Newbie questions on PV panels and battery

waveydavey48

Hi, I've exchanged contracts on a new build house and expect to move in around April. The house will have 8 PV panels, an EV charging point and no battery. I don't have an EV at present but will probably get one when I change cars in 2 years time.
Please excuse the newbie questions I'm just starting to consider the whole subject.
The MSE forum tells us
 "The average three-bedroom household will save £582 per year on electricity with solar panels and a solar battery – around £130 more than with solar panels alone."
No doubt that's right but it seems odd to me. I would have thought a battery would save more than that because the average household will use more power after the sun has set, especially on a winter night when we have most appliances on. I'd welcome any comments.

Also,I hear a lot of people saying that it's less lucrative to have PV panels now because the tariffs have changed and householders get a lot less for the electricity they sell back to the grid. Is that right?

Any advice on selecting the best tariff?

Thanks folks 
Dave


    

Netexporter

Simply put, you can sell solar for more than you pay to charge your battery overnight. So, as a normal routine it is simplest to just run the house from batteries, as you can do that winter and summer, and just sell the solar for the best price you can get. One caveat is that you'll need enough battery capacity to cover your daily needs, although you'll still be covered from the mains in addition, if required.

Octopus have the widest range of tariffs, so you should be able to find one to suit your use case. Both the Gary Does Solar and Tim & Kat's Green Walk Youtube channels have plenty of information and calculators to help you find the most suitable tariff.

Slinky

I'd caveat  Netexporter's comments by saying you can 'often' buy electricity in at a cheaper rate than you can sell it but it's not always the case, and certainly isn't at the moment with grey skies and low wind speeds, overnight rates are higher than the 15p you can get for selling any excess. Summer you'll do much better than winter in this regard.

matt_drummer

Slinky said:

I'd caveat  Netexporter's comments by saying you can 'often' buy electricity in at a cheaper rate than you can sell it but it's not always the case, and certainly isn't at the moment with grey skies and low wind speeds, overnight rates are higher than the 15p you can get for selling any excess. Summer you'll do much better than winter in this regard.

Odd.

I buy all my electricity overnight from Octopus at 7p per kWh .

QrizB

matt_drummer said:

Odd.
I buy all my electricity overnight from Octopus at 7p per kWh .

Don't be disingenuous.

You're on an EV tariff, and have enough battery capacity to see you through the day.

waveydavey48 said:

The MSE forum tells us
 "The average three-bedroom household will save £582 per year on electricity with solar panels and a solar battery – around £130 more than with solar panels alone."
No doubt that's right but it seems odd to me. I would have thought a battery would save more than that because the average household will use more power after the sun has set, especially on a winter night when we have most appliances on.

The MSE article is making some assumptions about the house, the solar installation and the battery size. But it's a reasonable guide.

There's hardly any sun in the winter months, so you are unlikely to be able to store much electricity in a battery.

In the summer months, there's lots of sunlight and you'll end up generating more PV electricity than you can store or usefully use.

Reed_Richards

If you had the EV you could be on an EV tariff which will give you a cheap overnight rate to charge your car and also any solar battery you might have.  Without the EV it might be harder to find an overnight rate that is as certain to be inexpensive. 

Almost everyone here is such an Octopus fan that they overlook other options, but Eon Next will currently give you 7 hours at 6.7p per kWh and will pay customers 16.5 p per kWh for exported electricity.  

matt_drummer

QrizB said:

matt_drummer said:

Odd.
I buy all my electricity overnight from Octopus at 7p per kWh .

Don't be disingenuous.

You're on an EV tariff, and have enough battery capacity to see you through the day.

waveydavey48 said:

The MSE forum tells us
 "The average three-bedroom household will save £582 per year on electricity with solar panels and a solar battery – around £130 more than with solar panels alone."
No doubt that's right but it seems odd to me. I would have thought a battery would save more than that because the average household will use more power after the sun has set, especially on a winter night when we have most appliances on.

The MSE article is making some assumptions about the house, the solar installation and the battery size. But it's a reasonable guide.

There's hardly any sun in the winter months, so you are unlikely to be able to store much electricity in a battery.

In the summer months, there's lots of sunlight and you'll end up generating more PV electricity than you can store or usefully use.

The OP will have an EV charger.

My battery capacity doesn't change the fact that you can buy electricity for less than 15p per kWh to store in any batteries the OP may install.

That was what they were asking.

@slinky said you can't buy electricity for less than 15p per kWh at the moment due to the weather, well you can, and so could the OP with their EV charger.

They only need to do one charge on it to activate IOG and if they don't have their own EV, just find somebody who has.

subjecttocontract

You don't say where your new house is located. There is a massive difference between being located in Scotland or on the south coast. In any event there will be many days throughout winter when there is very little solar energy to charge a battery.

matt_drummer

There's also Tomato Energy.

Don't they do tariffs with 5p per kWh slots?

I am sure lots of people are on that with no EV.

So, with batteries, on TE, you could buy some, most, or even all of your electricity at 5p per kWh depending upon use and battery capacity.

tlcgrantham

matt_drummer said:

There's also Tomato Energy.

Don't they do tariffs with 5p per kWh slots?

I am sure lots of people are on that with no EV.

So, with batteries, on TE, you could buy some, most, or even all of your electricity at 5p per kWh depending upon use and battery capacity.

Tomato Lifestyle tariff offers 5p per kWh from 1:00-6:00am and their EV version 5p per kWh from midnight to 6:00am + 14p per kWh from 10:00pm to midnight and 9:30am-11:30am.

wakeupalarm

Do you get paid for export on Tomato Energy, if so how much do they pay?