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As the evil hand of corona came into play, Eesti Energia´s Environmental Day "Renewable Energy in My Backyard #YIMBY" was postponed to September. In the meantime, the moderator of the event, Tarmo Soomere, President of the Estonian Academy of Sciences, took the time to reflect on the topics of renewable and controlled energy sources, new technologies, and a carbon-neutral world.

Tarmo, you agreed to moderate Eesti Energia's Environmental Day this year. How does this topic speak to you?

Without a properly functioning energy supply, it is impossible to imagine the functioning of modern society, let alone the organization of it. The importance of energy supply was reminded by the winter accident at Võru substation. Fortunately, the weather was not very cold then.

Fossil fuels can be used to generate electricity for many years to come, technically it is possible. Substances suitable for incineration in one way or another will last for hundreds of years. However, if it will be done this way, the burden of side effects on nature will probably be too great. Besides, there are many other things to be done with the organic matter found in the Earth's crust which are also more useful than to shovel it into the oven.

There is one important difference between procuring energy from fossils and procuring it from renewable energy sources.

There is quite a lot of energy in every kilogram of fossil fuels. It is obtained through a high-temperature energy carrier via relatively small furnace. Energy is converted into electricity by a turbine that is as small or even smaller. In this way, the energy needed for the whole country can be produced at one quite small place. In this regard, it is said that the energy density of fossil fuels, e.g. per unit mass, is quite high.

Image Tarmo Soomere (Photo: Reti Kokk)

The story is different with renewable energy. With the exception of hurricanes, tornadoes, and their small sisters whirlwinds, there is not much energy in one kilogram of moving air or one square meter of solar radiation. Thus, the energy density of renewable energy sources is quite low compared to fossil fuels. There isn’t much energy hidden even in sea waves with a decent energy density. For example, the waves reaching the Estonian coast have annually approximately 1–2 kW of energy on average per meter of coastline. If we could turn it all into electricity without losses, we could ideally cover half of our energy need. But to do that, a system of nearly a thousand kilometres of wave energy converters would have to be put at sea. Four years ago, a 60 megawatt wave power plant in Australia was estimated to cost around EUR 150 million (https://arena.gov.au/assets/knowledge-bank/Bombora-Wave-Power-ARENA-Cost-of-Energy-Study.pdf). Our beach reaches an average of 1,000 megawatts of wave energy per year. The cost of the equipment needed to capture it is therefore at least EUR 2 billion. In fact, it is many times bigger, because most of the time the sea is calm.

The same goes for wind turbines or solar energy. Hundreds of wind turbines need to be built to create a wind-based energy supply. It would be good if they were supported by many square kilometres of solar panels. Moreover, it is often the case that the sun shines or the wind blows on one side of Estonia, but it rains or is quiet on the other side. Thus, there is quite a bit of complexity in the construction of these devices in only one specific place due to additional transmission line costs. It makes much more sense to place wind turbines and solar panels near consumption points. This requires less equipment than building things in one place.

While large oil shale boilers are generally more economical than small ones and oil shale transport itself is expensive, it is simply not possible to build very large wind turbines, and there are places that are more or less suitable for solar panels everywhere. Even on the roadside. So, if one wants to be consistently environmentally friendly and focus on renewable energy as the basis for the future, it is logical that every home has its own energy source on the roof, outdoors, or in the backyard. It is very difficult to imagine a different future.

Given the current climate policy, has a sufficiently strong start been made to the development of renewable energy?

The introduction of renewable energy has not been really good in Estonia. There has been a lot of talk and plans. The reality is that the pace of renewable energy installations has not kept pace with the number of fossil fuel-based sources being shut down. There are many reasons for that here, from national defence arguments to people's fear that the windmills will overshadow the sea view.

There is no action plan for hydrogen energy and there does not seem to be even a vision. Hydrogen is one of the few, if not the only, energy sources that can be easily generated, stored, transported, and quickly deployed in almost all quantities.

Only the designers and builders of near-zero energy houses have kept pace with the times.

One should not rush in such situations. Modern society needs a constant and large amount of electricity. Maintaining our current core solution, energy based on fossil fuels, for as long as the new sources are able to replace the existing ones is not so much a matter of habit, cheapness, convenience or even social policy, but above all, a matter of energy security.

Current battery-powered electric cars are likely to be a dead end in the long run, but they are an essential step forward in the short term. The same applies, for example, to heat pumps. At least as long as they consume electricity from fossil fuel combustion. Colleagues' calculations say that compared to cars with internal combustion engines, the use of fossil electricity in electric cars and heat pumps increases total carbon emissions instead. In this way, the efforts made so far have been a step backwards, but it is a step that is needed for a serious move.

To make the development of the energy sector even greener and more sustainable, should we then turn to even newer technologies?

Not only bold solutions take the world forward, but also the need to do something different. Let us ask ourselves not how, but why did Estonia manage to launch modern information technology, create a pleasant and efficient e-banking, skipping the epoch of chequebooks, for example, and build an e-state? One component was that we did not have much to take over from the time of the Estonian SSR. There was no need to worry about old-fashioned systems that people were already used to. For many things, you could start from scratch.

The fact that Estonian energy is well developed, secure in terms of security of supply, guaranteed with good competence and, at times, at a reasonable price, is one of the bombs at our feet. Expensive systems that work properly have high inertia, also in people’s consciousness and attitudes. Turning off from a well-known road, even if the new direction seems appealing, is not easy. Ignorance still causes unrest and it is not possible to know the exact future. However, there are a growing number of arguments that the energy sector that is based on the burning of fossil fuels and even biomass may be sustainable in the narrower financial sense, but it is certainly not environmentally friendly enough.

But how environmentally friendly is the development of renewable energy?

The environmental footprint of renewable energy development is currently likely to be severely underestimated. We simply cannot imagine the entire life cycle of equipment, processes, and materials in this sector yet. I would compare this with estimates for nuclear power plants, where construction costs are gradually compounded by large indirect costs, the storage of used fuel and, finally, the disposal of the plants themselves after their resources are depleted.

A good analogue is biofuels. While at first their introduction to energy use in the transport sector seemed almost like a turnaround, it has gradually become clear that more than a litre of oil is needed to produce one litre of several biofuels. Add to that the land and water.

However, I am convinced that there are opportunities to reduce the environmental footprint of renewable energy by many times, if not by magnitude. A much more important aspect is the possibility of decentralizing renewable energy production. If the solar panel covers an entire hectare, the normal ecosystem of the meadow under it is unlikely to survive. However, if it is on the roof or covers about twenty square meters, its effect is much smaller.

Rather, the problem arises when industrial solutions for renewable energy production, such as megawatt wind turbines, emerge near homes. Then people will certainly have the right to ask why the device that produces energy for hundreds of families must be around their homes. Such situations cannot be resolved either by force or by persuasion. If people's quality of life deteriorates, it must be compensated in some way, on much higher level than market prices, if necessary. In the long run, it is not that expensive.

Should there be a balance between renewable energy sources and managed energy sources and which then?

Of course, it cannot be said that renewable energy sources are all uncontrollable. Solar panels also produce energy in cloudy and rainy weather. The central bottleneck here, or the biggest unknown, is the possibility of storing energy. Because, to our current knowledge, electricity cannot be stored at a reasonable price. It must be used immediately at the same time it is produced.

It is quite well known for how long the energy needs must be covered in some other way when the sun is not shining and the wind is not blowing. A rough assessment says that a week should be enough in our area. If it is not possible to store and reuse energy, the capacity of the entire country must be kept in reserve. This can be either in the form of our own power plants or the production capacity at the other end of the cables. Alternatively, a special regime can be created for the time when no renewable energy is generated.

Such a battery bank, which would cover Estonia's weekly energy consumption, currently costs at least EUR 100 billion. Electric car batteries can cover it a little bit, but the electricity coming from them is shamelessly expensive, as these batteries can deal with roughly 500 charge cycles. Newer batteries can handle more, but not by much.

A possible solution is storing either hydrogen or other easily produced and easily stored fuel combined with the construction of appropriate conversion equipment. If such a reserve and, for example, fuel cells could cover Estonia's weekly need, we could give up oil shale energy with a light heart. It would be quite interesting to calculate how much it would cost compared to oil shale mines and power plants.

What do you think would be a sensible way to reach a carbon-neutral world?

The price of real estate is formed by three main characteristics: 1) location, 2) location, 3) location. The answer to the question is also quite similar: 1) energy storage, 2) energy storage, 3) energy storage.

After all, high carbon emissions must be produced not so much by inexperience, but by the fact that both the energy content (or energy density) of fossil fuels and the possibility of storing them (or preparing them for extraction underground) are significantly greater than our ability to store electricity.

Unless there is an unexpected breakthrough in basic sciences in the field of batteries or super capacitors, we are bound to existing substances – gaseous, liquid, or solid fuels, the production of electricity from which we can control.

At the moment it seems that the core of a carbon-neutral world will be hydrogen-based energy, supported by a whole bunch of other solutions from roofs with solar panels to small (modular) nuclear power plants.