Continuous programming for Smart Energy Buildings
Best practices in high performance buildings recommend continuous commissioning. Keeping building systems at peak performance requires knowing what high performance looks like, and how that performance changes over time. But performance requirements change over time. Policy based system management requires that we know the purpose of each room. We need continuous programming for buildings.
Building programming is the name of the pre-design conversations about what an owner expects to get out of a building. Designers ferret out each purpose. The design team and the owners establish clear expectations of the expected performance for each function. Some praxis defines the energy performance expectations for each space as well. This one time activity is complete before serious design begins.
This program should guide the initial commissioning requirements. Does this space support the ventilation requires of a dining area within it energy budget. Does another space meet its energy budget while supporting high-end retail? Does the ventilation support maintaining alert cubicle workers throughout a long day? These considerations can support policy based building system management.
There are two barriers to developing systems to support this model. There is no standard for passing the original program information to the commissioning process. Programs change.
It is quite common at Universities to spend 100 grand to renovate a brand new building. During the years between programming and construction, some purpose changes, some new program started, and 4 offices are now a classroom. The break area is now a data center. The back lab is now a reception space for the new academic discipline; it now has an exterior door. In commercial buildings, each new tenant may have new requirements. Things change
Even without renovations, the building program changes, and with it, the performance requirements. The squash court becomes a spinning class, supporting many sweating exercisers rather than two. The conference room becomes a break room, and adds a refrigerator and microwave. The new break room must be better ventilated, to avoid tormenting the work force with the smell of microwave popcorn. These changes create new program requirements that should in turn update the energy performance requirements.
To meet their promise, LEED buildings need to be commissioned against their designed performance, the design that was built on the original programming. To maintain that performance, this commissioning should be continuous and automated. To keep that commissioning meaningful, it its targets should be updated as the buildings program requirements change. And that requires continuous programming.
Building Codes for the Smart Grid Ready Home
Companies were looking to put standards into production at the Smart Grid Interoperability Panel (SGIP) Face to Face meeting in St Louis this week. The most interesting new question I heard was “Where are the model home building codes to support smart energy?” I don’t think there are any.
Smart grid-ready homes must go beyond smart thermostats. LEED and other models design for energy efficiency but do not manage actual use. Smart energy demands that homes respond to changing energy prices and changing requirements of their occupants. No existing code plans for new patterns of electrical use, ones that may change the wiring requirements of the home. Today’s codes do not plan for rapid changes of technology in the future.
Energy efficient design means little without monitoring. Tomorrow’s smart homes must monitor their actual energy use; they must know if they are delivering the performance promised. They should measure live or plug energy load just as they measure energy for the installed systems and sections of the house. Without the means to measure and verify energy use, efficient designs are not ready for smart energy.
In the home, the highest energy efficiency may actually hinder some interactions with smart grids. Smart energy supplies will be intermittent, in price if not in availability. Smart grid-ready homes must be able to store energy during abundance for use during scarcity. Storage will never be as efficient as instant use, so smart energy homes will be less than perfectly efficient.
Some energy based services achieve their effect right away; lights come on almost instantly. Some services require time; air conditioning and humidity control may require hours to show their effects. The most efficient systems have run constantly with just enough capacity; they do not have the excess capacity to respond on demand.
Smart grid-ready homes must anticipate their occupants’ needs, even as the price of energy changes over time. Smart energy homes must learn the schedules of their inhabitants and make plans to provide services at the right times while buying energy in response to markets.
Smart energy must support distributed energy generation and storage, both today and tomorrow. Smart grid-ready home designs will have places to site energy generation and storage systems. Home circuit panels must accept multiple energy inputs. These systems must be able to connect and disconnect, enabling the home owner to upgrade as new technologies come on the market. The smart grid ready home must be able to disconnect automatically from the grid, both for safety and to avoid power quality problems to and from the neighborhood distribution.
Distributed energy changes the wiring requirements for the home. Today’s wiring is undersized for its load, designed provide rated power for only a few minutes at a time. Energy storage and electric cars will require full power for hours at a time, causing cables to fail early. Internal wires to support, say, a 50 amp services for such uses must be larger than those for a 50 amp service today. Even the cable supplying the house must be larger to support the stresses of continuous outside, lest it to fail early.
Most energy use in our homes is, or could be, supported by Direct Current (DC). Traditional power coming from the grid is Alternating Current (AC). Batteries and many forms of distributed generation produce DC. Energy is lost when power is converted DC to AC for local distribution just as it is when converting AC to DC for point use. (This is what your wall-warts do.) Internal DC distribution and DC plug standards may be part of building codes for smart-grid ready homes.
Building a new smart grid ready neighborhood of smart grid ready homes requires care, attention, creativity, new technology, and planning for a steady stream of technology changes in the future. It probably starts with BIM-based construction to establish a known baseline building performance and capabilities. It will require standards for energy information exchange that are only now nearing completion. Each home will be filled with sensors to inform the systems of today, openly accessible to share with tomorrow’s systems that today we do not know. Each home must interact with the computers, PDAs, and smart phones that run the lives of its inhabitants. Above all, each home must be designed to allow for constant and regular upgrades.
We don’t have those building codes yet.
The view from 400 miles, and 100 years away
As I walked the dog to the store this morning, I thought of the different way we know things today. The sky was clear, but I could tell. The air was cool, but I could tell. I didn’t need to hear the announcers from the weather service. I wondered how I knew. And I pondered what it would have been like to know, a hundred years ago, with no way to tell whether it would affect me and my life...
As I walked the dog to the store this morning, I thought of the different way we know things today. The sky was clear, but I could tell. The air was cool, but I could tell. I didn’t need to hear the announcers from the weather service. I wondered how I knew. And I pondered what it would have been like to know, a hundred years ago, with no way to tell whether it would affect me and my life...
One of the great gifts a dog gives its owner is dawn. Rusty is getting slow now, and white about the jowls; he really prefers to keep his travels to those between the cushion in his kennel and the mat by the glass door where he can watch the yard. Still, in the morning, he complains until we go out. Nowadays, he can’t make it all the way to the store and the paper. He slows. He pretends to be interested in something half way, and he waits until my return. Still he has given me the pre-dawn, again...
At dawn, the roads don’t smell like cars. The night shift, the animals that come out at night, is sleepily returning home. In Bynum, for the last decade, guinea fowl wander in the early morning. They cruise across yards, gobbling up ticks and fleas. The dogs seem to leave them alone. I think it’s the noise; a flock of guinea fowl makes the most horrendous noise when harassed. This morning, they were silent.
The air, the quiet still air had an ineffable feel. Perhaps there was a hint of sea in the wind, but there was no wind yet. The humid summer air in North Carolina always blurs things in the distance just a bit; perhaps today it blurred it less. The skies were clear of clouds, in a way I don’t usually expect until fall. This clearing seems to come before the clouds of a hurricane.
Everything felt like a hurricane. I don’t know if I would have noticed, without years of dawn walks, led by and leading a succession of dogs. This morning I knew. And I thought of what it was like, walking here, a hundred years ago.
What would it be like to know, but to have no idea whether the storm was coming to land, or staying at sea?
As I drove into town, driving North, I could see the summer sky to my left, to the East. I could see those long banded clouds that surround a hurricane, catching the morning sun. They were silver and gold, and beautiful, and ominous.
The storm, at that time, was 400 miles away. I knew it wasn’t going to get any closer to me, than that. But a hundred years ago, the signs would have been just as clear, without that knowing.