Renewable Energy Storage -- What's Real?

[Ampster]

@omgwtfbyobbq

Can we agree that this is how current (electric field) flows:

Conventional Current Direction. The particles that carry charge through wires in a circuit are mobile electrons. The electric field direction within a circuit is by definition the direction that positive test charges are pushed. Thus, these negatively charged electrons move in the direction opposite the electric field. Source: www.physicsclassroom.com/class/circuits/Lesson-2/Electric-Current​

 

[omgwtfbyobbq]

I fail to see how this example is relevant at all.

I'm elaborating on what I think congestion is, because in your reply, you contended that I didn't understand what it was.

If you understand congestion better than I do, great. I'd like to understand how the situation I described isn't representative of an increase in congestion. If not, I don't see why you're replying to my post.

 

[omgwtfbyobbq]

@omgwtfbyobbq

Can we agree that this is how current (electric field) flows:

Conventional Current Direction. The particles that carry charge through wires in a circuit are mobile electrons. The electric field direction within a circuit is by definition the direction that positive test charges are pushed. Thus, these negatively charged electrons move in the direction opposite the electric field. Source: www.physicsclassroom.com/class/circuits/Lesson-2/Electric-Current​

Sure. Here's a link from Wikipedia. The direction of conventional current is arbitrarily defined as the direction positive charge flows, so the charge carriers in metal wires and many other circuit components flow in the opposite direction of the conventional current flow.

Electric current - Wikipedia

In a conductive material, the moving charged particles which constitute the electric current are called charge carriers. In metals, which make up the wires and other conductors in most electrical circuits, the positively charged atomic nuclei are held in a fixed position, and the negatively charged electrons are free to move, carrying their charge from one place to another. In other materials, notably the semiconductors, the charge carriers can be positive or negative, depending on the dopant used. Positive and negative charge carriers may even be present at the same time, as happens in an electrochemical cell.

A flow of positive charges gives the same electric current, and has the same effect in a circuit, as an equal flow of negative charges in the opposite direction. Since current can be the flow of either positive or negative charges, or both, a convention is needed for the direction of current that is independent of the type of charge carriers. The direction of conventional current is arbitrarily defined as the same direction as positive charges flow.

The consequence of this convention is that electrons, the charge carriers in metal wires and most other parts of electric circuits, flow in the opposite direction of conventional current flow in an electrical circuit.

 

[Ampster]

Sure. Here's a link from Wikipedia. The direction of conventional current is arbitrarily defined as the direction positive charge flows, so the charge carriers in metal wires and many other circuit components flow in the opposite direction of the conventional current flow.

So take your pick how you want to define congestion. Positive direction or negative direction? It really doesn't matter which direction we define as current flow, it is still only measured in one direction. Wire carrying capacity (Ampacity) is a function of wire size and is usually described in Amps. A congested wire or circuit is one that is carrying amps at or near its capacity.
You seem to have a fundamental misunderstanding of the physics of electricity. We are all here on this forum because of the vision of Elon Musk. I know several people that work for him and the remarkable thing about his thought process is that when there are tough issues, he reminds his executives to look at the laws of physics to see if they pose any constraints. I think this is what we could benefit from in this sub discussion.

 

[Ampster]

I'd like to understand how the situation I described isn't representative of an increase in congestion.

It is representative of increased congestion but I also don't see how your illustration is relevant to the discussion that we have been having. There is no disagreement that congestion exists. What is your point?

 

[Ampster]

In California storage is real. Tesla got a small portion of this but I don't have details.

California's SGIP program closes first funding round with $90M allocated

 

[mspohr]

@omgwtfbyobbq

Can we agree that this is how current (electric field) flows:

Conventional Current Direction. The particles that carry charge through wires in a circuit are mobile electrons. The electric field direction within a circuit is by definition the direction that positive test charges are pushed. Thus, these negatively charged electrons move in the direction opposite the electric field. Source: www.physicsclassroom.com/class/circuits/Lesson-2/Electric-Current​

Thanks to Benjamin Franklin for this convention.

 

[mspohr]

Back on track.
Household batteries will be key to UK's new energy strategy

Household batteries will be key to UK's new energy strategy

In the UK, Ofgem has a new plan to promote home batteries

 

[Ampster]

Thanks to Benjamin Franklin for this convention.

Yes, it is not a new concept.

 

[rays427]

I don't know how the powerwall would be economic for me. Under PG&E Ev rate I sell power to them during the summer for about $.45 and buy it back at night for around $.12. During the winter my output is so low it wouldn't help to have storage.

 

[Economite]

In theory yes, if you charge a battery bank at night and then somehow force-dump it onto the grid on the following sunny afternoon there would be an oversupply issue. Why would anyone ever do that?

Because rate structures (at least for homeowners with solar/batteries) aren't particularly dynamic. They don't (at the moment) change minute by minute or even hour by hour. Instead, broad "peak" and "off peak" periods are defined well in advance and the rates for buying energy from the grid or selling energy to the grid don't change that often. If the price structure incentivizes folks to pull energy from the gird at night to charge up batteries, and then to sell that energy back during the day, folks will do what the price structure incentivizes, regardless of whether the grid actually needs the energy at the point where they discharge.

And, in general, folks with home solar installations dislike the idea of a more dynamic pricing structure, since their investment is made up front and they don't want to risk that they'll stop getting the pricing benefits after they do their installation.

With truly dynamic pricing (and good availability of batteries/home solar), the price difference between peak and off-peak would keep getting smaller as peak usage becomes closer to level with off peak usage. That would badly squeeze early adopters, since the cost of panels/batteries will keep going down.

 

[EV-lutioin]

Because rate structures (at least for homeowners with solar/batteries) aren't particularly dynamic. They don't (at the moment) change minute by minute or even hour by hour. Instead, broad "peak" and "off peak" periods are defined well in advance and the rates for buying energy from the grid or selling energy to the grid don't change that often. If the price structure incentivizes folks to pull energy from the gird at night to charge up batteries, and then to sell that energy back during the day, folks will do what the price structure incentivizes, regardless of whether the grid actually needs the energy at the point where they discharge.

And, in general, folks with home solar installations dislike the idea of a more dynamic pricing structure, since their investment is made up front and they don't want to risk that they'll stop getting the pricing benefits after they do their installation.

With truly dynamic pricing (and good availability of batteries/home solar), the price difference between peak and off-peak would keep getting smaller as peak usage becomes closer to level with off peak usage. That would badly squeeze early adopters, since the cost of panels/batteries will keep going down.

Yes, and I am still confused why utilities are charging peak rates during the day when solar is pumping the grid full of cheap power. In California, they actually have to pay other states to take excess energy created during the day from solar and wind production. It seems like rates should be lowest during solar-hours. I am fine with it because with my solar panels I never have to pay peak rates, but the whole thing seems a little backwards to me.

 

[derekt75]

Yes, and I am still confused why utilities are charging peak rates during the day when solar is pumping the grid full of cheap power. In California, they actually have to pay other states to take excess energy created during the day from solar and wind production. It seems like rates should be lowest during solar-hours. I am fine with it because with my solar panels I never have to pay peak rates, but the whole thing seems a little backwards to me.

Because we're generally a long way from being "full of cheap power".
California ISO - Todays Outlook
Rooftop solar is significant, but for most days of the year, the increased solar supply is dwarfed by the increased demands during the day.

 

[EV-lutioin]

Because we're generally a long way from being "full of cheap power".
California ISO - Todays Outlook
Rooftop solar is significant, but for most days of the year, the increased solar supply is dwarfed by the increased demands during the day.

Wow, great information! What I see, looking at yesterday, is that solar is making a big dent in net demand until about 4 pm, then declining solar and increased usage collide to create peak demand in the late afternoon and early evening. Oddly, PG+E sets partial-peak rates from 7am-1pm, when net demand is actually the lowest and then starts peak rates at 2 pm when it really shouldn't start until 4 pm. Of course not every day is sunny, but it seems like they are operating their rate schedule on pre-solar data. I am impressed that between 1-4 pm nearly a third of the state's power is coming from solar! Would like to see more wind in the mix.

 

[SageBrush]

And, in general, folks with home solar installations dislike the idea of a more dynamic pricing structure, since their investment is made up front and they don't want to risk that they'll stop getting the pricing benefits after they do their installation.

Then have the utilities give them a guaranteed rate return on the cap expenditure. Sound familiar ? ;-)

 

[Economite]

Then have the utilities give them a guaranteed rate return on the cap expenditure. Sound familiar ? ;-)

That doesn't really work unless the home installations come with some sort of service commitment to the grid. Utilities get paid in tis manner in exchange for a must-serve obligation. They have to provide more-or-less uninterrupted service to all comers. Home installations have the opposite deal. Instead of an obligation to provide electricity to the grid, they want an option to provide electricity to the grid (at times and in amounts they-- or the sun/weather-- chooses) in exchange for relatively guaranteed payments.

Home installations aren't a public service utility, they are more like a generator/wholesaler.

 

[mspohr]

Interesting report predicts huge growth in both utility scale and distributed energy storage
Global Annual Utility-Scale & Distributed Energy Storage Capacity Additions To Exceed 50 GW By 2026

 

[AntronX]

There is 1300 MW ~ 20 GWh of potential renewable energy storage capacity right under your noses at Eagle Mountain pumped hydro project located on the site of the inactive Eagle Mountain mine, in Riverside County, California. At $2B project cost and 20 GWh of maximum storage capacity, it comes out to only $100/kWh installed cost, about 4x cheaper than battery. The LCOE is expected at $31/MWh during first year in service. Average daily cycling would be 11.8 GWh on average, equal to 4300 GWh of annual energy stored. Benefits are low cost, no capacity degradation over time and long life of ~ 40 years before major repairs. FERC filing docs have a ton of useful info: FERC: Hydropower - Proposed Eagle Mountain Pumped Storage Hydroelectric Project (P-13123-002) (FEIS)

 

[SageBrush]

There is ~ 20 GWh of potential renewable energy storage capacity right under your noses at Eagle Mountain pumped hydro project located on the site of the inactive Eagle Mountain mine, in Riverside County, California. At $2B project cost and 20 GWh of maximum storage capacity, it comes out to only $100/kWh installed cost, about 4x cheaper than battery. The LCOE is expected at $31/MWh during first year in service. Average daily cycling would be 11.8 GWh on average, equal to 4300 GWh of annual energy stored. Benefits are low cost, no capacity degradation over time and long life of ~ 40 years before major repairs. FERC filing docs have a ton of useful info: FERC: Hydropower - Proposed Eagle Mountain Pumped Storage Hydroelectric Project (P-13123-002) (FEIS)

I hope so, but pumped hydro has a long history of not meeting promises. I presume with experience they will get better but for now these projects are highly risky and speculative -- I would say still in the realm of government funded applied research.

 

[EV-lutioin]

There is 1300 MW ~ 20 GWh of potential renewable energy storage capacity right under your noses at Eagle Mountain pumped hydro project located on the site of the inactive Eagle Mountain mine, in Riverside County, California. At $2B project cost and 20 GWh of maximum storage capacity, it comes out to only $100/kWh installed cost, about 4x cheaper than battery. The LCOE is expected at $31/MWh during first year in service. Average daily cycling would be 11.8 GWh on average, equal to 4300 GWh of annual energy stored. Benefits are low cost, no capacity degradation over time and long life of ~ 40 years before major repairs. FERC filing docs have a ton of useful info: FERC: Hydropower - Proposed Eagle Mountain Pumped Storage Hydroelectric Project (P-13123-002) (FEIS)

I think this one is in for a long protracted environmental battle... too much potential impact on Joshua Tree National Park, it appears.

From spectacular vistas to the pits: A decades-long public land battle continues in the California desert