[jmcgough]

My gf is an electromechanical engineer at a solar power startup (and obviously supportive of solar power initiatives).

Just asked her about this, and she said that: 1) the electrical grid wasn't designed for transferring power this way, and it can damage the grid 2) because solar power isn't a constant power source (say, a cloud blocks the sun for a minute), power companies need to keep power available for someone who's using solar. The amount of this is dictated by their peak power usage. May not seem like a big thing, but as more and more people switch to solar, they suddenly need to hold massive amounts of power, as disruptions can affect people in entire regions.

Then she started getting heavy into the physics of reactive power and my brain stopped working T_T

Anyways, there's a reason that they're charging fees for solar usage. You're using their electrical grid, and it costs money to maintain it and improve it to handle some of the new challenges of solar power.

[peppaz]

Good thing Tesla is making huge battery packs for our homes so we can ditch the grid entirely.

[ams6110]

I think it will never be the case that you can run a household solar/battery plant for less than a utility can do it on massive scale and just run a wire to your house (remember to factor in depreciation on all your household kit, batteries and inverters don't last forever).

[azernik]

I think this applies more on the battery side than the solar side. There are certain options for storage that are totally impractical for home use. For example, vanadium redox batteries [1] are so bulky that you probably don't want to put them in expensive residential real estate, but they're pretty cheap and effective.

But a mix of residential solar and utility-managed batteries could be viable; it's not clear to me that the economies of scale for large solar installations are very strong.

[1] https://en.wikipedia.org/wiki/Vanadium_redox_battery

[jackmoore]

I think this is true too, but it depends on how efficiently the utility company runs their business, and how much profit margin they are allowed to extract.

Utility companies aren't competing directly with each other for the lowest price, so in practice there could be a lot of places where, while less efficient, it's cheaper for home owners to have their own means of power production.

[DamnYuppie]

You don't need to wait for Tesla, you can buy Lithium battery packs now. Heck even AGM or wet cell batteries work fine. I have about 800 ampH and I can do pretty much anything I want except run an AC off of it.

[artmageddon]

How much did it run?

[DamnYuppie]

Batteries were about $650.

[yourapostasy]

I wish more engineering work would be performed on different chemistries in redox flow batteries. I'd rather spend the capital up front for a much longer-lasting redox flow battery (they are way, way bigger than other batteries, but that's not a concern when you are working with building sites and are willing to put the battery bank underground) than a lithium battery.

[jmcgough]

Legislation around blocking non-profit internet and cable is just evil though :\

[g8oz]

It goes both ways. Widespread grid-tied distributed generation can save on distribution equipment maintenance wear and tear further upstream. Neither side has honestly acknowledged or studied the trade offs.

[stale2002]

Solar power REDUCES peak grid usage; it does NOT increase it.

When do you think solar power is producing the most electricity? In the afternoon on a hot summer day.

When do you think peak grid electricity usage peaks? In the afternoon on a hot summer day!

Solar power helps get rid of the peak electricity usage problem. If anything, power companies should be paying solar users even more, because they are reducing costs for the power company, not increasing them.

[rhino369]

It reduces peak grid usage on average. But you still need replacement gas plants on standby ready to start up when clouds go over for 20 minutes on a hot day. So you save money on not burning as much natural gas, but it doesn't reduce the amount of peaker plants you need to have.

I'd be all in favor of having solar power sell at the going rate that utilities are paying. But that's not how it works. And that's not how solar advocates want it to work.

[extrapickles]

While solar and wind reduce peak demand, they have problems where they can suddenly loose a significant fraction of their output capacity (lull in wind, clouds) and that capacity has to be filled in by traditional peaking power plants, otherwise the grid will fail. Also the amount of power generated is not very predictable[1], and peaking/load following plants are needed to remain in standby to cover the shortfalls as the base load plants can take quite a while to respond to shortages in the supply of power.

[1]: https://www.ise.fraunhofer.de/en/downloads-englisch/pdf-file...

[brianvan5155]

It's creating new peaks at previously non-peak times.

We don't know precisely what effect that will have on the grid utility business, or what effect that will have on overall grid supply price rates. One could argue that grid power should get cheaper... one could argue that there would be a net canceling effect among all the factors involved... or one could much more reasonably say that it's a chaotic system so no outcome is guaranteed.

Disruption!

[lambertsimnel]

Why does grid electricity usage peak on hot summer afternoons? If it's because of air conditioning, it's probably not universal.

I imagine hot summer afternoons are a time when factories operate below capacity (or not at all), and people heat their homes less and spend more time outside away from TV, etc.

[ptaipale]

Certainly not universal. Could be true in California or Texas, possibly. For sure it's not here.

Where I live, the peak is a winter morning which is windless and therefore particularly cold, at 8:00 (before sunrise). Solar output is zero, wind power output is zero. Everyone turns extra heaters on, puts the kettle on to make a hot cup before taking a warm shower.

[stale2002]

The point isn't that it is 100% universal for all places. The point is that it is true for most places.

[ptaipale]

[citation needed]