Will we have HVDC in home socket one day?

[supton]

Just for the fun of it, how many of you out there know what a saturable reactor AC variable power controller is and how it works?

No, but I do know how to use google. Fascinating, but I wonder what kind of distortion occurs. Unless if go into full saturation far enough that the DC bias is always dominate, I would think there would be distortion from the inductance changing over a single cycle. But perhaps that is easily filtered out, power factor filter or the like.

 

[alarmguy]

Electric usage in the USA has not increased in the last almost two decades, we as a country are using about the same amount on electricity that we were 20 years ago and our population has increased almost 50 million people/almost 20% in that time frame.
I doubt we will need more, technology is constantly finding more efficient ways for everything we know in life to be more efficient. Our population as a country has grown, the devices we use has increased what? Ten Fold? Yet our electric use remains the same for the last 20 years and that is a pretty amazing feat. Technology will lead to even more efficiencies which as just waiting in the desk draw and being improved for when he "time is right"
Granted, some of the unknown is the electric vehicle, but to speculate on that is nothing more then baseless speculation at this point and will be efficiencies in that area as well.

 

[OVERKILL]

Electric usage in the USA has not increased in the last almost two decades, we as a country are using about the same amount on electricity that we were 20 years ago and our population has increased almost 50 million people/almost 20% in that time frame.
I doubt we will need more, technology is constantly finding more efficient ways for everything we know in life to be more efficient. Our population as a country has grown, the devices we use has increased what? Ten Fold? Yet our electric use remains the same for the last 20 years and that is a pretty amazing feat. Technology will lead to even more efficiencies which as just waiting in the desk draw and being improved for when he "time is right"
Granted, some of the unknown is the electric vehicle, but to speculate on that is nothing more then baseless speculation at this point and will be efficiencies in that area as well.

View attachment 55089

My takeaway from that graph is clearly different from yours. It seems to sharply increase until around 2010 and plateauing around 2011 until 2017 (6 years, where we had the financial collapse and recovery) where usage started to increase again in 2018, but then COVID happened, and has now driven consumption back down.

And yes, if EV's gain significant market share, it is going to take considerable amounts of electricity to charge them all.

 

[PandaBear]

I think both views of "efficiency improvement" and "economy in recession" make senses and coexist. The easiest way to reduce them is to move energy consumption elsewhere (i.e. outsource factory activities). Even using imported aluminum vs local steel is likely an import of energy in disguise. We do have a lot of new stuff that uses far less electricity, like newer refrigerants for HVAC / AC, LED lighting, cloud servers (more efficient in energy use per compute power and storage space actually used), etc.

I think it makes more sense to look at the whole nation or world's energy consumption instead of just the electrical grid, as many forms of energy can be switched between them: natural gas heating vs heat pump, EV vs plug in hybrid vs gasoline vehicles, etc.

 

[MolaKule]

The problem with trying to frame grid policy around rooftop solar is that at some point penetration will need to be curtailed for grid-tie systems, which dovetails into my next point:...

AC grid equipment, mostly large turbines, keep the grid stable. While HVDC is a good fit for long transmission hauls between disparate grids (intentionally not synching their frequency) that doesn't mean that HVDC is a viable, or even logical, option for grid construct.

AC has numerous benefits that @JHZR2 has touched on, including the ability to be phased, stepped...etc. Most large generators (nuke plants, gas plants, coal plants, hydro dams...etc) are AC and play that critical role in providing inertia and stability to balance the loads coming on and off the grid.

I see no benefit in trying to reinvent the grid to better fit a technology that will never be able to provide the value necessary to make the investment worthwhile. The mild complication of conversion behind the meter for VRE installs is far better kept there then trying to make everything DC to avoid that IMHO.

When you look at the totality of the economics of power distribution and the technology involved, this is the reason Westinghouse's AC won out over Edison's DC. If the name of the game is energy efficiency then AC is the preferred delivery and end user method for the transfer of electrical energy.

""...After Edison developed the first practical incandescent light bulb in 1879, supported by his own direct current electrical system, the rush to build hydroelectric plants to generate DC power in cities across the United States practically guaranteed Edison a fortune in patent royalties. But early on, Edison recognized the limitations of DC power. It was very difficult to transmit over distances without a significant loss of energy, and the inventor turned to a 28-year-old Serbian mathematician and engineer whom he’d recently hired at Edison Machine Works to help solve the problem. Nikola Tesla claimed that Edison even offered him significant compensation if he could design a more practical form of power transmission. Tesla accepted the challenge. With a background in mathematics that his inventor boss did not have, he set out to redesign Edison’s DC generators. The future of electric distribution, Tesla told Edison, was in alternating current—where high-voltage energy could be transmitted over long distances using lower current—miles beyond generating plants, allowing a much more efficient delivery system. Edison dismissed Tesla’s ideas as “splendid” but “utterly impractical.” Tesla was crushed and claimed that Edison not only refused to consider AC power, but also declined to compensate him properly for his work. Tesla left Edison in 1885 and set out to raise capital on his own for Tesla Electric Light & Manufacturing, even digging ditches for the Edison Company to pay his bills in the interim, until the industrialist George Westinghouse at Westinghouse Electric & Manufacturing Company, a believer in AC power, bought some of Tesla’s patents and set about commercializing the system so as to take electric light to something more than an urban luxury service. While Tesla’s ideas and ambitions might be brushed aside, Westinghouse had both ambition and capital, and Edison immediately recognized the threat to his business..."

Edison vs. Westinghouse: A Shocking Rivalry

The inventors' battle over the delivery of electricity was an epic power play

www.smithsonianmag.com

Specific instances where DC is useful. Some of the data in the text is open to debate:

Benefits of High-Voltage Direct Current Transmission Systems

High-voltage direct current (HVDC) technology offers more efficient bulk power transfer over long distances compared to alternating current (AC) systems.

www.powermag.com

 

[OVERKILL]

When you look at the totality of the economics of power distribution and the technology involved, this is the reason Westinghouse's AC won out over Edison's DC. If the name of the game is energy efficiency then AC is the preferred delivery and end user method for the transfer of electrical energy.

""...After Edison developed the first practical incandescent light bulb in 1879, supported by his own direct current electrical system, the rush to build hydroelectric plants to generate DC power in cities across the United States practically guaranteed Edison a fortune in patent royalties. But early on, Edison recognized the limitations of DC power. It was very difficult to transmit over distances without a significant loss of energy, and the inventor turned to a 28-year-old Serbian mathematician and engineer whom he’d recently hired at Edison Machine Works to help solve the problem. Nikola Tesla claimed that Edison even offered him significant compensation if he could design a more practical form of power transmission. Tesla accepted the challenge. With a background in mathematics that his inventor boss did not have, he set out to redesign Edison’s DC generators. The future of electric distribution, Tesla told Edison, was in alternating current—where high-voltage energy could be transmitted over long distances using lower current—miles beyond generating plants, allowing a much more efficient delivery system. Edison dismissed Tesla’s ideas as “splendid” but “utterly impractical.” Tesla was crushed and claimed that Edison not only refused to consider AC power, but also declined to compensate him properly for his work. Tesla left Edison in 1885 and set out to raise capital on his own for Tesla Electric Light & Manufacturing, even digging ditches for the Edison Company to pay his bills in the interim, until the industrialist George Westinghouse at Westinghouse Electric & Manufacturing Company, a believer in AC power, bought some of Tesla’s patents and set about commercializing the system so as to take electric light to something more than an urban luxury service. While Tesla’s ideas and ambitions might be brushed aside, Westinghouse had both ambition and capital, and Edison immediately recognized the threat to his business..."

Edison vs. Westinghouse: A Shocking Rivalry

The inventors' battle over the delivery of electricity was an epic power play

www.smithsonianmag.com

Specific instances where DC is useful. Some of the data in the text is open to debate:

Benefits of High-Voltage Direct Current Transmission Systems

High-voltage direct current (HVDC) technology offers more efficient bulk power transfer over long distances compared to alternating current (AC) systems.

www.powermag.com

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The one thing I touched-on is that HVDC decouples inter-grid frequency dependence, which may be desirable.

 

[brianl703]

And yes, if EV's gain significant market share, it is going to take considerable amounts of electricity to charge them all.

Some electric companies are offering lower off-peak rates for charging EVs.

I figure that, at least in this area, the grid must have sufficient capacity to run all the electric heat strips in the heatpumps installed in the drafty, poorly-built houses around here when the temperature drops below 35F.

(I have a heatpump. My house is sealed up very well; I personally made sure of that during construction. I have disabled the electric heat strips. They can only come on during defrost, and then only 10kW of them, not the full installed 20kW).

 

[OVERKILL]

Some electric companies are offering lower off-peak rates for charging EVs.

I figure that, at least in this area, the grid must have sufficient capacity to run all the electric heat strips in the heatpumps installed in the drafty, poorly-built houses around here when the temperature drops below 35F.

(I have a heatpump. My house is sealed up very well; I personally made sure of that during construction. I have disabled the electric heat strips. They can only come on during defrost, and then only 10kW of them, not the full installed 20kW).

Yes, and they will continue to do so until off-peak is no longer off-peak. Here in Ontario, we are able to sign up for flat-rate billing now (no TOU rates) which I'm going to be opting for, as the convenience of being able to use whenever is significant. I've never liked TOU, so I'm glad we now have the option to opt-out. Charging an EV here means that it is mostly going to be powered by nuclear anyways (Darlington is 45 minutes up the road).

 

[PandaBear]

Yes, and they will continue to do so until off-peak is no longer off-peak. Here in Ontario, we are able to sign up for flat-rate billing now (no TOU rates) which I'm going to be opting for, as the convenience of being able to use whenever is significant. I've never liked TOU, so I'm glad we now have the option to opt-out. Charging an EV here means that it is mostly going to be powered by nuclear anyways (Darlington is 45 minutes up the road).

Around here we have TOU or tier based choices. If you install an EV charger you are only allowed to use TOU based rate.

For me tier based rate is actually cheaper despite their claim that most people will save money. Most of my family use is at 6-8 so there is nothing I am doing that will be moved, and I typically don't dry laundry at this hour anyways (too busy, but happens to be helping them offload electricity from peak).

I think there will be a future when appliances and EV will "self start" based on the $/kwh rate you set at. Some people may end up not charging their EV for a couple days and let it sit at 30% charged, then charge it to 80% when the price goes to 5c/kwh, and to 100% when it is 2c/kwh, for example.

 

[OVERKILL]

Around here we have TOU or tier based choices. If you install an EV charger you are only allowed to use TOU based rate.

For me tier based rate is actually cheaper despite their claim that most people will save money. Most of my family use is at 6-8 so there is nothing I am doing that will be moved, and I typically don't dry laundry at this hour anyways (too busy, but happens to be helping them offload electricity from peak).

I think there will be a future when appliances and EV will "self start" based on the $/kwh rate you set at. Some people may end up not charging their EV for a couple days and let it sit at 30% charged, then charge it to 80% when the price goes to 5c/kwh, and to 100% when it is 2c/kwh, for example.

Yes, though of course that depends on there being an abundance of cheap power. The flat rate I'm able to sign up for is $0.128/kWh, which is pretty reasonable, but not as cheap as if I was just latching onto the output from one of the main generating sources. Right now, the COVID flat rate is $0.089/kWh IIRC, which is well below the cost of generation (which is roughly in-line with the rate I can sign up for).

It will be interesting to see how this push for further electrification, EV adoption...etc plays out in grid terms. TOU is designed to shift consumer consumption habits based on expected availability of surplus power (off-peak) but if things change such that this peak period moves and you drive things like EV charging to periods that are currently off-peak and drive-up demand at those times to where you need more power, the cost will go up.

 

[PandaBear]

Yes, though of course that depends on there being an abundance of cheap power. The flat rate I'm able to sign up for is $0.128/kWh, which is pretty reasonable, but not as cheap as if I was just latching onto the output from one of the main generating sources. Right now, the COVID flat rate is $0.089/kWh IIRC, which is well below the cost of generation (which is roughly in-line with the rate I can sign up for).

It will be interesting to see how this push for further electrification, EV adoption...etc plays out in grid terms. TOU is designed to shift consumer consumption habits based on expected availability of surplus power (off-peak) but if things change such that this peak period moves and you drive things like EV charging to periods that are currently off-peak and drive-up demand at those times to where you need more power, the cost will go up.

"Cheap" is a relative term. Electric will be cheaper than gasoline in energy cost, assuming you already have a vehicle of the same price. To be honest the time of use is going to happen eventually as there's always a different cost to produce the energy vs consumption. I am actually more concerned about Wind than Solar.

 

[OVERKILL]

"Cheap" is a relative term. Electric will be cheaper than gasoline in energy cost, assuming you already have a vehicle of the same price. To be honest the time of use is going to happen eventually as there's always a different cost to produce the energy vs consumption. I am actually more concerned about Wind than Solar.

Depends on what you are driving and where. A car that gets very good gas mileage operated where gas prices aren't obscene may be cheaper than an EV, particularly if we are looking at rates in places like California.

Yes, TOU will probably always be "a thing" but how that looks may change significantly. Most current TOU plans are geared around off-peak happening overnight, obviously, if a lot of EV charging starts happening then, TOU will need to be modified accordingly.

Using the Tesla SuperCharger network is already approaching price parity with gasoline/efficiency in some states, so the allure is clearly with charging at home, which will of course hinge on electricity remaining inexpensive (cheaper than gasoline in a cheap to fuel car). If electrification drives up rates, this drives up more than just the cost to drive a car, it drives up household costs too.

 

[PandaBear]

Depends on what you are driving and where. A car that gets very good gas mileage operated where gas prices aren't obscene may be cheaper than an EV, particularly if we are looking at rates in places like California.

Yes, TOU will probably always be "a thing" but how that looks may change significantly. Most current TOU plans are geared around off-peak happening overnight, obviously, if a lot of EV charging starts happening then, TOU will need to be modified accordingly.

Using the Tesla SuperCharger network is already approaching price parity with gasoline/efficiency in some states, so the allure is clearly with charging at home, which will of course hinge on electricity remaining inexpensive (cheaper than gasoline in a cheap to fuel car). If electrification drives up rates, this drives up more than just the cost to drive a car, it drives up household costs too.

We also have very high gas price, so likely we will still have cheaper electric per mile than gasoline (assuming those $25k EV eventually happen). I do agree with you that eventually the EV charging rate needs to be cheaper than home electric pricing or the whole situation can cause a lot of backlash. In the future I hope they have smart meter inside EV so you can go anywhere and charge, and the "rate" will be deducted from whoever hosting the plug and subtracted from their smart meter. That way we will have more people willing to let you charge wherever you stay at, despite level 1.

 

[MolaKule]

...I am actually more concerned about Wind than Solar.

And I don't see either one contributing to evening peak demand without expensive battery banks and massive DC to AC inverters, which will drive up total system cost.

 

[PandaBear]

And I don't see either one contributing to evening peak demand without expensive battery banks and massive DC to AC inverters, which will drive up total system cost.

You mean the duck curve peak? That would be hard to address other than filling up the rest of the "curve" with EV charging or smart electric dryer. The only way to address duck curve really is heat (laundry dryer) / cooling (ice based AC) or battery (as in charging EV).

Keeping battery close to solar and charge them with DC will likely save money on the reusing the inverter, I am sure the same for wind as the wind speed are variable to begin with.

Maybe solar tower to shift some production, but it is expensive and kill birds (hard to clear environmental study).

 

[OVERKILL]

And I don't see either one contributing to evening peak demand without expensive battery banks and massive DC to AC inverters, which will drive up total system cost.

Yes, with wind, you have periods where it shows up, and then periods that it doesn't. It's not predictable other than it typically accompanies storms and is absent during heat waves and cold spells. Day ahead can be wildly wrong (check out the ERCOT stuff, it's wild!) and even if it's right, it telling you that you need another source for two weeks in a row isn't helpful in keeping emissions down. You aren't storing two weeks of wind output.

That said, if your goal is just high penetrations of VRE, then the fact wind needs copious amounts of gas backup is irrelevant. If the goal is true deep emissions reduction, wind is the worst possible choice of power production, because you are absolutely married to fast-ramp gas unless you have absolutely massive reservoir hydro resources that can be used to hold back water when it is windy, and even then the primary generator is hydro, wind is window dressing whose presence isn't required to keep emissions down.

 

[OVERKILL]

You mean the duck curve peak? That would be hard to address other than filling up the rest of the "curve" with EV charging or smart electric dryer. The only way to address duck curve really is heat (laundry dryer) / cooling (ice based AC) or battery (as in charging EV).

Maybe solar tower to shift some production, but it is expensive and kill birds (hard to clear environmental study).

CSP has proven to be a complete trainwreck. More expensive than a nuke per MW and massively less reliable. Its land usage is also jaw dropping.

Solar PV can work with ULE baseload as a complimentary arrangement provided its penetration is sufficiently limited that it doesn't cut into that baseload's generation. As soon as you start displacing ULE baseload with solar, you impact the efficiency and cost competitiveness of those sources and you create a mess.

You could use some form of storage (pumped hydro, or, if necessary, batteries) to cover morning/evening ramps in the above scenario, minimizing fast ramp gas use. But again, this is an "in moderation" approach with respect to solar installed capacity.

 

[PandaBear]

I think, eventually we still will have to pay a lot of these generation capacity to sit on standby, to have the solar and wind to work. Today we haven't really pay any of these plants to standby when we factor in solar and wind cost, but eventually we will have to. That means solar and wind are going to compete with fast ramp gas on fuel price. If solar and wind capital cost compete with gas fast ramp fuel cost, that's going to really skew the competition a lot.