the ministry of trade and industry -lrb- miti -rrb- , the ministry of construction -lrb- moc -rrb- , the ministry of transport -lrb- mot -rrb- , the ministry of home affairs -lrb- mha -rrb- , and the environment agency -lrb- ea -rrb- are jointly proposing strategies for a low-interest loan system to encourage commercialization of low-pollution vehicles and for the incorporation of photovoltaic power and other energy conservation systems into residential housing .