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Comment by slater | Hacker News Reader

$5k?!?!? How?!

My house normally uses 70kwh/day. We have an electric heater and with this cold weather we were on track to use 150-200kwh day. At $5/kwh for 5 days of 200kwh due to the cold puts me at $5,000.

Holy cow! How in the world do you use that much? My old house in Colorado would use ~350kwh/month. Swap out that electric heater for a heat pump asap!

Big house (3700sqft or so), tall ceilings, four people working/schooling from home and an electric car as the primary family car. In 2019 I literally did not turn the heater on a single time, I don't think the investment in a heat pump would be worth it.

Heat pump systems can sometimes be an upgrade to standard air conditioning systems

Does your AC has not heating function (I assume everyone in Texas has AC)?

I'm guessing most Texas AC systems don't have a reversing valve, and a defrost system and all the other goodies you need to run it for heat. It adds to the equipment cost when many years heat isn't needed, and if the temperatures are 10F, you'd still likely need other heat sources.

> a defrost system

What does a defrost system includes? My dad manages a place where defrost system on one of the devices broke. Technician replaced something and hence it was fixed. IIRC it was temperature sensor. All defrost system does is periodically warms up the outside grill basically. It used to get stuck at -15C or so.

That's the gist. It's not much, but if the outside unit is iced over, there's not going to be a lot of heat exchange into the working fluid, so you're not going to get heat into your conditioned environment.

So, a defrost system will include a temperature sensor, and a resistance heater, and often something to signal the inside unit to run the emergency/auxiliary heat until (unless) the outside unit can get up to a temperature where it will work.

We have colder weather where I live, but I see I used 550 kwh per month (at most). Even if my house is half your size, 70 kwh seems like a lot for a daily baseline. I have a similar situation (kids at home studying, me working at home).

Does the the car that drives up your electricity usage that much?

Car adds about 500kwh/mo. During offpeak rates charging this amount cost between $1 and $12 for the month.

A don't think a heat pump would help them in this weather.

Modern ones and designed for purpose go to -20C.

I bet absolutely nobody in texas asked "how efficent is the heatpump at -20c" when buying them. Same reason why all the windmills froze: "would like this wind mill model that produces eletricity at -20, or this cheaper one that freezes at 0c?"

No, but those who make heat pumps know that to sell in the north people care so they try to make one model that works anywhere.

Have you seen how houses are insulated in TX/LA?

New construction is actually pretty good in Texas. But most houses are not new and have little.

It would make sense for you to turn off your water, drain all the pipes, turn off the heat and go somewhere else for a few days.

and go somewhere else for a few days

Or put a tent up in the living room.

Wow! European here. Family of 5 and we are at 8kwh per day. Total yearly electricity bill is < 1000 EUR.

Even higher this morning. Up to ~ $6000/MWh or $6/kWh. http://www.ercot.com/content/cdr/contours/rtmLmp.html

$0.05 to $0.10/kWh seems like normal pricing.

Average US house uses ~1100-1200 kWh (I don't actually know this, based on googling, assuming most places in Texas are standalone houses) per month.

If prices are $3000-9000 per MW, then ~40 to 60 kWh/day (let's be generous, people are explicitly turning on heat for this extreme cold) for a week...

Even $2/kWh (which was exceeded days ago) would demolish peoples' budgets.

I think most people are on fixed prices though. The supplier gets a big mark up over the wholesale cost and then is expected to have a plan to deal with situations like this.

Griddy is a different provider which gives you grid prices for power

Yeah, this is the answer to slater's question, that some people have signed up for exposure to wholesale prices.

griddy's twitter is full of people angrily demanding refunds because "i signed up for cheaper rates and it's been cheaper til now why am i paying higher rates??? this is a scammer"

Those prices are far below normal prices. Normal is 28-50 cents in places like San Diego (https://www.sandiegouniontribune.com/business/energy-green/s...).

In Texas griddy exposes you to real time spot pricing. I was frequently getting paid to use electricity at night due to excess generation by wind. As an electric car owner this was fantastic as I frequently got paid to recharge my car. My average delivered rate before this week was 7c/kwh all in.

Does anyone there get a battery system, like a Tesla Powerwall, to save up negative priced night electricity to use in the daytime?

It doesn't happen enough that I've seen to make it worthwhile

Of course, during these cold snaps, the battery doesn't really work well, right?

Powerwalls have an operating temperature range of -4 F to 122 F (-20 C to 50 C), although they recommend 32-86 F (0-30 C).

They can also be mounted indoors.

My power comes from, I believe, a nuclear plant in Wisconsin.

$0.098 per kW-h, with $15 a month connection fee.

Wi has a lot of coal by the lake, where is there a nuke? Chicago was almost all nukes at one point

Point Beach is still operating afaik. Kewaunee shut down several years ago though.

CA power is hilariously expensive compared to the rest of the country. 10c is much closer to average.

The weighted average price is 10.54¢ per kwh. In California it's 16. Both 5 and 35¢ are pretty poor estimates.

I paid $.36 last month living an hour north of SF.

Average or marginal? Most PG&E customers have a “baseline allowance” with a higher marginal cost as you draw more energy over the month.

Marginal. I was doing a back-of-the-envelope calculation about getting an EV and realized that the $/mile cost to charge it would be about the same as paying for gasoline on a car which gets 30 mi/gallon.

I'm paying 8.5-8.3 cent kWh on a fixed contract.

Power is very very very cheap in Texas.

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