In one hour enough solar energy reaches the Earth to provide energy for everyone for a year. But how will we harvest and store it? Spain has the solution.
“In one hour enough solar energy reaches the Earth to provide energy for everyone for a year!” Ivar exclaims. Floris curbs Ivar’s enthusiasm: “That may be so, but it all gets lost unless we learn to harvest and store that energy.” Yet in southern Spain they are doing just that. The region is one of the sunniest in Europe and harvests solar energy on a large scale. Various techniques are used to convert sunbeams into energy.
Solar Panels Are Getting Better
We sail along the Andalusian coast under a sunny sky. Good news for the temperature and energy production on board. The photovoltaic (PV) cells in our three solar panels turn the solar energy into power and charge the on-board batteries. It’s a proven method, but still under development. To illustrate, our two-year old solar panels supply more electricity than the four-year panel, which is considerably larger. They were cheaper, too.
PV panels are also popular in Spain. Not just on roofs, but also as big installations along the highway. Unlike on our boat, they do not charge batteries but feed directly into the power grid. As a result, they only provide electricity when the sun shines. As light cannot be stored easily, the Spanish apply different techniques to make us of the sun’s energy. So what are they?
Solar Heat as a Source of Energy at Home
Since we have started paying attention to them, we have seen them everywhere: solar water heaters on roof tops. They look like solar panels with a tank above it. Water flows through the panel, is heated by the sun and then stored in an insulated tank. In other words solar energy is stored in the form of hot water, which can be used in the bathroom or kitchen. To encourage the transition to solar energy, solar boilers are required by law for all renovations and new constructions in Spain.
Our newer flexible solar panels are much more effective
PV panels alongside the road
Rooftop solar boilers
Power at Night thanks to Mirrors
While it’s nice to be able to take a hot shower after sunset, we wonder if it is also possible to store solar energy to generate electricity. The answer is yes! It is achieved by using bundling solar beams to generate extreme heat. The technology is called Concentrated Solar Power (CSP).Various solar-power plants using CSP can be found in Andalusia. We drive around the countryside in search for these big installations. Half an hour’s drive from Seville we see thousands of shiny mirrors, set in endless rows. And a little further down mirrors surround a high tower. It is a futuristic sight in the wide and barren landscape.
Chain Reaction: From Light to Electricity
So how does it work? We visit a CSP plant in Palma del Rio, between Seville and Córdoba to find out. Engineer Andrés Lastra explains it to us while leading us along large, curved mirrors. Andrés points at an arm-thick pipe which runs in front of the mirrors. “Synthetic oil flows through the pipes. The mirrors reflect the sunlight and concentrate it on these pipes, which heats the oil to almost 400 degrees Celsius. The hot oil turns water into steam, which drives turbines to generate electricity.”
And what about storage? “The hot oil can be stored in tanks so that electricity production can continue even at night.” The storage of energy is thus built into the design of these plants. A similar technique is used in the high-tower CSP plant which we saw along the road. There, the sunbeams heat a salt solution in the tower. The salt slowly releases the heat to turn water into steam.
Ivar and Andres at the solar mirrors
Heated oil collector pipes
Transfer from heated oil to steam production
Ivar near the turbine house
Andres touring us around
Gemasolar tower CSP
A Big Role for Government
We are impressed by these power plants, which provide a part of Seville with renewable energy. But at what cost, we wonder? Energy is a political issue in Spain and therefore widely discussed in the media. We read that a legal maximum on the electricity price for consumers led to a financial debacle. Due to rising fossil energy prices, fossil energy was more produced at above the maximum consumer price. The government had to compensate the difference, which caused a large deficit.
In addition, when solar power producers were given access to the energy network in 2008, they were promised a fixed rate for energy delivered. Based on the expected returns from this “feed-in rate”, companies and investors built large solar power stations. Yet as part of austerity measures in 2012, the government scrapped the feed-in rates for solar energy. It also restricted the capacity of new solar energy plants. As a result the growth of the Spanish solar power industry was stopped in its tracks.
Subsidies Drive the Energy Sector
We dig deeper into the financial aspects. “According to some sources, the Spanish government has contributed a few tens of billions of euros to solar power plants,” Ivar summarizes his findings. “Subsidies in the energy sector are the rule rather than the exception, both in fossil and renewable energy,” Floris counters. “We often forget that fossil energy is also subsidized. A recent study shows that the fossil industry receives almost a thousand billion euros worldwide on subsidies each year.”
Ivar adds: “Additionally, the enormous costs of pollution and climate change are not included in fossil energy prices.” Surely, if we want to survive on this planet, we need to look beyond the financial costs of energy.
Solar Energy Key for Transition
It has become clear to us that solar energy plays a key role in the transition from fossil to renewable energy. Spain proves that the potential of solar energy is enormous. “But are there enough resources available worldwide to build such a renewable energy infrastructure?” Floris asks out loud. “It consists of so many elements, such as solar panels, sun mirrors, steam turbines, wind turbines, electric motors, batteries and all cabling.”
Ivar thinks he knows the answer. He just read a research report by Ecofys. This agency acknowledges that huge amounts of material are needed for the construction of a renewable energy infrastructure. There could even be a shortage of certain raw materials. But the good news is that many efficiency improvements are still possible, which would mean that less capacity is needed to generate energy. Add to that a high potential for technological innovation and recycling and a renewable energy transition seems to be possible.
We are pleasantly surprised by what we have seen and learned about the transformation of sunbeams into renewable energy through various techniques. The pioneering Spaniards have learned to utilize the abundantly available solar energy. In the process they have stimulated the development of CSP technology. As a consequence, new solar energy projects worldwide have become better and cheaper. We can thus be grateful for their contribution. Now it’s up to the rest of us to apply the Spanish learnings on a large scale and accelerate the transition to a renewable energy infrastructure.