True . Renewable energy sources have disadvantages, when it comes to our using them. By themselves the renewable energy resources are completely advantageous and will never vanish. But the problem is in our ability to use them.
Renewable energy resources are Solar, wind power, ocean tidal power, biomass, geothermal etc.
1. Some of these energy resources are weather dependent. It is easy to understand that solar and wind power are not available 24 hrs/day.
2. We cannot produce energy in huge quantities like we are able to do using the conventional energy resources. We will need very heavy industries to produce in high quantities.
3. We do not have the best technologies required to efficiently produce large quantities of power at economically viable rates yet. It will take time for that to happen. At the moment the solar energy has a high capital investment.
4. Not all renewable energy resources are available sufficiently in all countries/regions.