Where do you live, anyway, if you don't mind my asking? (Fair trade - I live in Maryland, USA.) Have you ever spent a summer in a place like Houston? No, I'm not dismissing the need for conservation and alternative energy sources, but I am wondering if your personal "climate history" may shape your perceptions about things like air conditioning.
I live in Toronto, Canada. We get winter days well below freezing and summer days in the 80s. I was born in Brazil. I have family in places like Brasilia and Uberlandia where the temperature gets even higher. I just looked up Uberlandia, where it's 95 degrees at the moment, and summer there is yet to come. They don't have air conditioning. They build sensibly. Their houses with stone or tile floors, deep porches, high ceilings and other features, are more comfortable than air conditioned houses here. And they don't have to make them airtight. Windows let in breezes all day. And their houses aren't even insulated, though they are built with hollow bricks.
My first house was an end-of-row townhouse with a huge south-facing wall. Even with modern insulation it was a hell hole in the summer. Completely unliveable without air conditioning. I think to do without air conditioning, you'd need about a foot of insulation on that wall. We did put insulation in the roof when we re-roofed. It helps but doesn't solve the problem. If we had stayed in that house, re-insulating would have been a priority.
The house I live in now has no insulation. It's an 80-year old house of triple brick construction. It should be an oven. But it's not. It doesn't require air conditioning. The street has majestic old trees, the houses are so close that the deep eaves almost touch. They all have gracious porches. At nightfall in summer, we open our windows. Even in the summer, by the morning, I actually wake up chilled. Then we shut the windows. It can be 35 degrees outside, but it never gets uncomfortably warm inside.
Heating is another issue, and the reason why I'm planning on investing in a lot of insulation.
A few months ago, I went out to see a local housing development which featured energy-efficient homes. The first thing that struck me was that the designs were identical to homes that didn't have the Energy Star rating. The eaves are no more than 2 inches out. Each house stands on its own field. There's no consideration for where windows are placed. Even for a market that demands efficiency, the builders are just slapping on an extra layer of insulation. They're cookie-cutter models. We built more intelligently 100 years ago, even though we didn't have the tools we have today. And still, by making almost no effort, they're achieving 20% reductions in energy use.
All of this built environment will need to be addressed. I'm well aware of the challenges. Some re-insulation can be done economically now, some will become economical if fuel prices rise, and some will require subsidies. It's definitely cheaper than investing in new generation.
I think there's a place for air conditioning. It's vital for hospitals and seniors residences. It would work well there with ground source heat pumps. But I think, given the huge demands it places on the system, that it should be avoided where possible.
Can it be eliminated in Houston? Based on my experience in Brazil, I suspect it can.
But even assuming you find some very special case where air conditioning is absolutely necessary, you can definitely still reduce the load to a tiny fraction with appropriate insulation and smart features and design.
