Table 6

1 January 2000

Table 6, Qualitative comparison of the environmental performance of a hypothetical linked-basins TPP of the flow-through type, as described in this section vis--vis the chosen standard of comparison, a single-basin, double-effect TPP, Type Z, at Fundy s Cumberland Basin. The tabulation shows which of the two types scores highest for optimum environmental performance.NOTE: Re D, Sea-mammal survival: TPPs should be designed and operated to keep sea mammals away from the hydraulic turbines. This applies equally to both types B and Z and therefore does not affect a comparison between the two.DE = double-effect; SE = single effect; HB = high-basin; LB = low-basin Linked-Bs = linked-basins

Environmental effects			A	B	C	E	F
Type of TPP	Linked-Bs, SE, flow through type at an imaginary site	Single-basin, DE, at Fundy Cumberland Basin. Tyoe Z					Size of linked-bs too small to affect tidal regimes
TPP parameters
Mean, natural tidal range	5.64 m	10.0 m
Mean tidal range within hign basin as % of natural tide	49%	68 %	Z	Z
Mean tidal range within low basin as % of natural tide	46%	68 %	Z	Z
Mean water level within high basin, compared to natural conditions	+1.28m	-0.12m		Z		Z
Mean water level within low basin compared to natural conditions	-1.02m	-0.12m		Z		Linked-Bs
Number of passes through turbines for a fish going in-and-out of TPP	1	2			Linked-Bs
Plant operation at or close to the rhythm of the natural tide	no	yes
Maximum head across turbines	3.68m	4.62m			Linked Bs
Maximum water velocities through turbines	11.47m/sec	11.9m/sec			Linked-Bs
Stagnant flow within high basin % of the time	35%	18 %	Z
Stagnant flow within low basin % of the time	35 %	18 %	Z
Simplicity and effectiveness of flow patterns	See Fig. 6		linked Bs
Total scores for Linked-Bs, SE plant, through-type layout			10	0	3	1
Total scores for Type Z, DE			4	4	0	1

Post to:

Delicious

Digg

Facebook

StumbleUpon

Linked In

Twitter