The smart grid will need smart buildings to talk to, if it’s to fulfill its promise of connecting utilities to their customers. But the vast majority of today’s smart grid projects pretty much end with the smart meter. Meanwhile, building energy efficiency technology remains, for the most part, concerned with what’s happening within its four walls, not on the grid at large.

Still, we’re seeing the first real-world examples of a new stage in the smart grid-smart building nexus. In some cases, we’re seeing utilities reaching into customers’ homes and buildings via new pricing schemes, demand response signals or direct load control switches.

In other cases, advanced building energy management systems, distributed generation sources and even campus-wide microgrids and virtual power plants are hooking up buildings in ways that make them more responsive to grid operators’ needs.

Most of today’s buildings aren’t nearly this smart, though, and we’re a long way from anything resembling a seamless integration of grids and buildings. Still, the potential rewards of that integration are pretty enticing, and that’s made the smart building-smart grid nexus a target of software startups, energy equipment and services giants, and government-funded pilot projects, all with their own approaches to bridging the divide.

We’ll be covering developments in the space at Greentech Media’s The Networked Grid Conference, to be held at the Washington Duke Inn in Durham, NC on April 4-5, 2012, but here’s a preview of the ground to cover. Let’s approach from the building side first. Everyone’s seen the dire statistics on how much energy the commercial building sector wastes -- up to one-third of a typical building’s power use, according to most estimates.

The first step in any building energy management project must be identifying and fixing these obvious sources of waste, which involves the typical low-tech steps of replacing old fluorescent lights with newer, more efficient models, or upgrading an HVAC system with the latest variable-speed fans and high-efficiency compressors and chillers, and the like.  

Beyond that, we’ve got a host of companies looking at applying software, sensors and controls to buildings to squeeze more efficiency out of the system. Startups in the space include SCIenergy, SkyFoundry, Serious Energy, Telkonet, Adura, Daintree Networks and many others. They’re being joined by giants in the space like Schneider Electric, Siemens, General Electric, Johnson Controls, Honeywell and others with software-hardware combinations of their own. The fundamental goal is to make building systems run properly to shave 10 percent to 20 percent off power bills -- but again, that’s not meant to be connected to the grid.

Moving from overall energy savings toward actually shifting­ energy use to take advantage of demand response programs or variable energy prices isn’t yet a priority for most buildings, though demand response projects from the likes of EnerNOC, Constellation Energy, Viridity Energy, Verisae and BuildingIQ are tackling the challenge.

It isn’t easy to get buildings to respond to real-time prices, peak power signals or direct load control. In fact, it takes a careful balancing of the needs of the utility to get a predictable load drop from a building, and the needs of the building owner and tenants to keep the building’s business running smoothly while shaving energy use.

But get the balance right, and the investment made into running buildings more efficiently can suddenly start yielding additional savings from avoiding high peak power prices, or even bidding energy reductions into energy markets to earn revenues, said Building IQ CEO Mike Zimmerman.

“We’re seeing a multiple of the savings we can verifiably deliver to the customer by doing direct load control, as well as providing the sophistication of self-learning and adaptive behavior,” Zimmerman said in an interview last month. BuildingIQ does things like pre-cool buildings before peak afternoon prices hit, then turn off air conditioning systems and let temperatures gradually drift upward, saving money or bidding the reduction back as “negawatts” for the grid.

Knowing just how much you need to pre-cool to leave the building still comfortable at the end of a peak period is a matter of analyzing the building and its energy systems beforehand, Zimmerman said. That’s the same kind of building energy profiling that SCIenergy, Serious Energy and big energy services companies aim to provide. Hooking it up to the grid takes another layer of sophistication. Right now, BuildingIQ has pilots underway with several Australian utilities, and recently announced a deal with San Francisco-based energy services company Syserco to roll out its product in the United States.

Another startup with a lot of building-optimization-to-smart-grid projects underway is Viridity Energy. The Philadelphia-based software vendor analyzes buildings and campuses to identify energy saving potential, and then works with partners to install the demand response capabilities to play the capabilities into the energy market. It just launched a partnership with ConEd Solutions, the energy services and trading arm of big New York utility Consolidated Edison, to create a commercial-scale program serving regions from New England to Texas.

On the other end, Viridity connects and interfaces its “microgrid” projects into the network of IT and legacy systems that allow grid operators, utilities, generators and buyers of power to conduct their daily business. That sector covers everything from old-fashioned emergency demand response from vertically integrated utility sectors to fast-reacting, market-based energy shifting based on wholesale power prices or spot demand for grid balancing power.

Most of these smart building upgrades require some sort of building management system (BMS) to connect to. Most big commercial properties do have building automation systems installed, but many lack energy data. Getting accurate energy measurements can require installing sensors or doing complex analytics to estimate discrete building energy costs against meter readings, for example.

We’re seeing companies take different paths to enable buildings for grid integration. Constellation Energy’s VirtuWatt platform, a customer interface for bidding buildings into energy markets, has been deployed at customers like Marriott where it serves as an ad-hoc BMS for hotels that lacked one, as well as being integrated into pre-existing building systems. Johnson Controls bought customer-facing demand response tech vendor EnergyConnect last year, and has integrated it into its new Panoptix building energy management platform.

Honeywell, which owns the Tridium line of BMS integration systems, also does automated demand response via its Akuacom acquisition, and is linking building controls to demand response signals in Hawaii, California, the U.K. and China. U.S. demand response market leader EnerNOC saw its EfficiencySmart energy efficiency and building management services business grow 77 percent in 2011, with big customers including Southern California Edison.

At the end of the building-grid connection, LIES A dashboard that a building operations manager or real estate portfolio owner can read to get at the numbers they really care about: dollars and cents. That includes what’s being wasted, what can be saved, what can be controlled in close to real time, and what the return on investment may be for all of the available options.

Siemens recently acquired Pace Global Energy Services, a Fairfax, Va.-based company that manages more than $5 billion in global energy spending for clients with about $100 billion in energy assets. Siemens plans to use the acquisition to “extend our reach into the energy market and enhance our current building automation portfolio.” Likewise, Schneider Electric acquired energy procurement company Summit Energy last year, giving it a reach into Summit’s $2 billion business in energy trading that it could connect with its dominant market share in building-side power systems.

Schneider is also working with Cisco, using the networking giant’s EnergyWise protocol to integrate energy data into its new StruxureWare line of building management software. Cisco has apparently abandoned the goal of building servers to control building energy, but its EnergyWise technology could find broader adoption with other BMS vendors.

IBM is another big player in the smart building space, with partnerships with Schneider, Johnson Controls, Honeywell and others to find ways to optimize efficiency. IBM also bought building software startup Tririga last year.

Last but not least, we’ve got the slew of companies aimed at the data center efficiency market. Data centers are, after all, buildings, only with lots of very complex and intelligent power users called servers, rather than assembly lines or office cubicles. Expect much data center expertise from the likes of Microsoft, Cisco, HP and others to seep into the building management world.