Peak power * time gives you just an upper bound, which might be much more than the actual power consumption. When I run my washer, the peak power might be about 2kW and it might run 1.5 h, but the power consumption isn’t 3kWh. It is rather like 0.3kWh.
Tumble dryers might vary by the power consumption very much. Some generate heat just by burning the electricity, some have heat pumps.
I know that it’s peak power, but the appliances take this peak power during start for 15 to 30 minutes. If I want to run them on solar power only I need to make sure that I have enough excess energy or some energy left in the battery.
I already thought of some kind of automisation that takes care of the complete profiles eg.
start the dish washer if there is enough excess power for the initial peak and start the washing machine as soon as the initial peak is over and there is enough excess power left to run the washing machine. I would need to create energy profiles with a resolution of around 15 minutes and I have no idea how to do this without using python.
Drying over night / outside is our prefered way but with 4 kids it’s impossible during winter time
I switched to a heat pump dryer and the power reduction / cost had been dramatic, I was seeing regular consumption over 2kW with our old dryer.
Here is a load of towels:
Here are the resultant energy consumption and costs using solar.
This is something that I still struggle to understand. The initial power always much higher than the solar panel power production.
Let’s say oven, I measured it starts with 2000 watts. At that time, I measured the solar panel power and it’s 1000 watts. Just for example.
Those are power in watts. To convert into kWh energy, we need how long does it run, the time.
But, I don’t know how this plays out with the return to grid, that’s also in kWh.
So, if anyone know how all this calculated, I need to understand. Especially if this can be compared to the energy company calculation.
No, that’s different. The oven example, it will use 2000 w to heat up the oven chamber. That’s how it works. So, there’s nothing wrong with that.
The solar panel power output would depend on the sun shine. In clear day it can output 2500 watts, just an example. But on cloudy day, it’s only 500 watts. This is normal.
What I want to understand, how all this calculated when we are talking about energy in kWh.
Does the smart meter device calculate the energy every hour or every X minutes? When sending back the data to the energy company.
Do you have a 1 or 3 phase installation? It is highly depends on the country’s legal regulations what you are asking.
Energy is basically power integral time.
This can help to understand how is energy calculated. There is a section of the Riemann Sums as well.
Mine is 1 phase, live in the Netherlands. I have been trying to figure this out, but still not clear.
1 phase is far more easier than the 3 phase setup. With 1 phase either you consume or produce. Meanwhile at 3 phase you have 3 separate phases to produce and consume and there are plenty ways to calculate it.
If I would be you, I would take my contract from the electricity company and I would check in that how it is regulated, or I would search PV sites from the Netherlands where they explain how is it working according the current regulations.
It is one thing, how it reports, the other is how much it costs you or how much money it makes for you. Is there peak hours, or is it at a flat rate, etc. Better to dig into your contract and local websites.
Some country’s has recently changed regulations multiple times, depending when you signed your contract, you fell under that category/regulation. Maybe you are even grandfathering an older one.
Ie.: California has now NEM 3.0 (Net Energy Metering), which caused a serious setback for the PV industry there.
