September 9, 2008
Ask an ordinary citizen where our energy comes from and he will tell you from the gas station or the power plant. If you insist he might add from coal or oil and gas; he might even mention nuclear fission, wind turbines, wooden chips or maize turned into biofuel.
These answers miss a crucial point: these energies are nothing but different manifestations of solar energy. Oil is fossil solar energy turned into biomass and stored during millions of years; wind is kinetic solar power, which we can use after rotors have transformed it into electricity.
Fossil solar energy is finite. At present rates of consumption it will all have been burned within another 100 years or so. The fossil era will not have lasted less than three centuries, no more than a minute in human history.
Humanity cannot afford to burn even the last drop of fossil fuels. The carbon dioxide, which this will generate, would turn our tiny planet into an increasingly uninhabitable place.
Though we fully understand what is going on we fail to draw the appropriate conclusions. We remain addicted to fossil fuels! We are about to lose the race against climate change and global warming, because we underestimate the pace of climate change and overestimate our capacity to wean from fossil energy.
Climate change does not yet hurt the well-to-do urban elites, and human beings are not geared to think and act a long time ahead. No wonder that the global political class fails to rise to the challenge.
Every day the sun sends more than plenty of energy to the earth to fully satisfy humanity’s present and future energy demand.
We only have to collect the huge amounts of solar irradiation and deploy the most cost-effective technologies for transforming them into the two basic types of energy human beings need, heat and kinetic.
Our future energy will have to come exclusively from “harvesting” the daily sun shine. There is no alternative: nuclear fission is also finite and carries incalculable safety risks, nuclear fusion may never reach the stage of large scale generation, only geothermal heat might become an important complement to solar irradiation.
In order to “harvest” the sun’s energy we have to deploy appropriate technologies and make these as cost-effective as those we have applied to exploiting fossil solar energy.
Humanity has developed four basic technologies for “harvesting” solar energy:
- Concentrating solar heat and transforming it into steam and from there into electricity. (CSP)
- Capturing the solar irradiation and transforming it directly into electricity (PV)
- Capturing solar kinetic power (hydro, wind and waves) by mechanical rotors and turbines and transforming it into electricity.
- Transforming biomass into heat or fuel and transforming it into heat, electricity or kinetic power.
Humanity will need each of these technologies for satisfying its growing energy hunger. Combined they will constitute our basic energy mix and replace oil, gas and coal. The sooner this transformation takes place the better it will be for future generations and the less devastating climate change will become.
Different regions of the earth will apply these technologies according to their natural endowments: some wind, others concentrated solar power or hydropower. But every continent will be able to cover essentially all its future energy needs from indigenous sources.
The future energy mix will be more expensive than fossil energy; but only if we fail to include the high external costs from burning coal or oil. Moreover, fossil energy will increasingly more expensive, while the cost of harvesting solar energy will decline thanks to technological progress. Within the coming 20 years wind and solar concentrated power will out-compete electricity generation from oil or gas.
Electricity will be become the mainstay of the future energy system. With the exception of biofuels all available technologies for harvesting solar energy generate electricity.
This will accelerate technological revolutions in the way we heat our buildings, drive our cars, ships and airplanes. Electric engines are most likely to power future automobiles; the transition is about to start, but it will take a few decades before the transition will be complete.
We shall heat our buildings by a combination of improved insulation, solar devices and heat pumps. We shall have no other choice.
Fossil fuel will become so expensive that we shall limit their use to inputs for chemicals, fertiliser and high process heat.
In view of accelerating the transition towards directly harvested solar energy, humanity has to reduce the price of electricity generated from wind or CSP to that of coal-generated electricity. To that end, we have to charge coal-fired power plants the full cost of the climate damage they cause and/or subsidise electricity generated from wind or concentrated solar power. Europe is about to introduce such a combined system of taxation and subsidies, through feed-in tariffs for renewable energies and C02 emission quotas.
But it does not proceed at the required speed because major competing countries like USA, Japan, Russia, China etc. fail to provide comparable incentives. This issue is at the centre of the international negotiations on the future climate regime that should succeed the unsuccessful Kyoto Protocol as of 2013.Author : Eberhard Rhein