The pros and cons of our energy options

The global need to find a sustainable energy source is growing (sustainable meaning ongoing and cost-effective, and energy meaning substance to produce electricity or power machinery).

Indeed, not only are we are using up fossil fuels faster than they form, but harmful carbon gases are being released into the atmosphere in the energy making process.

Putting climate change concerns aside, it’s simply dangerous to depend on resources that will eventually run out. So what are the options?

The traditional fossil fuels of coal, petroleum and natural gas still provide most of the world’s energy needs, and are the cheapest and easiest resource to extract and process. Their energy density (amount of energy in a unit of substance) is also largely superior to alternatives.

But accessing them is becoming harder and more dangerous (see Louisiana example). Known deposits are being stripped, mines are getting deeper and oil rigs are further out to sea.

Many believe that nuclear power, derived from controlled nuclear reactions, is the answer. With estimates of up to thousands of years supply for some types of uranium (the raw material needed), it has the potential to be sustainable.

It doesn’t produce air pollution and already supplies about 15 percent of the world’s electricity. Some even say uranium is safer to mine than coal.

However, few dispute the threat posed to people and the environment through radioactive contamination and nuclear waste. Not to mention nuclear weapons production and terrorism.

Lots can go wrong and opponents claim the risk of catastrophic accidents, such as the Chernobyl disaster in the Ukraine, is too high.

Biomass is one alternative. Crops, algae, corn and other vegetables are among natural goods used to generate electricity through the methane produced and captured when the matter decomposes.

Primarily it’s an environmentally sound option, but fossil fuels used to produce it like petroleum for farming equipment and natural gas for fertiliser production, have to be considered in the overall impact.

And while the food industry experience and infrastructure already exists, the huge amount of land required for growing is not feasible and would compete with food production needed for consumption.

Two other renewable alternatives being used are geothermal, which uses heat found under the ground, and hydroelectric, where water pressure powers turbines. Both can provide high capacities and don’t cause immediate air pollution.

Geothermal is relatively cost effective but can only be sourced at very specific locations.

Considerable potential exists for hydroelectric, but the necessary construction of a dam requires huge investment and has a major impact on the surrounding environment.

A flooded valley destroys the habitats of many species and requires the relocation of people living there. Continued water supply and flood risks may present problems as well.

Tidal power is also produced using turbines in water, which are controlled by changing currents. It is reliable but can only produce for about 10 hours a day, and at a relatively low capacity.

Infrastructure costs can be high too with some systems requiring a tidal barrage (similar to a dam).

Solar power – converting sunlight into electricity – seems harmless in comparison. It’s free, doesn’t cause pollution and can be sourced anywhere there is sun, using photovoltaic equipment and solar panels.

Unfortunately the equipment is expensive and the pay back takes a while. It’s also weather dependent and can’t be produced at night, although storage systems can help with this.

Solar is a particularly good option for residential water and air heating however. And there is an indication that costs will decrease which will make it a more viable option in the future.

Wind powered turbines don’t pollute either and farming can exist around them. Like solar, it can be done in remote places but is also weather dependent. Construction costs are relatively low but the turbines are an eyesore on landscapes and often unpopular with locals.

Without a doubt, huge investment is required in developing alternative options and this should rate highly in today’s sustainability-focussed age.

A recent United Nations Environment Programme report showed new investment in renewable energy is outdoing that in fossil fuels.

And after looking at all the options, another somewhat easier alternative is conserving energy and using it more efficiently.

The way forward might lie in a combination of options, but in the meantime the most important thing is that we’re preparing for the day when fossil fuels run out.

By Carolyn Thomas

Photo – Coal train