"Green Electricity" Scam
I don't know if this is a trend in other countries, but in Slovakia there begun this heavily advertised trend in selling "green" electricity to household consumers. The way it's presented, that by paying an extra fee on top of your monthly bill (usually just a couple euros), they will make sure you only get electricity that came from renewable sources instead of the dirty ones; reducing your carbon footprint and helping to develop renewable energy in your country. And while on surface this might seem like a nobrainer for any environmentally conscious individual, you should really understand what such a deal actually means.
First you should understand, that there is no way anyone can ensure that your specific electricity came from any concrete source. That's not how it works. Once the electricity is put into grid they can't really control where it's consumed. Also there isn't separate grids for clean and dirty electricity, pretty much everywhere there's only one electrical grid. It wouldn't really make sense to have multiple parallel networks to every house.
They way it works that you consume some amount of energy from the grid, you pay some money to your provider, and with that money they'll 1) pay power plants to put the same amount of energy back into the grid and 2) pay for maintaining and developing the grid infrastructure.
So you might think, okay, so the extra money I pay them is so they can afford to buy the more expensive energy from renewable sources to offset my consumption. And that would be true if 1) they weren't already doing that and 2) they had any say in the matter.
The thing about energy production is that you can't really store it. You have to make it when it's needed. (There's a tiny bit of storage capacity in the system but that's mostly used to deal with unexpected spikes).
The problem with renewable energy is that you get what you get. Solar panel will produce more energy when it's sunny, wind turbine when it's windy, river dam when it's rainy etc. The power plant company doesn't really regulate how much energy it makes, other than continuing to build more power plants. And they will always sell all the energy they make. It makes no sense for them not to sell it, since they can't store it for later. If there's low demand they'll sell for less, if there's high demand they'll sell for more. They're not in position to negotiate prices based on how clean the energy is, they have to sell it.
The same is true for nuclear energy, while it's not considered renewable, the company is in the same position. When they start the fission they can't really stop it. They can slow down a bit, but they also always sell all the energy they make.
The only players in the game who get to decide when to make energy, and as such negotiate the prices are the dirty guys. Coal, gas, oil etc. If the demand is low, they'll just extinguish the fire. Basically when all the renewable and nuclear energy is used up and there's still more demand, that's when they start burning and making big profits.
As you can see, there's nothing your provider can really do about where they get the electricity from. Unless they can control the weather.
There are two ways you can think about the energy you use up. Let's say 25 % of the energy production in you country comes from renewable sources (which is roughly true for Slovakia). You could say that 25 % of the electricity you used was clean and 75 % dirty. You could also convince yourself that 100 % of your electricity was in fact clean, because the dirty went to other people. Or you could pay extra for your provider to send you a PDF that says so. It doesn't make a difference. It doesn't change the proportions of production.
But I hear you say, "What if everyone else got the service, then they would have to make sure that all of the energy is renewable! They would have to, idk, build more renewable power plants, right?" No. This service targets specifically households, and quite a low portion of them at that. And households only make up on average less than around 20 % of all energy usage. Most of the energy actually gets used by big industrial consumers, transportation and businesses. And they don't care where their energy comes from. Not that these offers even apply to them.
Even if literally everybody paid for these stupid green energy certificates, the providers wouldn't have to do shit about the state of renewable energy and they would still technically hold up their end of the bargain. It's just a way for them to exploit environmentally conscious people without having to do anything.
Only question is what exactly they do with the extra money they collect, and I have yet to find a company that would disclose that information. At most they say something vague like "we will help develop renewable energy production" which could mean anything from building big farm of wind turbines to sticking a solar panel on the roof of their office. Only thing they really promise is that you get a PDF saying you only used green energy. An maybe some stickers.