For the last 200 years, since the invention of steam power, all the technological and economic growth is narrowly tied with energy consumption. There are many ways by which humanity harnesses needed energy, and most energy sources can be divided by their value, potential, availability and cost of conversion into usable energy. However, in the scope of our existing technology and demand the most important division of energy sources is whether an energy source or fuel is renewable or not.

All energy sources are renewable to some extent, even including heating oil, but oil and other fossil fuels such as coal take millions of years to collect as underground deposits rich with energy we need. Energy resources which do not regenerate fast enough will be consumed, so we need to find another ways to harness all amounts of energy we need.

On the environmental side, many people make a wrong statement that all renewable sources provide clean energy. Take wood for example. Wood grows steadily, and if you live in a rural area and use your own energy you are long term secured on the economic side. But burning all that wood releases some potentially dangerous fumes into atmosphere. Also, many people still believe that nuclear power is renewable, which is wrong. Nuclear reactors require uranium which is mined, and hence like any other mined resource is limited to what Earth has to offer.

Physics teaches us two important things:
1. We do not destroy energy, we just change the form of its appearance by burning it
2. Our energy needs are minuscule compared to gross energy potential of our own planet.
Knowing that, we can draw a conclusion that our major limiting factor is not energy availability, but technology of getting it. It is known that crude oil, coal, natural gas and propane have are not renewable and that in several decades we won’t be able to find any more of these, but the number of possible renewable sources is growing. Nuclear energy is both dangerous and non-renewable.

HydropowerOne of the oldest renewable sources is hydropower. Natural water circulation on Earth is inexhaustible, but means of getting it require drowning large portions of land to get reserve water for feeding each hydropower plant. Wind has little effect on nature, but has petty potential in most parts of the world. Solar panels are useless over night and in subpolar areas they’re useless most of the time. The oldest known energy source – wood is renewable if carefully consumed, but is not quite environment friendly. Some people in less densely populated area would remain on wood as source of heat, since individual furnaces don’t produce much air pollution, or can use filters to reduce emissions.

The world needs to find a way to effectively rely on renewable energy sources on a sustainable way. A way that doesn’t do harm to the environment and doesn’t demand from us to dedicate much of some other resources such as arable land, to renewable energy production.

One of the solutions for this would be acquiring ways to effectively generate electricity from nuclear fusion. Majority of stars, including the Sun are nuclear fusion reactors. This means that all the energy we use now has once been a part of fusing four atoms of hydrogen into one of helium, which unleashes energy rich protons and electrons. However, developing industrial resources for nuclear fusion on Earth is just in theoretical phase and we need to make temperatures high enough to support the process, namely, temperatures of the Sun’s core and vessels which would sustain that heat to be used in reactor construction. This won’t happen any soon, but is realistic and will definitively become actual when prices of other fuel sources require from us. Other “futuristic” fuel sources discussed include GMO plants extremely rich in oil which can be refined into biodiesel.

In meantime we need to get what we can use now. Currently we are on a mix of renewable and non-renewable sources. Neither of them is now enough to cater for our energy needs, so using both of them to a high extent has no alternatives for now. Renewable energy can be taken from rivers, wind, tide of the seas, sunshine, hot water springs and plants. Some of these can even be harnessed on an individual level, for both own and commercial use as fuel or energy source.

There are “defensive” ways of keeping more energy for ourselves: it is technological advent of energy consuming devices which enables them to deliver the same effect with less energy. Fuel economy car engines, high efficiency oil furnaces and other fuel effective technologies come along with initiatives to decrease power consumption “per capita” such as carpooling or increased mass transit use. One can clearly see that these measures target primarily non-renewable energy sources. The next to come is electric mobility revolution. There will be many new plug-in and hybrid cars, since most other things are now electric powered. Oil, both crude and biofuel will be processed in power plants, since large electric generators are much more energy efficient than any petrol engine.

What if peak oil day came today?

We will not just be required to redefine our energy consumption, we will need to contribute some of it, too. As the peak oil event approaches, we should expect that governments require from us to contribute some energy from sources we need. Farmers would be required to use part of their arable land for oil rich crops, people living in wind areas would be likely to install windmills and turbines, and those in hot places with long hours of sunshine would use much greater solar panels than they do now. Despite today’s cheap oil period, we may pass beyond peak oil which will be followed by a continuous rise of energy prices. For all energy, not just fuel oil.