[Editor’s Note: In the column below, building energy expert David Wolins examines the issue of “energy drift” — a little-known problem with major ramifications for the utility and construction industries.]

The need to “go green” is more pressing than ever. And nowhere is this more evident than in the multi-billion-dollar commercial building market where the move toward energy efficiency is no longer about feel-good corporate posturing — it’s a necessity.

The biggest challenge facing these companies? Something called “energy drift” — the constant, imperceptible loss of energy from commercial buildings that ends up costing billions of dollars and generating tons of toxic waste every year. It is this problem, more than any other, that has motivated the venture community to scout out the next killer startup that addresses this huge market opportunity, worth $4.5 billion in the U.S. alone.

It might seem that so many structures are being built “green” these days that the issue of energy leakage has been solved. Wrong. The moment a building is commissioned for “optimal performance,” it is already fading from green to gray. Building designers and tenants immediately start tweaking thermostats and changing settings so that systems start sliding in efficiency yet again.

On average, commercial buildings experience 17 percent more energy loss every one to two years — an alarmingly high rate. To put it in context, a typical 100,000 square-foot office typically spends $200,000 a year on electricity. That amounts to an undetected annual burn rate of $34,000. With more than 370,000 commercial buildings exceeding 50,000 square feet in the U.S., simple math bears out the magnitude of this largely invisible problem.

There are literally hundreds of thousands of hard-to-detect variables that can rob commercial buildings of their annual energy spend, ranging from electrical, mechanical and HVAC system faults to anomalies in building tolerances, the impact of seasonal change, and the influence of changing tenant occupancy rates. And that’s just the tip of the iceberg. Fortunately, new technologies aimed at fixing the problem — under the banner of Automated Continuous Commissioning — are on the horizon.

What is ACC? Instead of configuring a building for optimal performance just once with occasional “tune-ups,” ACC performs 24-7 monitoring and analysis of a building’s energy consuming ecosystem. Looking at the inevitability of building systems degradation — which can reach levels as high as 25 percent over a one to two year period — the need for ACC is clear. This degradation can result from things as mundane dirt buildup, improper control use, changes in the operating demands on the system and many other subtle mechanisms.

At the root of the problem is too much reliance on evaluating building performance via a “snapshot in time” approach. Until recently, re-commissioning conducted every few years with scheduled maintenance was considered state of the art, and was assumed to be the best way to minimize unforeseen problems. Unfortunately, there are many reasons why even the best-case scenario leaves buildings vulnerable to significant downtime and unpredictable energy gaps.

Consider this recent case: The corporate headquarters of a major electrical component manufacturer had a cutting edge Building Automation System operating all of its systems, in addition to an aggressive operations team maintaining all aspects of the building’s environmental systems. But after thorough analysis of the building data, it was discovered that heat was being turned on at 5 a.m. to maintain a minimum room temperature. An hour later, the cooling system would turn on and pre-cool the building as employees arrived at work. Clearly, this programming blunder resulted in substantial wasted energy. This kind of programming error is rarely caught.

To the benefit of the building industry, there has been a huge proliferation in data management and analytical capabilities in the sustainable space. By continuously collecting internal data about what’s going on inside a building, plus external data on things like the weather changes and utility pricing, limitations on operations’ forecasting are beginning to lift. And with ACC solutions making their way to market, energy efficiency is evolving from buzzword to benchmark.

David Wolins is the chief executive officer of Scientific Conservation. He was the co-founder of EnFlex, a company that developed connectivity and enterprise solutions for the delivery of building systems data. EnFlex was acquired by SunEdison last year.