New York Solar-Thermal Technology Models Home Efficiency
The Solar Roofpod is a piece of urban infrastructure which captures the most underutilized energy, the sun, and utilizes it through innovative engineering systems to feed power to a single pod, whole buildings, and the city’s power grid.
The Roofpod is engineered as a “smart house” rather than a “passive house.” Accordingly, it features a number of sophisticated, innovative active systems to regulate and control the lighting, HVAC, water systems, and appliances. To ensure optimal performance, the photovoltaic design uses micro-inverters in each individual panel, rather than regular inverters, to prevent shadows that might fall on only a portion of the array from decreasing the total output—as might happen in the city from neighboring building shadows or from leaves and snow. The HVAC system is driven by the sun’s thermal energy, using much less electricity from the PV array than would a vapor-compression system.
Solar thermal collectors on the Solar Trellis gather the sun’s heat, making direct use of this often-neglected abundant energy source. The thermal energy runs the adsorption system as well as the radiant floor system for cooling and heating. However, this system has a drawback: thermal energy from the sun cannot be collected when it is dark. Therefore, we have designed a unique and innovative thermal storage system using a Phase Change Material (PCM) tank composed of a paraffin and graphite composite. The use of PCM rather than a more typical water-based thermal storage system reduces the space requirement of the tank by half. The PCM tank will also supply thermal energy to the hydronic system, to supply hot water. Black water will be collected into a septic tank (though in an actual rooftop installation the black water would be tied into the host building’s system), while graywater will be stored separately. Stormwater will also be collected and used for irrigation, along with the graywater.
To integrate all the active systems of the Roofpod, the energy management and control system is designed to ensure seamless levels of comfort quality and to regulate energy consumption for maximum efficiency. The integrated monitoring system senses and responds to weather conditions by regulating artificial light levels and controlling exterior shading. Sensors collect lighting, heating, and cooling performance data and assemble it in a logger system. A next-generation graphic digital display allows the inhabitants to be aware of the Roofpod’s minute-to-minute performance and encourages active energy-conscientiousness and may assist the city with peak load management.