Europe’s sunny future
Europe can gradually phase out the use of nuclear energy and in the longer term even fossil fuels and replace them by renewable energy sources. Solar power in particular has great potential to supply much of the energy Europe needs at no extra costs. In this transition to a “green” future, nuclear power is not needed at all, argue researchers Jaap Hoogakker and Eva Bik.
|- The authors have designed what they call a “European Energy Transition Model” to assess the potential contribution of solar power to European energy demand.|
|- Based on very conservative estimates, the model shows that it is very well possible for solar power to contribute one-third of total primary energy supply in Europe by 2050.|
|- What is more, solar power will be cost-competitive with conventionally generated electricity within one to two years for households in Southern Europe and within a decade in Central and Northern Europe.|
- Thus, nuclear energy is not necessary to make a transition to a future without fossil fuels.
Our research, however, makes clear that, contrary to popular belief, sustainable sources, in particular solar power, are capable of providing all the energy we need at reasonable cost. We do not need nuclear power to make a transition to a fossil-fuel free energy supply.
There are many misconceptions about solar energy. First of all, there is a widespread belief that PV (photovoltaic solar energy) can contribute only marginally to the (primary) energy supply. Actually, given the efficiency of today’s state-of-the-art solar panels, an area of just 800 by 800 km is sufficient to meet total global primary energy demand. This is less than 10% of the size of the Sahara desert. Nor is there a need to turn to Africa to achieve this, as solar energy can be created almost anywhere on the globe. The yield of PV in a cloudy, chilly country like the Netherlands is half of what is yielded in Northern Africa.
A second common misconception is that manufacturing the solar panels costs more energy than they produce. In reality, the time required to recover the energy needed for manufacturing is just one to three years, depending on the technology used and the latitude at which the panels are placed. As solar panels have a lifetime of 25 years, they deliver a net energy supply for about 23 years.
By and large, PV is an inexhaustible, clean and reliable source of energy. Consequently, it is not surprising that the use of this form of power generation is becoming more and more popular in Europe. Germany is the best example of a successful PV market. The number of solar panels installed on roofs continues to grow in this country. In addition, large solar parks have been constructed. For now, this is made possible by a subsidised feed-in tariff. But our research shows that it is possible, in future, to rely to a large extent on solar energy without subsidies.
The “European Energy Transition Model” which we developed was specifically intended to assess the potential of solar energy in Europe. We derived the expected energy demand from the business-as-usual scenario used by the European Commission, which runs till 2030. (DGTREN, “European energy and transport, trends to 2030, update 2007”.)
We have assumed that the period to 2050 will see a diminishing increase of energy demand. After 2050 the demand curve is assumed to be almost flat (population as well as energy demand in the developed European countries are expected to stabilize).
In our model we assumed that the share of fossil fuels will decline gradually to 50% of demand in 2050. After 2050, fossil fuel use is expected to be reduced to almost zero by 2100. The share of natural gas, widely seen as the most desirable “transition fuel”, is reduced at a slower pace than coal and oil. Nuclear energy, which currently makes up 13% of the European primary energy mix, is assumed to be gradually phased out by 2050.
We have given the supply of renewable sources other than solar power deliberately less weight in terms of their technical potential. This ‘worst case’ scenario for other renewables makes our model more robust when it comes to predicting the potential of solar power. For example, we assume that environmentally compatible biomass provides 8% of European energy supply in 2050, half the number used by the European Environmental Agency. We assume hydropower to account for 2% of energy supply in 2050, large-scale geothermal energy for some 4%, and wind power just 2%. Wave and tidal energy are assumed to contribute only marginally. The same holds for solar boilers. Although concentrated solar power (CSP) could contribute substantially in countries like Spain and Greece, it is left out of consideration in our scenario. In sum, all renewables excluding PV solar are assumed to account for just 17% of primary energy supply by 2050. The remaining 33% of primary energy supply in 2050 should thus be covered by solar PV. Our research shows that this is entirely possible.
By using a method developed by the International Energy Agency (IEA), it can be shown that about 10% of European energy demand can be covered by integrated photovoltaics (i.e. PV panels integrated into buildings). The remaining gap (23%) needs to be covered with large-scale PV power plants. To achieve the 33% target, total installed capacity, including the integrated PV, would reach about 5000 GW by 2050, generating 6000 TWh of electricity.
For the PV parks, a surface area of roughly 200 by 200 square kilometres would be needed, taking into account the fact that not every square meter can be covered, as some space between the panels is required for practical considerations (1 m2 of solar panels on every 3 m2 ground surface). We also take into account the efficiency improvement projected by the IEA, from 10% to 14% currently to 21% in 2040. To put this into perspective, this area corresponds to just 2% of the surface in Europe used for agriculture. No fertile agriculture land would be needed.
This ambitious scenario to generate solar electricity on a large scale in Europe, would demand strong but not unprecedented production growth. Over the last decade, the global PV industry has grown at an average rate of 40% per year. In 2008 alone, growth amounted to 80%. In order to make our projected transition possible, the average production growth rate of PV panels requires an annual growth rate of 30% in the first decade, 20% in the second and 10% in the third decade.
If we look at the period till 2100, we believe that the use of fossil fuels could be phased out and largely replaced by solar energy as the output of the next generation solar panels will be even higher. Twice the output of today’s panels is certainly feasible. In that case the surface area required for PV after 2050 will not be much larger.
A lingering misconception is that solar energy will remain too expensive. The current prices of solar electricity may still be higher than those of electricity generated with conventional sources, but the costs have been declining steadily over the last decade and continue to do so at a rapid pace. First Solar, a manufacturer of solar panels, announced recently that its production costs had dropped by two-thirds, from $3 to around $1 per Watt. It is expected that solar energy will be cost-competitive with conventionally generated electricity within one or two years for households in Southern Europe and within a decade in Central and Northern Europe. The accompanying graph shows the realised and expected cost curves of PV.
Historical and expected cost decrease in PV
In a recent article Wim Sinke, a senior researcher at the Energy Research Centre (ECN) in the Netherlands, reported on the results of a global project called Crystal Clear, in which nine companies, three universities and four research institutes were involved. They achieved a cost reduction of PV panels to about €1 per Watt. Adding the cost of converters, cabling and so on, the cost for a complete PV system would amount to €2 per Watt. This translates into a cost of €0.10 per kWh in Southern Europe and about €0.15 for Central Europe.
Households in Europe currently pay on average €0.20 to €0.25 per kWh, including transmission and distribution costs, excluding VAT. This is more than the €0.10 to €0.15 for a roof-mounted, grid-connected solar system. Even when transmission and distribution costs of some €0.07 per kWh are taken into account, solar electricity from a large-scale PV power plant is cheaper for households in Southern Europe.
A solar cell has no chimney
In most cases, the fuels in our energy mix are transformed or converted into energy before they can be used by the consumer. For example, oil needs refining before it can enter a car in the form of petrol, and both oil and natural gas are combusted to make electricity. The process of conversion generates losses that are usually disposed of as useless warmth. Electric power plants have an average efficiency ranging from 35 to 60%. In other words, on average at least half of the resulting primary energy is lost.
However, this does not apply to wind and PV energy. The energy generated by these sources does not require any conversion and can be used directly, avoiding the aforementioned losses. This means that if we had generated all the electricity in the world in 2006 by means of solar and wind power, total primary energy demand would have been 10,000 Mtoe (million tons of oil equivalents), instead of 11,700 Mtoe. Hence, as the share of renewable energy increases, less energy is wasted through the “smoking chimney”.
Recent developments show there is every reason to believe that cost reductions will continue. The growing efficiency of solar cells will reduce the need for raw material, which, in combination with mass production, will reduce costs even more. Maintenance costs of a solar system are negligible thanks to the steady state technology. A welcome side-effect is that this growing industry generates many new jobs.
The path towards a more sustainable energy supply varies by country, depending on the energy mix and the local potential for renewable energy sources. Thus, alternatives to our solar-dominated “energy transition pathway” are possible.
But our scenario, which leads to 30% lower CO2-emissions (1,700 million tons) by 2050 compared to 2005, does not rely on far-fetched assumptions. In fact, we have deliberately left out other developments that even strengthen the case for a sustainable energy transition scenario. For example, the expected growth in electricity use in the transport sector will lead to a considerable reduction of primary energy demand. Electric cars are more energy efficient than fossil fuel-driven cars, so that less energy is required to reach the same mileage. In addition, we make very modest assumptions about the contribution of wind and biomass and have left out concentrated solar power altogether. The possible gains of energy savings, which are in theory much larger than the contribution of wind and biomass, are also left out of consideration.
It should be noted that a well-functioning renewable energy market, both at a local and international level, is necessary for the energy transition to be successful. A well-integrated, flexible electricity network is also an important element. An example of a successful integration of markets is the NorNed-cable through which Norwegian hydropower is supplied to the Netherlands and Dutch off-peak electricity is supplied to Norway.
During the transition, gas-fired power stations should be able to deliver the flexible capacity which is necessary to supplement the supply of power from renewable sources. In the final phase of the transition, a growth in energy storage is needed to accommodate for the large quantities of intermittent renewable energy. This will require improvements in storage technologies, such as batteries and hydrogen.
In sum, the contribution of renewable energy to the primary energy mix is sufficient to enable a transition to a future free of fossil fuels. We do not need nuclear power to make such a transition possible. Renewable energy, especially solar power, has abundant potential to supply Europe with clean, reliable and affordable energy.
Who are Jaap Hoogakker and Eva Bik?
Jaap Hoogakker (firstname.lastname@example.org) is a senior business analyst at GasTerra, the Netherlands. This article represents his personal view.