Is there a method to Calc, Gas vs Electric Cost allowing for 6 hours cheap rate electric?

Paul_Poole

A simple assessment of Gas vs Electric cost is visible in the rates charged per kWh. Gas is cheaper being the answer.

But over time things have changed. Below are my considerations, I do hope someone can make suggestions that could be considered, at present the quantity of gas used is massive compared to the electric, but I do feel we are moving forward.

DATA (ANNUAL USAGE)
Electric Used - 1100kWh
Exported, extra over self usage - 2600kWh
GAS - 8500kWh (7 Rads aver. overall usage  1215 kWh)

Gas includes hot water and a Combi Boiler, 1 heat source, 7 radiators

*** The additional bonus here is having an EV, we get 6 hours per night when 'the whole home' electric is just 7.5p (Which includes topping up the battery in the low months.)

Those 6 hours are all year, but in winter they are the coldest, when heating cost are greatest.

My mind has got thus far, but being able to better assess the savings and how has brought me to a stand still.

I welcome any comments, suggesting, formulas people may be aware of for specific areas.

Thanks in advance

born_again

What is the aim?
Swap to heat pump instead of Gas heating?

Paul_Poole

Hi, John 3:1-21 'in Full'

THE AIM: I am looking to maximize savings from what I have or tweak things to make further improvements.

Sadly neither system does everything, have a true south facing roof elevation in south UK, solar made sense.

We did consider, Heat Pump, but we felt it didn't offer us as much benefit compared to Solar. One reason being the amount of heat it would generate for the central heating may require larger radiators as well.

Thanks for your comment, enjoy the day.

MultiFuelBurner

The only way to save is to cut down on usage. Or maximise the price you get for your solar export which will cover most of your gas bill if exporting 8500 and will more than pay for it if with Octopus selling it back at 15p kWh and on tracker gas at 4p kWh.

Veteransaver

Not really sure what the question is here. Your gas usage is high primarily because that is the heating requirement of your house. 
If your gas boiler is 90% efficient then your heating requirement is 90% of 8500kWh
There isn't really a way round this requirement, unless you improve the household insulation and reduce hot water use and have the temperature set lower.
Obviously there are different ways of getting that c8650kWh heat requirement, Eg with electric / heatpump/ different boiler etc.

Alnat1

Have you considered the benefit of a heat pump to the planet, rather than yourself? The cost to run it would probably be quite similar to what you use for gas heating, so it won't, most probably save you money, although with a good electricity tariff and no gas standing charge to pay, it might. 

Could be worth getting a quote from Octopus which will include the price of any radiator upgrades you need. A quote costs nothing.

Paul_Poole

MultiFuelBurner said:

The only way to save is to cut down on usage. Or maximise the price you get for your solar export which will cover most of your gas bill if exporting 8500 and will more than pay for it if with Octopus selling it back at 15p kWh and on tracker gas at 4p kWh.

Hi MulitiFuelBurner,

Thanks for the bottom line.

Solar export is 2600kWh

we get the 15p kWh from Octopus 

Paul_Poole

Veteransaver said:

Not really sure what the question is here. Your gas usage is high primarily because that is the heating requirement of your house. 
If your gas boiler is 90% efficient then your heating requirement is 90% of 8500kWh
There isn't really a way round this requirement, unless you improve the household insulation and reduce hot water use and have the temperature set lower.
Obviously there are different ways of getting that c8650kWh heat requirement, Eg with electric / heatpump/ different boiler etc.

Hi VeteranSaver

Thanks for your very clear reply.

I think I got frustrated trying to work out the cost of gas in total, compared to 7 electric heaters, with the octopus intelligent EV giving 6 hours per night at 7.5p kWh

Paul_Poole

Alnat1 said:

Have you considered the benefit of a heat pump to the planet, rather than yourself? The cost to run it would probably be quite similar to what you use for gas heating, so it won't, most probably save you money, although with a good electricity tariff and no gas standing charge to pay, it might. 

Could be worth getting a quote from Octopus which will include the price of any radiator upgrades you need. A quote costs nothing.

Hi Albat1

Our Solar is only in its second year so not been installed long, the 7.5p nighttime rate started me thinking, can I save a little more, have I missed something, at this stage I am probably trying to squeeze juice from a squashed lemon. 

A more positive saving may be to have another 8kWh battery installed in parallel and fill them overnight in winter at 7.5p kWh, drawing from the battery through the day. That would bring the whole home and EV electric down to the same amount.

But probably £3500 for a second battery, I would need to consider payback period.

Thanks for your suggestions. 

born_again

If you can, try charging car during the day to get extra benefit that IO provides. This would give you whole house @ 7.5p while car charging. 

Have a look at EVM on U-Tube _ Home Battery, solar or heat pump Also done some others on the costing to show savings.

QrizB

Paul_Poole said:

I think I got frustrated trying to work out the cost of gas in total, compared to 7 electric heaters, with the octopus intelligent EV giving 6 hours per night at 7.5p kWh

Gas costs what it costs (you haven't shared your full tariff details). If we say it's 7p/kWh, and your boiler is 90% efficient, that's an effective cost of ~7.8p/kWh net.

The comparative cost of electrical heating will depend on when you need the heat. If you only need heat during the daytime, electric heating will be equal to your day rate which I guess is around 30p/kWh - almost 4x more expensive than gas.

If you require constant heat 24h of the day, the average cost of electricity for heating will be 18/24 (ie. 3/4) of your daytime rate plus 6/24 (1/4) of the nighttime rate. So something like 25p/kWh, still more than 3x the price of gas.