Before we can answer that question we first need to look at what characterizes each power source. We need to look at the advantages and disadvantages of every power source and weight them against each other.
Let’s look at the traditional power generators. We’ll start off with
Coal – It’s an inexpensive resource to obtain and it’s very simple to return the investment made made for it.
However, it has a drastic impact on the environment. Coal-based power plants are a very large contributor to global warming and they require expensive anti-air-pollutions measures employed to reduce the negative effect they have on the environment.
Gas and Oil – As one of the main resources used for power production, it has a very well developed infrastructure and distribution system. The roads of both supply and demand are well paved. Both gas and oil can also be used for heating purposes, and thus can support more than just the role of power production.
On the down side, as a limited resource and with its high use on the entire planet, the price of both gas and oil is constantly on the rise. Both have limited availability and using them to generate energy is not exactly cheap. It also contributes to global warming and oil can represent a serious environmental risk when accidents occur during its transportation. (Oil spills are a perfect example of such an accident)
Nuclear – The power of the atom. Among the advantages of nuclear power generation we can count an inexpensive fuel and the fact that it does not contribute to global warming. A single nuclear power plant has a high yield and can generate a lot of energy, unlike other power sources than need to take up a lot more space.
The disadvantages however are severe. The plant requires a large capital and so far, a viable, long term solution for waste storage has yet to be found. And the largest disadvantage by far, is the disaster scenario. The environmental damage is huge and it’s only second to the risk it presents to human life, like we’ve already seen with the disasters at Chernobyl and Fukushima.
Now that we’ve laid down the groundwork, let’s move up to the renewable power sources. First off, we’ll go ahead and put as “free” on the advantage of list for every one of them, to get it out of the way. Now, let’s start with
Water – It can provide power at a very low cost once the dam is built, and the resource is pretty much inexhaustible as long as the river doesn’t dry out.
The disadvantages however are presented by the limited number of rivers that can prove powerful enough to sustain a hydroelectric dam and it also has negative effects on the river’s fauna. As far as worst-case scenarios go, a river dam could be compared to a ticking time bomb, just like a nuclear power plant. In case of a catastrophic failure, the caused damage can be huge with dire consequences to the community that resides in proximity to the dam.
Wind – As far as advantages go, the costs for using wind to generate electricity are fairly reasonable. Wind is also an exceptional solution for small installations and is ideal for rural areas.
Unfortunately, wind turbines are very dependable on the climate and can only be constructed in certain, remote areas. Also, there power output is very small per unit, and as such their use is limited to small generators.
Sunlight – Considering that we’ve already listed “free” at the beginning of the discussion, the only real advantage we can add is that the costs for using sunlight to generate electricity have been going down.
One advantage that sunlight seems to present at the moment is that technology isn’t that far away from creating a viable, mass producible solar car. This would help to relieve some of the workload that needs to be covered by oil, freeing it up to be used more in energy production.
The use of solar panels is limited to bright, sunny areas and a large surface needs to be dedicated to solar panel to generate even a small amount of energy.
Hydrogen – the energy-production energy also generates water as a byproduct. Other than that, it can’t really be called an energy source, since the process of generating power takes up more energy than it yields. The process itself is also a very costly one.
Fusion – it can use both hydrogen and tritium and it has a higher energy output per unit mass than fission. The level of radiation that is resulted as a byproduct is also considered to be a low one.
Unfortunately, at the moment, fusion mainly exists to turn scientists into villains in comic books. After 40 years of research, a viable project for a fusion power plant is nowhere in sight.
With all this information structured and put in front of us, the initial question is now pretty simple to answer. Alternative power sources have not evolved yet to the point where they can replace the traditional ones. While it may be reached in the future, at some point, right now, renewable powers sources cannot match the energy output of traditional power plants.