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

Petriix

I understand what you're trying to do. The answer is that it's complicated. Ultimately you want to minimise consumption and maximise exports. You obviously want whatever consumption you can't avoid to be at the cheapest rate possible. Gas is likely very close in cost to your off-peak electric so there's an obvious advantage to gas because it's the same price whenever you use it. 

The only wins would be:
1) if you could remove the gas supply completely then you wouldn't pay the standing charge
2) any electricity you use inside the house will give consequential heat. If you run appliances close to the end of the cheap period then that heat might be useful in reducing demand on your central heating. 

I've been running a 400W dehumidifier for the whole 6 hour window and, as well as doing its primary job, it's effectively a small heater which increases the background temperature (albeit at a suboptimal time).

A battery might be cost effective coupled with some kind of heat pump but it would be a long ROI. Ultimately, if you can heat your house at a COP of 3+ using electricity at 7.5p per kWh (less round trip losses) you might be looking at ~ 3p per kWh of heat vs maybe 8p for gas in the real world. Over a year that might save you 5p x 8,500kWh so over £400. That's obviously contingent on tariffs staying as they are.

My suggestion would be to avoid making any big outlay at this point and only replace the gas boiler with a heat pump at the end of its useful life. Maybe invest in the Ripple Energy 'Big Wind' project and see where things are in a couple of years. 

wrf12345

I wish the govn would do something simple like offer £5000 grants for permanent removal of the gas supply rather than creating layers upon layers of agencies and companies to implement things like Eco4, that would open up the market for much more competition in fitting heat pumps (personally I favour air to air individual units, some of which are DIY). The body is designed to sleep in cool bedrooms, BTW so heating the house overnight is not a good idea.

Paul_Poole

born_again said:

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.

Hi
Not sure what IO refers to here?
The package I have is....  Intelligent Octopus Go with 7.5p only between 23:30 to 5:30,  daytime is at higher rate about 30p kWh through the day.

Paul_Poole

Paul_Poole said:

Using the details from my first post on this thread

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.

Putting my thoughts another way

We use 8500kWh of gas over the year, this is from the combi-boiler to 7 radiators (Leave hot water out of the equation for now). Should I expect 7 electric wall heaters to use as similar amount of kWh? Depending of course on the type of electric wall heaters. A general idea is all that is required, is the thought feasible or incomparable?

Gerry1

Paul_Poole said:

born_again said:

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.

Hi
Not sure what IO refers to here?
The package I have is....  Intelligent Octopus Go with 7.5p only between 23:30 to 5:30,  daytime is at higher rate about 30p kWh through the day.

See the Bits in Bold !

QrizB

Paul_Poole said:

Putting my thoughts another way

We use 8500kWh of gas over the year, this is from the combi-boiler to 7 radiators (Leave hot water out of the equation for now). Should I expect 7 electric wall heaters to use as similar amount of kWh?

This question has been answered at least twice in this thread.

We don't know how efficient your boiler is, but assuming a 90% efficient gas boiler, switching to direct electric heat you'd be using ~7650kWh of electricity instead.

This would probably cost between 3x and 4x as much as your current gas bill.

Petriix

Paul_Poole said:

born_again said:

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.

Hi
Not sure what IO refers to here?
The package I have is....  Intelligent Octopus Go with 7.5p only between 23:30 to 5:30,  daytime is at higher rate about 30p kWh through the day.

Intelligent Octopus Go is 7.5p whenever the car is scheduled to charge by Octopus in addition to the 6 hour overnight window. If you plug in at 7am and set the app to add say 50% of the battery capacity by 11am then you'll likely get some extra slots at thay cheap rate. However it's probably a bad idea to base medium to long term investments on the current pricing because it could change.