5 ms·
By my power-wasting standards, I use about 8 KWh a day. A max 7 MW(h?) turbine generates at most 1.94 KWh of electricity a second. It seems to take 3-4 seconds
by z2 7y ago
By my power-wasting standards, I use about 8 KWh a day. A max 7 MW(h?) turbine generates at most 1.94 KWh of electricity a second. It seems to take 3-4 seconds for a single turn. The math checks out and this is, as you say, incredible.
- verall 7y agoThis math checks out but the way you present the units is deeply confusing. It's not your fault though, I blame watt-hours. You use 8kwh==28.8MJ of energy per day. 28.8MJ/7MW turbine is about 4 seconds, as a watt is a joule per second.
- jessriedel 7y agoI found his units to be significantly more clarifying than yours. There's nothing wrong with having units of time (or distance) in both the numerator and the denominator, depending on the context. For instance, the Hubble constant is commonly expressed in km/s/Mpc, and astronomers purposefully don't cancel the units of distance. In this case, there are two distinct timescales involved: the scale on which the energy is used (an hour or day) and on which it's generated (a second). It's ok to keep track of those separately.
- verall 7y agoThere's nothing "wrong" with the units, besides that it is easy to get confused, evidenced by GP calling the turbine "7MW(h?)". If you want to compare, however, you will have to convert to common units, and I at least find it easier to use watts and joules than watt-hours/second and watt-hours. By all means convert to stationary-bike-hours and big macs or whatever unit at the end but calculations are easier in the SI units. Hubble's constant is expressed like that because it is a nice unit for the math.
- perilunar 7y ago> In this case, there are two distinct timescales involved Three really: seconds, hours and days. 8 kWh per day = 8 Joules per second ⋅ hours per day ~= 330 Watts Sometimes you even get four time units in one go. e.g. "I averaged 8 kWh per day last year" It's madness.
- js2 7y agoMy home uses 72 kWh/day (16-20 of that is charging a Chevy Volt), so even at my extreme usage, it's less than two minutes to provide my daily power needs. These are amazing: https://www.siemensgamesa.com/en-int/products-and-services/offshore/wind-turbine-swt-7-0-154 https://www.siemensgamesa.com/en-int/products-and-services/o...
- driverdan 7y agoWhy are you using so much power? Do you use electric for everything including heat and cooking?
- js2 7y agoOver 4000 sq feet, three stories, mid-atlantic. I need to have an energy audit done though; it's still a lot.
- tialaramex 7y agoYeah, that seems entirely crazy to me. I was like "That seems high" so I checked my usage meter and it say 112kWh. OK then. Then I notice it's set to monthly. So that's about 4kWh per day. It will be a bunch more in winter, and your place is much bigger than mine, but still - that number seems kinda crazy huge to me.
- megaremote 7y agoThat is awful.
- rsynnott 7y agoThat’s a _lot_. That would cost you 5k euro a year here! Do you have a good sense where it’s going? Unless there’s something obvious, you might want to get the meter checked.
- Symbiote 7y agoIt's the kind of figure that suggests someone has tapped the supply and has a cannabis farm next door.
- driverdan 7y ago8 KWh/day is very impressive. How did you get it that low?
- z2 7y agoI guess it's all relative! I'm not home much of the day, live in a newish condo with LED lights, and heat and cooking use natural gas. 8 KWh feels like a lot to me as it's enough electricity to power an oven for several hours each day.
- thomaslkjeldsen 7y agoThe common advice (in Denmark) is to buy energy efficient electrical appliances. Fridges, washing machines, dishwashers, and led lights are labelled[1] so consumers can decide for themselves. School kids are taught (well, at least I was) small habits such as boiling just the amount of water that you need, cooking with the lid on, turning off the oven 5 minutes before the meal is done, etc. These energy saving habits are motivated by taxes on energy consumption. The average household in Denmark use 4.4kWh/day per person (1600kWh a year) and the current recommendation is to be aiming at 1000kWh/year[2]. [1] https://en.wikipedia.org/wiki/European_Union_energy_label https://en.wikipedia.org/wiki/European_Union_energy_label [2] https://sparenergi.dk/forbruger/el/dit-elforbrug https://sparenergi.dk/forbruger/el/dit-elforbrug (in Danish)
- benj111 7y agoIs it low? My last bill said I averaged 5kwh/day last month, my February bill averaged 7kwh/day. That's gas heating and hot water though.
- Symbiote 7y agoI have a smart meter in my apartment. A few weeks ago I was on holiday. Usage was 2.5kWh per day, about 100W, which is the fridge and a low power PC (NUC). Otherwise, it's 3-6kWh per day, and depends whether I did laundry and cooked or not. District heating and water.
- rsynnott 7y agoMine is 7kW a day; smallish house, LED lighting, gas heat and stove (though electric oven). I believe a good bit of that is the drier, tho.