Negative electricity prices are becoming more frequent in Europe, and whether they fall in windy hours depends on whether wind or solar feed-in causes the surplus. We ask how this driver affects the operation, the economics and the environmental value of a wind farm that stops its turbines on revenue signal. We simulate the Lillgrund offshore wind farm hour by hour in one model of control, fatigue loads, contract settlement, financing and carbon accounting, on three constructed price futures with the same share of negative-price hours, driven by wind, by wind and solar, and by solar. One farm-wide rule stops all turbines in hours in which the projected farm revenue falls below a threshold, which we vary from zero to low positive values. The controlled shutdown removes the hours of lowest revenue, and the driver decides what else these hours carry. Under wind-driven prices they are windy hours with high fatigue loads, and the fatigue budget  left unused permits a lifetime extension of about ten years. Under solar-driven prices they are hours of average wind, and the extension is about one year. The years gained are worth a few million euros in every future. The net displacement of emissions rises by about 17% under wind-driven prices and falls slightly under solar-driven prices. Three contracts for difference require the same support in present value, but the strike of the production-based contract, which pays nothing on energy delivered at negative prices, rises by about 40% under wind-driven prices, while the strikes of two capability-based contracts, which pay on the energy the farm could have delivered, stay near their historical level. Raising the threshold above zero adds little value here, and a contract settled on delivered energy blocks any load-reducing control whose fatigue value lies below the difference payment. Only a contract that pays on available energy at every price leaves the decision to the operator.