Making the most of cheap energy rates

leeruddecology

I have EoN economy 18

My rates are as below.

7 hours between 00.30am and 7.30am – off peak rates for all consumption.

7 hours between 9.30am and 4.30pm – off peak rates for heating/water heating purposes only.

4 hours between 6.30pm and 10.30pm – of peak rates for heating/water heating purposes only.

I have a couple of questions I hope you can help with.

1. If I have a Shower at 07:30. Will the ASHP system then top up the temperate and charge me at standard rate or will it top up the temperate when it's the next cheap rate?

2. If I use hot water during the night say 01:00 will I pay night rate or stored heat rate?

3. I was told these are the winter times. Does that mean in spring I need to add an hour to all these times. Ie night rate will then be between 01:30-08:30.

Thanks in advance guys

jbuchanangb

Because you have an Air Source Heat Pump, you are on a very unusual tariff. However the usual advice for users who have a 7 hour off peak rate during the night (such as Economy 7) is to run appliances, such as washing machines, on timers to take advantage of this.

I hope there may be an ASHP expert in the forum who can give specialist help for you on how the equipment will perform, or maybe the manufacturer has a customer help line.

During British Summer time all the times will effectively seem one hour later.

matelodave

It depends on the sort of ASHP you've got, how its wired and how it's controlled. Have you got any more info. Does your heatpump run outside the cheap tariff times or is it only switched on during cheap times (which seems more sensible). What tariff are you on - how much is cheap rate and full rate

My ASHP is on standard rate electricity and heats the hot water when I tell it to using the inbuilt controls - the tank gets heated at 0700-0830 in the morning and the hot water then lasts us until the next heating cycle. If I was on an off peak tariff then I'd time it to heat the tank during the off peak period.
We are at home all day so the heat pump runs all day and evening and reduces it's temperature a few degrees overnight whilst we are asleep so I can't see any benefit of running ours on a strange complicated expensive tariff.

leeruddecology

I have a nibe fo25p system.

As far as I can make out, and I should try and be more diligent when the nibe compressor starts working, but I believe it's only during off peak periods.
My costs are with the economy 18 eon tariff are;

Standing Charge (for payment with a Monthly Direct Debit) – 16.422p per day.
Standing Charge (for payment by any other method ) – 26.019p per day.
Day usage – 16.989p per kWh. Register 04 on the meter.
Night usage – 7.361p per kWh. Register 03 on the meter.
Stored Heat usage – 9.492p per kWh. Register 05 on the meter.

I don't have settings to say when hot water is heated apart from I assume it's on demand and only then when during off peak rates which is 18 hrs of the day. As per above.

I run the washing machine during the night.

Former_E.ON_Company_Representative:_Malc

Hi leeruddecology

With Economy 18 meters, there's 18 hours of off peak electricity for heating/hot water purposes. To allow this, the meter will be wired into the heating/water heating circuits.

Also within these 18 hours, there's 7 hours at night where all usage is charged at off peak prices.

There's two rates though. Stored Heat at 9.492p per kWh and a night rate of 7.361p per kWh.

All heating/hot water usage going through the dedicated circuits during the off peak times is classed as Stored Heat and charged at 9.492p per kWh.

The other off peak usage at night (00.30am to 7.30am) is charged at 7.361p per kWh.

Other forms of heating (eg convection heaters/Air Source Heat Pump) not wired into the dedicated circuits will be charged at the higher prices even if used during the late morning/afternoon/evening periods (9.30am to 4.30pm and 6.30 to 10.30pm).

If your Air Source Heat Pump is being used outside of the night hours the consumption will be charged at the higher day rate of 16.989p per kWh. Or, 7.361p per kWh if used at night.

Unless, that is, the pump is wired into the dedicated circuits. If it is, the price will be 9.492p per kWh during the off peak times and 16.989p per kWh at other times.

Must admit, not come across a case where an Air Source Heat Pump is wired into these circuits but could be wrong and happy to be corrected.

For question 2, if you heat water at 1am it will be charged at 7.361p per kWh unless it's using an appliance wired into the dedicated circuits. If it is, the rate will be 9.492p per kWh.

You're right on question 3. During British Summer Time, the 7 hours of off peak electricity for all usage will be between 1.30am and 8.30am.

If the washing machine is used during the night period (00.30am to 7.30am), it'll be charged at 7.361p per kWh.

Hope this answers your questions leeruddecology. Let me know if you need any more details as happy to help.

Malc