Taiwan Kuosheng Nuclear Plant 2 Reactor 1 Shuts Down – Forever

Natural gas fired replacement power will contribute nearly 1000X more CO2 emissions every day

Chart of Taipower’s generation mix at 3:25pm, July 2.

Last night, the first reactor of the Kuosheng Nuclear Power Plant shut down permanently, six months prior to its scheduled retirement date of December 27 due to lack of spent fuel storage capacity, preventing spent fuel from being removed and replaced with fresh fuel. The reactor closure is a significant step towards Taiwan’s nuclear free goal and its energy transition, which aims to eliminate all nuclear power generation on the island, and replacing it with renewables and natural gas.

Through its energy transition, Taiwan aims to be a leader in green energy in the Asia-Pacific region, while also eliminating what is sees as a significant threat to health and safety in nuclear power and reducing greenhouse gas emissions. President Tsai recently pledged Taiwan’s goal of net zero emissions by 2050 and the country is looking to take the rare step of putting this goal into law by amending its Greenhouse Gas Reduction and Management Act.

Already, Taiwan has made huge strides in policy implementation of offshore wind and can claim the leadership role in APAC. Solar PV installations have increased by nearly 400% since Tsai took office, and the Chinshan Nuclear Power Plant (NPP1) is being decommissioned. With the shutdown of Kuosheng-1, Taiwan is halfway to achieving its nuclear-free ambitions.

Taipower expressed confidence to me that energy supply will be sufficient this summer because it has already commissioned Kuosheng-1’s replacement power: the 500MW combined cycle gas turbine (CCGT) Chiahuei 2 Independent Power Provider (IPP), as well as 500MW of solar PV. Taipower is also bringing back several units CCGT units that have been sidelined for repairs.

Chart depicting Taipower’s generation mix at 2:20pm July 2. Solar power (light green) reached 8.72%, while nuclear (pink) dropped to 7.64%.

Already, at 2:20pm peak when demand breached 37,000 megawatt hours (MWh), nuclear’s share of power generation feel to 7.6%, down from the usual 9~10%, while solar reached 8.7% — the first time that solar has exceeded nuclear in power generation. Reserves fell from yesterday’s 16% to 11.84%, but still comfortably in the green.

However, as the day wanes, this won’t last, and Taiwan will again fall back on natural gas fired power to maintain supplies to compensate for Kuosheng-1’s sizable output.

Prior to its coast down in which Taipower operated the reactor at lower output to preserve fuel, the 985 megawatt (MW) Kuosheng-1 had been operating at or near (or even over) 100% capacity. Taipower statistics reveal that the 985MW Kuosheng-1 reactor operated at 101.94% capacity in March, generating 710,131 megawatt hours (MWh), or 22,907MWh daily.

Solar PV, by contrast, operates at 15% capacity factors in Taiwan (annualized – this is somewhat higher during the summer), generating about 75MW per hour, or 1,800MWh daily.

The Chiahuei 2 IPP unit is operating at capacities as high as 98%, generating roughly 11,760MWh daily. Together, these generate 13,560MWh daily, far off the generation of Kuosheng-1. Further, while natural gas-fired power emits less CO2 than coal-fired power, it is still substantial. The US EPA estimates that combined cycle natural gas power plants emit 407 kilograms of greenhouse gases per MWh, suggesting that the Chiahuei 2 adds 4,786 metric tons of CO2-equivalent into the atmosphere every day. Further, the 1000 combined MW of Chiahuei and solar PV will not fully replace Kuosheng-1, and the two additional CCGT units needed to make up the difference will add another 3,804 tons of GHG emissions into the atmosphere every day, for a total of 8,590 tons per day.  

Nuclear power also has a carbon footprint, primarily in the construction phase but also in the mining and refining of uranium. Through the life of the plant, this is estimated to 400 grams per MWh – resulting in Kuosheng-1 emitting 9 tons of GHG daily.

          Taiwan’s EPA representative suggests that these are just hiccups on the path towards a greener future, and perhaps they are correct. Yet this CO2 being emitted today will spend centuries in the atmosphere.

Maanshan-1 returns but High Demand keeps Margins Tight

The Jingmei River behind NCCU was swollen with much needed rainfall, but most of Taiwan remained dry.

Amid torrential rains that potentially put water behind the dams at Taiwan’s hydropower plants as well as the restart of Maanshan Nuclear Power Plant(NPP3), Taiwan might expect that its energy squeeze would have eased today. Hydropower makes a small but important contribution to Taiwan’s power supply, and the end of the longstanding drought would improve Taiwan’s energy situation. Maanshan unit 1, which was offline for several weeks of annual maintenance, is a major factor in Taiwan’s power supply, and the restart of its 951 megawatts (MW) brought nuclear power once more to 10% of total power generation. The 800MW coal-fired Linkou unit 3 also returned to service, likewise adding to capacity.

Unfortunately, reserve margins remained stubbornly at Yellow, reading 6.01%. Below 6%, Taiwan’s power supply would be at risk of shortages.

Taiwan’s reserve margins flashed Yellow, for tight supply, despite a boost in capacity. Source: Taipower website

Several factors are contributing to this situation.

First, the rains were confined to northern Taiwan, while the bulk of hydropower is in the central and southern regions. Hydropower remains less than half of 1% of Taiwan’s total generation. Wind, never a big factor during the hot summer months, likewise generated less than 1% of Taipower’s load.

Heavy rains fell in northern Taiwan, but the rest of Taiwan remained hot and dry. https://www.cwb.gov.tw/eng/

Prevailing sunshine did enable solar PV to generate at high volumes, reaching 3,320MWh at 1pm, according to Taipower data, nearly 9% of the total at near peak demand and not far behind nuclear’ s 3,694MWh recorded at the same time. But solar drops off quickly and by the evening peak after 6:30pm, solar is almost nonexistent.

Screenshot of power supply by fuel — solar is topmost green, nuclear is bottom pink. https://www.taipower.com.tw/tc/page.aspx?mid=206&cid=404&cchk=8ccc1918-8cae-4f40-a2d0-b43454f4f218

Another issue is the number of large scale combined cycle gas turbines (CCGT) which remain offline. Datan CCGT unit 6, Xingda CCGT unit 2, Dalin CCGT unit 6, along with the 500MW oil-fired Concord unit 4, remain offline for maintenance. Together, they comprise 2,219MW of capacity that is not operating.

The single biggest factor, however, is demand that continues to exceed expectations. Sunshine and high heat result in high demand, and Taipower’s peak load at 1:50pm reached at least 37,763MWh. Taiwan’s industrial output apparently remains on track despite the pandemic, with no respite in demand from the industrial sector. Taipower says that demand has risen at least 3% in Q1 2021, and the Bureau of Energy forecasts a sustained annual rise of 2.5% through 2027.  

Coal remains vital to Taipower’s supply, and Taichung’s power plant continues to operate at nearly full power. Coal generated over 40% of the total load today, neck in neck with natural gas, while multiple other units were dragooned into service, including backup diesel power at 1.3% (greater than hydropower and wind combined) and pumped storage, which generated 2.5% of total load at the peak at 1:50pm, generating 940MWh.

All three units of Linkou’s ultrasupercritical power plant are operating at over 94% (top), while eight out Taichung’s 10 units are running full steam.

Supplies will remain tight through the week on extraordinary demand before finally easing up on the weekend. Next week will likely also be tight, as Kuosheng NPP2 unit 1 will be coming offline permanently perhaps as early as next week.

It’s not just Nuclear — As Demand Surges, nearly 10% of Capacity is Offline

Power demand rose 3% in the first quarter of 2021, and Taipower’s capacity has not kept pace.

Maanshan Nuclear Power Plant in Pingtung County. Photo: Jnlin/Wikimedia Commons

Taipower’s reserve margin sat uncomfortably in the yellow at 6.19% today, just 0.2% above the critical Red Line. This decline in reserve margins is at least partly due to a current reduction in nuclear power. Nuclear power comprised less than 8% of today’s energy mix, down from the typical 12%. Maanshan NPP3 unit 1 is still offline for its annual maintenance but even more crucially, Kuosheng NPP2 unit 1 is already starting to wind down. Throughout April this unit has been operating at 96.34% capacity (Taipower data), but has now begun its inevitable decline. The lack of spent fuel storage capacity prevents the reactor from being refueled, and it will be permanently shut down probably by the end of May.

Maanshan unit 1 is still down for maintenance as Kuosheng unit 1 winds down.

The nuclear plants are at least partially making up for this shortfall through the operation of their emergency natural gas turbines, which are intended to maintain power in the event of a nuclear disaster. These were operating at high capacity today.

It’s not just Maanshan unit 1 that is down for maintenance, however. When the power went out on May 13, nearly 4.6GW of generating capacity was offline for maintenance, amounting to 9.24% of Taipower’s total installed capacity. This is almost equivalent to the 10% of reserve capacity Taipower claimed to have available at the time of the outage.  

The state-owned utility was chided by Minister of Economic Affairs Wang Mei-hua during an online press briefing yesterday for having so many units down simultaneously. She also called for Taipower to upgrade its power distribution systems and to revise how it calculates reserve margins. Longer terms goals include upgrading the grid and improving regional development.

“Thorough improvement is necessary,”she said during an online press conference.

Plants that are currently offline due to maintenance include:

  • Unit 1 of the Third Nuclear Plant (951MW)
  • Unit 3 of Linkou Coal (800MW)
  • Unit 3 of Mailiao Coal (600MW)  — now back in service
  • Unit 6 of Datan Combined Cycle Gas (724MW)
  • Unit 2 of Xingda Combined Cycle Gas (445MW)
  • Unit 6 of Dalin Gas (550MW)
  • Unit 4 of Concord fuel oil (500MW)

Total capacity currently offline is 3,970MW.

Power Demand

Taiwan’s need for electricity has risen sharply over the past year, and the MOEA reported yesterday that power demand increased 2.1% in 2020 on surging industrial production and repatriation of manufacturing capacity. Power consumption reached 271,000 gigawatt hours (GWh) (note – this includes Taipower’s generation as well as industrial self-generation) in 2020, and that rise has only gained so far in 2021. Industrial production rose 6.8% and exports 4.9% in 2020 compared with 2019, according to MOEA data. Demand from the industrial sector, which consumed 56% of Taiwan’s power in 2019 (Taipower Sustainability Report 2020), rose by 2.1%, while residential demand rose 6.4%. Taipower reports that Q1 2021 power demand rose another 3%.  

The MOEA sees power demand rising by 2.5% annually through 2027, higher than the previous decade’s average of around 1.7%, as Taiwan’s industrial resurgence looks set to continue.

To meet this rising demand, gas-fired power capacity will be increased by a net 14.5GW within the next seven years. This capacity, however, is constrained by Taiwan’s LNG (liquified natural gas) importation capacity.  The MOEA admits that the Third Terminal at Kwangtung in Taoyuan will be delayed until 2025. Sources from several companies working on the project say it will be likely be delayed even longer, not to mention that it faces a referendum this August. Taipower’s Taichung LNG terminal has not even passed its EIA, nor has the LNG terminal planned for Keelung needed to fuel the proposed natural gas power plants that are to replace the fuel oil units currently in operation.

The MOEA also continues to express confidence that coal-fired power will be reduced even lower than 30%, to 27%, and touts reductions in coal fired power in 2020. Taipower’s data this year shows most coal-fired units operating at full power, though.

The ministry is also fully confident that Taiwan will see its full capacity of 20GW of solar and 5.7GW of offshore wind delivered on time by 2025, to offset the loss of all nuclear power.

That, however, is not likely, most sources within the industry agree, .

Regardless, the capacity that is currently offline for maintenance should be up and running within days or weeks, ameliorating the power situation at least somewhat. Maanshan unit 1 has been approved by the Atomic Energy Council for restart earlier than scheduled, and it is ramping up at this moment. Taipower anticipates an improved reserve margin over the next few days, albeit only slightly.

The Once and Future King Coal

Nine out of 10 units at the Taichung coal-fired power plant are operating at high capacity.

Along with shutting down all the nuclear power plants, a key goal of Taiwan’s ongoing energy transition is the reduction of coal in the power generating mix to 30%. Unfortunately, Taipower’s data show that as power demand increases, Taiwan has few other options than to rely even more heavily relied upon coal. Nearly all of Taipower’s self-owned coal-fired units and its network of IPPs (Independent Power Producers) are operating at near to full capacity, including nine out of 10 of the 550MW coal-fired units at the notorious Taichung Power Plant.

The actual condition of Taipower’s reserve margins remains unclear.  Natural gas power is the usual go-to when capacity gets tight, but with most combined cycle units already operating at near or even above capacity, they have little more to give.

Pumped storage, which makes up 2,600MW of reserve capacity, was brought into play on May 13, with nine out of 10 units generating power, but even these were not enough to stave off power outages. With the drought continuing unabated and reservoirs declining daily due to evaporation, Taipower is facing an inexorable loss of capacity.

Taipower’s 800MW unit 3 at the Linkou coal-fired Power Station is also down for maintenance, along with coal-fired IPP Mailiao unit 3.

Yeh Tsung-Kuang, National Tsing-Hua University Professor of Nuclear Engineering and Science, disclosed in an interview that the Atomic Energy Council has approved the restart of Maanshan NPP3 unit 1 nine days earlier than scheduled. The unit is currently down for annual maintenance but is being returned to service early to compensate for the energy shortfalls. Kuosheng NPP2 unit 1 will be shut down permanently by the end of May, a consequence of the intransigence over Taiwan’s nuclear spent fuel storage.

With little hope for any offshore wind capacity coming online before the end of the summer peak, solar’s obvious temporal limitations, and LNG importation facilities at full capacity, it looks like Taiwan will be increasingly dependent on coal to power its economy.

What this means for Taiwan’s efforts to reduce its carbon footprint will be examined in a later post.

It’s going to be a smoggy summer in Taichung this year.

Taipower Data hint at causes of power outage

In the wake of the power outage yesterday, it’s worth looking at Taipower’s supply data for hints as to possible contributing factors.

The cause of the outage was a tripped busbar, or human error, or a surge in demand that exceeded capacity… the news seems to be all over the place. The sudden loss of 2 gigawatts — GW (2,000 megawatts –MW) at 2pm during peak demand tripped out the entire grid, resulting in the rolling blackouts experienced yesterday. Engineers working in the energy sector have told me that only the loss of 4GW or more would take down the entire grid. This raises suspicions that reserves were already dangerously low before the outage. The fact that Taipower’s website went dark in the aftermath of the outage, no doubt caused by a surge in traffic, didn’t help allay suspicions.

Possible contributing factors include:

  • Maanshan Nuclear Power Plant 3 unit 1 is down for maintenance, bringing the current contribution  by nuclear to less than 9%.
  • Hydro is less than 1%.
  • Diesel generators at Kuosheng NPP2 and Maanshan NPP3 are running at full steam – those are intended as backup power in the event of a reactor outage, not for meeting demand at 10:30 at night.

With Maanshan unit-1 offline, and hydro and pumped storage out of commission, that raises questions as to what the reserve margins really were just prior to the shutdown.

Meanwhile, coal, including Taipower-owned, IPP, and cogen, is at 41.24%, and LNG, including both Taipower and IPP, is at over 47%. Taipower is running most of these units at over 90% capacity – really high for gas, and I wonder how many days LNG supply that leaves us with.

Kuosheng NPP unit-1 will shut down permanently soon — probably in the next few weeks. I assume they are doing their best to at least keep it running until Maanshan unit 1 is back in operation. Kuosheng is scheduled to be retired at the end of this year, but with its spent fuel storage pools fully saturated, the reactor cannot be refueled and will be shut down early. Everyone I talked with in the power sector is surprised they have managed to keep it running for as long as they have.

Taiwan looks set for another interesting summer in power~

Japan in Hot Water Over Nuclear Wastewater

Region greets Japan’s plans to dump nuclear wastewater with skepticism

Japan’s TEPCO promises that its ALPS process will purify Fukushima wastewaterhttps://www.tepco.co.jp/en/decommision/planaction/images/disposal_05.jpg
  • Japanese power company TEPCO announced plans to dump 1.25 million tons of wastewater used as coolant for the ruined Fukushima Daiichi nuclear power plant.
  • TEPCO says that it has filtered all the radioactive isotopes from the water except for relatively harmless tritium.
  • Critics say that TEPCO is untrustworthy and cannot be relied on to effectively clean up the water.
  • Taiwan is seeking to join the international effort to monitor TEPCO’s efforts.

Ten years on the shadow of the Fukushima disaster still looms large over the region and the global nuclear sector. Although caused by the March 11, 2011 Tohoku earthquake and tsunami, a Japanese government inquiry concluded that the disaster was “profoundly manmade,” the result of “a multitude of errors and willful negligence that left the Fukushima plant unprepared for the events.” Now the company that owns and operates the plant, Tokyo Electric Power Company Holdings (TEPCO), has announced its plans to release some 1.25 million tons of contaminated seawater used to cool the melted reactor cores directly into the ocean. TEPCO says that the 62 of 63 radioactive isotopes have been removed from the water, including dangerous and long-lasting strontium 90, cesium 137 and 134, and cobalt 168.  The remaining isotope, tritium, cannot be filtered from the water but is largely benign, with little impact on human health or the environment.

The plan, which has obtained approval by the Japanese government and at least tacit support of the United Nations International Atomic Energy Agency (IAEA), was announced on April 12 and was instantly met with outrage within Japan and the surrounding countries. China condemned the move while South Korea called for further investigation. The issue has become political fodder in Taiwan, with critics accusing the government of sacrificing human values for closer ties to Japan. Environmentalists and fishing associations in Japan and the surrounding region condemn the move, claiming it will ruin Fukushima’s natural environment and its beleaguered agriculture and fisheries sector.

The plan is scientifically valid, however, according to scientists.  An IAEA statement notes that sea-disposal of the wastewater is “both technically feasible and in line with international practice.” adding that controlled water discharges into the sea are routinely used by other nuclear power plants.

TEPCO is using an extensive processing and filtration system known as ALPS (Advanced Liquid Processing System) that both cools the remaining residual heat at the melted cores of units 1,2, and 3 at Fukushima Daiichi, but also filters out most of the radioactive elements.  According to National Tsing-Hua University professor of nuclear engineering and science Yeh Tsung-Kuang, the ALPS system is quite effective in filtering out radioactive isotopes, and the remaining isotope, tritium, which forms from water molecules in a nuclear reaction, emits beta radiation that can easily be shielded by human skin, and only presents even a minimal hazard when ingested.

“It’s very low energy, and for it to present a health risk you would need to drink the amount of water equal or greater to your body weight all at once,” he said in an interview on April 20.

According to TEPCO, the wastewater will be diluted to 1500 becquerels (Bq) per liter, https://www.nrc.gov/reading-rm/basic-ref/glossary/becquerel-bq.html per liter, one seventh the limit set by the WHO of 10,000Bq per liter.

 But Yeh even offers a caveat: “there is no third-party verification of the process or results” and that obtaining the trust of the public will be difficult.

“TEPCO has consistently lied about nuclear safety and downplayed the Fukushima disaster,” wrote Jeff Kingston, Director of Asian Studies at Temple University Japan and a frequent critic of TEPCO, in an email. “As a result, it does not enjoy public confidence.”

Kingston cites numerous safety lapses in TEPCO’s nuclear power operations that the utility has tried to cover up. A recent article in the Daily Beast by acclaimed writer Jake Adelstein observed that Japan’s Nuclear Regulation Authority rejected TEPCO’s plan for restarting the Kashiwazaki-Kariwa Nuclear Power Plant in Niigata due to safety concerns and security lapses. Kingston added that TEPCO had already declared the wastewater at Fukushima safe in 2018 before backtracking and redoing the process, reinforcing public skepticism.

The issue will further tarnish the already beleaguered Fukushima brand of seafood and produce, Kingston also noted.  

“TEPCO and the government have not been effective at convincingly addressing public health concerns due to a lack of transparency,” he wrote.

TEPCO reportedly considered several other options, including evaporation, subsurface injection, burial in barrels, and gasification. All were considered either too expensive, impractical, or having an even larger global impact than sea disposal. The ocean disposal won’t begin for at least another two years.

The IAEA is forming a committee to investigate and monitor TEPCO’s efforts at filtering the water, and Taiwan is aiming to participate.

A Question of Trust

Does Taipower have the proper safety culture to manage nuclear power?

As Taiwan debates the merits of nuclear power and the prospects of reviving the Lungman Nuclear Power Plant (NPP4) project, safety is of topmost concern. Like flying an airplane, there is no room for error while operating a nuclear power plant and no second chances if something goes wrong. Trust in the system and the operator are essential.

A couple of news reports released last week, however, raise questions over the safety culture of nuclear operator, Taiwan Power Company.

On April 8, a United Daily News (UDN) headline trumpeted a major incident at the decommissioned Chinshan NPP1. According to the report, a critical seawater (ESW-A) pipeline was ruptured by contractors working at the site on December 21 last year, creating the risk of catastrophic fire and radiation plume.

ESW pipelines bring seawater to the plant to absorb heat generated by the decaying spent fuel in Chinshan’s twin cooling pools and transferring it out to sea.  Without this cooling system, water in the cooling pools would gradually heat up until it boiled off. Exposed fuel could then ignite and cause an explosion and cataclysmic release of radioactivity, as is suspected to have happened during the Fukushima disaster in 2011.

That same day, April 8, more bad news broke for Taipower as a worker was struck by a falling pipe at the Maanshan NPP3 in Pingtung and needed to be treated at hospital.

Neither of these incidents resulted in serious consequences. The AEC reports that the ESW system has two lines, and the ESW-B line continued to be operational. The ESW-A pipeline was repaired within a week and the spent fuel was never in any danger. Meanwhile, the injured Maanshan worker was back on the job the next day.  

Spent fuel pool, courtesy of United States NRC

Yet both point to worrying lapses in safety awareness and judgement. While the AEC considered the damaged pipeline at Chinshan a minor event, the fact that it was revealed only months later and through a whistleblower raises questions of transparency at Taipower and the AEC.

More pressingly, how could such an incident have happened at all? National Tsing-Hua University Professor of Nuclear Engineering and Science Yeh Tsung-kuang, speaking on his own behalf but based on his extensive familiarity with the plant and its operations, said that the contractor at Chinshan deployed all the necessary geotechnical tools, including site maps and ground penetrating sonar. Groundwater literally muddied the findings and obscured the presence of the pipeline, however. Regarding the Maanshan injury, the AEC chided Taipower to maintain a safe working environment for all crewmembers, while stating the incident did not affect other crew members.

Neither incident would have made it on the 7-level International Nuclear and Radiological Event Scale (INES), created by the International Atomic Energy Agency to evaluate the consequences of a nuclear incident. The partial meltdown at Three-Mile Island in 1979 rated a 5, while both Chernobyl and Fukushima earned the top level, 7, a major release of radiation with widespread and long-lasting consequences. According to INES, an incident at a spent fuel cooling in which redundant systems were in place and the temperature in the cooling pools was unaffected is considered Level 0 — Below Scale. Industrial accidents such as at Maanshan are not covered by INES.

Still, Taiwan has a history of poor safety awareness, and the recent railway accident is only the latest example of how a disregard for safety standards can take a horrific toll on society. A similar safety lapse at a nuclear plant would be far more devastating.

Nuclear proponents highlight Taipower’s excellent performance record. The state-utility has been lauded internationally for its safe and efficient operations of Taiwan’s nuclear fleet. Further, nuclear power plants are built to include layers of protection and safety features that are “idiot-proof,” enhancing their safe operation.

Nevertheless, if Taiwan’s nuclear proponents wish to see Taiwan to remain powered by nuclear, then Taipower must go further to reassure the public that both it’s safety systems and its safety culture are equal to the task of powering and protecting Taiwan.   These two incidents suggest that Taipower has room for improvement.

Balancing the Grid in the Renewable Age

Taiwan’s successful energy transition requires grid investment 

While the rollout of solar and offshore wind power steal headlines in Taiwan, investment and expansion into the power grid is equally vital to Taiwan’s successful energy transition. The island is planning on dramatically overhauling how it produces power, eliminating all nuclear power as well as swathes of coal-fired power while hiking renewable power from its current 6% to 20% of generation. Such dramatic shifts in energy production will require an equally substantial investment in Transmission and Distribution (T&D) network infrastructure to ensure system integrity and reliability. 

Taiwan Power Company (Taipower) operates 3.87 gigawatts (GW) of installed nuclear power capacity which generated over 12% of Taiwan’s power demand, while coal fired power generated 38% (including cogeneration) of total power in 2020, according to Taipower’s website. Taiwan’s policy of eliminating all nuclear power and reducing coal-fired power to 30% will create a substantial gap in power generation, which will be filled by a large jump in renewables as well as natural gas fired power. Taiwan is to raise installed renewable power capacity from its current 9.19GW to 27GW, including 20GW of solar and 5.7GW of offshore wind, with smaller additions of onshore wind, geothermal, and biomass. Natural gas fired power will be increased from 17.79GW to over 24GW. Taipower’s total grid was only 42GW in 2016 – by 2025, it will likely be over 60GW. 

Beyond the sheer scale of the shift is the differing functions of the power sources. Nuclear and coal operate more efficiently when running at high capacity, even over 100% of rated capacity for Taiwan’s nuclear power plants, while coal operates at over 80% capacity. Both are sources of baseload power, cheap, steady power that is always on, providing the minimum power demand that never ceases. This baseload power is going to be replaced by imported Liquified Natural Gas (LNG)-fired power, especially high efficiency Combined Cycle Natural Gas Turbines (CCGT), but also by intermittent solar and wind power. When Taiwan meets its solar and offshore wind goals, these will be significant sources of power, capable of generating huge amounts of power when conditions are good but dropping off entirely when conditions fail. Maintaining baseload power while integrating huge volumes of intermittent renewables will be a major challenge for Taipower. 

“The issue with renewable energy is basically that it’s unpredictable,” says Johannes Krause, technical manager at German energy firm EnBW Asia-Pacific Ltd. and a grid expert. “From a grid point of view, you always favour reliable, predictable baseload capable power generation because the more insecurity you have in the generation produces more stress in the grid.”

For power grids to remain operational, supply and demand must always be balanced in real time, and any variation risks causing serious disruptions. Electricity is transported through the grid at specific frequencies, 60 Hertz in Taiwan and the United States, and 50 Hertz in Europe. Too much electricity fed into the grid exceeding demand will raise the frequency and cause power plants to break off from the grid. If there’s too little power fed into the grid, then frequency will decline, forcing either the ramping up of additional power units or disconnecting consumers from the grid. The result in either case could be massive blackouts.  

Krause explains that large volumes of renewables in an energy grid heighten the risk of grid imbalance. If renewable power fails to generate sufficient power to meet demand and other sources must be tapped, or it generates too much and exceeds demand, both can lead to grid congestion, with too much power flowing through too few lines. Overloaded lines must be shut down, resulting in power generators losing access to their respective consumers, which could lead to further overhead lines shutting off, potentially leading to a general collapse of the system. “It’s like avalanche,” Krause says. 

The impact of 20GW of solar power on the grid demonstrates both the promise and risk of renewables. 

In Taiwan’s hazy, rainy climate, and because no power is produced at night, solar PV generates at some 15% of capacity over the course of a year, less than in the sunny southwest of the US, where the Energy Information Agency (EIA) reports Arizona experiences solar PV capacity factors at 29%, but on par with the US east coast and much of northern Europe. 20GW of solar capacity could be expected to generate 26,280 gigawatt hours (GWh) over a year, about 7.75% of Taipower’s total 2020 generation of 238,930GWh. 

But, while solar’s overall capacity factor is not high, during the bright sunshine hours of 10am to 5pm it can generate at very high capacities, theoretically 100% if conditions are perfect. These peak hours for solar power generation coincide well with Taiwan’s peak load, during midday when industry, commerce, and air conditioners are thrumming at full power. Taiwan has 5.8GW of installed solar capacity at present, according to data from the Bureau of Energy website. In midafternoon on 16 March, this capacity generated 3,120MW hours (MWh) at its peak, 10% of the total peak demand of 31,200MWh, giving it a capacity factor of just over 50%. At 50% capacity factor at midday, 20GW of installed solar capacity could likely generate 10,000MWh, nearly a third of Taipower’s total peak demand. Taipower’s baseload generates a steady 24,000MWh of power all the time, chiefly from nuclear, coal, and LNG. Solar will be increasingly vital in helping Taipower meet peak demand. 

Yet even in sunny central or southern Taiwan, this power cannot always be relied on, and if that power doesn’t show up, Taipower must generate the needed power from alternative sources, most likely LNG peaking plants. This issue is compounded by the vagaries of weather that can cause sudden, massive changes in the amount of power being generated. 

Offshore wind power presents another challenge. Industry sources have long estimated capacity factors to exceed 50% for offshore wind. At 5.7GW of installed offshore capacity, this would enable the sector to generate 24,966GWh of power over the course of a year, some 7.3% of Taipower’s 2020 totals. Unlike solar, however, offshore wind is often generated at night when the winds across the Taiwan Strait are howling. Industry sources are confident that wind turbines can reach or even exceed 100% of capacity. If all of Taiwan’s 5.7GW of wind power was generating at full capacity, it would generate 5,700MWh, nearly 24% of Taiwan’s current total baseload often at a time of day – night – when baseload is the only power operating. Wind turbines can be slowed, but this would eat into profits on long-term PPAs (Purchasing Power Agreements). 

To handle these contingencies and ensure that the maximum amount of power that is generated is utilised, as part of the energy transition Taipower has embarked on a comprehensive multi-billion-NT-dollar revamp of its existing grid. 

According to a presentation delivered by Peter Yuinhong Liu, Director of Systems Planning at Taipower, delivered at a Global Offshore Wind Summit in 2019, Taiwan will increase its reserve margin capacity to ensure that there is always sufficient power. It is adding 24.14 gigawatts of LNG combined cycle capacity, increasing its pumped storage hydroelectricity to 2.5GW, and is installing 590 megawatts (MW) of energy storage. Along with deploying automated demand response methods to use power more efficiently, Taipower says that it will increase its total operating reserves by 5.87GW by 2025. 

Taipower is also greatly expanding grid connection capacity to allow increasing amounts of diversified renewable access to the grid. The Changhua area alone will see its grid connection capacity increased by 6.5GW. A series of substations linked to power cables connected to the offshore wind farms will be added, including 1GW at ChangoneA, in 2021, followed by 1.5GW,ChangoneB, in 2024, a further 2GW in Changgong in 2025, and then 2GW at Youngxing, also in 2025. A further 0.64GW will be added in Taoyuan by 2025. 

While most of Taiwan’s solar and wind power is being generated in central and southern Taiwan, the demand center continues to be northern Taiwan, accounting for 39% of demand. Northern Taiwan accounts for only 34% of supply, and much of that in nuclear and coal that will be phased out, leading to even greater regional imbalances.  

To carry that power from its source to northern Taiwan, Taipower is upgrading its 345kV Extra High Voltage (EHV) lines and adding new 161kV New Lines. Taipower is also installing “smart grid” tools and processes that generate volumes of data that can be crunched in Big Data software to enable Taipower to more accurately predict both supply and demand. 

Projects are already well-underway, and while the offshore wind sector struggles to find qualified local suppliers, Taiwan’s many electronics and Engineering, Procurement & Construction (EPC) firms are already on the job. 

Local EPC firm Pacific Constructors Ltd. (PECL) is involved in handling many of the engineering, design, and EPC services for offshore wind farm lines that will lead into the Changone 1 substation project. Electronics firm TECO and Taiwan’s largest EPC firm CTCI are also involved in building up the grid to ensure offshore wind connection capacity.