New batteries being installed - is it worth going to eco 7 to charge them overnight?

Hi @Llamedospete and @Transparent - some really interesting discussion here that I am keen to delve in to a little!

When you say 'proper time of use' tariff @Llamedospete , what sort of thing are you referring to?

If, as @Transparent says, it's a similar type of thing to what Octopus provide, I'm really curious as to how you would see this working for you? How would you use it to your benefit?

Really look forward to hearing more on this.. anyone else reading this with an interest in time-of-use tariffs, we would love to hear from you too!

That's a massive question @Hari_OVO !

I guess most electricity consumers don't yet realise the parameters which might be taken into account when TOU Tariffs are being set.

Most, like @Llamedospete, probably imagine it will be some kind of extension to the present Economy-7 system. As such they envisage still going through an annual comparison-site and selecting an Energy Supplier who provides preset rates at a number of time-zones during the day.

I don't see it like this. Since we're on the open Forum, let me put forward two scenarios which show alternative reasons why the cost per kWh might vary:


A. I live in a rural region that has a surplus of renewable energy. There is insufficient capacity in the Transmission Grid (above 32kV) to send this surplus back up the line to cities that are in energy deficit.

So on sunny or windy days, the cheaper rates are more likely to be available to me in the middle of the day rather than at night.

If I have a Storage-Battery or an EV connected to my charger, I might configure these to

• take in electricity when the cost per unit falls below 10p, or
• take in electricity when it is at least 5p /unit lower than the evening peak

I don't need to micro-manage this, and I don't care which half-hour (HH) slots of the day are actually used. I've simply used the touch-screen on my IHD to facilitate savings which fit within my preferred energy-usage profile.


B. Electricity DNOs are financially incentivised to minimise losses in the Distribution Grid (32kV and below). Currently this RIIO-ED1 strategy is having little effect.

Technical Losses (ie excluding theft!) have increased from around 5% to 10% over the last 20 years, not helped by numerous customers adding solar-panels to their single-phase domestic supplies!

The graph here shows the current being drawn by the three-phases (L1, L2 & L3) on a Feed named "Ash" at a sub-station about 2Km from where I'm based.

When there is a current imbalance between phases, the efficiency of the substation transformer falls. This energy-loss causes a corresponding rise in the core temperature.

It is quite possible that a DNO might wish to meet their RIIO-ED1 targets by reducing the phase-imbalance. In short, I could instruct my Storage Battery to "Track Δ-Phase of my sub-station" and be rewarded with a financial bonus for reducing the losses.


Now I'm not suggesting that customers should in any way need to get involved with the technicalities of how the price-per-HH timeslot is actually calculated.

The reason I have access to this substation data is so we can test what sort of incentives are likely to result in consumers changing their energy usage. The actual user-interface may be extremely simple.


(Aside: The above graph is in reverse time notation. As it's a snapshot of a "live" data-feed, new readings are being added to the left side of the x-axis.

These are average figures per HH per phase. The 93A average on L2 around 7pm on Saturday evening was actually a peak of 139A coinciding with the start of Michael McIntyre's Big Show on BBC1 and Top Gear Highlights on BBC2.

I can provide further explanations if requested!)

Hi @Hari_OVO - you work funny hours. Just as everyone else leaves OVO at the end of the day, you post another provocative message on the Forum!

I mentioned only Battery Storage because that's the Topic title which @Llamedospete started. I think the whole subject of stored energy is actually far wider.

I see four main reservoirs of energy in homes:

• Storage Battery
• EV with V2G charger
• Thermal-store or Hot-water cylinder (using immersion heater)
• Electric Storage Radiator

The first two have bi-directional capabilities whilst the latter two are input-only.

Some homes will also be micro-generators. Most commonly these will have PV-panels (single-phase 4Kw max). However, a few may have a wind- or water-turbine etc.

I also discriminate between two different categories of imbalance which is wasting energy in the UK:

• Phase imbalance causing losses in the Distribution Network (32kV & below)
• Surfeit of renewable generation in a geographical region

All of these need a better level of management using Smart Meters, LV-CAP (in sub-stations) and a national computer management system with knowledge of the distributed resources (Vcharge).


If there is need to balance the distribution grid in an area, VCharge could dump excess generation into the energy reservoirs of that region based on the parameters set up by the customers.

Some customers may have only storage radiators (connected via ALCS to their SMETS2 meter). Typically these might be elderly people or historic houses. In either case it doesn't matter how/when the radiator is supplied with power, so long as the building meets a preset temperature profile.

Vcharge may in fact elect to dump energy into a local network of OVO's customers on the PSR who have storage radiators by taking it from neighbouring houses with PV arrays and hence avoid having to pay for any transportation across the Transmission Grid!


Equally, if there is a regional/local energy deficit (eg the evening peak), then Vcharge can call on the available Storage Batteries and EV's according to their preset parameters.

An EV owner with V2G may, for example, set up preferences on their IHD to set up the following rules:

* You may access 70% of my vehicle's stored energy between 6-10pm. This leaves me 30% if I need to pop out during the evening.

* You must credit me at least 1.6p /unit more than I paid to charge my EV

* You must recharge my EV between 10pm-6am to a minimum 50% so that I have enough energy to drive to work.


Interestingly, many of the constituent parts of this 21st century smart-grid are in the hands of the OVO Group! However, we have as yet seen little sign of these being promoted into the innovative roles that I've outlined above.

I think OVO needs to migrate from seeing itself as a Domestic Energy Supplier and mutate into being a Domestic Energy Facilitator. This requires a bolder, more adventurous path to widen the income-stream beyond a defined set of customers with an account!

This will include offering VCharge's distributed network management system to Community-run Microgrids, particularly on new-build estates where every house will have SMETS2 meters and EV Chargers.

The Community Group pays for access to VCharge, whether or not individual customers are signed up to OVO. However, OVO may elect to receive that payment in kind, as renewable-energy exported from the Microgrid which it needs to satisfy its growing demand from customers signed up to a Green Energy Tariff.

... and once again, @Hari_OVO , you've opened a massive subject area which I can hardly do justice too with a text-only posting on the Forum!

Hey @Transparent , sorry for the delayed response!

You've got some really great ideas and I think one thing we are certainly agreed on is that the end consumer should be able to optimise their device behaviour with minimal complexity, through intuitive user interfaces!

As a start point, I don't think our VCharge platform is a million miles off getting to some of the things you have outlined. For example, if you have a V2G Charger, with the accompanying app you will be able to tell us the minimum charge level you want in your Nissan LEAF at any time, then based on network signals we will:

• Charge your car when demand on the grid is low
• Export power to the grid when it needs it most

And best of all, we'll pay you your import unit rate + 6p for every kWh exported. And, if you need your car in a hurry you can override any signals via one simple click of a button in-app.

I appreciate this is probably only the tip of the iceberg (and I really like the idea of being able to make money from pausing my washing machine and dishwasher!) - but we're regularly looking to understand how we can bring flexibility to more people, as I said above, with minimal complexity and in an intuitive manner. With our V2G Charger, and our Smart Charger - we're just at the beginning!

Exciting times...

Hari

HI guys
Sorry for suddenly going quiet but have been busy monitoring my batteries to see how they perform before taking the plunge.
What I have found is that on a full 100% charge overnight the battery (winter time) will last up until around 10.30pm before running out. So if I charged at eco7 overnight the battery would cover most of the day, but when heavy use is made I.e. tumble dryer (no timer on it) the battery will only last until maybe 3.00pm before running out. This would mean paying a higher rate for the rest of the day.
I can mitigate this to a certain extent by only using the washing machine overnight.
Now the decision I have to make is overall would I still see savings even though at some times I will be paying a higher rate for my electricity and I think that the answer is yes but it will be reduced by my tumble dryer having to be used during the day.
The other use (and the main reason for the batteries) is that I have 4KWp of solar PV on an east facing roof. This means that during the summer I lose generation around 3.30pm, my idea is to have the PV supply all my power needs during the day till 3.30 and charge my batteries so that they will take the load from then on to even out my solar generation, this means that during the summer months having eco 7 would not matter as should not use any higher rate electricity.
So I think that yes eco7 should see worthwhile savings over the year.
Rregards to all Pete.

HI .@Transparent
Yes very interesting times, and I have started hearing about the buy back of electricity if you have batteries, would definitely be interested in these schemes when they get going. Monitoring the batteries you are right, I have already worked out that for winter use I may have to add another 2.4KWh battery as current 7.2KWh stack is struggling to cope and what I don't want is a future scenario of being on ToU tariff and my battery gives up during the early evening while using the cooker in the most expensive time period, my battery needs to be able to take me through to at least 8.00pm.
Rregards to all Pete

HI .@Transparent

Yes and where I am would be a brilliant area to trial it as have a large offshore wind farm and a huge solar farm both feeding into my towns 11kv substation, so chances are we nearly always have renewable power feeding the town.

Just seems that the DNO's are being a bit slow off the mark with domestic battery use, maybe not enough out there yet but I think that that's about to change as domestic batteries are now down to an affordable price at last, only reason i have taken the plunge. (Beware of electricians who are buying batteries at wholesale price then doubling the price to you for installation, they are conning you)

Rregards to all Pete

Keep us posted, @Llamedospete !