1TABLE 3.1-1 Technology-Specific Assumptions for Environmental Impact Analyses

aLand area estimates were based on areas required for existing facilities and estimated areas for proposed facilities. In some cases disturbed area estimates were not available; thus values were based on total plant area (should approximate disturbed area). The estimated land use values for parabolic trough and tower facilities are minimums; the land area requirement could be higher if thermal energy storage (TES) were incorporated into facilities.

bWet-cooling and dry-cooling requirements are based on estimates given as gal/h/MW in DOE (2009). An

assumed range of operational hours of 30 to 60% of annual hours (1 gal = ~3.1 10–6 ac-ft) was used to generate ac-ft/yr/MW values.

cHybrid systems are assumed to use 20% of the water requirements of wet-cooling systems.

dThe mirror washing estimates originate from the assumed 2% of total water needs of wet-cooled parabolic trough facilities from DOE (2009). This estimate equals 20 gal/h/MW, which corresponds to 0.5 ac-ft/yr/MW, with no assumption on operational time (conservative estimate). The panel washing estimate for PV facilities was assumed to be a factor of 10 less than that for CSP technologies (see Appendix M of the Draft Solar PEIS).

eNA = not applicable.

2

3

4 3.2 DEVELOPMENT PROCESS OVERVIEW FOR ALL TECHNOLOGIES

5

6

7 3.2.1 Site Characterization

8

9During site characterization, generally very little modification of the site occurs. The

10activities could include construction of meteorological towers, surface hydrology assessment

11and floodplain mapping, slope evaluation, soil stability studies, due diligence assessment for

12lands with previous industrial uses, evaluation of seismic stability and potential storm event

13runoff, and soil coring (especially where substantial foundations would be required). The site

1characterization phase would include conducting surveys for ecological, cultural, and

2 paleontological resources (including surveys for special status species if needed). Many of these 3 activities would involve minimal or no site disturbance. The more detailed description of these 4 activities provided in the Draft Solar PEIS remains valid.

5

6

7 3.2.2 Site Preparation and Construction

8

9Construction of any solar energy development project is likely to involve the following

10major actions: establishing site access; performing site grading; constructing laydown areas and

11an on-site road system; removing vegetation from the solar field and construction and laydown

12areas (primarily for fire safety); and constructing the solar field, power block area (for parabolic

13trough and power tower facilities), central control building, electrical substations, and

14meteorological towers (if not done during site characterization). Additional activities may also

15be necessary at some facilities, including pile driving, constructing a concrete batching plant,

16constructing sanitary facilities and temporary offices, and landscaping. Construction would

17generally be divided into two phases, which would include a site preparation phase of relatively

18short duration (e.g., a few months) followed by a much longer assembly, testing, and start-up

19phase. The description and information about site preparation and construction activities

20provided in the Draft Solar PEIS remains valid.

21

22

23 3.2.3 Operations

24

25Operation of solar facilities would require varying numbers of on-site personnel,

26depending on the technology and the capacity of the facility; PV facilities might require very few

27(less than 5) personnel on-site daily, whereas larger solar trough or power tower facilities would

28require an operations workforce on the order of 100 individuals. All facilities would require

29facility control staff to monitor solar array and substation operations, and the power block if

30present. All solar facilities would require provisions for reflector/mirror washing at frequencies

31appropriate to the technology being utilized. Facilities utilizing steam cycles and circulating both

32steam water and heat transfer fluids (HTFs) would have additional maintenance activities. The

33description of operations in the Draft Solar PEIS remains valid.

34

35

36 3.2.4 Decommissioning and Reclamation

37

38Decommissioning would include removal of equipment, removal of permanent structures

39and on-site roads, proper closure of all on-site wells, removal of all hazardous materials and

40wastes and closure of related storage areas, remediation of all spills or leaks of chemicals, and

41return of the site to its native state to the greatest extent possible, including re-establishment

42of the native vegetative communities. The removal of electrical substations would require

43inspection for contamination of the soil and decontamination as necessary. The description of

44decommissioning and reclamation in the Draft Solar PEIS remains valid.

45

46

1 3.2.5 Transmission Facilities

2

3 As described in Section 3.2.5 of the Draft Solar PEIS, construction and operation of 4 transmission lines to tie solar energy facilities into the main power grid would be required for

5 most new solar energy facilities. The length of transmission line required would depend on the 6 distance from the site to existing lines having sufficient uncommitted capacity to accept power 7 from the facility (if such lines exist). If no capacity is available on existing lines, it is possible 8 that entirely new lines would be needed to transmit electrical power from solar facilities to load 9 centers (i.e., populated areas with a demand for the generated electricity).

10

11An analysis of the distance from all eligible solar facility locations on BLM-administered

12lands in the six-state study area to the existing transmission grid or to federally or locally

13designated transmission corridors was provided in the Draft Solar PEIS; the analysis showed that

14few locations are greater than 25 mi (40 km) from these existing lines or corridors1

15(see Appendix G of the Draft Solar PEIS).

16

17The general information on transmission facilities provided in Section 3.2.5 of the Draft

18Solar PEIS remains valid. The following paragraphs describe the changes in the analysis of the

19impacts of construction and operation of transmission facilities to support solar energy

20development that are being presented in this Final Solar PEIS.

21

22In Chapter 5 of the Draft Solar PEIS, a general analysis of the impacts of transmission

23line construction and/or line upgrades was provided for each resource area addressed. The

24description of these impacts remains valid.

25

26The analysis of transmission impacts for the proposed SEZs presented in the Draft Solar

27PEIS assumed land disturbance from construction of a new line from each SEZ to the nearest

28existing transmission line; it was acknowledged that if additional construction or line upgrades

29were necessary for specific solar projects within SEZs, developers would need to analyze those

30environmental impacts. The transmission analysis for the SEZs did not evaluate the available

31capacity on existing lines; the assumption was made that existing lines could be upgraded if

32additional capacity were needed. Comments were received stating that this assumption was

33generally not valid because of almost full allocation of the transmission grid capacity in the study

34area. These comments correctly pointed out that it was possible that new transmission line

35construction might be required to transport power from the SEZs along at least part of the route

36to the purchasing load center. For this Final Solar PEIS, an analysis for each SEZ has been added

37estimating the potential costs and land disturbance associated with constructing new transmission

1 Subtitle F of the Energy Policy Act of 2005 required various federal agencies, led by the DOE and the BLM, to designate corridors for energy transmission in the 11 western states, including the six-state study area of this PEIS. Local BLM offices have also designated corridors under separate authorities. Both federally and locally designated corridors are addressed in the Programmatic Environmental Impact Statement, Designation of Energy Corridors on Federal Land in the 11 Western States (Corridor PEIS) (DOE and DOI 2008). The Corridor PEIS, as well as various state and regional initiatives, such as California’s Renewable Energy Transmission Initiative (RETI) (see http://www.energy.ca.gov/reti/index.html and Appendix D of this PEIS), should help to facilitate solar development by creating corridors through which power from remotely located solar facilities can be efficiently delivered to customers with minimum adverse impacts.

1 lines along the entire route to likely load centers. These analyses also include estimates of costs 2 and land disturbance associated with required new transmission substations, as requested in

3comments. The new analyses provide upper bound estimates of the costs and environmental

4impacts (in terms of land disturbance) of providing transmission to each of the SEZs. SEZ-

5 specific dedicated line transmission (DLT) analyses are provided for each of the proposed SEZs 6 carried forward in the Supplement to the Draft Solar PEIS (BLM and DOE 2011) in Chapters 8 7 through 13 of this Final Solar PEIS.

8

9

103.3 LAWS AND EXECUTIVE ORDERS POTENTIALLY APPLICABLE TO SOLAR

11ENERGY AND TRANSMISSION LINE PROJECTS

12

13Section 3.3 of the Draft Solar PEIS discussed in general terms the existing major laws,

14E.O.s and policies that might impose environmental protection and compliance requirements on

15the siting, construction, operation, and decommissioning phases of utility-scale solar energy and

16transmission line projects. Related lists of specific E.O.s, federal and state laws, and county

17ordinances that might be applicable, were provided in Appendix H of the Draft Solar PEIS. The

18information presented in Section 3.3 of the Draft Solar PEIS remains valid, with the following

19update.

20

21The text of Section 3.3 of the Draft Solar PEIS stated the following regarding noise: “The

22EPA issued guidelines for outdoor noise levels that are consistent with the protection of human

23health and welfare against hearing loss, annoyance, and activity interference. The guidelines

24state that annoyance and undue interference with activity will not occur if outdoor levels of noise

25are maintained below an energy equivalent of 55 dB. However, these levels are not legally

26enforceable standards.” Note that noise and soundscape protection policies have been developed

27by the NPS. These policies are discussed in Section 5.13 of this Final Solar PEIS.

28

29

30 3.4 TRANSPORTATION CONSIDERATIONS

31

32Section 3.4 of the Draft Solar PEIS addressed transportation requirements to support

33solar energy development during construction, operations, decommissioning, and reclamation.

34This information is summarized below; there are no updates for this section.

35

36In general, heavy equipment and materials needed for site access, site preparation, and

37solar array foundation construction are typical of road construction projects and do not pose

38unique transportation considerations. Solar collectors would be assembled on-site, and materials

39would be delivered to the project location by regular truck shipments without the need for

40oversize or overweight permits. The total number of shipments over the course of the

41construction period would depend on the type of solar technology and the size of the facility. The

42number of workers required during different phases of development would vary, but increased

43commuter traffic in the vicinity of the project may require road improvements or other measures

44to alleviate congestion or traffic hazards. Deliveries of materials during operations could also

45include hazardous materials such as fuels or ammonia. Shipments from facilities would include

46wastes for disposal.