Where shall we put them?

So just where can we install our PV arrays?

The first consideration is that they should be at or adjacent to the point of need. It doesn't matter if that need is a house, a factory a distribution warehouse or even an airport or car park.

Next we need to take advantage of the existing below ground (and occasionally overhead) infrastructure. The power grid is already there so we have no infrastructure costs, just the costs of the actual installation.

Planning laws could almost have been written for rooftop solar installations. So long as it isn't a conservation area, a listed structure and it stays below the ridge line there are few issues.

Finally, the bigger the green problem, the bigger the need and potential for making a real impact. So think airports, car parks, transport hubs, factories, docks, motorway intersections and service stations.

These are the places with actual energy need, and an actual environmental problem. The more savvy operators will understand why they need to do something, but many others will need to see a good business case before they go for it. It's OK because we can do both. If they only see the PR benefit then so be it, at least everyone else will know that they have also done the right thing.