Part One: Why are we struggling with the goal of 100% renewable energy?

Wärtsilä—with our innovative technological solutions—is helping lead the way toward a renewable energy future, a future that we can achieve faster than we may think. An important step is what the International Energy Agency projects: in three years, renewables will be the world’s top electricity source. This is indeed very important, but a core part of the drive toward 100% renewables often gets ignored: to really decarbonize, we have to focus much more on reducing our use of fossil fuels, not just adding renewables. These are two quite different things as adding just renewables to a power system will lead to a dead end, not decarbonization! 

Take Germany as an example. Despite leading the “green way” since the millennium with heavy investments in renewables, Germany still has 40 GW of operating coal plants and 45 percent of its electricity is still generated from fossil fuels. Even with a world record fleet of more than 120 GW of wind and solar capacity, only some 40 percent of their electricity comes from renewables because at the same time, they continued installing and inaugurating new coal plants, the largest single source of carbon. As it takes days to stop and restart a coal plant, they must keep operating and producing carbon all the time, day and night, even when there is enough renewables to cover the whole load. Sad truth: Coal runs first, renewables second! Despite the good intentions, the outcome after more than 20 years is electricity costs twice as much for consumers and the country has only achieved a moderate reduction in carbon.

Today, on windy days, Germany often generates too much green electricity for their own use —due to lack of storage and flexible gas generation which would enable shutting down coal plants—and has to donate much of it to its neighbors, often at a loss. 

The lack of planning is startling. Or let us say, there was a renewables plan but not a decarbonization plan!

As evidenced by Germany, it’s important that any future decarbonization plans include fast construction of renewables and factor in the fastest realistic closure of coal-fired power plants. The latter requires large fleets of wind and solar power plants, but also adequate quantities of storage and firm flexible gas capacity to integrate the renewables so that the power system can provide security of supply at any weather, without the coal capacity. The coal-closure transition takes years and should be the key focus area of all nations trying to decarbonize their electricity.

Another example: fast growth of China's economy was enabled by the ability to provide adequate electricity for all new businesses, which China did mainly by building coal fired power plants. Today China is home to more than half of the world’s still operating coal generation—close to 1100 GW— and is the largest national contributor to climate change from electricity generation. 

In China renewables are upticking steadily, and the share of wind and solar has now grown to close to 10 percent of energy, but a lot more is needed. Figuring out the optimal approach to decarbonize Chinese electricity must be in the center of the global “green screen” as this is where improvements have the biggest impacts. Adding renewables without a solid integration plan would become costly for all of us around the globe - China must succeed in their decarbonization at first attempt!

Needless to say, decarbonization must be done in every country, not only China. Getting rid of coal is the fastest way to achieve a rapid reduction in carbon. Unfortunately renewables are variable: At times they produce too much energy, and at calm nights far too little. So we cannot decarbonize electricity just by adding renewables, we must ALSO build correct amounts of energy storage and flexible firm gas capacity to fill the gaps and ensure security of supply. The gas plants will be converted to renewable green hydrogen-derived fuels when convenient, and will keep ensuring access to reliable green electricity also in the decarbonized world.

Increasing renewable capacity is a must do but alone they cannot form a reliable power system. At Wärtsilä, we are continuing to develop innovative solutions for power generators to integrate wind and solar efficiently, faster and better. Green technologies to support and integrate renewables exist, and the most economical ones are battery storage and highly flexible power plants using low-carbon natural gas and later renewable fuels. Now the conversation needs to shift from adding renewables to planning decarbonization!