Water and Electricity

We do know that they don’t mix well.

In an article in the Guardian about the floods in York, I read about the flood barrier on the River Foss that

Problems arose at the weekend at the Foss barrier and pumping station, which controls river levels by managing the interaction between the rivers Foss and Ouse. In a model that is commonplace around the country, pumps behind the barrier are supposed to pump the water clear. The station became inundated with floodwater after the volume exceeded the capacity of the pumps and flooded some of the electrics, according to an Environment Agency spokesperson, who said that a helicopter was due to airlift in parts to complete repairs on Monday.

It is particularly ironic that flood-control measures are rendered ineffective through flooding of their controls. But it’s not a one-off.

At the beginning of this month, December 6, much of the city of Lancaster (and reportedly 55,000 people) were left without power when an electricity substation in Caton Road was flooded in a previous storm.

Here is Roger Kemp’s take on the Lancaster substation affair.

In March 2011, when the tsunami resulting from the Tohoku earthquake flooded the Fukushima Daichi nuclear power station, the electrics for the emergency backup generators were also awash. If I remember correctly, in the US some of the Mark I BWRs had been modified so that the electrics controlling the emergency power generation were installed higher up in the buildings than the basement, where they still were at Fukushima Daichi. The bluff on which the power station was built had also been lowered by 15m during building to enable easier access from the seaward side.

I’ll leave it to readers to connect the dots. The question is whether the resources will be made available in the UK for review of the placement of critical electrics, and for prophylaxis. And also what we can do as members of professional societies for electrotechnology to encourage those resources to be mobilised, in the UK and elsewhere – big cities in Germany such as Hamburg and Dresden have been flooded in recent years.

I suspect that some measures would be relatively simple to implement, for example putting effective sealing accessways on vulnerable substations and other critical installations. Maybe one could seal at ground-level permanently, install sealed doors two meters up, with steps on both sides? And install an effective pump for what might nevertheless leak through a seal, with starting through a sealed battery with a float-activated switch. And so on.

As societies, we are becoming more dependent on electricity as an essential component of living, and there are plans to become even more so. This leads to vulnerabilities which I believe we haven’t yet thoroughly considered.

When I was a child, house heating came through burning coal, coke or occasionally wood. If there was an electricity cut, you could still heat your house. Nowadays, almost all building heating is electrically controlled. Even fancy wood-pellet-burning stoves, which may be connected to the circulating heating water. Take out the electricity, take out the heating too, nowadays.

According to EU statistics, in 2013 11.8% of inland energy consumption in the EU-28 was from renewable resources, and in the same year 25.4% of electricity was generated from renewable resources. Which suggests that less than half of energy consumption in the EU-28 is via electricity; much of the rest will be transportation, I suppose. Transportation’s use of energy from renewable resources was only 5.4% in 2013. There is scope for change – everyone seems to be thinking about electric road vehicles (ERVs).

I doubt whether the infrastructure exists to supply appropriate amounts of electricity for recharging ERVs if they constituted a large proportion of vehicle use, and I am not alone. The RAEng suggested in 2010 that current supply could be “overwhelmed” (Roger Kemp chaired the committee which produced the report.)

Amongst the issues are quality of electrical infrastructure. The German electrotechnical industry association ZVEI pointed out some years ago that 70% of building electrical installations have outlived their design lifetime of 30-35 years and are still in operation; also that 50 years ago there were typically 6-8 electrical devices in the average household, and now there are typically more than 70. In the presentation in which these figures appear, they were more worried about the functional safety of the installations, in particular fire risk. Malfunctioning electrics causes 15-20% of all building fires in Germany, they say. If I remember rightly, about ten times as many people die per year in building fires caused by electrical malfunction as die from electrocution: 200 as compared with 15-20. I don’t recall anything in the presentations I have seen on vulnerabilities to flooding.

When York, Lancaster and Leeds have streets lined with charging points for ERVs, I hope those points are adequately protected from floods. When half the cars along a street are electric, and the street floods to a meter depth, what is going to happen to and around those cars? Would you touch one after the floods recede? Recall there is enough stored energy in a fully-loaded vehicle to power your average Western house for a few days.

I spent a couple of years on and around German standardisation committees on ERVs. In all the meetings, I don’t recall questions concerning effects of submersion ever arising. I think they should be considered.