Large scale particle accelerators eat a fair amount of electricity, and the ILC will be no exception, reaching 164 MW at peak power and consuming one billion kWh per year. While these needs pose no problem for Tohoku’s electricity supply, it’s still a lot. Most of this electricity will end up as waste heat under 100 degrees Celsius and released into the surrounding environment.

These conditions are an opportunity for those working on the Green ILC, the movement to make the ILC as sustainable as possible. I sat down with Dr. Masakazu Yoshioka, emeritus professor at KEK and guest professor at Iwate University and Tohoku University, to hear more. He’s been working to supply electricity to KEK projects like TRISTAN and B Factory (TRISTAN II) for about 20 years, all the while considering how to make these facilities more sustainable. Now, along with other researchers, groups like AAA, universities including Tohoku University, local government and businesses, Dr. Yoshioka is working for a future where the ILC not only uncovers new truths about our universe but acts as a resource for its community and a reference for society.

A Green ILC can be separated into components including:
• Designing an ILC that gets the maximum results out of electricity,
• Making the parts of the ILC efficient as possible,
• Using sustainable energy sources to power the ILC, and
• Storing and utilizing waste heat,

but in this article, we’ll focus on that last component.

Japan makes a lot of waste heat already—from factories, garbage facilities, unused heat from hot springs and geothermic energy plants and more— and with the exception of the occasional swimming pool, much of this is released into the air unused. This is a shame, because this heat could be put to use: in agricultural hothouses, to dry timber and woodchips, to heat buildings, and to raise marine products.

Enter HAS-Clay. HAS-Clay is a material originally developed by AIST (National Institute of Advanced Industrial Science and Technology) and that can store 580 MJ in 1 cubic meter. You need 13 cubic meters of natural gas to produce that much energy.

Dr. Yoshioka talks about the Green ILC

What Professor Yoshioka and others are proposing is a heat supply system encompassing the entire prefecture: use HAS-Clay to store waste heat from sources within Iwate including the ILC, and distribute that heat to facilities that can use it. Replacing the electricity consumed for heating in these facilities with waste heat would reduce CO2 production and costs for industries struggling to stay profitable like agriculture. It would also provide another potent answer to the question many local people will have: how does the ILC directly benefit my life?

The heat supply system still has some technical and logistical obstacles to overcome, but it’s developing actively and rapidly. Two papers on this subject—one focused on HAS-Clay and one on the proposed system itself—were just published in August for the Particle Accelerator Society of Japan’s annual meeting.

A picture with Dr. Yoshioka at Aiina (where LCWS 2016 was held)

The proposed heat supply system is part of a larger picture of an environmentally friendlier, innovative ILC. Dr. Yoshioka relates the ILC could run 100% from renewable electric energy, thanks to Tohoku’s generous renewable electric power capacity (19% of its total supply). Also expected to be part of the ILC’s legacy are using local wood for ILC campus buildings and a system of self-driving cars. As Professor Yoshioka pointed out, “We don’t need for the ILC to be finished to act.” The ILC is already changing Tohoku, right now.