I'm a power systems engineer. Ask me anything!

[Daxis]

...as long as it's not "will there be blackouts this winter" 😁

I work in quite a specific area so I won't know everything but if you have a question I'll do my best!

Would it be possible for the power grid to cascade and have a complete power grid failure ?

How much work / how many years is it going to take before we all have electric cars on our driveways and electric heat pumps?

Yes! It is possible. A total failure of the power grid is called a Black Start.

It hasn't happened in the UK but it has happened elsewhere for example in Texas (great video explaining what happened ).

If you remember the (mostly) London power outages in 2019. These were caused by low frequency. A couple of generators tripped at almost the same time which meant supply and demand weren't matched. When supply is higher than demand the frequency drops. This is a problem because everything on the system (and even the electronics in your house) are designed to work in a narrow bandwith of frequency.

All the assets on the system have protection - set parameters at which they will automatically operate. So for example if a circuit breaker sees a voltage spike it will open automatically to stop anything 'downwind' of it being damaged. There is also automatic load shedding to keep supply and demand balanced.

A cascading failure like you mention could happen due to lines being overloaded. All powerlines have ratings of how much power they can take. If you have an outage on one line the power has to find another route which puts the other lines in service at greater risk of tripping. This happened in north eastern USA in 2003 (another great )

Are our lovely girder pylons really going to be replaced by those horrible white ones?

Is it realistic to replace our current UK power demand entirely with renewables? I'm thinking cost, buildability, tech spec, capacity etc

Oooh good AMA

In Germany I believe they have a kind of localised power grid system, with small community power stations planned into neighbourhoods and housing developments. It’s always struck me as a good way of having a ‘grid’. Do you have a view on this kind of set-up?

Also: is the power grid/National Grid in the U.K. as crumbling and under-invested as the railways, school system, NHS and water supply?

I can't comment on heat pumps but there are some challenges around EVs which lots of people are currently working on.

One issue is that to fast charge at home you need a three phase supply which most domestic premises don't have. So that needs to be installed if people want fast charging.

If we all drive EVs we'll need a lot more electricity on the system and it's likely that demand patterns will change. At the moment overnight demand is quite low but if you have an EV you probably want to charge it overnight.

So at a high level the big issues for EVs is making sure we have enough electricity (and a huge amount of new generators are lined up to connect to meet this) but also making sure that the infrastructure is there (ie there are no bottlenecks on the system).

But, increase in EVs also introduces possibility. There are companies looking at using EVs for system balancing. So if you have a full battery (and it's plugged in) then you could sell some of that charge back to the grid.

I also love the girder pylons! The new pylons are only on the new circuit from Hinckley point. I think it's unlikely that existing pylons will be replaced any time soon and getting permission for new pylons is very difficult... I think we'll just have those few at hinkly point

What does a typical day look like for you?

What experience and qualifications do you need to learn your job?

Yes it is realistic to run on 100% renewables, but we aren't there yet. There are countries who already run on exclusively renewable power but they are uniquely blessed eg with large amounts of hydropower which in many ways act like a "traditional" power station.

Why this matters: traditional power stations are essentially spinning hulks of metal. The speed that they spin at sets the system frequency and what's more because they are so big they have inertia - it takes time for them to slow down or speed up. This means that inertia stops the frequency changing too quickly.

There are alternatives to manage frequency (some batteries can, flywheels etc) but they aren't widespread enough to provide all the inertia we want.

Then of course we have supply and demand. If the sun isn't shining and the wind isn't blowing... At the moment we don't have enough storage on the system to address that. We do have interconnectors which make use of renewable energy in other countries (eg the link from Norway) and they will be increasingly important if we want to move to 100% renewables.

@Daxis , interesting. I'm a civil engineer, work for a large public body, and I've recently picked up a role in improving operational sustainability.

I'm not familiar with Germany's power grid but it looks like they are part of the synchronous continental grid. If that's right then they might have more dispersed generation (ie community power stations) but they are still interconnected not just to each other but to the rest of continental Europe.

We'd call a local power grid an island and they do exist either from necessity (I studied briefly with a poor bastard running an islanded power grid in Siberia) or... Other reasons (Texas is an islanded power grid). But islanded power grids are less flexible and less resilient. A lot of work has gone in to making the GB powergrid more interconnected via the interconnectors (I can't keep track but they link us to France, Netherlands, Norway and Ireland).

But, dispersed generation in the form of community power stations is a positive as there would be less worry about bottlenecks on the system. The GB system was built for generation in the midlands/north flowing south. But now we have a lot of generation in Scotland but not always the capacity to move it around.

In my current role I do a lot of client facing meetings, it's mostly office based. Checking that the technical requirements are being met.

There are a couple of routes into it. You can do a degree and then get a graduate job with National Grid, Scottish Power transmission or one of the DNOs. There's also consultancies which offer graduate roles. Or, there are a lot of apprenticeships about. You'd need an A-Level in Maths and a driving licence but generally the industry is very keen on increasing diversity and getting people into roles. There is a huge shortfall. Some apprenticeship start on £25k with a free degree!

Can you tell us what A levels you did and the type of degree you studied? Did you always want to be a power systems engineer?

I ask this as someone who knows very little about this industry but finds it interesting.

I did Maths, Physics and Psychology at A-level. I didn't want to be a power systems engineer but I needed a job 😂rather cynically I figured I'd do an apprenticeship and worst case scenario I'd have a better wage for a couple of years while I figured things out. But I really loved it because there are so many facets to it. You can go hardcore with system modelling or you can do project management, asset management, policy, it's a great entry route into working with renewables.

My degree was a BEng in Power Systems Engineering and I did it as part of my apprenticeship. We studied fault analysis, frequency response, system modelling but also looked at how transformers work, the impact of renewables on the system, energy policy. Its maths heavy but not all maths.

Bit late to this, but hopefully will be seen.

How much of a threat are solar flares to the power grid? Is there much protection built in?

It's pretty rare to have a solar flare large enough (and in the right place) to significantly impact the power system - I believe chance-wise it's something like a once a century event. And if we did have a solar flare event it wouldn't impact the whole country to the same extent - it would be more like a localised storm.

Solar flares could cause spikes in currents and voltages which there is protection against - equipment would disconnect to protect itself. If enough equipment disconnected then there could be powercuts, but there is redundancy in the system which means power can usually be rerouted if needed.