In this what paper, it's mentioned that one of the reasons to use blockchain technology for the energy trading is:
Provide 3rd party liquidity.
What does "third party liquidity" mean in blockchain technology ?
In a rough sense, liquidity is the ability to convert your assets into hard cash.
In the blockchain world, liquidity refers to people willing to pay fiat so they can acquire a token.
In the energy world, there is a market for people who want to offset their carbon footprint by investing in clean energy. When Company A wants to reduce their carbon footprint but they're already using non-green energy, they can give money to a green energy Company B which will supply that energy to Company B's local grid. Company A is still using non-green energy (they can't up and destroy their local power plant), but by increasing the global supply of green energy, they're off-setting their carbon footprint by reducing the footprint elsewhere.
Based on a quick reading of this *white paper, their goal is to make a green energy token so that people can easily buy that energy without needing to set up specific deals with companies.
This project is trying to help Company B make their green energy "liquid" by converting it into a currency which Company A can easily buy without having to make a specific deal with Company B.