"The addition of energy storage to buildings is of utmost importance whether we plan to use power plants or nature, or both, to make those buildings comfortable." — Steve Baer, May 2002.
Baer's essay makes a case that applies regardless of energy source. The 24-hour day/night cycle sets the requirement: store heat when the sun shines for the cold night, or store coolth during the night for the hot afternoon. This is obvious for solar and night-sky systems, but Baer points out it's equally true for grid power: "Better one power plant on 24 hours a day than two 12 hours a day. Nuclear and coal burning power plants are particularly grateful to be allowed to run at a steady pace."
The convergence is the key insight: "Whatever suits natural heating and cooling will also suit the electric grid." A building designed for thermal storage works with both strategies. You can "forget the controversy over sustainable vs. non-sustainable until the last stages."
Modern lightweight, well-insulated buildings have lost what old masonry buildings had naturally — thermal mass. "Ages ago our masonry buildings had plenty of heat storage. They were also often uncomfortable, but for different reasons." The essay argues that storage is not an accessory but a basic building function that modern construction has accidentally discarded.
Internal heat from people, lights, and appliances totals about 250 BTU (75 watt-hours) per square foot of floor per day. Three gallons of water can absorb that much in a 10°F rise. The ceiling is the ideal surface — it absorbs rising warm air in summer and radiates heat downward in winter.
Plain water at room temperature is "perfectly satisfactory." If phase-change materials are found, they can be added as a slurry: "One day's storage becomes two." The developments in extruding and molding plastics make water-based thermal buildings "inevitable."
Why would the utilities wish to help develop thermal storage that would allow buildings to evade using electric energy?
In many climates, thermal storage lets heat coast into the building in winter and coast out in summer — no heat pump needed. Utilities lose business to natural systems. But in difficult climates, heat pumps gain business from natural gas and propane. And wind and solar generators create fluctuating power that demands storage — the same storage that serves natural heating and cooling.
Baer's sardonic observation: "Unfortunately those favoring power plants are unlikely to favor heat storage that is compatible with natural heating and cooling." The politics work against the physics.
Engineers and interior decorators can make such systems if each group can refrain from passing off their own incompetence by patronizing the other.
Industrial buildings will probably come first. Houses will follow "if the all-powerful forces of fashion take a notion."