Installations of solar panels are expected to soar by a third this year, the price of solar power is now cheap enough to compete neck and neck with gas and coal-fired power in places like California, and the fledgling industry received a vote of confidence last week when U.S. President Barack Obama announced a groundbreaking plan to curb power plant emissions. Wall Street, however, has been dumping solar shares this year, largely on concern, which investors say is misplaced, that tumbling oil prices will sap demand for alternative energy, even though oil isn’t used to generate power.