From The Boston Globe
Despite its recent growth, solar power remains an expensive energy alternative and accounts for only a small percentage of electricity generation in Massachusetts. If the state is going to make sharp reductions in carbon emissions as well as enjoy healthy economic growth, solar generation will have to be greatly expanded. But given the already high cost of electricity in Massachusetts, it is critical to obtain solar power as cost-effectively as possible to ensure that all consumers benefit.
In a recent study, an MIT team that I led presented a set of policy changes to make solar more affordable. The study shows that because of current policies, we are paying a good deal more for solar electricity than we need to. Residential solar systems are significantly more expensive per unit of capacity than utility-scale systems — about 70 percent more expensive on a levelized-cost basis. In addition, high levels of residential solar penetration often require substantial investments in distribution systems.
Residential solar continues to grow robustly, nonetheless, in large part because it is more heavily subsidized than utility-scale solar. The main federal subsidy, the investment tax credit, has just been extended for an additional five years. Since the amount of the tax credit is directly proportional to system cost, residential systems, which are more expensive on a per-unit of capacity basis, receive larger tax credits per unit of capacity than megawatt-scale, utility systems. This translates into a higher subsidy per kilowatt-hour of residential solar electricity, paid by taxpayers.