OGBs energy usage

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Oldgreybeard
Posts: 1873
Joined: Thu Sep 09, 2021 3:42 pm
Location: North East Dorset

OGBs energy usage

#1

Post by Oldgreybeard »

Seeing Nowty's report prompted me to dig into my energy consumption spreadsheet and see what the numbers look like here. We are all-electric, no gas, oil or solid fuel, just heat pumps for heating and direct electrically heated hot water (mostly from PV generation). Just tallied our electricity consumption since 1st April (when the prices went up) to now.

Our average peak rate electricity consumption was 0.097kWh per day, our average off-peak rate consumption was 5.64kWh/day. Most of the off-peak is charging the car on days when there's not been enough PV.

This is the plot of our peak rate and off-peak rate energy use so far this year. Highlights that we barely use any peak rate electricity at all:

Energy use.jpg
Energy use.jpg (44.14 KiB) Viewed 768 times
25 off 250W Perlight solar panels, installed 2014, with a 6kW PowerOne inverter, about 6,000kWh/year generated
6 off Pylontech US3000C batteries, with a Sofar ME3000SP inverter
ducabi
Posts: 172
Joined: Sat Sep 10, 2022 5:32 pm

Re: OGBs energy usage

#2

Post by ducabi »

Slightly over 20kwh a day in winter looks really good. How is your house insulated? Im tempted to go for ASHP but everyone says it's no-go for a late 80s detached house with no insulation in cavity.
Oldgreybeard
Posts: 1873
Joined: Thu Sep 09, 2021 3:42 pm
Location: North East Dorset

Re: OGBs energy usage

#3

Post by Oldgreybeard »

ducabi wrote: Tue Sep 13, 2022 2:53 pm Slightly over 20kwh a day in winter looks really good. How is your house insulated? Im tempted to go for ASHP but everyone says it's no-go for a late 80s detached house with no insulation in cavity.
The house was a new build in 2014, so pretty well insulated and also airtight. It was built with triple glazing and a heat recovery ventilation system too, and they help. The true winter energy consumption for the house alone is a bit lower than those numbers suggest, as we have an electric car, so its running cost is included in the total electricity used.
25 off 250W Perlight solar panels, installed 2014, with a 6kW PowerOne inverter, about 6,000kWh/year generated
6 off Pylontech US3000C batteries, with a Sofar ME3000SP inverter
Oldgreybeard
Posts: 1873
Joined: Thu Sep 09, 2021 3:42 pm
Location: North East Dorset

Re: OGBs energy usage

#4

Post by Oldgreybeard »

Just been comparing the "forecast generation" feature in HA against reality. The forecast uses the local Met Office data, from a weather station only about 5 miles away, but is pretty diabolical in terms of accuracy, especially on a dull day like today. This was the predicted generation for today:
Solar generation forecast.jpg
Solar generation forecast.jpg (22.38 KiB) Viewed 725 times
and this is what we actually got:
Solar generation actual.jpg
Solar generation actual.jpg (24.86 KiB) Viewed 725 times
Seems we generated a fair bit more than the forecast, but still only a total of 4.85kWh for the day. The battery is now down at 52%, so will see us through until the off-peak period OK.
25 off 250W Perlight solar panels, installed 2014, with a 6kW PowerOne inverter, about 6,000kWh/year generated
6 off Pylontech US3000C batteries, with a Sofar ME3000SP inverter
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