Sequestration only is possible if the concentration of CO2 is high enough, like on the exhaust of a coal fired power station. So where is the extra energy coming from to drive the process? Not from renewables as there is insufficient to meet the needs of decommissioning. More fossils have to be burnt paid for by the tax payer, Sequestration is pretty much a smokescreen to.avoid transition from fossil fuels.

But if CCS operations leak, they can pose significant risks to water resources. That’s because pressurized CO2 stored underground can escape or propel brine trapped in the saline reservoirs typically used for permanent storage. The leaks can lead to heavy metal contamination and potentially lower pH levels, all of which can make drinking water undrinkable.

Can someone explain this to me in a easy way?

As a layman I would be worried of large amounts of CO² suddenly leaking near where people live. But how does it make water undrinkable? I thought some people like their drinks with CO². And where do the heavy metals come from?

The leaks can lead to heavy metal contamination and potentially lower pH levels, all of which can make drinking water undrinkable

Brine contamination, I know very little about, but if it stayed near bottom of lake, may not pose a fish or water source risk. Salt may dilute to rest of water, but heavy metals would not? Water becoming Perrier, or otherwise high co2 levels, may affect fish, if they don’t move, but not a human drinking hazard.

What I do know about is CCS projects. The most successful CO2 capture project from a 100mw coal turbine cost $1B, and captured 65% of CO2. In Saskatchewan. These costs ($10/watt above the fossil plant) are comparable to power costs of on budget nuclear (not a cost/time effective climate solution). The CC process involves a giant building that replaces a chimney, and passes the flue through a liquid that will capture the CO2. Coal interests are avoiding all CCS projects because they are completely uneconomical. Other FF electricity use a similar process, though coal emits H2S (acid rain and smog problem) that needs to also be captured. Blue H2, has a problem of while the process gasses can be separated, the heat needed from the process is usually NG powered, and needs a chimney like electricity production.

A far cheaper way of reducing coal or other FF emissions by 65%, is to replace them with solar+4 hours batteries, and keep the FF plants as a backup peaker that will run far less than 35% of the year. Because land around a coal plant is extremely undesirable for any other purpose, it is often sufficient to produce the same energy as the coal plant from solar.