In the section on Energy and the Home we saw that total energy use in Ireland in 2008 amounted to 13,400,000 tonnes of oil equivalent.  Only 4.5% of that figure came from renewable sources.  We import 89% of our energy needs making us the least self-sufficient country for energy in the industrialised world.  Sources of renewable energy in Ireland are hydro, wind, landfill gas, biogas, biomass, liquid bio-fuels, geothermal and solar - with wind, biomass and hydro dominating.

In the section on That Changing Climate we saw the threat posed by continuing to burn fossil fuels and the urgent need to switch to other sources of energy.  So there is a major challenge to overcome if we are to make progress in this area. 

Fortunately Ireland has fantastic wind resources and these resources are being exploited at an increasing rate with 23% growth in 2008 following 21% growth in 2007.  Wind energy suffers from the vagaries of the weather – when the wind dies down there is no electricity generated - and is not as reliable as fossil fuels but recent proposals to combine wind energy with hydro power offers the potential to replace our fossil fuelled electricity entirely.  The idea is to use wind energy to pump water to a reservoir uphill when the wind is blowing and to use the stored water to generate electricity when the wind dies down.  Details of the project can be seen at http://www.spiritofireland.org/

At a global level solar energy offers the best hope of finding a replacement for fossil fuels in the long term.  The Sun provides Earth with as much energy every hour as human civilisation uses every year.  This enormous potential is already being  exploited by solar panels that heat domestic water and by photo voltaic cells that convert sunlight to electricity.  Like wind energy, solar power suffered from the problem of what to do when the sun sets.  Recent developments overcome that problem by concentrating the sun’s energy using parabolic mirrors to generate molten salt that retains sufficient heat in the hours of darkness to keep the electricity flowing.

The question is ‘will these renewable energy technologies come on-stream before we exhaust our fossil fuel reserves or before we have runaway global warming?’

Calculating fossil fuel reserves is difficult in a world where countries such as China and India are developing quickly.  The general consensus is that we will exhaust oil and gas reserves around the middle of this century while there is enough coal to last for one or two hundred years.   Unfortunately climate science tells us that we cannot wait that long to address global warming and we need to make dramatic reductions in greenhouse gas emissions over the next 10 to 40 years starting immediately.  

Capturing and storing carbon dioxide underground and using nuclear power may help to bridge the gap until renewable energy technology is fully developed.  The first of these is unproven as yet and suitable storage sites may not be available in Ireland.  While there is strong opposition to nuclear power in Ireland at present, the debate may have to be reopened as alternatives disappear.  

For Ireland the best approach is to develop our excellent wind resources and, combined with pumped storage, it has the potential to meet our domestic needs and to allow us to export clean renewable energy to other countries. 

At the domestic level we should install solar thermal panels on south facing roofs and purchase our electricity from renewable suppliers where possible.  As electric cars come on the market in the next few years all of us could reduce our carbon footprint significantly by switching to such vehicles and charging them with renewable energy.

That would truly be a move towards sustainability without major changes in lifestyle.