Smart energy names the techniques and technologies needed to manage energy flows and energy supply and demand when energy generation and energy storage are as distributed as energy consumption is today. Grid assets are managed by central control. This only works so long as the assets are central and the assets are centrally owned. Distributed assets should have distributed ownership. We must turn the centralized model on its head. Smart energy manages from the edges, not from the center. Smart energy treats homes and commercial buildings as microgrids responsible for their own power.
The concern of smart energy policy is to remove barriers to enable rapid entry and virtuous markets for new technologies. Policy is implemented by regulations and codes. Today’s post arises because I am wondering when we will have a model building code for the smart energy-ready residence. What should a commodity builder do if he wishes to claim that each home in a neighborhood is “smart energy ready?”
Let’s start with the interconnect. Today’s rules for distributed energy focus, as they should, on safety first. To this end, they mandate anti-islanding, i.e., if the grid goes away, power systems shut off. This prevents a linesman from being electrocuted when the downstream side of a downed line is “hot.” The model smart energy ready building should instead choose safe islanding. Local power systems, generation, batteries, even electric vehicles, should work safely within the home no matter what the local conditions. Software and hardware at the building entrance should support this safe islanding.
Within the home, there should be an emphasis on safety and extensibility. The Electrician working in a house needs to be just as concerned with unexpected power sources as does the linesman outside the house. If there are distributed energy resources, then there will be unexpected power sources in the home. The interconnect in the house is as important as that between the house and grid.
So we need two interconnects.
Rooftop solar requires paths and connections. If added during construction, conduit to the roof to support the eventual installation of PV costs almost nothing. This conduit can be put in while the walls are open and before siding is installed. Designed-in conduit is less likely to leak then after-thought retrofits. Preparing for roof-top PV likely means planning for an inverter closer to the home’s power distribution panels.
A similar logic suggests that garages should plan for plug-in electric vehicles, even as the standards for them have not gelled. My guess is that this area will come to be dominated by smart charging stations coupled with storage. Whatever the technology, there will need to be wiring able to safely support high power flows over long periods of time. In the smart energy ready home, empty conduit may be enough for now.
The smart energy ready home should plan for power storage. Chemical based storage systems may lose much of their capabilities at extreme temperatures. There should be some space for storage installation that has an adequate and safe path to and from central power distribution. Again, empty conduit may be adequate for now.
To achieve reliability goals, some homeowners will opt for site-based generation. At its simplest, this requires a pad and conduit back to the central power distribution for the house. At its most complex, it requires very complex configuration. Because utilities today must pay above market rates for solar generated home power, they must watch carefully to make sure that the homeowner is not selling them “solar power” sourced from a backyard gasoline generator.
The answer is to get rid of the above market rates, and let the homeowner operate in the market. Distributed energy resources are first and foremost to serve the needs of the distributed site.
When I consider smart, distributed energy, I always call to mind the words of Doug Gwyn, when asked of a feature in UNIX: “UNIX was not designed to stop its users from doing stupid things, as that would also stop them from doing clever things.” We must be careful that we apply the same thinking to distributed energy.
To get more participants in smart energy, we must make it easier. A good start would to be to define the requirements for a smart energy-ready home. We can then see if builders would be willing to build them, and whether the market will bear the trivial costs, or at least trivial if designed in.