What energy sources will we use in the future and what will the future energy system look like? It is addressed in this fact sheet.
The energy sources of the future
An energy source is something that exists in nature and that can be converted into useful energy forms such as electricity, heat, and movement in, for example, a car or a train. Examples of energy sources are solar radiation, flowing water, winds, oil, uranium and biomass.
The energy sources we humans use can be divided into renewable energy sources and non-renewable energy sources. The renewable energy sources are constantly supplied with new energy from the sun and therefore do not end. The non-renewable energy sources, on the other hand, exist in a certain amount on our earth and are rebuilt very slowly or not at all. They can, therefore, run out and the more of those used today, the less will be left for future generations. Moreover, since fossil fuels emit large amounts of carbon dioxide, we need to quickly stop using fossil fuels to stop climate change.
Globally, today’s energy system consists largely of fossil energy, despite the great potential of renewable energy on the planet. A few percents of the surface of the Sahara desert would theoretically be enough to, with the sun’s radiation as a source, produce as much energy as we humans use in total on the globe.
Although renewable energy has been talked about for a long time, it is only in recent years that the expansion of renewable energy sources has really taken off in many parts of the world. The technology has evolved and become cheaper, but at the same time, political targets for renewable energy have been adopted in many countries.
The energy system of the future
In today’s energy system, electricity is produced in large plants – such as coal-fired power plants, hydropower plants or nuclear power plants – and then electricity is distributed to everyone through an electricity grid. It is an efficient system, but where power is concentrated to some players and a system that is sensitive to major interruptions in the electricity grid.
The important difference is that renewable energy, and especially solar energy, is easier to access for everyone. A solar revolution thus means not only a transition to more sustainable energy types but can also mean that more people have access to energy and that the power over the energy is transferred from the large companies to the consumers.
Today, more than one billion people still lack access to electricity. This is something to be addressed within Agenda 2030 and the global goals for sustainable development. Here, the transition to renewable can contribute. In countries that today do not have extensive electricity grids, small-scale renewable electricity can give people access to energy faster, easier and cheaper than conventional energy types such as coal and oil. Just as many countries have not built any fixed telephone network, but have gone straight on mobile telephony, they can skip fossil fuels and nuclear power and go straight to the energy of the future.
Small scale or large scale?
Even a completely renewable energy system can look very different depending on what energy sources are available and how the system is structured. In windy Ireland, wind energy may play an important role, while solar and wave power may be more important in Portugal. On remote islands in the Pacific, you need to be self-sufficient in energy, while many countries in Europe can share energy when you have surplus electricity.
Techniques for transporting electricity long distances (so-called transmission) exist and continue to develop. Being able to use the electricity grid to transport energy from the place where it is blowing most of the time or where the sun is shining will be important. At the same time, there is a movement that talks about cutting the cord to the electricity grid and becoming self-sufficient in energy by having its own small-scale solar, wind power, bioenergy and its own batteries that can store the electricity.
For many, being self-sufficient in energy is an appealing thought. At the same time, everyone must then build large amounts of reserves, energy production and storage to ensure that they always have electricity and heat. The already completed electricity grid has the potential to be used as a sharing platform, which is an argument for continuing to be connected. Through the electricity grid it becomes possible to buy and sell surplus electricity.
Flexibility, storage, and smart grids
Electricity cannot be stored in the electricity grid, but there must always be a balance in the system. This means, for example, that when a lamp comes on, it must, at the same time, run water through a hydroelectric plant, a windblown blow past a windmill or the sun shine on a solar cell.
As the world now reigns towards completely renewable energy systems, our electricity generation will follow the supply of flowing energy sources such as solar and wind. The electricity supplied to society will be more variable. At the same time, the price of electricity will be low when there is plenty of energy from the sun and wind, and higher when it is cloudy and wind quiet and we need to burn biofuels or use other more expensive renewable energy sources.
In the future, the entire energy system will need to be more flexible and we need smart electricity grids that can adapt to different situations. More flexibility can be created in several ways.
Flexible production: Power plants that have a stored resource and can produce electricity when it suits them constitute a flexible resource in the energy system. Examples are hydropower plants that store water in a reservoir, or biopower that has stocks of biofuels. Moreover, since electricity prices get higher when it does not blow and the sun does not shine, it is more profitable for them to save on their resources and produce their electricity on these occasions. Building new electricity generation is often expensive, so mixing flexible production with other cheaper flexible resources can be good.
Flexible use: Another solution is that users of electricity become more flexible and use more electricity at the right times. For example, electric customers can take the opportunity to heat hot water, charge the electric car and run demanding industrial processes when it is extremely windy and the sun is shining. Many of these processes can be completely automated so that the user can think of something else. If you, as the user, buy smart appliances and agree that they are flexible, they themselves or through your electricity retailer can be directed to buy electricity when electricity is the cheapest.
Storage: A third way is to store the electricity. So far, it has been difficult to store electricity and this has resulted in large losses of electricity. This means that you could not get as much electricity as you put into the storage system. Techniques for storing electricity in batteries are now under strong development. For example, in the future we will be able to recharge our electric cars on the day when the sun shines on the solar cells at the school or the workplace. The electricity is then stored in the electric car’s batteries, and we can use it when we drive home in the evening. Another example is to make hydrogen gas for industry or district heating when there is an excess of cheap electricity from the sun and wind.
Smart electricity grids: A fourth way to meet the challenges of variable electricity generation is to connect larger systems with smart grids. The control of the electricity grids and what is connected to the grids can be smarter and use energy more efficiently. With a combination of solar, wave power and wind power in different places, for example at sea, on land and at high altitude, it will always be possible to get energy from any source. For this to work, it is necessary to transport electricity long distances, and more countries need to connect their electricity networks.
By combining different flexible resources with energy efficiency and renewable energy, it is possible to achieve fully renewable energy systems. It is a big change to go from today’s global energy system, which consists mostly of fossil energy to a completely renewable energy system, but it is a change that is possible with the knowledge we have today.
Future energy technologies
Already, there are plenty of renewable energy types, which have come a long way in their technological development and are starting to compete for fossil energy types. Nonetheless, technology for capturing and storing renewable energy can be better, more efficient and used in new ways.
Much research is underway on new ways of utilizing the sun, wind, water and biomass. How about completely transparent solar cells that can be used as window glass? Or solar cells based on nanotechnology or graphene, which makes them so thin and light that they can be built into anything?
Also in wave power, many different projects are in progress, ranging from floating snake-like wave power plants to buoys on the water that are anchored in the seabed to kites that “fly” underwater or turbines immersed in tidal currents.
New sources of bioenergy are also something that both research and development is focused on, since biofuels from forestry and agriculture may not be sufficient for future needs. For example, cultivation of algae can be seen as promising, cultivation can take place both in tanks and in sea and lakes. In addition, much research is being done on the development of warehouses, smart grids and other flexibility.
Merger and new nuclear power
There are also those who believe that fusion power can become a profitable energy source in the future. Fusion is the energy source that makes the sun shine. Fusion is just like nuclear power based on a nuclear reaction, but her energy is extracted by merging two light atomic nuclei at high speed.
The advantage of fusion power as an energy source is that it can give us almost unlimited amounts of energy for a long time to come. It also does not entail the same risks as today’s nuclear power based on fission, that is, energy is extracted by atomic nuclear division. The big problem with fusion is that very high temperatures are required to make the process work – about 100 million degrees – which requires large amounts of energy into the process and places high demands on the materials. So far, scientists have failed to build a fusion reactor that provides more energy than it needs. The question is whether the technology will be cheap enough in the future.
New forms of nuclear power, the so-called fourth-generation nuclear power, are also being researched. This could provide the community with energy for a very long time because it can use today’s nuclear waste as fuel. While this is an advantage, there are still drawbacks compared to renewables. The risk of accidents remains, even if it is significantly less, and radioactive waste is formed which must be stored safely for 500-1,000 years.
What happens in the future?
How the energy system of the future is developed depends a lot on what the politicians decide and how companies and private individuals choose to invest. Large-scale energy solutions take a long time to build and once a system is built it is difficult and expensive to change it. If those who make the decisions do not think right from the start, and do not have a complete picture of the energy system, there is a risk of lock-in effects. For example, it may be unnecessary to build flexible production, which can cover up when, for example, it does not blow, if smart electricity grids simultaneously make users prefer to adjust their consumption.
Much of the electricity generation will need to be replaced within the next 20-30 years. This applies to both old nuclear power plants as well as many wind farms. New plans are needed soon as it can take more than ten years to build large power lines and power plants. But it is difficult to know how the energy system will develop.
Our electricity demand may increase. For example, more cars will run on electricity in the future, because we do not want to use oil and gasoline.
Energy efficiency is an important puzzle piece for the conversion from fossil energy. Since all energy use affects the environment, the only sustainable way to use renewable energy is to reduce our energy use, so that renewable energy is enough for everyone.