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Comment by pilom | Hacker News Reader

Hawaii is another great example. $0.40-$0.50/kWh for their oil generated electricity. Solar comes in even cheaper than the article mentions. There have been so many solar installations in Hawaii that the power company has effectively put a moratorium on installations that don't include storage because they can't cover the swings in demand when a cloud rolls through town.

They expect things will get better once they install a connection between the islands to connect their grids, but for the moment, the power company can't handle the market penetration.

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> the power company can't handle the market penetration.

When it comes to solar power, and anything else with externalities, it's always best to be clear whether "can't" means "has no economic incentive to do so" or not.

In this particular case I'd say we are below the optimum level of solar, and it's just poorly aligned incentives.

edit: just to re-iterate this in clearer language:

If they "can" do something if they spent $X million dollars, and $X million dollars is less than the total amount saved by the economy of Hawaii by doing so, then it's not a technical problem, it's an economic co-ordination problem.

If the utility is going to lose money from doing something, because they can't capture all the resulting profit (like lower pollution meaning healthier people) then their employees will say they "can't" do something, as no-one gets promoted for making children healther on the utility shareholders dime. Even though they could if someone gave them the money.

There's lots of BS surrounding solar, and a main thread of it is to pretend that it's going to blow up the electrical grid. The only thing it destroys is some current utility business models.

Well, consider that the conditions are quite a bit different. With conventional power, you have a small number of sources (plants) and relatively slow, predictable swings in demand. Things like temperature changes throughout the day, or the end of rush hour and resulting spike in entertainment electronics usage.

Contrast this with solar, with a large number of much smaller sources, and on top of the large predictable swings in demand, you add rapid, unpredictable swings in supply to the mix. That is a very different problem. It's solvable, just not using the same techniques and equipment that worked before.

While there is certainly a market incentives problem, accomodating large quantities of rooftop solar does require infrastructure upgrades and an associated massive capital investment. It may not be practical for a relatively small island utility to do this on their own, even if it had a more clear ROI. Ultimately, some government support may be required here, since a fee on solar installations wouldn't be popular.

When clouds roll in, people are not OK with their TVs turning off. So you'd always need the traditional grid in place, even if it's for a few days a year.

In that case, the utilities would charge a standby fee for keeping their multi-billion dollar infrastructure in place (it's called a "demand charge" in the utility industry). Then, when you use the electrons during the cloudy period, you'd pay an astronomical "consumption charge", beyond $100/KWh because everyone in the city wants/needs those electrons. The utility share-holders would be fine.

But the people of Hawaii would have the cost of the solar installation PLUS the cost of the traditional grid. The calculation in the article misses this point and only shows the $/KWh consumption costs on the utility side.

So, yes, a huge amount of solar can figuratively blow up the electrical grid.

> When clouds roll in, people are not OK with their TVs turning off. So you'd always need the traditional grid in place, even if it's for a few days a year.

Sounds like a great argument for municipal generation and storage. If nothing else, it's both cheaper than "everyone on his own" and could lesser the strain for long-distance infrastructure (which could still be nice for geographic smoothing).

> So, yes, a huge amount of solar can figuratively blow up the electrical grid.

Demand-controlled EVs could take a lot of the load. In fact, it's probably one of the sanest applications of massive solar installations (beyond the potential of future power-to-gas tech).

There's a lot of ways to store energy if you're basically getting it for free, and these are generally more efficient at scale. It would be great if a utility could help buffer this for you.

Yes, that's another reason why a municipal grid would be useful: city-wide storage could work better than each house having a small battery (but the roofs are still useful for panels, of course). But it may not need to be a utility in the traditional sense (unless the US meaning of that word is different from what I understand it to be). Just some local company with a contract. Or a few of them.

Here the power company was split up into a generation unit and a distribution unit. What you're talking about is having a third type, a storage unit, to help manage demand.

If you can pull power off the grid very cheaply, even get paid to "dispose" of it, then later return it at a profit, you could arbitrage solar capacity.

Interesting example about the TV switching off. That would of course be inconvenient but there's already multiple large industries and consumer level smartmeters that will turn things off when electricity demand is high in return for cheaper energy:

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

The basic reason for this to exist, even before renewable energy was a thing, is that, as you point out in your comment, building enough capacity just to serve a peak that may only last for a few hours a year is stupidly expensive. So you take the money that you would have spent on a power plant that would only run for a few hours and you give it to people for turning down their air con or their blast furnace for a few hours, keeping a portion to yourself for being so clever. Free-market solutions that save customers and utilities money, save energy, and save the planet. Everyone is happy!

Not to be too picky but it is actually the swings in supply they can't handle. Demand is inelastic and pretty much constant in the near term.

The problem is that the clouds roll in, supply from solar drops off, conventional gen must compensate because the demand is pretty much constant and price insensitive. When the clouds roll-out the dispatchable gen has to back down so the wires don't melt. There are a bunch of concerns with this: generators often don't like being turned on and off, the generators often can't get paid enough to be there when they are needed, they often can't just be turned on and off (more of a problem for steam), and these peak shaving plants are expensive to fuel, burn dirty fuel, and burn it inefficiently.

Swings in "demand to the utility company".

I wonder if capacitors could be used to moderate such short reductions in solar power. Not necessarily at the power plant, but as part of the solar installations.

When clouds roll in, the solar panels still generate power, just less of it. A lot of things in the house could be automatically turned off during such brownouts - the refrigerator, the car charger, the HVAC, etc. - until the cloud passes.

>swings in demand when a cloud rolls through town

Reminded me of this article about abrupt power swings during commercial breaks in the UK:

http://www.geek.com/news/tea-time-in-britain-causes-predicta...

They solved it with partly with on-demand power generated from dams.

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