Power Grids (Nonfiction)

I've been reading "Living On the Grid", www.amazon.com/Living-Grid-Fun… a basic introduction to how power grids work. I knew very little about the topic, so while it's not electrifying reading, it is enlightening. A bit of what I've learned, mostly new to me:

-The main point of having a power grid is reliability. In return for the enormous complexity of tying together multiple power plants, you can mostly eliminate blackouts and other poor service. Our dependence on "the cold chain" for food makes this steady supply more than a luxury.
-A power grid acts as a single pool of electricity with providers dumping energy into the system, so that it's sometimes hard to distinguish who's contributing what.
-There are three grids covering most of North America: the eastern, the smaller western, and Texas's own network. (This is a deliberate choice by Texas to evade some federal control, and one reason why Texas could become a free country.)
-The grid generally doesn't store power. This is a huge problem because managers must constantly try to balance the output of the power plants with demand, which is constantly changing. It's possible to predict demand somewhat based on daily and yearly cycles, but plant managers sometimes end up praying for an afternoon thunderstorm to cool the area off so that people will turn their A/C off. There are some technologies for storing power already, but what might really make the concept practical is... millions of electric cars whose batteries are hooked up to the grid, available to charge and discharge for non-automotive purposes.
-There are tricks that customers barely notice to balance load and generation. Besides various levels of public notices saying "please don't run all your appliances at noon on a hot day, damn it", power companies can let the alternating current frequency (60 Hz in North America) slip slightly, which saves energy, and ramp power plants up and down.
-There are countless contracts constantly happening to buy and sell power across various regions. As technology has advanced there's been somewhat of a move toward a free market with ever-more-complex transactions, but some players have been kind of clueless about points like thinking they can buy power and "store it on the grid" somehow. One big change is that generation is now mostly marketed separately from transmission (getting it to the customer). One thing that hasn't changed is that the whole system is regulated to hell and back. The author comments on the California "deregulation" experiment as having had regulations that doomed it.
-The grid is built to handle a "single contingency", meaning any one major equipment failure at a time. The operators constantly run simulations of the next hour or day to be ready for anything, and something somewhere breaks almost daily. As a result, there needs to be extra production and transmission capacity, built years in advance of it being directly needed. Often a power company will buy this extra capacity for a few years to hold off on upgrading their own equipment.
-Because there's a need to balance supply and demand in real time, it's necessary to bring power plants online and offline, or dial their output up and down. This process is very complicated. Power plants often have minimum output levels, and can take hours or days to start from a dead stop. Some also need considerable energy to get started, which means recovering from a total blackout is especially hard. ("Lucifer's Hammer" alludes to this problem by mentioning that having one power plant running would help rebuild civilization.)
-Renewable energy can be a problem for the grid. One reason is that they're unreliable. If you're obsessing over perfectly matching two numbers, you don't want one of them to be fluctuating with every passing cloud. (The author cites Europe's experience with wind power, saying that spreading windfarms over a large area helps even out the chaos.) Second, owners of renewable sources hate being told to throttle down their output, because that means throwing away "free fuel" compared to, say, telling a coal plant to just shovel less coal into the furnace. Nuclear (fission) power is like renewables in that the fuel is shedding energy constantly no matter what, so taking <100% output is a waste. As we put more "green" energy online, these problems will tend to get worse. There's also the matter of political uncertainty. Rightly or not, there are proposals to severely tax or subsidize some types of power, and the uncertainty of who gets elected is going to have big effects on the profitability of each type. It's tough to invest in new power plants if you don't know whether the next president or prime minister will have it in for your industry. Even leaving the politics aside, we don't know for instance what the future price of natural gas will be, so market factors make the ideal power mix even less certain.
-Because having spare capacity available is important and some plants have a minimum output, it sometimes happens that a specific power plant is usually offline or barely running. Yet "they also serve who stand and wait". To keep the plant owners from shutting down and firing everyone, it's necessary to have some kind of payment structure such that people get paid for being ready to produce, similar to renting a car so that it'll be at your command despite your not using it constantly. There's also an arcane type of "reactive power" that needs to be available in specific areas regardless of where the main power supply comes from.

In conclusion, it's complicated!