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So the total area decomposes into parts that different analysts include or exclude: $A = A_{\mathrm{direct}} + A_{\mathrm{spacing}} + A_{\mathrm{excluded}}$. A recent multi-method study makes the sensitivity explicit rather than arguing about it. Covey and colleagues measured 60 onshore and 24 offshore wind plants and 54 solar plants across six countries, computing capacity density four ways on the same plants. Onshore wind comes out at 4.9 megawatts per square kilometre by Voronoi polygon, 6.2 by five-diameter buffer, 4.0 by eight-diameter buffer and 4.4 by convex hull [ 9 ] . The plants did not change. The choice of boundary moved the answer by more than half.

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