‘Who’s using the hot water?!” You can often hear that shout from someone trying to have a shower while someone else in the house is trying to do the dishes. The reason is simple; most houses don’t install multiple hot water systems to ensure that everyone in the house can simultaneously use as much hot water as they want. It is of course possible to design a house’s plumbing to ensure ever-present hot water, it’s just that it would be quite expensive. Most families, conscious as they claim to be about the cost of living, seem happy to suffer the odd inconvenience in exchange for cheaper homes and cheaper electricity bills. But the exact opposite is, we are told, the case when it comes to designing our electricity grid. Indeed, we learnt this week that we spent $11 billion installing electricity poles and wires that are only used 100 hours a year. That’s less than two hours per week. The ”problem” is that on really hot days everyone with an air conditioner wants to use it at the same time. Similarly, those who can afford a swimming pool are probably lounging in it, with the pool filter running. While we don’t build public hospitals that can cope with peak demand in winter and we don’t build public transport systems that can cope with peak loads in the morning it seems unchallengeable that we must build an electricity distribution grid that can cope with peak demand. Why the difference in approach?