No storage is cheap enough to store solar and wind energy on day-to-day scale, let alone seasonally.

Please don't let the brainwashing gets to you and inform yourself.

The actual power from your outlet is going to be the same no matter which company you buy from, but it's still buying "green power" in a more meaningful way than a zero-sum relabeling.

Since this thread is about Germany, and not everyone on HN reads threads in scope, it's worth pointing out that this is not universal.

In most of Texas, for example, the wind blows most fiercely — and regularly — at night. Solar power contributes to the grid during the day, and wind power picks up that generation loss when the sun goes down. I once saw a graph of it from a utility regulator published in a newspaper.

Not every geography is so lucky in this manner. But because this is the global internet, it's important to point out that solar and wind aren't exclusively daytime sources on most of the planet.

What Germany needs is a source of wind that works at night. I've read that Spain imports energy from North Africa. Perhaps a more robust link in that direction is the solution.

that is bullshit. also besides that germany is small compared to other countries and dense, there is no time of the day where its nowhere windy nor sunny. so at the moment there is just no need to purchase green energy certificates for the bigger providers, they can either buy power from other providers or they can produce their green power. and also it does not matter, since if you need 3kW and they can't deliver green power at the moment they will deliver more green power later, thats how it usually works.

> No storage is cheap enough to store solar and wind energy on day-to-day scale, let alone seasonally.

also bullshit. it has nothing to do with cost, more with there is no storage for everybody.

most providers that offer 100% green power actually do generate the amount of power in green that you use (that is their premise) of course they can't create different power lines, thus it's a mix.

(in germany it's forbidden to mark your product as "100% green power" if you buy certificates, of course you can write it some where but if your contract states it, it would be illegal, but there is a difference between contract and marketing, of course... Energiewirtschaftsgesetz - EnWG §42)

In a lot of countries customers are billed significantly less during the night than during the day for electricity, so the incentives already exist to make it financially worthwhile if a home battery pack that can provide a days typical use can be installed at a reasonable cost.

This would substantially smooth out base load requirements and mean that renewables could make up substantially more of the energy mix.

Can you explain why, please? I'm genuinely interested. I don't understand how this would be anything other than rich prepper niche market.

Installing batteries in all homes is going to be more expensive than grid storage, since you will need to pay more in total installation costs rather than installing ginormous grid batteries (or reversible dams, where feasible) in bulk.

At scale the costs could come down quite substantially given that the basic chemistry is iron, salt, water and little else - at which point it's a substantial financial boon to the customer given that they could see an up to 50% reduction in their energy costs (going by tariffs in my own region) to compensate.

The net effect would be the same but might be cheaper overall.

This is what I think the real benefit is, and also why I think we'll see both. I don't see the political will or financial commitment materialising for large scale energy storage in the short term because it's an upfront cost to a taxpayer whichever way you slice it.

Individuals are free to self-fund their own battery pack installations though, and can then decide if the upfront cost is worth the reduction in rates to shift energy usage to non-peak times. Once that sufficiently takes off it becomes easier to sell the public at large on the idea, and will also drive down costs, at which point I could see wide-scale grid storage becoming thing. At that point, renewables are scalable to almost 100% of energy usage (assuming vehicles and industry transition away from combustion machinery).

Iron flow sounds great though. Thanks for mentioning, I'll look into it.

On the other hand, if there is no government mandate, or if customer demand for renewable energy exceeds that mandate, then it provides a profit incentive for the utility to install/purchase more renewable energy.

They stopped, publicly reasoning that the proceeds from selling certs could be used to build their own additional renewable generation. I suspect it was just leaving too much money on the table, though.

Of course, even a 100% renewable supplier needs to buy from the market to smooth out peaks in energy consumption for their customer base.

(disclaimer: i work for such a renewable energy supplier)