The federal tax credits for renewable energy have been a major barrier to widespread ownership of renewable energy. The production tax credit, for example, can only be taken against passive income, a type of income that very few of us actually earn. Accelerated depreciation or investment tax credits can be taken against ordinary income – slightly better – but again the credit provides more benefit the higher one's tax bracket and the more tax liability one has. The overhead costs in aggregating sufficient tax equity to finance wind and solar projects have proven very high. Nevertheless, to date the industry has grown rapidly based on this inefficient and cumbersome arrangement.