Fig. 4

Breakdown of the key components contributing to the minimum diesel selling price (MDSP). a Scenario 1 (for profit model) shows that 10 locations are profitable at an MDSP of US$ 2 L⁻¹. b Scenario 2 (public utility model, not for profit) includes production system costs (blue), land and misc. (yellow), and low interest (red) with 0% tax and 0% profit. Under this scenario, 8 locations (Mombasa, Kenya, Recife, Brazil; Tunis, Tunisia; Acapulco, Mexico; Darwin, Australia; Kona, USA; Chennai, India and Almeria, Spain) could achieve an MDSP of < US$ 1.25 (under black dotted line), almost at parity with maximum historical fossil diesel prices. Far right: shows an improvement in MDSP and profitability that could be achieved in Almeria (Spain) if the EU adopted a carbon tax (CT) of US$ 100 tonne⁻¹. *Interest figures shown in this figure represent total interest payments over a 10-year loan repayment period at respective interest rates (values in Table 2). The inclusion of a carbon price in Scenarios 1 and 2 reduces the contribution of each costed item to the MDSP. c CapEx breakdown of the 500 ha facility ranged between US$ 128–245 Million (i.e., US$ 256,000–490,000 ha⁻¹), d Annual OpEx ranged between US$ 7.7–16.4 Million (i.e., US$ 15,400–32,800 ha⁻¹)