10秒後に新サイトが表示されます。
2020年9月29日より「Dont't Go Back to The 石炭!」のコンテンツは、「Japan Beyond Coal」に移行しました。URL:beyond-coal.jp

Don’t go back to the 石炭〜石炭火力発電に反対 |石炭発電|石炭火力発電|反原発

東電、福島で新規建設予定の石炭発電所のCO2排出への配慮は省略!? ~環境配慮書を公開、意見募集中~TEPCO’s new coal power plants in Fukushima set to be built, CO2 emissions not considered in impact statement

東京電力が、2020年から運転開始予定の2基の新規石炭火力発電所の環境配慮書を5月16日に公開し、6月16日(必着)までの1か月間、意見募集を行っている。一か所は、福島県いわき市に建設予定の50万kWの勿来(なこそ)発電所、もう1か所は福島県双葉郡に建設予定の50万kWの広野発電所。いずれも、IGCC(石炭ガス化複合発電)を採用した最高効率な発電所だという。IGCCについては、常磐常陸共同火力10号機(25万kW)が、日本第1号として2013年4月から運転開始をしているが、50万kWという規模は初めてであることから、今回の2基は「実証計画」と位置付けられ、入札対象から外れ、福島復興予算も入っている。

それぞれの「福島復興大型石炭ガス化複合発電設備の実証計画 計画段階環境配慮書」をひもとくと、驚くことに、CO2に関してはほとんど記載がない。なぜなら、最新鋭のIGCCを採用するから、従来方式(汽力)に比べ「発電電力量当たりの二酸化炭素排出量を15%程度低減」し、CO2については「重大な影響を回避・低減することが可能」だから「配慮事項として選定しない」(第4.1-3表(2))のだという。2020年か30~40年運転し、排出し続けるCO2は検討しないということらしい。

IGCCの48%の熱効率は、確かに現状の石炭汽力発電(USCでも)の熱効率42%より高いが、それでもCO2排出の原単位としては約700g-CO2/kWhと思われる。他の燃料種と比較すると大量に放出する。例えば、東電の川崎火力発電所(燃料:LNG、2009年稼働の1号系列)の熱効率は58.6%でありCO2排出量は、350g-CO2/kWhを切るほどで、どのような高効率化したにせよも、石炭のCO2排出は比較にならないほど膨大だ。そして当然「新設」だから、追加的な排出だ。これを検討しない、ということは、問題認識として問題だ。

東京電力管内では、原発停止によるCO2排出増加が強調されるが、2003年12月運転開始の常陸那珂・石炭火力1号機(100万kW)、2004年7月運転開始の広野・石炭火力5号機(60万kW)がCO2排出を増やすことに寄与している影響も大きいと考えられる。短期の経済合理性を追求するばかりで、「安い」燃料の石炭を優先的に使用していく方針では、東電管内のCO2排出量は改善するはずがないしようもない。アセスメントのプロセスでは、CO2排出影響についてもきちんと評価することが必要だろう。

出典:

「福島復興大型石炭ガス化複合発電設備の実証計画(広野)計画段階環境配慮書の公表について」2014.5.16
http://www.tepco.co.jp/csr/hirono/assessment/index-j.html

「福島復興大型石炭ガス化複合発電設備の実証計画(勿来)計画段階環境配慮書の公表について」2014.5.16
http://www.tepco.co.jp/csr/nakoso/index-j.html

TEPCO released its environmental impact statement on May 16th, 2014 for 2 new coal-fired power plants in Fukushima set to start operations from 2020. TEPCO will take comments concerning this statement for 1 month until June 16th. One of these is set to be built on the premises of Nakoso Power Plant (500MW) of the Joban Joint Power Company in Iwaki city and the other on the premises of the Hirono Power Plant (500MW) in Futaba district. It has been reported that both of these high-tech power plants will use IGCC (integrated gasified combined cycle). Joban Joint Power Company’s Nakoso Power Station No. 10 unit (250MW) was the first IGCC power plant to start operations in Japan when it opened in April, 2013. However, because these 2 new power plants are the first in the 500MW class, they are considered “experimental” and no bidding will take place. In addition, they are supported through the Fukushima reconstruction budget.

When you take a look through each plant’s “Planning Phase Environmental Impact Statement for Reconstruction of Fukushima: Demonstration plan for large scale coal based integrated gasification combined cycle”, it is surprising to see that CO2 is hardly mentioned. The reason is that because state of the art IGCC will be used and “CO2 emissions will be reduced by approximately 15% for each unit of power generated compared to conventional technology (steam) thereby enabling them to avoid or reduce their harmful effects”. As a result, CO2 was not chosen as one of the pollutants to consider in the statement (Table 4.1-3 (2)). In other words, it seems that the CO2 impacts for these power plants that are set to emit CO2 for 30-40 years during their lifetime from 2020 will not be assessed.

While it may be true that utilizing IGCC results in better thermal efficiency (48%) than current coal power plants (even with USC) which have a rate of 42%, CO2 emissions are said to be approximately 700g-CO2/kWh which is incredibly high compared to other fuel sources. For example, TEPCO’s Kawasaki LNG thermal power plant No. 1 series which started operations from 2009 had a thermal efficiency of 58.6% and CO2 emissions are as much as (approximately) 350g/kWh. No matter how efficient the technology, the CO2 emissions from coal power are so great that it is impossible to make comparisons. And of course because these plants are “new” constructions, these are additional emissions. The fact that TEPCO don’t consider its impact in the statement is clearly a problem.

For TEPCO, an increase in CO2 emissions due to the shutdown of nuclear power plants are emphasized greatly. However, it is also true that Hitachinaka coal-fired power plant No. 1 (1000MW) and Hirono coal-fired power plant No. 5 (600MW), which started operations in December, 2003 and July, 2004 respectively, have contributed greatly to this increase in CO2 emissions. TEPCO appears to only be considering the economic short-terms benefits of coal in that it is “cheap” thereby continuing their use of the fuel source with no intention of lowering CO2 emissions. But this cannot solve the problem of the plants’ impact on the climate. During the environmental assessment process, it is imperative that the effects of CO2 emissions be assessed properly.

Sources:

Reconstruction of Fukushima: Demonstration plan for large scale coal based integrated gasification combined cycle (Hirono), May 15th, 2014 (Japanese)
http://www.tepco.co.jp/csr/hirono/assessment/index-j.html

Reconstruction of Fukushima: Demonstration plan for large scale coal based integrated gasification combined cycle (Nakoso), May 16th, 2014 (Japanese)
http://www.tepco.co.jp/csr/nakoso/index-j.html

Press Release: Submission of the Planning Phase Environmental Impact Statement for Reconstruction of Fukushima: Demonstration Planning for Large Scale Coal Based Integrated Gasification Combined Cycle and Its Public Inspection, May 15th, 2014
http://www.tepco.co.jp/en/press/corp-com/release/2014/1236529_5892.html