It is a desparate situation! This is the impression one may get when reading reports about climate change and the energy transition: Some claim that the energy transition is not possible at all, that it would cause blackouts and destroy our economy.

Prof. Reinhard Haas, head of the Energy Economics Group at the Institute of Energy Systems and Electrical Drives at TU Wien, takes a different view: Of course, there are major challenges to be overcome in the energy transition. It is not yet clear whether we will actually succeed in turning things around in all areas. But there are no fundamental technical hurdles that make this goal seem impossible. Overall, Reinhard Haas is rather optimistic about the future - especially in view of the tremendous progress that has been made in the field of renewable energy in recent decades.

Four sectors: electricity, buildings, industry and mobility

If decarbonization is to succeed, it is not enough to focus on electricity supply only. Solutions must be found for four major sectors: Electricity, Industry, Buildings and Transportation.

"Electricity is the sector that is easiest to reform," says Reinhard Haas. Austria's electricity supply is to become CO2-neutral on balance by 2030 – quite soon. This means that surpluses will be produced in the summer with solar power, and in the winter a few percent from gas-fired power plants will be added. In addition to PV, wind power in particular still has great potential. Here, in addition to the construction of new plants, "repowering" will also play a central role – the replacement of first-generation plants with more powerful, modern plants. "These power supply targets are ambitious, but realistic," Haas says.

The rise of electromobility is not a major obstacle for the energy transition: By 2030, electric vehicles will increase electricity demand in Austria by about 3 TWh per year – which is modest compared to the current electricity demand of about 78 TWh per year.

Reforming the building sector will take longer. By 2050, it could be possible to decarbonize the heat supply of buildings in Austria, Haas believes. Heat pumps will play an important role in this transition. But Haas warns against seeing heat pumps as a panacea: They have to be combined with good building insulation. Often, thermal refurbishment can even achieve higher efficiency gains than just installing a heat pump.

The changeover in industry is more difficult. Hydrogen will play a role there. However, Haas is critical of the idea that in the future we will import hydrogen on a large scale from desert regions where cheap solar power can be generated and used to produce hydrogen: "If these countries were to use the solar power themselves instead of generating hydrogen gas for us in Europe, the overall CO2 savings would be much greater. Apart from that, we have not had good experiences with becoming dependent on monopolists when it comes to oil or natural gas. We should not repeat the same mistake with hydrogen." All industrial processes that can be run electrically instead of with gas should be electrified first, Haas says.

The decarbonization of mobility will also be a major challenge. Reinhard Haas does not think much of e-fuels: "It's a waste of primary energy," he says. Generating e-fuels with electrical energy is inevitably less efficient than using the same electrical energy to charge a battery-electric vehicle – and even if we assume that the potential for renewable energy will become much greater: We should still use it efficiently, because renewable energy is also limited in principle.

Nevertheless, Haas does not believe that simply converting all of our current mobility to electric vehicles is the right solution: We have to increase the overall efficiency of mobility. This starts with choosing a sensible size of cars: "A small electric car with 35 kW needs less electricity than a Tesla," emphasizes Haas. But it's also important to reduce traffic overall and make public transportation more attractive – this can also save a lot of energy.

No fear of blackouts

A major challenge will be long-time storage of energy from alternative sources. Creating excess capacity in alternative energy can reduce the problem – but it will still remain necessary to store energy for the winter, when heating demand is high and photovoltaic output is low. There is no single perfect solution for this; it will be more a matter of wisely combining various smaller solutions, such as pumped storage power plants, biomass plants, and syngas.

The transformation of our electricity supply also necessitates a transformation of the electric grid infrastructure. But this should neither frighten nor surprise us, says Reinhard Haas: "Most of our network infrastructure is 50-60 years old. It is clear that after such a long time, some things will have to be renewed. Our telephone infrastructure, for example, has changed even more dramatically in recent decades."

Reinhard Haas does not expect major grid problems such as blackouts caused by fluctuating power generation from alternative energy sources. "We are in a much better position in Europe in this regard than Texas, for example, where prolonged power outages do indeed occur from time to time." Nevertheless, grid capacity needs to be adjusted in some areas – but this is rather a political problem than a technical one.

A lot has improved

The fact that Reinhard Haas believes the energy turnaround is feasible is mainly due to the great successes of alternative energy in recent decades "When I started working on photovoltaics in 1989, it was an experimental field for a few alpine huts," he recalls. Since then, there have been great technological advances, and prices have dropped massively.

Photovoltaics is now cheaper than electricity from coal or nuclear power. For this reason, Reinhard Haas believes that subsidies for photovoltaics are no longer necessary, even in the long term: Alternative energy can hold its own in the market – provided, of course, that the market is not distorted by direct or indirect subsidies for fossil fuels. The true costs of emissions must be priced in via a CO2 tax, then renewable energies will be the most cost-effective solution – and will therefore prevail in the end.

Contact: Prof. Reinhard Haas

Text: Florian Aigner