Is there a fair use requirement for dual rate tarrifs?

ruddoug09

Hi!

I'm on the British Gas EV Driver tarrif that has overnight rates of 7.9p/kWh and 25.1p/kWh at all other times.

I'm charging my car as expected on the overnight rate only, but, I recently installed solar panels on the house with battery storage.  My SEG tarrif (also from British Gas) sees me paid 15p/kWh for everything I export.

As a result of the above, I'm charging my house battery overnight at 7.9p and then exporting most of my solar generation back at 15p.  The battery is sufficient to avoid having to import anything on most days at the high tarrif.

As a true long term MSE'r, I feel I'm maximising the situation but am I breaching any terms of agreement of fair use?

Reed_Richards

You are doing the grid a favour by spreading the load.  I doubt that that would contravene any fair use policy but you must have T&Cs for your particular tariffs.

Netexporter

It certainly doesn't breach Octopus' Go tariff terms.

Scot_39

Reed_Richards said:

You are doing the grid a favour by spreading the load.  I doubt that that would contravene any fair use policy but you must have T&Cs for your particular tariffs.

Whilst its all perfectly legal I suspect.  Given OP has an EV.


Dumping solar export at periods of low demand isn't doing the local or national grid - and so other consumers costs - as many real favours as solar converts believe.

When excess generation capacity exists at grid managed level - it also directly adds to balancing - conventional standby or renewables curtailment costs.

The LV distribution network - in UK and elsewhere - is simply not designed for GW of micro generation.  Significant local voltage issues can occur. Exceeding peak voltage limit during day a known side effect of badly regulated solar invertors.

In other nations - invertors have to automatically shut down export capacity well below voltage limits.  Not sure about UK market.

In some other nations people have been rightly stopped from exporting - whole areas now covered by 0kW export limitions.  And in other areas export limits applied so export limitted well below invertor / solar array capacity - meaning excess or any solar at all only for personal consumption.

Not saying the uk there yet or anywhere near  - but over 1.3m homes at say 4kWp ave - so circa 5GW - an increasingly significant factor in off peak domestic demand in many areas.

Ectophile

In other nations - invertors have to automatically shut down export capacity well below voltage limits.  Not sure about UK market.

All grid-tied inverters in the UK must meet standards.  G83 or G59 for older ones, G98 or G99 for new ones.  That requires them to constantly monitor the mains and shut down if the grid is out of specification.

The rules for solar generators have been relaxed over the years to prevent a cascading failure if the grid goes slightly out of spec.  If every inverter suddenly shut down, that would place a big step load on power stations.

There's generally a bit of extra wiggle room allowed to account for voltage drip along the cable runs.

In some other nations people have been rightly stopped from exporting - whole areas now covered by 0kW export limitions.  And in other areas export limits applied so export limitted well below invertor / solar array capacity - meaning excess or any solar at all only for personal consumption.

And all too often, those countries have monopoly electricity suppliers who hate the idea that homes might generate their own power, and not use the supplier's.  So they make life as difficult as possible for micro-generators.