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Comment by roenxi | Hacker News Reader

> When there’s enough surplus energy supply from renewables, prices can even go negative. That's great news for consumers - who get paid to use energy - but it's bad news for renewable generators.

That isn't correct, it is just bad news for everyone. Sure if there was a sustainable deal that offered negative prices that'd be good, but in this case it just means the prices when positive will have to go up to cover the overall profits of the energy producers. Negative prices represent waste and it is quite unusual for waste to be good for consumers.

Although this is a minor point. The solar revolution is pretty exciting.

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I disagree that it’s bad news. It gives additional incentives for consumers to get battery systems to go with their solar.

I live in the UK where prices go negative during periods of high wind/low demand.

There are also times where demand is so high that the electricity companies will pay a big premium for consumers who cut their consumption for a couple of hours, or who sell back to the grid, to avoid having to start up reserve coal-fired power stations.

I got batteries for my solar without any thought of them being very useful in winter, but in fact they are. I automatically force-charge when prices go negative and when the grid announces there is going to be an emergency need for power (usually a few hours notice), I’ll force charge and then force discharge during the time of need.

https://octopus.energy/blog/farewell-saving-sessions-wrap-up...

My standard response to negative energy prices is, it's oh noes for energy suppliers and oh yes baby for industrial users.

A medium electric arc furnace consumes 60MW. 17 of those can draw a GW.

There's a whole industrial technology -- bulk resistive heat storage -- that's popping up to deal with intermittent low or negative power prices. Temperatures as high as 1800 C can be stored in resistively heated refractory materials, then used to displace fossil fuel combustion in various industrial processes. The stored energy/mass and energy/cost in such materials can be very high.

Yeah if you're calcining concrete clinker you'll happily use resistive heating if electricity is cheaper than nat gas.

I like to bitch about people that think the free market solves everything but oh noes the price of electricity is negative is one thing I think the free market can totally solve.

It's bad news for anyone who wants to buy a solar panel, because they'll be joining the thundering herd of people generating energy when the energy price is negative and there's too much generation in the grid already, and that is a complete waste.

It's great news for someone who wants to buy a battery and actually reduce that waste by consuming it and making good use of it later.

I have thought for a few years now that solar panels are no longer the best thing to expand - it's batteries instead now, and all the better if they are situated right next to the solar panels.

Having said that, if you're on a fixed price domestic electricity supply, then yes it would make sense to install solar panels without batteries to match your peak power usage during the day, but that is going to be a very small installation in most cases. If you expand beyond that, then you're exporting to the grid and getting paid next to nothing for it.

I don't have solar panels on my house, and have no intent to get them. I'll be happy if modest sized PV arrays pop up on unused land in my area and if I can tap that energy from the grid. The cost/W of such installations will be much below what I could get for my roof.

If we get dynamic pricing, I very well may get home batteries though, especially if these could double as backup in case of grid outage.

> I'll be happy if modest sized PV arrays pop up on unused land in my area and if I can tap that energy from the grid. The cost/W of such installations will be much below what I could get for my roof.

Not sure what state you're in, but community solar is very popular in several states, and if it is not in your state, I would encourage you to advocate for it. It is a reasonable alternative for those who do not want to install rooftop solar (or cannot, for whatever reason).

https://www.energy.gov/eere/solar/community-solar-basics

https://www.seia.org/initiatives/community-solar

https://www.nrel.gov/state-local-tribal/community-solar.html

One of the problems is that storage inefficiency is already built-in to most new PV installations. Well over half of new installations are based on grid-phase-sync microinverters. Adding storage to the system involves adding rectification and re-inversion losses.

If solar installers would default to building out DC -> primary inverter systems, then adding storage would be much less lossy. But as it is, economics drives the industry to strongly prefer microinverters.

Negative pricing will lead to people building storage which can make use of it to charge, and then sell back when prices are positive again. It's an excellent signal of opportunity.

There is a sustainable deal that can work with negative prices. Charge EVs when price is negative and pay the carowners. For this, car owners have to be always plugged in (except the 20m - 1hour) that they drive. When demand peaks, the cars can supply power back to the grid and make even more money! Households can put solar panels, provide the entire energy infrastructure: production and storage.

Car batteries are ~6 times larger than powerwalls and powerwalls can make money supplying power back to the grid: https://electrek.co/2023/07/05/tesla-electric-customers-repo...

We don't need peak power infrastructure (natural gas) which runs only a few hours per day. All of it can be replaced by EVs.

More storage and Virtual Power Plants are a big part of the answer!

By aggregating and networking more energy consuming resources, we can make load dispatchable to deal with intermittent renewables, and respond better to price signals. Cheaper, cleaner, and more reliable energy has the opportunity to be good for everyone. I wrote a book on this!

Negative price for production = positive price for storage.

It is not bad news or good news in the aggregate, it just shifts things.

No it doesnt mean either of those things. It means you built too much solar and made the grid more unstable given the physics constraints on short term supply and demand. Its not waste, it is not good.

Let the market forces deal with it?

Yeah. The way market forces will deal with it is some energy sink will be figured out for the mid-day peak, and prices will stop going negative.

But when that happens the average price of power generated from solar panels will probably drop (because less of the power generated by a panel is wasted, so the capital cost/power generated ratio improves) and consumers will be better off. I expect. These market effects are complicated.

It is the opposite of what happened in, say, Germany. They started seeing negative power prices on the wholesale market then they ended up with average electricity prices that were among the most expensive in the world.

The EEG subsidy program is a joke. The government guarantees a minimum price on your feed-in tariff. This means if the price is negative 8 cents and the feed-in tariff is positive 8 cents (numbers are for illustration purposes), the government pays 16 cents.

It's no different from what the central bank does with its zero lower bound guarantee on interest rates. The market rate on capital is negative? Gotta subsidize private capital holders with infinite QE. The guaranteed minimum price floor is zero, the interest rate is say -3%, the central bank essentially pays 3% interest to keep the house of cards from collapsing. Since negative interest rates cannot be represented in the current system, we have inflation as the band aid.

The thing is, negative prices or interest rates aren't evil or bad on their own, they become dysfunctional the moment there is a guaranteed price floor. It's no different than a price ceiling. The only difference is shortage vs oversupply.

First of all, this isn't true. In case the prices drop negative, the solar plant will be disconnected from the grid remotely and the solar plant owner will get what he had gotten if the solar plant had not been disconnected from the grid.

Second, subsidizing once expensive but mostly cleanenergy production technology, allowed renewable energy to thrive to the number 1 energy source worldwide, theoretically allowing to ditch fossil energy production completely by 2050 and stay within low risk climate warming - without significant degrowth, which otherwise would have been required for a certainty.

So no, EEG isn't a joke, but a huge win for humanity.

It was a huge win for humanity, kickstarting the rapid decline in PV cost over the last 15 years, but don't pretend there wasn't a cost to Germany. Acknowledge this remarkable act of global altruism.

It wasn't cost to Germany, because it resulted in lower electricity prices.

I'd call it investment

Yes, there was a decline in electricity prices, for the world as a whole. The cost was to Germany. Like I told you above, don't ignore that.

Are we talking about a specific policy or the whole transition?

The Wikipedia page on the EEG suggests that it's globally recognised as a success, and even when political pressure was being applied to reduce solar PV feed in tariffs faster than the original plan called for due to better than expected uptake, the merit order effect introduced in the same legislation was reducing the spot price of electricity by more than the cost.

https://en.wikipedia.org/wiki/German_Renewable_Energy_Source...

It's ironic that this is what the carbon industry used to preach back when solar and wind were very expensive and people believed it.

Now, the carbon and nuclear industry preaches the opposite - that the market absolutely cannot handle this "problem" and we need the government to give them money instead.

It was a lie both times, and it was widely believed both times.

During the 2022 energy crisis, it was the citizens of practically every country in EU that declared in unions that the market had failed and that government had to step it to fix it. Multiple elections around that time was defined by political discussion around who was willing to pay more of citizens energy bills and save companies that would have gone bankrupt. Estimated €200 billions in a single year went towards that single purpose of fixing what the market failed to do.

It was demonstrated beyond doubt that if governments let the market forces deal with instability in energy prices, then the citizens will vote to kick those politicians out and replace them with someone else.

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