PHYSICALLY BASED HOUSE DYNAMICS MODEL

reACT  house simulation system runs automatically once a day in the early morning hours after hourly outdoor air temperature and cloud cover forecasts are downloaded from weather prediction websites corresponding to the location of each house. With the day’s weather information in hand, the simulator predicts each house’s expected performance over the day.  For more information contact http://reactvirtual.eng.umd.edu/

SIMULATION ELEMENT MODULES

IRRADIANCE

A model predicting the sun’s normal irradiance as a function of house location and time of year is combined with the cloud-cover forecasts to determine the incident global irradiance on each external surface of the house, including all windows and PV modules.

PERFORMANCE

A single-diode equivalent-circuit PV cell model is identified using the PV manufacturer’s performance data to determine the current versus voltage characteristics of the PV arrays over the course of the day using the predicted irradiance levels.

CONSUMPTION

Nominal scheduled electrical loads have been identified and are stored in an XML file; the loads are read by the simulator and used to compute energy consumption associated with regularly scheduled events.

TEMPERATURE

Incident radiation and indoor/outdoor air temperature variations are used to determine heat transfer rates through the house external walls.

NET POWER PRODUCTION

External wall and window heat transfer, direct radiation through the house windows, and waste heat produced within the house determine HVAC loads, indoor air temperature, and overall net power production.

 

ELECTRICAL POWER COST/VALUE MODELING 

The need to model net electrical power production/consumption as a function of time of day is made clear by the rate schedule set by the US Department of Energy Solar Decathlon organizers. In this schedule, we see the differences between consumption cost and production value during five different periods during the day, contributing to the large jumps in instantaneous profit/costs predicted by our economic simulator.

No contribution is too large or too small.  All contributions are appreciated and go towards helping us achieve our goal!