Texas grid close to edge tonight ?

[EastTexCowboy]

Like so many things, it depends on the source of the data among other things, and remains subjective from one source to another. I found a lot of variance when looking for data on average Texas electricity usage. I found an article from Motley Fool on home sizes dated this year. I'm certainly not claiming they are a trusted source, but they are a source. According to them the average home size in Texas is 2170 sf. Then I found a chart on a site called electricrate.com for average electric bill in Texas dated April of last year. Once again, not saying it's a reliable source. They consider a "large" home anything over 1500 sf with an average usage of 2000 kwh. How do you average an open ended dataset like that? Anyway, the numbers are all over the board depending on who you ask. If you throw out apartments what does that do to the average size? Who knows? My average monthly usage over the course of a year is close to these numbers even though the house is 3700 sq ft plus the garage. That's because the house has 6" of blown on insulation and great windows and doors. I think it comes down to the fact that there is no "average" home so the "average" usage is a skewed number and essentially, YMMV.

What I do know is that along with installing solar I've added 500 sq ft of climate-controlled space this year (garage) and two freezers, but I've more than offset that by upgrading the heat pumps so that my total usage, solar + grid, is less than last year, even with the higher average daily temperatures.

Here's my usage graph for the past 20 months along with snips of the two charts I mentioned above.

 

[Shimmy]

The "average" home is considered 5kW from a load planning point of view. A Level 2 charger is 7-9kW. In general, charges tend to be used overnight, opposite peak day demand. So, adding a Level 2 Charger is like doubling the electrical load of your house.

Most people need <10kWh if they charge every day. While it is not automatic, a smart driver is going to charge at under 2.5kW for their average day, and maybe less if their utility has demand charges. If someone does charge at 10kW, they are done in an hour and the utility gets the diversity in the time domain.

 

[wattmatters]

It will be interesting to watch how the utilities adapt.

With EV charging it's less about the total energy requirement (most grids have ample energy generation capacity for supplying EV energy demand) and more about management of peak power demand (which is what gets stressed at times).

There are several approaches by power supply companies;
i. do nothing,
ii. ramp up time of day price signals,
iii. limit the demand via physical control, or
iv. see the opportunity EV's present for supporting the grid.

The electricity distributor in the state north of me, Queensland, has taken option iii. and mandated that any home EV supply equipment which is capable of supplying more than 20 A (4.6 kW) on a single phase (we are 230/240 V) must be connected to a controlled load supply.

These dedicated CL supplies are separate circuits to the regular power supply circuits and are pretty commonly used for appliances such as water heaters and pool pumps. They supply power for a minimum number of hours per day, basically all hours excludes the peak demand periods. They are also separately metered and charged at off-peak rates.

EV owners can still use their portable low power plug-in chargers at any time.

Come home, plug in using the wall mounted EVSE and the car starts to charge when the power company turns the CL supply on after peak period has ended. The start times for CL supplies is typically staggered - they are triggered via a ripple signal sent down the power lines.

It's actually a reasonable strategy to ensure EVs don't add peak power demand on the grid when it is least desirable, while also giving the car a long charging window overnight or during the daytime when renewables are pumping it out and they need the load.

That said, it does remove the opportunity for option iv. which enables the use of EVs as a source of grid energy during peak demand periods - which is something a state south of me (South Australia) is trialling with V2G EVSE charge points. This latter approach is smarter and more flexible but is, for now at least, very expensive to install.

 

[Texican]

Reliant just sent out email asking for conservation from 2pm to 9pm for the next 5 days
thursday thru monday

 

[EastTexCowboy]

Reliant just sent out email asking for conservation from 2pm to 9pm for the next 5 days
thursday thru monday

And NRG Stadium is air conditioned to the tune of 12,000 tons. I wonder if they volunteer to conserve? Nothing against the stadium specifically. Just sayin. Malls. Half empty hotels. As a society we use a lot of energy for things like that. I don't know the answer. If I go to Lowe's I expect it to be climate controlled.

 

[GuyG]

In general, charges tend to be used overnight, opposite peak day demand. So, adding a Level 2 Charger is like doubling the electrical load of your house.

Wut?
We both agree that EV charging generally is done during off-peak hours. I conclude that off-peak charging does not increase peak loads; you seem to conclude it doubles the load.

 

[GuyG]

Stress on the grid in southern states during the summer is mainly due to AC that picks up in the afternoon and continues until nighttime when things cool down a bit. If people with EVs get home from work and plug in, then yeah, that stresses the grid. Especially if it’s done while they also are cooking supper, doing laundry, running a bunch of TVs, etc.

But most EV owners don’t do that. We can easily set our charging to begin after midnight, when loads are light. If you have a TOU plan, you’re crazy not to.

 

[Supervstech]

Bigger and more expensive than my first car!

More expensive than most of the cars I have combined...

 

[ejfluhr]

Central Texas here, outside Austin but only have Austin Energy as power option.
Most recent bill is $307 for 2415kWh over 31 days. About 78kWh per day for a 2100 sq ft house running all electric with 2004-ish central A/C. 12.7 cents per Wh with a generally very reliable grid. Over the past year, our lowest monthly consumption was ~1400 kWh and the avg is just over 1700kWh.

Not a lot for me to complain about w.r.t. Texas electric cost and availability.

 

[webbbn]

I really don't understand some of the resistance to EVs on a forum dedicated to solar power. It's a (in most cases) 70-100kWh battery, plus a very advanced (luxury in most cases) car in one packages that doesn't cost much more than an equivalent car. You can charge it whenever electricity is the cheapest, and in some locations you can sell back when it's most expensive. Not only does that not adversely affect the electrical grid, it helps reduce peak demand. Add solar charging on top of that, and it's even better.

Most EVs don't currently support bidirectional charging, but that's going to change very rapidly over the next year or two. When that starts becoming mainstream it will only help the adoption of large-scale solar installations by using the EV network to draw on at night and during peak hours.

Edit: I should add that my EV adds about $5 a month to my electricity bill, which averages around $350. It's pretty much the same usage as my office, which has a computer and some networking equipment.

 

[Texas-Mark]

I really don't understand some of the resistance to EVs on a forum dedicated to solar power.

An EV is not solar power.
But to answer the first part of the question, while I have no issue with EVs in general, I do have an issue with them being rammed down our throats without thinking things through long term (i.e. infrastructure needed, costs, battery material availability, battery disposal, etc. etc.). Why not just let the market go where it takes it without mandating things that many if not most people really don't want at this point?

 

[SparkyJJO]

And I cannot afford to buy one.

Is there an EV minivan? No? Ok, so almost useless to me. Cramming 3 full sized car seats in an EV might work, but again I do not have $50k or more. I spent near $20k on our used minivan and that hurt enough already!

 

[740GLE]

I do agree the financial feasible market is saturated with these useless mini “crossovers” that kinda have zero function more than a tailgate. Where’s the three row option? I’m holding out for the ID buzz or Id7 depending on price.


I do support Tesla putting the squeeze on recent price drops. Hopefully others smarten up and respond accordingly.

 

[DIYrich]

And I cannot afford to buy one.

Is there an EV minivan? No?

VW ID.Buzz coming to USA next year.

 

[EastTexCowboy]

I really don't understand some of the resistance to EVs on a forum dedicated to solar power. It's a (in most cases) 70-100kWh battery, plus a very advanced (luxury in most cases) car in one packages that doesn't cost much more than an equivalent car. You can charge it whenever electricity is the cheapest, and in some locations you can sell back when it's most expensive. Not only does that not adversely affect the electrical grid, it helps reduce peak demand. Add solar charging on top of that, and it's even better.

Most EVs don't currently support bidirectional charging, but that's going to change very rapidly over the next year or two. When that starts becoming mainstream it will only help the adoption of large-scale solar installations by using the EV network to draw on at night and during peak hours.

Edit: I should add that my EV adds about $5 a month to my electricity bill, which averages around $350. It's pretty much the same usage as my office, which has a computer and some networking equipment.

I'm not against EVs per se, but I agree with @Texas-Mark that mandating EVs is not in the best interest of consumers or the country. Beyond that, if you live in the city or suburbs and only drive short distances I can see the advantages. Taking a long trip in one has shown to be a trainwreck by many accounts, including the recent article about the CEO of Ford taking a Lightning across route 66 and getting a rude awakening. I know Will had so many issues with his that he got rid of it post haste. For me personally, I don't drive enough anymore for it to matter but when I do it's often with a one ton dually pulling a trailer. There's not really an electric solution for that with an EV - at least not until @timselectric finishes his prototype.

Then there's the whole issue of piling a bunch of EVs on the grid when POCOs across the country have been dealing with brown-outs and asking people to voluntarily cut consumption or to not charge their EVs because the grid is overloaded. If our power grid is struggling now, how's it going to handle adding a few million EVs? So, I don't think it's so much resistance to EVs as it is a feeling that they are often not a practical solution. If I could buy a Lightning today and know that there is a functional rapid charging station just about anywhere I need to drive, that I could get more than a couple hundred miles on a charge and pull a trailer, that I could find someone to work on it, and that I could depend on it not to have a lot of maintenance problems, I'd certainly put it at the top of the list for next vehicle. Unfortunately, none of that is true.

 

[GuyG]

I do have an issue with them being rammed down our throats

This is news to me. Who is forcing you to buy an EV? Have you been threatened? Penalized?

 

[EastTexCowboy]

This is news to me. Who is forcing you to buy an EV? Have you been threatened? Penalized?

13 states have adopted ZEV mandates, so yeah, there is at least political pressure. For CA, ALL vehicles sold by 2035 must be zero emissions. That's forcing you to buy or move to another state. Not that I would ever consider living there, but the fact remains.

 

[wattmatters]

For CA, ALL vehicles sold by 2035 must be zero emissions.

New vehicles. You will still be able to buy and use existing ICEVs beyond then. And PHEVs as well which have an ICE enabling use of regular liquid fuels.

2035 is a long time way away. The EV market will have matured a LOT by then.

One thing which puzzles me is why Tesla does not provide V2L capability with their cars.

 

[wattmatters]

News release 23 August from Public Utility Commission of Texas:

‘Virtual Power Plants’ to Provide Power to ERCOT Grid for the First Time - Pilot Project Launches First Aggregate Distributed Energy Resources in Texas.

 

[Shimmy]

One thing which puzzles me is why Tesla does not provide V2L capability with their cars.

Tesla does a lot of things badly; their ecosystem relies on a Powerwall to be the hub of the home energy system. Based on teardowns done a few years back, the cars have the electrical capability to V2X... but the functional concern is likely that the battery life will not meet consumer expectations if cycled twice the typical rate-- 10kWh driving and 10kWh V2X average per day.