Nick Hill

I've owned this domain since the mid-nineties. For most of that time, I haven't known quite what to do with it.

Not because I had nothing to say. If anything, the opposite. I've spent most of my life building things, fixing things, and thinking carefully about how things work — from electronic circuits to water systems to questions about the foundations of mathematics. The doing has never been the problem.

The problem is the telling.

There's a kind of singer who can deliver a gruff sea shanty and not care about the notes, because the character is the point. And there's another kind — the one singing an aria in front of a thousand people — who hears a slightly off-pitch note and it stays with them all evening. I have always been the second kind. Not a perfectionist exactly, but someone with a sensitivity to the gap between what I mean and what comes out when I try to put it into words. The thought is clear. The expression never quite matches it. And that discomfort has been enough, for thirty years, to leave this page mostly blank.

Then I realised something. That tension — between the thinking and the telling, between the doing and the expressing — is itself worth talking about. Not because my reluctance is interesting, but because what sits behind it might be. The way I approach a water pumping problem turns out to be the same way I approach an incompleteness theorem. The question is always the same: what do we actually need here? Not what's the obvious solution, not what would be easiest to defend, but what does the situation actually require?

That's what this site is. Not a portfolio, not a showcase. Just an honest account of how I think about things — told by someone who finds the telling harder than the thinking, and has decided to stop letting that be a reason not to.

What follows may interest you more than it interests me. I've made my peace with that.

I

When the power goes out, the water runs

A residential estate, three generators, and a better question

The estate where I live in Cyprus had three diesel generators. They cost about two thousand pounds a year each to maintain, they were ageing, and replacing them would run to nine thousand apiece. They existed because Mediterranean power grids are not perfectly reliable, and when the electricity goes, things stop working.

But which things? The generators ran pool pumps, path lighting, and the domestic water system. I started there — not with the generators, but with the question of what actually matters when the power cuts out.

The pools can sit for a day without circulation. No visible problem. You'd need several days before water quality starts to deteriorate. The path lights are a convenience. But the water supply is different. An extended outage means no water pressure, and that leads quite quickly to unsanitary conditions. Seventy Nine homes with no running water is not a nuisance. It's a health concern.

So the question wasn't "how do we replace the generators?" It was "how do we keep water pressure up when the grid goes down?" That's a much smaller problem, and smaller problems have cheaper solutions.

The existing pumping system had its own flaw. When the grid voltage floated towards the upper end of its nominal range — which happens regularly here — the electronic controller would lock out entirely. A system designed to provide water was failing not because of power cuts, but because of power that was technically present but slightly out of spec. I removed it.

Then I looked at the topology of the estate. Water tanks sit at various heights across the site. I chose the highest point for the new pump installation — not arbitrarily, but because gravity does free work. Every metre of elevation you start with is energy you don't have to put in from a battery. The less the pump has to push, the longer the battery lasts, and the smaller the battery needs to be in the first place.

This is where the engineering becomes a chain of reasoning rather than a parts list. How much water does the estate use per hour in realistic conditions? What flow rate does that demand? What pressure is the minimum for usable domestic supply? Now work backwards: impeller efficiency at that operating point, motor losses, inverter conversion losses, and you arrive at a number — the actual energy budget, in watt-hours, for a meaningful period of backup.

There was a further subtlety. Conventional systems use either a custom electronic controller with a pressure sensor, or a simple mechanical pressure switch. The mechanical switch would have worked — pump on when pressure drops, off when it rises. But I tested the pump and characterised its flow rate against pressure, and found that flow drops off steeply once you pass the minimum emergency pressure. Above that point, the pump is running hard but moving very little water. A mechanical switch can't see that. It just knows on and off. So the pump would cycle in a region where it's consuming battery power but achieving almost nothing. I designed an electronic control circuit that holds the pump in the narrow pressure band where it actually does useful work, and shuts it down cleanly outside that band. The difference in battery life is substantial — the difference between a system that lasts through a long outage and one that exhausts itself pumping against a pressure it has already achieved.

I proposed a budget. It was approved. The system was built and commissioned thirty percent under that budget.

The three generators have been removed. The estate now redirects six thousand pounds a year towards structural improvements — actual, visible work on the place where people live. When the power goes out, the water runs. Most residents have no idea how, and they don't need to. But the thinking behind it is the same thinking I bring to everything, and that's what I'm trying to show here.

Several people — including some who were firmly supportive of me in other matters — later confided that they hadn't believed it would work. I understand that. A battery-backed pump doesn't sound like it should replace three diesel generators. But it does, because the generators were answering a question nobody had examined carefully enough. Once you ask the right question, the answer is often smaller, simpler, and cheaper than anyone expected.