Solar cell manufacturer SunPower is expected to announce today that it has won a $330 million contract to supply solar cells to a global solar systems installer, PowerLight, over the next five years. The deal is the biggest in Sunnyvale-based SunPower's history and will help it expand its manufacturing capacity over time, said Tom Werner, chief executive of SunPower. The announcement also comes on the heels of the plan unveiled this week by state regulators to provide $3.2 billion in incentives over the next decade to encourage Californians to use solar panels on homes and office buildings. The incentive plan...