|Windmills in eastern Uruguay|
It depends on the context in which the technology will be applied. Most likely than not, it would be a combination of wind, solar, and water. For example a city's electrical power plant could be supplemented by wind farms, solar farms, and perhaps tidal or micro-hydro (think mini dams) power generators. None of these technologies by themselves will contribute 100% of the time.
Dr. John MacDonald, co-founder of MacDonald, Dettwiler and Associates (MDA) and Day4 Energy, pointed out during a presentation at the GreenTech Exchange forum, that the estimated time at which we will not be able to meet energy demand worldwide with traditional energy sources (coal, gas, petroleum) would be between 2012–2015 (pessimistic view) and 2030 (optimistic view). Much of the energy demand is related to the development and growth of the BRIC countries, so energy demand will continue to grow. We can curb the energy demand, just not enough ... we would only delay the inevitable.
To reach a sustainable state we need to reduce our energy consumption while increasing our energy production. This would mean replacing some of the traditional energy sources with alternative ones.
So, what needs to be done to allow alternative technologies to take hold within the energy production cycle? A couple of things: 1) develop system management software capable of responding to the energy demands within a city and selecting the appropriate power generator, and 2) develop systems to store the generated energy.
One company that is contributing to this solution is REV Technologies. They noted that fleet vehicles spend about 80% of their time parked in a parking lot. Their idea: convert these vehicles to electrical cars, store the grid energy in their batteries, and dump it into the grid when the power company needs it. The client earns revenue from selling the energy back to the power company and the power company can meet the demand without installing another power generator.
Another area of development in power generating technology is in fuel cells (FC). They have advanced far enough to be considered viable in a business sense. In fact, many of the major automobile companies have FC models ready to be produced. But they still face two problems: one is infrastructure — where do you go to fill up on hydrogen? The second is the catalyst used in FCs: platinum. A very small amount of platinum exists in the world and therefore, it's an expensive resource. Yet, so far, it is the only element that can catalyze the reactions within the FC and other important industrial chemical processes. Therefore, for FC to really hit the market we would need to replace platinum with an economically viable catalyst.
What I'd like to point out is that we have a long way to go before we can stop using the traditional energy sources.
So, what do we do in the meantime? Science will continue to discover new technologies and materials that take us closer to a sustainable state. But we need to modify our behavior as a collective: we need to take greater responsibility with regards to how we use energy and demand that measures are taken at a regional, national, and global level to modify our unsustainable use of energy.
At an individual level we can have a direct impact in the choices we make, from minimal details in our everyday life to considerable changes in our lifestyle. From the construction of our homes and use of public spaces, the selection of appliances, whether we use a car or public transport, take our own shopping bags instead of using more plastic bags ... the list goes on. After all, we can have all the technologies that would help us manage our energy use in a more sustainable and efficient manner, but it won't matter if we don't understand or choose to use these technologies.