New York City and Boston each launched ambitious solar power initiatives yesterday, both of which are going to require a few extra zeros on their initial budgets if they are to be at all meaningful.

In Boston, Mayor Thomas Menino announced a $550,000 initiative to help the city reach its goal of increasing solar energy output fiftyfold by 2015. The "Solar Boston" project is funded by city, state and federal agencies and will initially focus on mapping the city to find the best rooftops for photovoltaic panels.

Boston currently has half a megawatt of solar capacity. We're no experts in solar energy, but we do know it's going to take more than half a million dollars to reach 25 MW in less than seven years.

Meanwhile, fresh off the embarrassing defeat of his congestion pricing plan, New York Mayor Michael Bloomberg said the city would solicit proposals from private developers to install and maintain solar panels on city-owned buildings in all five boroughs. Bloomberg's goal, which is part the PlaNYC environmental initiative, is a bit more modest: Deliver 2 MW of solar power to city-owned buildings.

Federal support for the project includes a $200,000 grant and $200,000 in technical support from the National Renewable Energy Laboratory. Given that panels plus their installation cost more than $8 per watt on average, potential bidders are looking at a $16 million job. And that leaves the city about $15.6 million short at the moment.