FEATURE
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The solar imperative

Tom Pearsall, general secretary of the European Photonics Industry Consortium, believes solar energy can provide rich pickings for our industry

There are not many things that everyone can agree on, but here are two of them:

  • Every day the sun gives the earth useable energy that is more than 1,000 times our needs.
  • Global warming caused by greenhouse gas emissions is a threat to life as we know it on earth.

There are two take-home messages; the first is that there is plenty of available energy to supply the needs and even the fantasies of all the people in the world. The second is that, with all that energy coming from the sun, our energy consumption is not the cause of global warming; it is the creation of energy by burning fossil fuels, such as coal and petroleum, that threatens the planet.

To turn around an old saying: ‘Where there is fire, there is smoke!’ We still use fire to run electric power stations, run our cars and to heat our homes. It is the smoke coming from that fire that is a main contributor to global warming. Exhaust smoke produces toxic air pollution and acid rain, but it is the global warming caused by greenhouse gases in the smoke that has the potential to transform much of the EU to desert by 2100. In 2005, IEA studies showed that the measured level of CO2 in the atmosphere was 370ppm. This exceeds by far the natural range (180 to 300ppm) over the last 650,000 years.

The German Advisory Council on Global Change projects that photovoltaics and wind should provide more than 30 per cent of Germany’s energy sources by 2050, with all renewables providing about 50 per cent of the total. At this level, the market volume for photovoltaic power generation alone will exceed $500bn per year, about twice the size of the world’s current production of integrated circuits.

There are three main reasons given by those who wish to keep raising the world’s temperature by burning fossil fuels:

  • The cost of generating energies by solar-based sources is too high to be competitive with burning coal:
  • The electricity distribution grid excludes the use of solar-based energy in anything more than small amounts: and
  • Coal-fired generation plants are already running and should not be shut down until the end of their life cycle, which is 50 years.

These arguments are at best irrelevant and at worst just plain wrong. However, they will serve well to illustrate the opportunities for solar-based energy, and the important contribution that photonics can make to saving our planet.

In order to consider the cost issue, let’s start with the planet. The Guardian newspaper estimates that the entire planet earth is worth about $300 trillion. Of this total, what would be the value of Venice? My personal evaluation would be at least $10 trillion. What would be the value of Venice under five metres of water? We would all agree that it would be quite a lot less. You could ask a similar question about Amsterdam. What about both Venice and Amsterdam together? This is where global warming is taking us. The loss of Venice and Amsterdam, and much of the world’s agricultural land, is a real part of the real cost of burning coal. If we average only the $20 trillion cost of losing Amsterdam and Venice among Europe’s 500m citizens, it works out to about $40k per person just for the pleasure of burning coal. Today, it only costs about $25k to install a solar PV system that serves an entire family. It is true that the cost of solar PV power today is two to three times higher than the price charged by the power companies for electricity generated by fossil fuel sources. But, it is not true that electricity generation by burning coal is cheaper than electricity generation by renewable energies from the sun.

The 2050 vision of the energy mix proposed by German Advisory Council on Global Change requires a totally different distribution network. It is important to remember that the existing grid must not drive our choices about what energy sources we need to use. It should be just the other way around. Conversion of our energy supply network to handle the distribution of electricity from solar cells and wind farms represents an opportunity for engineers not seen since the creation of the internet.

Even though there is enough solar-based energy for everyone’s needs, energy efficiency and energy conservation have a critical role to play. Energy efficient solutions existing today can reduce power demand and thus delay and eliminate construction of fossil fuel-based plants. Twenty per cent of the world’s electricity expenditures are used to generate lighting. In Africa, the World Bank estimates that $35bn is spent each year to produce light from kerosene, generating poor quality light, greenhouse gases, and toxic pollution. Lighting is all about photonics. The largest potential in savings is the refitting of existing commercial office space with intelligent lighting systems, based on solid-state LED and OLED sources, and controlled through an ICT network to deliver the right quality of lighting, when it is needed and where it is needed. The intelligent lighting revolution has similarities to the electric grid revolution. We are witnessing the birth of a major new industrial market sector.

Photonics is a major contributor to environmentally responsible electricity generation – through photovoltaics, of course, and also in wind generation, where photonic sensors are extensively used to optimise the efficiency of the wind turbines. Photonics is the green technology that enables intelligent lighting and energy efficiencies that will help us to slow or even stop the deployment of more fossil fuel power stations. Do you want to save the planet? Photonics technologies are key to the solution.