Dec 01, 2021 · Nevertheless, in terms of current costs, the solar pavement would be economically attractive if the LCOE will be lower than 0.2 $/kWh. This value derives from the following considerations: the best solar pavement in terms of electrical output is Solar Roadways (4249 kWh/m 2 in 20 years), while the less expensive is the Hollow slab (NPV = 841 $/m 2). Under the hypothesis of coupling the best electrical output and the lower NPV, the LCOE would be 0.2 $/kWh.