How are people actually calculating their home base load?

Alnat1

https://forums.moneysavingexpert.com/discussion/comment/81964699#Comment_81964699

When you need to replace the kettle, choose a new one with a lower wattage. It will take a bit longer to boil but you won't notice the difference after a bit. I've gone with a 2kW but you can get right down to 1kW.

badmemory

The replacement kettle is in the plan but I didn't realise I could get down to 1kW.

I still have a lot of old electrical stuff which I will replace with less power intensive things when I finally get around to the new kitchen.

SAC2334

Mine is just 33 watts ( 34 watts if I dont switch microwave display off ) .router . , tv standbye, fridge .Freezer packed in two weeks ago and my base load dropped from 79 watts .

Easy to see on the excellent Octopus In Home Display showing watts in use now >

Scot_39

https://forums.moneysavingexpert.com/discussion/comment/81964751#Comment_81964751

If they were ever to follow the French SC model - banded by kVA - their could be a lot more demand for low power kit in the UK.

Of course as an all electric home - pulling a peak of 20kVA plus for short times - I wouldnt be so keen.

glennevis

https://forums.moneysavingexpert.com/discussion/comment/81964776#Comment_81964776

I have a "650W" kettle (actually draws 740W!). Capacity is 1 litre and is advertised as a caravan/camping kettle.

Heedtheadvice

I despair at times......

You have been getting lots of good but widely varying info about your headline question ( How to calculate base load effectively) but little comment about why you ask that and is it appropriate to your aim.

Your aim is "I’ve been looking into plug-in solar recently, but before jumping in I want to properly understand my base load and how much I could realistically offset.".

I will use 'baseline' as a starting point but highlight the caveats and limitations.

The fact is that your baseload (average, as it is variable over time) is a bit of a red herring to answer that question of how much you can realistically offset. The important thing is how much you can offset during periods of solar generation (assuming you have no battery storage!)

You can reliably estimate what the absolute maximum saving is and that will be the peak generating power of the solar.

You then need to factor in the panels alignment, daylight duration, any shading etc. The available model PVGIS is often mentioned on the forum and is reliable.

'Baseline' is an approximated figure for the continuous average power consumption over the whole day but you cannot offset that with solar for every 24 hours. Typically it will be something like 200 or 300 watts but daytime load ( consumption) varies a lot.

Much of that could be offset for a good portion of daylight hours in summer from an 800wattpeak set of panels. A reasonable assumption might be all of it for 8 hours a day as an average for say 180 days a year.

For sake of argument 250 watts x 8 hours x 180 days = 360kWh or about £90 per annum.

Some days no where near that amount that of generation so should be discounted other days a lot more but unless that peak generation coincides with a high power appliance consumption it will be exported and wasted.

Typically in the uk the peak theoretical generation from panels can be converted to whole year energy production by rule of thumb 1000w power panels give about 1000kWh energy or 1000units. Without a lot of effort matching comsumption to generation ( such as in sunny periods, being used by heaters kettles etc ) then it is difficult to utilise 50% of generation. 400 kWh or units might therefore be more realistic rather than 360.

You probably cannot get paid to export that wasted excess under SEG scheme ( not professional installed MCS certified etc.) unless those rules change too.

I conclusion you might be able to save about £100 per annum on electricity purchase and it depends on the balcony system purchase and installation cost ( and any hidden costs if there are any ) to decide if it is worthwhile.

Saving a £100 per year it could well be worth it?

born_again

To add plug in Solar at best is only ever going to supply 800w.

So to get the bast you need to think of batteries to go with it for the times when solar is not cutting it.

Scot_39

These are sold in part on low cost, adding a battery could easily double that - looking at one vendors pricing - pushing it perhaps beyond many's reach.

I wonder if for instance if more German homes and in particular flats use conventional panel electric heating, several hours a day - given FFH use German made tech iirc - so utilise the full power available more easily without battery costs.

lohr500

Drifting away from the original question but how do lower wattage kettles save money?

Google says the energy required to raise 0.5 litres water from 15 to 100c is 49.5Wh.

Surely a 2kW kettle will just boil the water in half the time of a 1kW version, but the energy used will be the same.

Or does a higher rated kettle risk wasting some energy because it is more likely to overshoot the cut off point slightly with small volumes of water?

QrizB

Drifting away from the original question but how do lower wattage kettles save money?

By drawing a lower power for a longer period, IF you've got a solar PV system (or similar) that can satisfy the lower power demand without importing but which is unable to meet the higher power need.

Surely a 2kW kettle will just boil the water in half the time of a 1kW version, but the energy used will be the same.

Yes. But …

Google says the energy required to raise 0.5 litres water from 15 to 100c is 49.5Wh.

49.5Wh = 178.2 kJ = 178.2 kW-seconds. Call it 180 kW-seconds.

A 2kW kettle will take 90 seconds to boil 0.5 litres. A 1kW kettle will take 180 seconds.

If, for that period, you are generating 1kW from solar PV, using the 2kW kettle means that half of the electricity for your kettle is being supplied from the mains. If you use the 1kW kettle, all the energy is supplied by solar PV and you don't draw any of it from the mains.

(Of course if you've got a big enough solar PV system (and/or a battery) that can provide 2kW on demand, you might as well use the 2kW kettle.)