Written by Yeh-Tang Huang.
On May 13th, 2021, Taiwan was paralysed by a national blackout. For five hours, multiple regions all over the country experienced periodic power outages that lasted for as long as 50 minutes at a time. Hundreds of people got stuck in elevators. The Central Epidemic Command Centre COVID-19 press conference that was happening was forced to end early. Traffic became a mess as traffic lights stopped working. Then on May 17th, another wave of blackout swept across the country. As disruptive as these blackouts were, they are only the tip of the iceberg. What lies underneath is a whole array of problems and risks associated with Taiwan’s current electricity system. Here, I will first identify these problems and risks. Then, I will explain why I think geothermal energy can mitigate many of these problems and risks and help Taiwan transition to 100% clean energy.
As an island nation, Taiwan has an electrical system independent of its neighbouring countries, so all of its electricity demand must be met by domestically generated electricity. Coal is the most dominant energy source in Taiwan, generating 44.95% of the total electricity output in 2020. The problems and risks associated with coal-fired power plants in Taiwan are manifold. One fundamental problem is their contribution to climate change. In 2016, coal-fired power plants in Taiwan emitted an average of 0.916 kg-CO2e GHGs per kWh of electricity generated, totalling an annual GHG emissions factor of 76.09 Mt-CO2e. If all these GHGs were converted to CO2, it would take 126 million tree seedlings grown for ten years to sequester all that CO2.
Air pollution is another underlying problem of coal-fired power plants in Taiwan. Air pollutant emissions from coal-fired power plants cause 900 premature deaths in Taiwan every year. Moreover, unlike CO2, many of these emitted air pollutants are unevenly distributed in the atmosphere, which gives rise to environmental justice issues as some places (my city, for example) have worse air quality than others.
Furthermore, the centralised nature of coal-fired power plants also makes Taiwan vulnerable to energy security incidents. Much of Taiwan’s electricity supply relies on a few large coal-fired power plants in central and southern Taiwan. A failure in any one of them can have serious repercussions all over the country. This was precisely what happened in the recent blackouts mentioned earlier.
Natural gas comes next to coal in terms of the amount of electricity generated, contributing 35.66% to the total electricity supply in 2020. In 2016, natural gas power plants in Taiwan emitted 0.417 kg-CO2e GHGs for every kWh of electricity generated, less than half of coal’s 0.916 kg-CO2e. However, natural gas’s overall contribution to climate change is only slightly less than that of coal. Compared with coal, natural gas emits much less NOx and SO2, which are cooling aerosol particles that reflect solar radiation out of the atmosphere. Thus, unless natural gas can achieve near-zero GHG emissions, it is hardly a better alternative to coal in terms of climate change mitigation.
The siting of natural gas facilities can also be problematic. The most notable example is the ongoing controversy over a liquefied natural gas project located in the vicinity of a millennia-old algae reef in Taoyuan. This controversy illustrates the potential environmental impact of natural gas facilities on local biodiversity.
Nuclear ranks third after coal and natural gas, contributing 11.22% to the grid in 2020. Although nuclear has little GHG and air pollutant emissions, Taiwan’s geography and topography are ill-suited for nuclear in many ways. For example, both operating nuclear power plants in Taiwan are near earthquake-inducing active faults, and one of them is even surrounded by active volcanoes. Taiwan also currently does not have the capacity for long-term nuclear waste storage. Much of the nuclear waste is currently stored in Orchid Island, and this has long been an environmental injustice to the local aboriginal Tao people.
Although they only made up 6.6% of the total electricity supply in 2020, renewable and semi-renewable energy resources are experiencing growth in Taiwan thanks to government incentives and increasing cost-competitiveness. Among them, hydropower is number one in terms of the amount of electricity generated, contributing 33% to the total renewable/semi-renewable energy supply and 2.21% to the total electricity supply in 2020. As baseload power, hydropower generally has stable and reliable electricity output. However, the recent drought in Taiwan, the worst in half a century, has severely affected hydropower capacity. In fact, this was one of the reasons that the recent blackouts happened. On May 13th, hydroelectricity output was 1.8 GW less than expected, and that shortage was almost 5% of the peak demand that day. Since water availability is becoming less constant due to climate change, a 100% clean energy Taiwan should not rely on hydropower as its only baseload power.
Solar generated 2.18% of the total electricity output in 2020, only slightly less than hydropower’s 2.21%. Given its current growth rate, it is no surprise if it surpasses hydropower very soon. However, limitations of solar include its intermittency, non-dispatchability and its land use. Land use is particularly challenging because Taiwan has limited space for large-scale solar projects. Therefore, finding a site for concentrated solar power can be challenging. Even for solar photovoltaics, controversies had arisen when developers tried to build solar farms on top of fish farms or cleared out woodland patches for solar development. Residential rooftop solar also faces scaling challenges given that almost 80% of the population lives in urban areas where multiple households share rooftops.
Though contributing only 0.87% to the total electricity output in 2020, wind has immense potential in Taiwan. 16 of the 20 best offshore wind sites are in the Taiwan Strait. Like solar, however, wind also has intermittency and non-dispatchability issues. Because there were less wind and solar radiation on May 13th, the electricity output from wind and solar combined was 0.55 GW less than expected; another important reason for the blackout that day. Building new wind projects are also challenging, especially in the permitting process. For onshore wind, the most promising sites are windbreaks protected by the Forest Bureau, and new offshore wind projects have also faced a lot of opposition from the fishing industry.
Although its electricity output in 2020, 1.34%, was higher than wind’s 0.87%, biomass grows much more slowly due to a lack of incentives, regulations, and expertise. The same goes for geothermal, whose electricity output in 2020 was so low that it was shown as 0.0% in the data from the Bureau of Energy. However, I would argue that geothermal could play an important role in Taiwan’s energy mix because it is free of many of the problems presented above and has additional advantages.
One of the most significant advantages of geothermal in Taiwan is that its resources are abundant and can be found in many parts. According to the Industrial Technology Research Institute’s assessments in 1985, geothermal resources in Taiwan, excluding those in nearby submarine volcanoes, could generate 31.8 GW of electricity. That is equivalent to Taiwan’s current total baseload power. Furthermore, these geothermal reserves are dispersed across the country. For example, they are in four of the six special municipalities: six of the 13 counties and two of the three cities in Taiwan. With such a wide distribution, these geothermal reserves can help decentralise Taiwan’s electricity system and make different regions, especially northern Taiwan, more energy independent.
If developed with care, geothermal has a minimal environmental impact. In general, geothermal plants have much lower GHG and air pollutant emissions than any fossil fuel plant. A closed-loop binary geothermal plant can even achieve net-zero emissions. Furthermore, according to the United Nations Environment Programme, a binary geothermal plant with similar standards as the Wairakei Power Station in New Zealand has the least overall impact on either human health and ecosystem diversity among all types of power plants.
Unlike solar and wind, geothermal does not have intermittency issues. It can serve as baseload power, and geothermal’s average water consumption is 1/3 that of hydropower, another semi-renewable source of baseload power. It also has the potential to become dispatchable, as Canadian geothermal company Eavor demonstrates to be possible. One other advantage of geothermal is its small footprint area. Geothermal can reach 20 MW of nameplate capacity per hectare of land used. Considering that the capacity factor of geothermal can be six times that of utility solar, the electricity geothermal can generate per hectare can be 120 times that which utility solar can generate. Of course, all of this is not to say that we should not use other renewables or semi-renewables. Rather, I argue that geothermal can help Taiwan overcome many bottlenecks in its transition to a clean, flexible, decentralised energy system.
If so, why is so little geothermal developed in Taiwan? Geothermal development in Taiwan actually started as early as 1981 when the Cingshuei Geothermal Power Plant was built. Unfortunately, this was a plant that shut down due to technical difficulties in maintenance. After that, however, the government shifted its interest to nuclear. As a result, for decades, geothermal has been a forgotten energy resource, and this has made Taiwan the only country in the Ring of Fire that does not have commercial-scale geothermal. Fortunately, exciting geothermal projects are already underway in many parts of Taiwan. This year, the Cingshuei Geothermal Power Plant will reopen, and the Swedish geothermal company Baseload Capital is also in the process of drilling geothermal wells in Hongye Village in Hualien County.
According to The Solutions Project, geothermal is projected to take up 30.4% of the energy mix in 2050 in a 100% renewable Taiwan, the highest among all energy resources. If that is the goal, it will be no small feat to go from 0% to 30.4% in a timeframe of fewer than 30 years. Still, it is precisely the ambitiousness of this “geothermal revolution” that makes it so full of excitement and possibilities.
Yeh-Tang Huang is an MA student in the Sustainability Science and Practice Program at Stanford University. He is currently back in Taichung, Taiwan, and has experienced unprecedented weather/climate abnormalities over the past year. Never has climate change felt so urgent to him, so he feels extremely motivated to act and make a difference.