x 10^15 sej/yr = | 0.48 | |||||
Emergy investment ratio: 749.7 x10^15 sej/yr / 0.096 x 10^15 sej/yr = | 7809 | |||||
* Solar Emergy in column 5 divided by 1.6 x 10^12 sej/1991$. | ||||||
1-12 Based on an interview with the site engineer for the city of Austin | ||||||
1 (2.67 x 10^7 kWh/yr)(3.6 x 10^6 J/kWh) = 9.61×10^13 J/yr | ||||||
13 (5.0×10^5 kWh/yr)(3.6 x 10^6 J/kWh) = 1.8 x 10^12 J/yr | ||||||
Source: R. King, personal communications, 1991. Data from King and Schmandt (1991). |