1. There is SO much being wasted right now — in many cases, simply because energy use was seen as so cheap and so consequence-free in earlier decades — that it’s going to take a LONG time to reach a society-wide point of diminishing returns. This is especially so since the key industries that will have to enact these efficiency gains (construction, electric utilities, etc.) are constrained by enormous capital costs, slow evolution of infrastructure, and a general cultural resistance to change.

2. Another metaphor that might work in place of the fruit tree is Moore’s Law. Part of the power of Moore’s observation is that it has held and held and held long after the obvious initial improvements to efficiency and miniaturization were made. I have little doubt that in a couple of decades, your energy-neutral house will be much closer to the norm, and that early adopters like yourself will have moved on to arrangements that routinely return energy to the grid, take carbon out of the atmosphere, etc.

3. Related to #2: When Jack Welch instituted the practice at GE of firing the bottom 10% of performers in each department every year, the process was easy for the first couple of years. Consider if you were the line manager of a team of ten: In Year 1, you get rid of the sorehead who never did much anyway, and everybody’s happy. In Year 2, you get rid of the nice guy who’s just not that good, and while it’s a little painful on a personal level, it’s fairly easy to justify from a performance standpoint. But then in Year 3, you dig in your heels and swear up and down that there’s no more fat to cut. But the underlying principle behind the system is that you *always* dismiss the bottom 10%, and by doing so you constant redefine — upward — the overall performance of the team and the organization as a whole.

My summary: as we get better and better, I predict, we will see more and more that we can be doing. Yes, there will be diminishing returns at some point — but we’re so very far from hitting that point that it need not concern us for at least several decades.

Joe, you wrote about the low-hanging fruit of conservation: “In fact, fruit grow back. The efficiency resource never gets exhausted because technology keeps improving and knowledge spreads to more and more people.”

I take exception to the use of “never” there. There is only so much fruit on a tree, and the new technology can still only be used to harvest some (or perhaps all) of what is still on the tree.

At a manufacturing company, you have to be using [read "wasting"] a lot to save a lot unless you simply stop operating/producing. Surely there is an enormous amount of waste due to inefficiency and a lot more due to foolish use and there are still a lot of low-hanging fruit falling off the trees and piling up and rotting around our ankles, as Amory Lovins wrote just a few years ago [http://www.rmi.org/images/PDFs/Energy/E05-16_EnergyEndUseEff.pdf].

But eventually you will be “lean and mean;” if you are really lean and mean and not using much, there may not be much room for improvement. Waste won’t grow back unless you are careless. There is some point of diminishing returns as you asymptotically approach zero total use.

It’s a little like tax deductions. My father taught me that you have to have income to benefit from deductible expenses. You need to use and waste a lot to save a lot. Of course you can simply turn whatever is running off, but then aren’t doing (producing) anything if your business is manufacturing. Supply of materials will still have to be delivered, even if by very efficient rail, and product will have to be exported, again by some means consuming some energy.

Think about it. Once your house is energy neutral (like mine) due to careful consumption, energy-efficient appliances and equipment, a solar hot water heater (paid for partly with California’s incentives of the late 70s and early 80s), and 2500 watts of PV panels on the roof (1/3 paid for by CA rebates and federal tax breaks), there is not much here that more conservation is going to save. Sure, LEDs and the next generation refrigerator will help.

Of course America is full of houses with lots of room to save by employing these and similar measures; I would guess that somewhere well beyond 2/3 of current residential building energy consumption could be eliminated rather easily and a similar value for most non-residential buildings. But then it starts to get rough to find ways to save. Especially since buildings are being designed and built assuming that they will be air conditioned (more than 80% of U.S. homes and a similar or higher fraction of offices and schools) and in so much in places where air-conditioning is considered essential – the desert southwest, the deep south, Florida, etc.

About 20 to 25% of the energy loads in buildings are electric plug-in devices, and most of them could be more efficient, like my present refrigerator which uses half the energy used by the 20-year old one it replaced 7 years ago. That first half was easy. Something like a 5- to 7-year payback. The next quarter is probably on the horizon. But after that, it’s an uphill battle without a quick payback – unless and until the cost of electricity goes out of sight.

Sitting here typing on the only computer I ever use anymore, either at home or on the road, a very small (10.1 inch screen) laptop with extremely low power consumption, I know my old 17″ CRT and 19″ LCD are simply not plugged in anymore. I don’t miss them at all. But LCD and plasma televisions have been getting bigger and bigger, so there’s at least one new place to save with conservation down the road.

The Bellona Foundation sees energy efficiency as the biggest wedge in a scenario that aims to reduce carbon emissions by 85% by 2050. Efficiency can contribute around 25%.

The second biggest wedge is carbon-negative bioenergy, which provides 20%.

The third biggest wench is all other non-biomass renewables combined (solar, wind, CSP, hydro), which provides around 10%.

So, as an individual blogger, Romm is not that far off the mark set out by a professional group of scientists.

Good job!

Thing is, cheap-cheap energy, which we had for a century-plus, tended to keep us from thinking / worrying about efficiency. But once you do start thinking of it — the sky’s the limit.

At some point, I hope, this will become such conventional, obvious wisdom that non-green business managers will automatically pursue energy efficiency in the same way that they now look for competitive low bids from product vendors.

Related, in this quarter’s issue of CalTech’s E & S magazine, there is an article mentioning that an additional $4 per square foot in construction costs for a new CalTech building going up is projected to save $67 per square foot over 20 years. That’s a decent ROI.

Joe, you should pitch it to them – to Elizabeth Kolbert probably…. Loved her article on the conservative farming Danish island going carbon negative:
http://www.newyorker.com/ reporting/ 2008/ 07/ 07/ 080707fa_fact_kolbert