According to the post, the whole system costs half a million pounds, but perhaps it forgot to mention how long the system can last. If it can be used long enoug

According to the post, the whole system costs half a million pounds, but perhaps it forgot to mention how long the system can last. If it can be used long enough, that it wouldn't matter how expensive it is to build, it will be the most environmentally friendly product in the world, like subways.