Smart Energy Usage
Posted 04 March 2016 - 08:32 AM
Posted 04 March 2016 - 08:43 AM
The solar PV was generating nicely, the dishwasher and Oven was on.
I recall every time the themostat on the oven clicked on, I went and stopped the dishwasher, and re started it when the oven thermostat clicked off. All very OCD but I thought "I wonder what it would take to automate this" and concluided far too much on that level.
I can see a well insulated freezer perhaps being able to avoid using power for an hour or 2 if "told to"?.
Posted 04 March 2016 - 08:54 AM
I estimated several GW of available 'virtual power station' in the UK from household devices alone:
Posted 04 March 2016 - 09:03 AM
The best method to get something done politically would be scheduled power cuts.
Posted 04 March 2016 - 09:06 AM
Posted 04 March 2016 - 09:41 AM
Just had a quick re-read of your bit about turning things off by using grid frequency. I am not so sure that it can be done on frequency as the national grid coordinates the ramp up and ramp down times to suit demand. This often means that there are times when frequency is high during low demand times (early morning getting ready for the kettles and showers) and late evening the frequency can be lower as things 'wind down for the night'.
Edited by SteamyTea, 04 March 2016 - 09:49 AM.
Posted 04 March 2016 - 10:51 AM
Edited by DamonHD, 04 March 2016 - 10:52 AM.
Posted 04 March 2016 - 11:20 AM
Not an insurmountable problem as the NG knows when it is ramping up and down and can look for, and act on, variation within those timeslots.
But it is not a simple model, like a generator and fractional loads, it is fractional generation and fractional loads, which is harder to manage.
Posted 04 March 2016 - 09:51 PM
Switching off freezers during peak for me is a must do thing
I would have saved us building a new power station had we been quicker off the maths
Edited by tonyshouse, 05 March 2016 - 08:55 AM.
Posted 05 March 2016 - 05:56 AM
Posted 05 March 2016 - 09:45 AM
Why? Do you have the most inefficient freezer you could buy 30 years ago?
We have 2 freezers. One of them consumes 50W for about 10 minutes every hour, the other consumes under 30W for about 20 minutes every hour. Turning them on and off is going to achieve absolutely nothing in terms of demand reduction.
Posted 05 March 2016 - 10:19 AM
Posted 05 March 2016 - 10:30 AM
Posted 05 March 2016 - 10:32 AM
If you have a look at Damon's Grid Intensity webpage:
At 18:00 last night, we used 46GWh of electricity.
If we say a fridge uses 10W when running, and there are 50 million of them, then that is 0.083 GWh.
Or 0.2 of generation capacity.
Posted 05 March 2016 - 10:48 AM
Posted 05 March 2016 - 11:35 AM
The numbers are HUGE. Those two alone would match the output of Hinkley Point C.
The issue here is to shift consumption away from peak times or when the grid is having a bad moment AS WELL AS reducing overall consumption (eg better freezers). The effect will be to reduce the amount of explicit reserves and the maximum system capacity, and thus costs.
Edited by joiner, 05 March 2016 - 11:42 AM.
"bad" for "bade"
Posted 05 March 2016 - 11:49 AM
AFAICS, most of the grid problems occur during the late afternoon/early evening, so greater take-up of PV would probably resolve this for much of the year. A bit of buffer storage to tide the grid over the couple of hours after PV generation stops whilst demand is still high would probably fix things, and from the scale of it it looks as if a couple more pumped storage schemes might achieve this, if we had a fair bit more PV.
I've been looking at what it would take to get our house totally off-grid, and it really comes down to having around another couple of kWp of PV plus around 20 to 30 kWh of storage. Not realistically economical for us at the moment, but it may well be in the next few years, I'm not sure that it's the right approach to take, though, and can't help but wonder if small scale community energy storage, grid connected, might not make more sense. The grid is pretty robust at its core, the weak areas seem to be at the ends of the distribution network. Buffer those with storage and the result is more beneficial than building a couple more Dinorwic scale storage systems.
Posted 05 March 2016 - 12:08 PM
It won't be quite the same in the UK as in CA, but it's one reason why when I get my hands on a SunampPV I shall have it only draw between (say) 11 and 4, in particular to spill whatever is possible to grid as peak demand ramps up starting at 4pm.
Posted 05 March 2016 - 12:10 PM