Planning and Infrastructure Bill

Debate between Baroness Bennett of Manor Castle and Earl of Lytton

Committee stage
Tuesday 9th September 2025 Lords Chamber

[The Earl of Lytton (CB)]

My Lords, I declare an interest, as I have nine water butts all collecting rainwater when it rains. However, further to what the noble Lord, Lord Cromwell, said, there are some issues. For instance, what falls on roofs does not necessarily arrive in a clean form; particularly in some urban areas and in others, it may be contaminated by things such as bird droppings, which would be quite a serious issue.

The noble Lord, Lord Cromwell, refers rightly to the problem of having dual plumbing systems in houses. There is a serious issue to do with potential cross-contamination and, therefore, who is responsible. But on the generality of what the noble Baroness, Lady Hodgson of Abinger, has put forward, supported by the noble Baronesses, Lady Bennett and Lady Parminter, it is right that we need to conserve water, so we do not use expensively treated water from the mains supply. It is absolutely daft to be using that for washing the car or watering the roses. The roses do not care how much bacteriological contamination there is in it—they love it. From that point of view, the more the merrier. The vehicle does not mind what you wash it with either, most of the time.

I learned a great deal from my late sister, the elder of my two sisters, who died earlier this year, that I did not learn from being a chartered surveyor. She was a very senior hydrogeologist, and her point about rainwater harvesting is that you have to be careful about the infiltration that is necessary and naturally occurring. When rainwater falls on a hard surface, it runs off to a drain. What then? Does it disappear off down through some massive Thames pipeline to somewhere beyond Barking, or does it go into the soil and replenish an aquifer? If it has all been put into the loo and is going off as foul water, you lose that to the infiltration process. The more that we build, the more hard surfaces that we have and the more we pipe it away, the more we have to be concerned about infiltration.

Previously in Committee, noble Baronesses raised the point about flooding. Of course, infiltration is part and parcel of that. If you have all the run-off arriving at the same point down a modern piping system that conveys water away very quickly, you will end up with trouble. If you can detain water in some way by storage and infiltration, you stand a better chance, little by little, of dealing with some of those problems. But it is a fine balance as to what is happening, and it certainly requires a lot of further investigation.

The other amendment that attracted my attention was the one on ground source heat pump installation. I absolutely take the point made by the noble Baroness, Lady Hodgson. All I would say is that, if a heat pump requires three-fifths of what you might call the energy demand to provide heating, that means that three-fifths of whatever the alternative will be—oil or gas—is put on to the grid.

The chief problem with the grid is that it does not have the distribution capacity—I am not sure that it has the generation capacity in total, but other noble Lords are much more knowledgeable about that than I am. This raises a particular problem with housing development. I recall not so long ago going to visit a small housing development in north Dorset. The developer there had to provide energy for cooking and heating via an LPG bulk storage tank, which noble Lords will know is a very expensive way of funding your energy. That was done because the tank was provided free of charge, provided that the LPG was purchased from the particular supplier, and the reason for that was because there was not sufficient capacity in the local grid to power these things from an electrical standpoint.

That ties in, to some extent, with the other point that the noble Baroness raised, about solar power. Yes, I agree that that ought to be part and parcel of it, but maybe there is a link to be made between solar power and the efficiency thereof and the ground source heat pump. Now, I know nothing about the wattage that is needed for a ground heat source pump, but again I say that there is a trade-off, a balance between that 60% of what would otherwise be the carbon load being transferred on to either the grid or a solar panel system.

I know that in places such as Austria, there are now things that they refer to as balcony panels or balcony sheets. These are flexible sheets of material composed entirely of solar PV material. People put them up and they can power small appliances. Other people tell me that solar panels in certain configurations have become so cheap that they can now be used as a fencing panel, because it is a cheaper way of doing it. Now, I do not know what the rate of deterioration and attrition is of these panels, and that is obviously a fairly important consideration, because they contain things which are not readily recyclable and therefore there is that problem of end-of-life disposal, but I think that perhaps the noble Baroness could encourage the Minister to think about and work on getting this balance right, so that at least we cut some of the consumption—maybe not all of it, but some of it—of these expensively produced and increasingly scarce resources. To that extent, I very much support these amendments.

[Baroness Bennett of Manor Castle (GP)]

I ask the noble Earl, and indeed the noble Lord, Lord Cromwell, perhaps rhetorically, whether they are aware of the One Million Cisterns project in Brazil, which aimed to deliver what it said on the tin and indeed has done so and was expanded subsequently. This is in the semi-arid area of Brazil, home to 18 million people. Brazil, of course, has a lot less infrastructure and is much economically poorer than the UK, yet it has been able to deliver a programme that has won United Nations awards and had all sorts of impacts. I hope the noble Lords will acknowledge that since other countries have achieved this, maybe it is not an unreasonable expectation for us to achieve it too.