The Romance of Renewables
An energy-themed roundup of infrastructure news from around the world
In the magical Swiss Alps, where snowy mountains meet sparkly blue water, a massive underwater battery, tucked beneath the snowcapped expanse, is working to stabilize Europe’s renewable energy grid. The battery is called Nant de Drance and sits in what translates from French as a “cave of machines.”
The cave is situated between two reservoirs, one lower and one higher. When the power is abundant, several pumps move water from the lower reservoir into the higher one. When the grid runs low, water plunges from the higher reservoir, spins through the six great turbines of the Nant de Drance, and falls into the lower reservoir. The energy produced shoots out of the battery to the grid.
But in addition to generating electricity, it also stores it. When demand is low and there is too much energy produced, the water is once again pumped back up to the higher reservoir for later use. The battery’s storage capacity could power 400,000 electric car batteries.
“With the flick of a switch, the plant can go from storing energy to providing electricity,” Robert Gleitz, a delegate of one of the board of directors for the project told CNN.
This is no Double-A. The battery requires an extensive infrastructure — 17 kilometers (10.5 miles) of subterranean tunnels were dug through the Alps and the battery sits 600 meters (1,970 feet) below ground. The whole plant is the size of two football fields. The reservoirs hold more water than 6,500 Olympic-sized swimming pools, and the water cascading from the higher reservoir passes through a steel pipe that’s taller than the Eiffel Tower.
Hydropower is often criticized for the ecological harm it can have. Many hydropower plants are built on river systems and require dams, which mean disaster for local biodiversity. But this one, which is limited to these two reservoirs, doesn’t interact with the natural rivers or wildlife. Andrew Blakers, who is quoted in CNN’s article about the plant, said that this is a signal that “the era of dam building is nearly over.”
A few years ago Singapore realized it needed more space and Australia realized it need more consumers. This is a love story between a tiny economic powerhouse and a vast expanse of countryside. Don’t worry, the relationship looks promising.
The two countries have decided to build a 4,200 kilometer-long cable (2,671 miles) under the sea, which will transport renewable energy developed in Australia to power Singapore. Australia has ideal conditions for massive renewable energy developments: lots of land, sun, wind, and no noisy neighbors. Meanwhile, Singapore has no land and it is generating about 95% of its energy from burning natural gas. The island nation does have a market for renewable energy, however, and many Southeast Asian neighbors that are quickly electrifying will also likely become big markets for renewable energy.
Construction is set to begin in 2024.
Solar panels, despite all their potential for decarbonization, take up a lot of space. We would need to build hundreds of thousands of square kilometers of photovoltaics around the world to decarbonize, which all have to be supported by copper, silicon, and aluminum mines. Where do we put all of them?
One option is just to cover all the available land in a desert, but some atmospheric models have predicted that this might irreversibly alter local biodiversity and global airflow patterns — solar developments in the Mojave Desert have already reduced the cacti in the region. Placing them in agricultural land will impact food production. There are only so many rooftops and parking lots in the world.
Water, whether it’s oceans or reservoirs, might be the answer. “Floatovoltaics,” would be placed above or right on the water which would both offer ample space and keep them cool, increasing efficiency. Shielding the water from the sun also reduces evaporation, helping to retain water for hydropower and consumption. Hydropower reservoirs, as we know from Switzerland’s battery, are also already connected to electricity grids, which reduces the amount of new infrastructure needed.
If Brazil and Canada covered less than 10% of their reservoir surfaces with floatovoltaics, they would meet their 2050 solar-energy demands.
The power station at the Kariba Dam on the border of Zimbabwe and Zambia shut down in December due to historically low rainfall. Lake Kariba is the world’s largest dam reservoir and is the source of water for both Zimbabwe and Zambia. The lack of water late last year forced officials to suspend electricity generation. In January, water levels started improving, but its temporary failure is an important reminder of the vulnerability of hydropower.
The dam was built in the late colonial era to support agriculture and industry. It has been used since as the main electricity source for Zimbabwe, which is otherwise forced to rely on aging coal-fired power plants. The dam is old and its infrastructure is questionable, but the primary problem is declining water levels, caused by increasingly volatile episodes of El Niño-Southern Oscillation. The reservoir hasn’t been at full capacity since 2011.
Over the last two decades, Africa has become a hot spot for dam construction with investments and expertise from China, Brazil, India, and the Gulf States. Recently, that boom has stalled due to local political struggles and waning interest from investors. Without efficient water sources, neither the financial models nor electoral futures really pan out.
Can't believe Singapore is doing that! I'm interested what % the transmission losses would be on a cable that long? Why don't they just rent land in West Kalimantan or something?
@roman 11% global CO2 emissions are in steel production, and people are doing surprisingly little about it...
-one of the extremely rare few academic startups these days that actually produce anything meaningful: https://www.bostonmetal.com/
-imo their technology or something very similar will almost certainly be the next generation of steel manufacturing plants built in the next 20-30 years
-ppl aren't really talking about it, do with this knowledge what you want