Besides the “traditional” renewable energies (solar power, wind, hydro and geothermal) other technologies are currently under development, among these there are artificial photosynthesis (exposed in the previous article), marine energy (which includes wave and tidal power), CPV (concentrated photovoltaic) and cellulosic ethanol (many companies such as Abengoa, Mascoma and BlueFire Renewables have invested significant amounts of money in this sector with the conviction that cellulosic ethanol will be a good investment for the future).

Why should we develop new technologies, still uncertain and requiring constant financial supports? We must consider that possible eventuality where “traditional” renewable energies can’t satisfy the worldwide energy demand. There’s also the possibility that these technologies, when they will developed completely, will be less expensive than “traditional” renewables. The only way to find it out is to invest in these technologies. DOE has already started to finance some of the laboratories that are bring forward these projects (between the laboratories there are NREL, National Renewable Energy Laboratory, and Sandia National Laboratories).

Cellulosic ethanol is surely the most profitable at this moment and the less expensive too. Biofuels can be a good alternative to fossil fuels and, as exposed before, many companies has started to produce them. Artificial photosynthesis sounds fictional but with the right investments can be a valid sector. Marine energy is at a good point: wave power is still at the beginning but the main project is well financed by E.ON and Scottish Renewables. Regarding tidal power there are many operating power stations, some of them have a capacity of 250 MW. To support completely these projects it’s necessary to have a clear vision of the future and of the advantages that these renewables can bring, economically and ecologically.