if it's a serious committment to being carbon-free, i think this sounds like a positive change. if it's a moonshot that they have no real intention of actually meeting, then it's a lot less impressive. i guess we'll see...
Not necessarily. In the UK the market for zero-emission electricity is separated from the actual electricity itself. So you basically sell the "greenness" of the electricity separately from the electricity itself. Customers who want green electricity buy the electricity, and buy some "greenness" (called a REGO).
It does make sense, and a lot of people claim it's some kind of scam when it really isn't... But it does make the relationship between the consumption and production of green energy more complex.
For example, suppose 10% of power comes from green energy, but only 5% of people care about it remotely. The market value of a REGO is basically zero. Even if the number of people who care about green energy doubles to 10%, there's still perfect supply so the market value is still zero and it won't have any effect on green energy production. That isn't quite the case but it doesn't seem far off - I couldn't find up-to-date numbers but it seems like the market price of REGOs is on the order of £5-15/MWh, which is very low. Probably because the UK's energy mix is actually very green these days.
No idea how common this system is in other countries.
If you are connected to the grid, the power you use is effectively generated by the power plant with the highest marginal costs. That often means fossil fuels. It doesn't matter whether you are buying generic power from the grid, or if you have a contract stating that the power you use is generated by renewables or nuclear. If you disconnect from the grid, the overall demand goes down, and some of the most expensive generation capacity is no longer needed.
In the long term, if there are many customers buying explicitly carbon-free power from the grid, it may increase the construction of new carbon-free generation capacity. But that effect is difficult to quantify.
Look at those numbers. 100% still is a very ambitious goal. Currently 0 global customers are buying 24/7 carbon free power from the grid, and even getting from 0 to 1 will require a lot of boots on the ground building real infrastructure. Afterwards, getting from 1 to [everyone] is just a matter of scale.
Even the "lazy" strategy of buying up capacity from existing nuclear plants requires outbidding the existing customers (if the law allows it), and only works in regions where nuclear plants actually exist.
It was a byproduct of the EU habit to create markets and competition where they don't naturally exist. You can buy electricity from any power company, and that company can then generate it itself or buy it from the market. Once you have a market like that, it's easy to add requirements such as carbon-free power. As long as the fraction of the market buying indulgences is lower than the share of the power generation meeting the requirements, fulfilling them is essentially free.
Okay, let's ignore "most of the time" and focus on times when carbon-free power was more expensive. Were these companies actually footing the bill in that case? Because increasing the marginal funding toward clean sources when the grid is dirtiest is the whole point.
In any case, carbon-free power from the grid is mostly a legal/financial construct with limited real-world impact. When the grid is dirtiest, market prices are set by fossil fuels with high marginal costs, and clean sources get the same price without any tricks.
You don't need climate pledges when the thing you're pledging to do saves you substantial amounts of money, and we really don't need quite so much climate moralizing when now the transition to carbon free electricity seems obvious, inevitable, and imminent because of direct immediate cost.
Now the question is just how can we accelerate this a little without creating false economies or distorting the market too much, just a small incentive here and penalty there along with funding for big projects to make them happen earlier.
That's precisely why a 24/7 goal matters. Energy is already cheap and clean for a large portion of the day, but covering the rest of the day will require significant investment.
There are a few residential utilities in Australia which give users free electricity for 3 hours a day to encourage users to divert their usage to that period.
Widespread solar deployment significantly changes the electricity market. Further deployment is going to push fossil plants to charge higher rates when they're needed to the point where supply outstrips demand and it becomes cheaper to shut down a plant which will further increase overnight prices.
If I emit 5g of CO2 but purchase similar in offsets - the offsets have to achieve a reduction of 5g unless something like a scam is going on.
the classic example is landowners selling offsets for the mature forests on their land - that's good! and incentivising the preservation of forests is good! but that forest already existed, and has existed for hundreds of years, so does it really make sense that some company can count it against their carbon emissions and claim to be "net zero" just because they paid a landowner to not cut it down?
it makes the whole concept of offsets less of an overall pure good than emitters simply not emitting carbon in the first place, because that is actually a very simple and clear calculation.
Sometimes, the carbon offsets are from projects that would be built anyway, and there is a lot of sketchiness all around.
It might be better than nothing or it might empower companies to pollute more and then say, "Look, we are offsetting all this!"
If you buy a 1 GWh block of wind/solar energy for a month, you're not doing anything to supply clean energy when it's dark and the wind isn't blowing.
"24/7 carbon free" means increasing the time resolution from 1 month to 1 hour, and funding projects that deliver clean energy when you're actually using it. This includes stuff like batteries, nuclear, and geothermal.