In this framework, marginal utilisation costs are, by construction, higher than average utilisation costs. Higher drops are featured for solar PV, for which the value factor decreases more dramatically, reaching about 60% of baseload costs at a penetration level of 15% (Hirth, 2015b). Recent quantitative analysis at the NEA also confirms such trends (NEA, forthcoming): in a highly flexible system, the value factor for wind onshore reaches about 80% and 70% of baseload at 30% and 40% penetration level. Solar PV reaches 60% of baseload price at 12.5% penetration and the value sharply drops at only 30% when a 20% penetration level is reached.