The major concern is its capital cost. Most of the people can not buy it at an affordable price.
How this trend can be changed. Now we can compare this with the mobile technology revolution. Now everyone has a mobile. Even a poor can buy a mobile. As more competitors have entered this mobile field, the price has come down to very cheap. This trend like in mobile field can be extended to the use of renewable energy sources also. If more competitors enter this field, then the manufacturing of solar panels, wind mills will grow, it automatically will reduce the overall cost, hence people can buy it. So we can have a green technology every where.