The Listener this week has an article highlighting a recent paper which argues that carbon capture and sequestration (CCS) is an inappropriate technology for New Zealand. Unfortunately, the Listener doesn't make its content available online - but the paper it is talking about is here [PDF]. The short version is that even if we are the fastest follower on the block, CCS is unlikely to be available before 2030, making it useless in meeting an interim 2020 emissions reduction target. In the longer term, CCS could be fitted to Huntly - or rather, its successor - which would make a substantial dent in our annual emissions. But there would be a substantial energy penalty (~5% - 20% assuming a modern plant) in doing so - and that's only considering the capture and compression, without transport and storage (which is site specific). This won't outweigh the benefits, but it will mean having to mine a lot more coal for the same net amount of electricity. Given this, the authors question whether money spent on CCS research is a good use of resources, given that it can't possibly help us until it is too late.
So far, so good. But then they suggest an alternative that that research money should be spent on: woody biomass. As in burning trees for electricity. The technology is mature - they do it in Scandinavia apparently - and wood gasification is pretty efficient. They go on:
A recent study has indicated that realistic areas of 2.5-2.7 million ha are available for planting without competing with food crops (Hall and Gifford, 2007). We estimate that a plantation of about 434,000 hectares (using marginal farmland) could produce the same amount of electrical output as the Huntly power plant in 2006, at arguably less risk (financially and environmentally) and with a greater chance of public acceptance.To put that number in context, we currently have about 1.8 million hectares of production forest, so we're looking at a roughly 25% increase. 434,000 hectares is 4,340 square kilometres - or about 1.6% of the total landmass of New Zealand. It's about two and a half times the area of Stuart Island. For one power plant.
Or, we could build a couple of windfarms...
