2016年6月12日 星期日

減碳承諾充滿疑問---美商的觀察(2)


本篇為美國商會今年白皮書對能源政策的另一重要建言。上篇及本篇文章都提供中英對照,大家可參考原汁原味的建言。

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

二、製定同時考量減碳承諾及穩定供電並確實可行的能源政策

如同世界其他國家,台灣也在去年12月宣布了“國家自願減碳目標”(INDC)。台灣承諾在2030年及2050年將碳排較2005年分別降低20%50%

台灣碳排一半以上來自發電。發電主要有三種方式:火力(燃煤、燃氣)、核能及再生能源。火力發電會排碳,核能與再生能源沒有碳排。台灣目前發電量中火力佔比78%、核能佔比17%、再生能源佔比5%。如果要達到“自願減碳目標”,台灣必需大量減少火力發電而大量增加無碳發電方式。然而因為政府的“非核家園”政策,台灣未來顯然不會再增加核能發電,而核電目前每年提供400億度電。目前不但核四已遭封存,政府並決定在2025年前將現有核電全數除役。問題在於再生能源能否提供400億度電,即使可能,也不過維持目前碳排而無法將碳排降低20%

在台灣發展再生能源面臨兩項技術限制。首先,台灣為獨立電網,未與鄰國接網,不論風力或太陽能都端賴天候條件方能發電,所以不穩定的再生能源佔比不能太高以確保電網穩定。第二個限制是容量因數,也就是可發電時數。火力及核能每年都有80%以上的時間可以發電,但太陽能及風力則分別只有15%30%的時間可以發電。因為有以上兩項限制,再生能源是否能取代400億度核電頗有疑問。

另外要考量的是電力需求成長。即使每年電力需求成長低於2%,到2030年每年電力需求將增加600億度。如果這些成長度數全部由火力發電提供,是否可達成“自願減碳目標”更有疑問。即使現有核電全數延役、核四啟封商轉,台灣仍然無法達到其減碳承諾。

台灣不可輕忽“國家自願減碳承諾”的重要,政府更不能忽視確保電力供電的重責大任。我們強力期望政府提出同時考量減碳承諾及穩定供電並確實可行的能源政策。


Suggestion 2: Set a realistic energy plan that considers both energy demand and carbon-emission reduction goals.


Last December, Taiwan joined other members of the international community in announcing Intended Nationally Determined Contributions (INDC) for reductions in carbon emissions. Taiwan committed to cutting the level of carbon emissions by 20% by 2030 and 50% by 2050, compared to a base line of 2005 emissions. The path to meeting that commitment remains unclear.

More than half of Taiwan’s carbon emissions come from power generation. There are three types of power plants: fossil fuel (basically coal or gas), nuclear, and renewable. Fossil-fuel power plants produce carbon emissions, while nuclear and renewable power facilities are carbon-free. Currently 78% of Taiwan’s power demand is met by fossil-fuel plants, 17% by nuclear, and 5% by renewable sources. To meet the INDC commitment, Taiwan would have to greatly reduce its reliance on fossil fuels power and greatly increase its capacity for power generation from other energy sources.

However, the government’s adoption of a “Nuclear Free Homeland” policy would seem to rule out any increase in the use of nuclear power, which currently contributes 40 billion kWh of electrical energy annually. Besides mothballing the uncompleted fourth nuclear power plant, the government’s intention is to retire the existing three nuclear plants by 2025. That raises the question of whether it is possible to generate an additional 40 billion kWh of energy from renewable energy sources. But even if that can be done, it would merely keep carbon emissions at the current level rather than achieving the proposed 20% reduction.

Two major technical issues confront renewable power development in Taiwan. First, Taiwan’s power grid is isolated, not interconnected with those of any neighboring countries. As the availability of both wind and solar power varies with weather conditions and time of day, the proportion of wind and solar power in the total installed capacity must be kept limited in order to ensure the stability of the power grid. The second issue is capacity factor – how much power is actually generated over a period of time compared to the maximum designed output. The capacity factor for fossil and nuclear power can be higher than 80%, but it is just 15% for solar and 30% for wind power. Due to these technical constraints, it is questionable whether renewable energy could fill the 40 billion kWh gap that would be created if all nuclear power plants are retired.

Another factor to be considered is growth in power demand. Even if only very modest (<2%) annual power growth occurs, the increased demand by 2030 will come to more than 60 billion kWh. If most of this demand must be met by fossil power, fulfilling the INDC commitment becomes even more problematic. Even with life extensions of the existing nuclear power plants and operation of the fourth plant, Taiwan would still fall short of its carbon reduction goals.

INDC commitments cannot be taken lightly. Neither can the government’s responsibility to ensure an adequate energy supply. We urge the government to come up with a realistic energy plan that gives proper consideration to both carbon-reduction goals and national energy demand.

沒有留言:

張貼留言