From Oslo Airport Gardermoen:
Whether arriving via domestic or international flight, the quickest and most convenient travel to the hotel is via the Airport Express Train, which leaves Oslo Airport Gardermoen at 10-minute intervals during peak travel times and arrives at the Central Railway Station adjacent to the hotel within 22 minutes.

Energy for All-hosts & hostesses
Upon arrival at Oslo Airport Gardermoen and at Oslo Central Station, there will be a welcome desk with "Energy for All"-staff who will direct you to the Express train and to the Conference venue; Radisson Blu Plaza Hotel 

How to get to the Conference Venue; the Radisson Blu Plaza Hotel: 

The hotel is located right next to the Oslo Central Station.
Exit the platform and stay to the right, exiting Central Station/Byporten Shopping via the north exit.
Follow the signs for the Oslo Bus Terminal.
The hotel is located on the right, across the walking path outside of the north exit.