Summer will be cooler today with the opening of Ocean Park's new entertainment zone, Polar Adventure, which is expected to attract 10 to 15 per cent more visitors this financial year, said chairman Alan Zeman. Ocean Park has consistently broken attendance records in the past few years. In the 2010-11 financial year, it attracted 5.1 million visitors, and received its 100 millionth theme park guest in February last year. The new zone, which is the final stage of a HK$5.55 billion redevelopment, is expected to lure even more people for the park's 35th anniversary. Covering more than 150,000 sq ft, the zone brings nine new attractions to the park, including three live animal exhibits and a new roller coaster called Arctic Blast. The zone is touted as a fun and exciting way to teach visitors about the endangered polar habitat. Among the nine new attractions are the North Pole Encounter, South Pole Spectacular and Arctic Fox Den. Species include sea lions, Pacific walruses, snowy owls, Arctic foxes, spotted seals and three types of penguins. To reduce the park's carbon footprint, several features were incorporated into the Polar Adventure's design. They include a water-cooled chiller system that consumes half the electricity of comparable systems, and carbon dioxide sensors that control the fresh air inflow. According to the park, it has lowered annual electricity consumption by 34 per cent. Despite the zone's green message, some environmental groups are concerned about the park's energy consumption. Yesterday, 10 activists from Green Sense protested at the main gate of Ocean Park. 'We want them to close the venue because it is really ironic to use so much energy and say they are helping the environment,' said Green Sense's Gabrielle Ho.