Since the ocean in general provides better wind conditions, offshore wind power plants typically have higher capacity factors than those onshore (Table 1; Fig. 3). This is why offshore wind farms are currently favored despite higher costs. However, the comparison between plant 2 and 3 shows the ultimate advantage of onshore wind power plants with respect to CO2 emissions. Better wind conditions experienced by offshore power plants cannot cover the higher environmental costs created by the additional efforts in construction, such as boat landing platforms, external sea cables and offshore transformer stations. Therefore, offshore power plants have higher CO2 emission per kWh. This conclusion is consistent with previous studies. However, compared with the CO2 emis- sion per kWh produced from traditional energy sources, the offshore wind farms still create significantly less CO2 emissions.