The 90 MW Alinta wind farm, planned by Renewable Power Ventures (RPV) for a site near Geraldton in Western Australia, is a step closer to reality following the Western Australian government's confirmation of "top up and spill" (TUAS) market rules which give renewable energy generators more equitable terms for balancing energy supply and demand. TUAS is a balancing arrangement where generators can buy power shortfalls (top-up) or sell power that has been contracted for, but which is surplus to needs (spill). "Put simply, renewable energy generators are charged heavily when they need back-up power from Western Power and are paid less when they sell excess power back into the grid. The charges will be equalised under the new regime," says state energy minister Eric Ripper. "The state government wants to see more renewable energy projects in Western Australia using wind resources. We have taken every step possible to boost the renewable energy industry within the constraint of Western Power remaining a vertically integrated monopoly." Alinta is to consist of 54 Vestas 1.65 MW turbines supplied under a contract agreed with NEG Micon before it merged with Vestas. The project will be the state's largest wind farm and is expected to start supplying electricity to the grid in mid-2005. RPV's power purchase agreement with local utility Alinta was conditional upon the TUAS rules being introduced.