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Comment by ljoshua | Hacker News Reader

Interesting to see the different power usage and electricity rates for a different part of the globe. Here in the Houston, TX area we used 848 kWh in a 30 day winter period for a mid-sized home, which is as much as the article states the household used in a 95 day period. During the summer, when my old AC unit is running like crazy, we'll use ~1800 kWh, and our rate is an average of $0.102 USD, which is around 60% of the top rate from the article.

A Powerwall unit still wouldn't make sense for us, but this is rev 1, and so in a couple of generations we could be looking at something that actually could be impactful.

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848 kWh sounds a lot. For a 4 person house in germany you have a yearly usage ~1800kWh. You have the same amount in a 1/3 year. That's a shitload.

Currently I'm single and use 848 kWh for a whole year.

Houston, TX is both very hot and very humid. It can exceed 30C for 4-5 months out of the year and it will be dreadfully humid for much of that time. A/C is virtually required to do anything productive.

That sounds so little. Just having two 50W lightbulbs shining 24x7 would be slightly more than that in a year.

Currently I'm below average something like 200kWh below.

However currently I'm only at home on Sundays, all other days I'm only be here to sleep and eat, however I barely cook, so a toaster and breed doesn't use so much energy and I have LED's everywhere so I use max. 7W per room (2 rooms total + 1 bath) however I turn off the light's after leaving a room. I have no dishwasher and my watching machine is really really good when it comes to energy. I barely watch TV and I use my MacBook for surfing which gets loaded at my company (I use it there, too). So I only need a light with 7W for like 4 Hours, have a router running 24/7 which consumes nearly nothing. I'm a single. So no problem there. (Btw. my invoice for food is definitely higher than most ;))

oh and btw. in germany energy isn't as cheap as in the usa. also if you use solar energy in germany you could only use 30% since the rest goes to the public (and you get nearly nothing for that).

I guess if he's in Houston, TX then a chunk of that goes on air con

The 848kWh is for winter, summer is 1800.

I'm guessing it's a ton of heating because houses are very badly insulated, both for historical reasons and because otherwise everything rots in hot and humid summers (and nothing ever dries completely).

Japan has the same issue (insulation is quite terrible throughout, central heating is also rare), I'm guessing Houston is even worse because people keep to western habits (light-ish indoor garments and heating the whole house).

There are several forms of insulation that work well in high humidity environments ex: foil. The real issue is they take more skill to install and home builders can save money on insulation without making an obvious lemon.

IMO, we need to start designing the equivalent of energy star ratings for new construction as there is a lot of low hanging fruit out there.

There is LEED.

http://www.usgbc.org/leed

Meh. If you are really looking for savings, I'm much more in favor of PassiveHaus [1].

To me, minimizing temperature variance is a much more useful goal than say "hey solar!"

[1] http://www.passivhaus.org.uk

LEED has a really wide scope.

People care about $ so they care about energy costs. If you just show them people will make informed decisions where now it's all up in the air.

EX: Heating and cooling costs for the average 3 bedroom hose in this area is X to Y$ per year, this house is estimated at: z$.

Another advantage of this approach is most savings shows up at the low end of the scale. Where LEED and other green certifications focuses on the high end of the scale which has diminishing returns. EX: Over 100,000 miles 10 vs. 11MPG saves 909 gallons, where 40 vs. 60 MPG only saves 833 gallons.

Is electric heating so common in the US?

In the northern states you'll often find furnaces, at least in older homes. In the southern states, it's pretty much all electric heating if it's recent (< 30 year old) construction.

That's not true. I've lived in the south all my life and I've never even seen electric heating. The predominant systems I've seen are all gas powered. Water heaters seem to be split 50/50 between gas and electric as are stoves.

As a counter-example, I grew up in Miami. We had neither A/C nor a furnace, only electric space heaters for when it got to the 40s and upper 30s. (Our house was built in the 1950s, before A/C, so built in the older style with high ceilings, many windows, a crawl space for even more cooling, and no insulation. When it was 40 outside, it was 40 inside.)

We did have a neighbor who contracted with a propane company to fill a residential tank, which was used for heat and cooking. But that wasn't common in the neighborhood.

In Tallahassee, the places I rented didn't have gas, only electricity. Eg, pulling up rental housing in Tallahassee, https://www.rentrange.com/tallahassee-fl/o-3316-calumet-nice... says it has "Electric heating". Searching for Atlanta, I found http://www.cbs46.com/story/21444870/atlanta-fallen-tree-leav... which says "'Fallen tree leaves Atlanta residents without lights and heat' ... "My house used electric heat so it's cold".

Rather than be anecdotal about it, I found "Space Heating in U.S. Homes, by Climate Region, 2009" from http://www.eia.gov/consumption/residential/data/2009/#sh . Of the 19.1 million homes in the "Hot-Humid climate region", 12.4M use electricity, 4.6M use natural gas, 1.4M have no heat, 0.5M use propane, and the others (fuel oil, wood, etc.) are too small to be meaningfully reported.

There is an apparent conflict between your observations and this survey (and with my own observations from living in Florida).

Oh! There's also a breakdown by state, including "Table HC6.10 Space Heating in U.S. Homes in South Region, Divisions, and States, 2009".

GA has 1.7M homes heated with gas, and 1.7M heated with electricity, out of 3.5M. That has the highest percent of homes heated by gas.

In FL, and in line with my observations, has only 0.4M heated with gas, and a whopping 5.7M out of 7M heated with electricity. That's the lowest percentage, which is reasonable for a place with little need for winter heating.

Overall in the South, some 13.3M homes are heated with gas, 24.2M with electricity, 0.6M with fuel oil, 1.9M with propane, 0.8M with wood, 0.2M with kerosene, and 1.0M have no heat.

Maybe in apartments, but in recently built single family homes throughout the south, a gas furnace is very common. I haven't known anyone that has anything else in the several southern states I have lived in, other than those people who tried to get away with heat pumps. Electric heating is significantly more expensive than gas.

I've lived in numerous houses and apartments in Georgia built in the 50s, 60s, 80s, and 00s. Every single one used a gas furnace. Every heat pump system I've seen had a propane or natural gas backup furnace. The only times I've ever seen electric were in water heaters and stoves.

Having lived in SC, NC, GA my whole life I can't remember a being in a home that didn't use a gas furnace.

I'm replying to you, but really you're all saying the same thing. I've lived half my life in GA and NC, and I've seen the opposite. Guess it's very dependent on the cities.

There are graphs at http://www.eia.gov/todayinenergy/detail.cfm?id=18131 showing the primary heating fuel choice, based on a US survey from about 6 years ago. Among other things:

> Everywhere but Northeast, fewer homes choose natural gas as heating fuel

> EIA data show that homes built since 1970 use electricity and natural gas as their main heating fuel in roughly equal proportions.

> The South is the only Census region where electricity is the main space heating fuel in the majority of homes.

The survey data is at http://www.eia.gov/consumption/residential/data/2009/ .

> and so in a couple of generations we could be looking at something that actually could be impactful.

But battery technology in itself isn't new; you could make a similar package out of car batteries if need be. I think that if it was economically viable, it would've been done ages ago.

Then again I'm probably wrong.

Battery technology has changed a lot over the past couple of decades. A good chunk of the cost here is in the controller electronics (you need a hefty inverter to allow the battery to power your AC household circuits) and that has, of course, changed enormously.

All of this changes the costs and the space requirements, and that in turn changes whether or not it's economically viable.

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