Save power to avoid blackouts

Article on the BBC, here... "Households will be offered discounts on their electricity bills if they cut peak-time use on a handful of days over the winter, as part of National Grid's efforts to avoid blackouts."

These sorts of things are incredibly difficult to get right.

Punished for being proactive?

Some of us have already been proactive. I am a high user, but now have solar and battery. The hot tub (a big chunk of usage) is now on a timer so largely heating in the middle of the night, and easy to avoid the 4-7pm peak. I am also on a special battery tariff, so for example, my usage 4pm-7pm is actually about -30% of my daily usage (yes MINUS 30%, i.e. I export around 30% of my net daily usage 4-7pm).

Now, this means it would be physically impossible for me to use less 4pm-7pm, whether net (i.e. allowing for export) or just import (i.e. currently 0kWh usage).

So no way I can benefit from the Octopus scheme as I see it, unless I have misunderstood, as I cannot "improve" my peak usage.

Had I *not* been proactive. Had I left the hot tub on 4-7pm. Had I not run the battery like this. I could be easily making that extra £100 on offer. I am being punished for my being considerate and proactive - or so it seems. That feels wrong, somehow.

Other approaches

My understanding is that some providers are working on getting people to make their 4-7pm usage a lower percentage of their net 24/7 usage. That would work for me, as I already do that, assuming they would even cope with a negative percentage, maybe I would get more than £100, LOL.

Encouraging bad behaviour

I need to work out the "reference" period for saving. Even on the tariff I am on, it would not be hard to make my 4-7pm usage really high. It would not be hard for anyone to do that by running the washing mashing, and tumble drier (and I know most people don't have one, a hot tub), even electric water heating as many have that as a backup for gas. And, of course, if you have one (we don't) charging your EV.

If doing that for a few days before, then during the key days you move the power usage away from 4-7pm, you can get that bonus. For a lot of people "moving" the power usage has not extra cost, so why not.

This is a problem with any system that is "relative improvement". Make it absolute, e.g. usage below X kWh for the period per hours, or even less than % of net 24/7 household usage, and that may work, no need to force a high "reference" against which you are saving.

Not in the spirit of the scheme

One criticism of anyone adjusting their usage before these saving sessions to get a better reduction is that it would not be in the spirit of the scheme. Not "the right thing to do". Even Octopus said that on twitter.

Well yes, that is true, but the whole scheme is based on people doing "what makes them money" not "what is the right thing". There would be no need for any financial reward if people would "do the right thing", so yeh, you kind of have to expect that people, as a whole, will do what makes/saves them the most money - that is how people as a whole tend to work, even if individuals do sometimes do the right thing - it's the very basis of economics (from what I remember).

Solar install, part 4 (export)

Read part 1 for more background.

I'm really pleased with the install, and we are making 40 to 50kWh a day at the moment. So now for some paperwork...

One bit is a micro generation certificate, this confirms it is all installed by approved installers, etc, and has the details. I need that for and export tariff.

I have been discussing with the installers - we have a 12.09kW system (i.e. 31 x 390W panels), but they are east / west split so never all get direct sunlight. With the split and roof angle they have determined that maximum is going to be around 9kW, so a 10kW inverter is more than adequate. It will be interesting to see in the height of summer - but interestingly, even though only April, the generation in June won't necessarily be as good as you expect just by sun angle, because it is hotter. Being hotter makes the panels less efficient, so may cancel out the extra sun angle.

I heard there is some trick with some panels with water cooling, i.e. using the waste heat as a heat pump and keeping the panels cool for maximum PV. But we don't have that :-)

So, I may be making 9kW some days, yay. But what do I do with that?

As you will have read, the primary target for this my own usage, and then the excess power goes to a battery, so I can then use the power later when the sun is not shining as much - maybe covering my whole 24 hour day's usage for most if the summer, which is mental.

The bad news!

The battery is likely to be August. So 4 months of no battery. So, I'll export to the power grid, simples!

Well, yes, but that needs paperwork to. The Distribution Network Operator have to give permission to connect, which they have. The DNO decide what they consider the limit for export, if everyone was exporting, before it would cause damage to transformers, etc.

It varies, it can be as low as 3kW. Thankfully, in our cause though, it is 6kW. So we cannot export more than 6kW, legitimately.

Well 9-6 is still 3kW, and whilst I have the hot tub heating during the day, normally, a daytime idle power (when hot tub not heating), is a bit more than 1kW.

The result is, on a really sunny day, we could be exporting 2kW too much. Ooops.

Well, not quite, the inverter is set up to limit to the agreed amount, 6kW. It adjusts the panel optimisers to ensure that overall they are not quite as efficient, if we go over 6kW. So on a sunny day I should see a flat top on my export stats at 6kW. It means I will be literally throwing away some sunshine, up until I get my battery.

Paperwork

However, there is another snag - the final handover paperwork is normally done when the install is complete. The permission covers the solar and the battery - but we have no battery for 4 months - so I have no paperwork. So I cannot get on an export tariff.

The installers are trying to work out with Western Power Distribution how the handle an interim paperwork handover for the solar only without losing the permission to install the battery later. Hopefully something we have sorted shortly.

Tariffs

So the next step is a tariff for the next 4 months. It looks like I can get 5p/kWh from so.energy, less from Octopus unless I move to them for import as well. Octopus also do an agile tariff, but not being able to control when I export (yet, no battery), just relying on sunshine, I am not convinced that makes sense (a variable tariff for every half hour noticed a day in advance).

So my plan for now is probably the 5p/kWh from so.energy for 4 months, if I can confirm how the 12 month minimum works penalty wise. Once I have a battery I will need to revisit tariffs as there are interesting options.