3 ms·

> 1,100 megawatt hours of energy per year, enough electricity to power up to 150 homes. That doesn't quite add up, that comes to only 837 watts (average use) p

> 1,100 megawatt hours of energy per year, enough electricity to power up to 150 homes. That doesn't quite add up, that comes to only 837 watts (average use) per home. For perspective, a microwave oven uses 1500 watts while it's on. A rough estimate for a central AC system is 3500 watts. http://www.senicaair.com/blog/how-many-watts-does-an-air-conditioner-use http://www.senicaair.com/blog/how-many-watts-does-an-air-con... Maybe they don't tend to have central AC in Portland, but electric heating can use even more.

toomanybeersies 11y ago
You're not running a microwave all day long, and you don't run much at all at night. I'm not sure what usage is like in Portland, but where I'm from (outside the USA, but still first world) I'm probably running about 200 W at night, a couple of energy efficient bulbs, and standby power. During the day, when nobody is home, I probably use about the same. So that leaves about 1800 W for 8 hours a day that you're at home. Judging roughly by what my power bill is, divided by the hours in the month, I use about that amount of power, at least in summer. This is for an uninsulated house in a temperate climate with 4 students in it. The power consumption in winter is significantly higher, which is in part due to the fact that 70 year old houses with no insulation at all leak heat like a sieve, and due to regulations, we can only use electric heating. Central AC pulls 3.5 kW when it's running, but it doesn't run all day long, it only runs for maybe 10 minutes per hour or so, if you have a well insulated house.
IanCal 11y ago
837W all day long is 20kWh, almost exactly so I guess that's the figure used. That's roughly double my usage in the UK, and I work from home. It's ~7300kWh/year, which is a bit lower than the US average of almost 11000kWh (https://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3 https://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3). In the UK it's an overestimate as we average closer to 4000kWh (chart 3: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/449134/ECUK_Chapter_3_-_Domestic_factsheet.pdf https://www.gov.uk/government/uploads/system/uploads/attachm...)

toomanybeersies 11y ago

You're not running a microwave all day long, and you don't run much at all at night. I'm not sure what usage is like in Portland, but where I'm from (outside the USA, but still first world) I'm probably running about 200 W at night, a couple of energy efficient bulbs, and standby power. During the day, when nobody is home, I probably use about the same. So that leaves about 1800 W for 8 hours a day that you're at home. Judging roughly by what my power bill is, divided by the hours in the month, I use about that amount of power, at least in summer. This is for an uninsulated house in a temperate climate with 4 students in it. The power consumption in winter is significantly higher, which is in part due to the fact that 70 year old houses with no insulation at all leak heat like a sieve, and due to regulations, we can only use electric heating. Central AC pulls 3.5 kW when it's running, but it doesn't run all day long, it only runs for maybe 10 minutes per hour or so, if you have a well insulated house.

IanCal 11y ago

837W all day long is 20kWh, almost exactly so I guess that's the figure used. That's roughly double my usage in the UK, and I work from home. It's ~7300kWh/year, which is a bit lower than the US average of almost 11000kWh (https://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3 https://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3). In the UK it's an overestimate as we average closer to 4000kWh (chart 3: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/449134/ECUK_Chapter_3_-_Domestic_factsheet.pdf https://www.gov.uk/government/uploads/system/uploads/attachm...)